BOLIDEN - MASTER Thesis - Examensarbeten-En

MASTER’S DEGREE PROJECTS

THE BOLIDEN VALUE CHAIN

Boliden is a base metals company with a commitment to sustainability. Our core competency lies within the ﬁelds of exploration, mining, smelting and recycling. Our roots are Nordic, but our business is 1global.

CONTENTS Working at boliden boliden ...... ............. .............. ............. ............. .............. ............. ............. ............. ............. .............. ............. ........4 ..4 Map .....................................................................................................5 Ideas for master master`s `s degree exploration: ex ploration: ..................................................... 6 1. EX EXPLOR PLORATION ATION .............................. .............................................................. ................................................................. .................................................................. ...................................................... .....................66 2. PROC PROCESSING ESSING ROUTINE TO HANDLE DISTURBANCES FROM FRO M POWER LINES, WIND TURBINES TUR BINES AND MAIN ROADS IN BOLIDEN’S EM GROUND SURVEYS .........................................................................................7 3. PETROPHYSICAL PROP PROPERTIES ERTIES AND INDUCED POLAR IZATION OF SANDS SANDSTONES: TONES: IMPLICATIONS FOR MINER AL EXPLOR ATION ............. ..................... ............... .............. ............... ............... .............. ............... ............... .............. ............... .........8 .8 Master’s degree project projects s in mining engineering engineeri ng......................................... .........................................9 9 4. SUGGE SUGGEST STIONS IONS FOR AI AITI TIK K OPEN�PIT MIN MINE E .............................. ............................................................... ................................................................. ................................ 9 5. AUTONOMOUS MIN MINE E............................ ............................................................. ................................................................. ................................................................. ......................................... ........12 12 6. ROADS IN UN UNDERGROUND DERGROUND MIN MINE E ............................. .............................................................. .................................................................. ............................................... ..............13 13 7. MET METHOD HOD FOR TE TEST STING ING ST STR R ENGT ENGTH H OF FIL FILLL .............................. ............................................................... .......................................................... ......................... 14 8. WITHDR WITHDRA AWAL OF INTER INTERMEDIATE MEDIATE LEVELS DURING SUB�LEVEL STOPING AT LAPPBERGET ......................................................................................................15 9. VENT VENTIL ILATION ATION SIMUL ATION IN RENSTRÖM RENST RÖM MINE ..................... ............................ ............... ............... .............. ............... ............... .............. ...........16 ....16 10. DESIGN OF OF PLANNING PLANNI NG TOOLS AND CONTROL RULES FOR ROCK TR ANSPORT IN KR KRISTI ISTINEBERG NEBERG .......... ................. .............. ............... ............... ............... ............... .............. ............... ............... .............. ............... .......... 17 11. OPTIMI OPTIMISATION SATION OF LOGISTICS FLOW FOR ORE ORE TR ANSPORTS AND INBOUND IN BOUND DELIVER DELI VERIES IES ....... ............... ............... .............. ............... ............... .............. ............... ............... .............. ............... ............... .............. ............... ............... .............. .......... ...18 18 12. REDUCED NITR NIT R ATE DISCHARGE FROM EXPLOSIVES EXPLOSI VES UNDERGRO U NDERGROUND UND ......... ................ .............. ............... ..............19 ......19 13. DESIGN OF MAJOR BLASTS BLAS TS �SLOT DESIGN� .............................. .............................................................. .............................................................. ..............................20 20 14.. OTHER SUGGESTIONS 14 SUGGE STIONS FOR MASTER’S MAS TER’S DEGREE PROJECTS IN ENGINEER ENGIN EERING ING ....... ............... ............... ...........21 ....21 Master’s degree projects in process engineering ....................................22 15. DESULPHU DESU LPHURI RISATION SATION OF TAIL TAILINGS INGS ................................ ................................................................. ................................................................. .........................................22 .........22 16. OPTIM OPTIMISATION ISATION OF REGRINDING REGR INDING IN A FLOTATION F LOTATION CIRCUIT ....... .............. ............... ............... .............. ............... ............... ............23 .....23 17.. LE 17 LEACHING ACHING OF PY PYRR RRHOTI HOTITE TE ............................. .............................................................. .................................................................. ......................................................... ........................24 24 18. PUR PURIFIC IFICATION ATION OF ACIDIC MIN MINE E WATER ................................. .................................................................. ............................................................... .............................. 25 19.. FIN 19 FINE E PARTIC PARTICLE LE FLOTATION .......................................................................................... ......................................................... ............................................................... ..............................26 26 20. FLOTATION FLOTAT ION OF TEL TELLUR LURIDE IDE MIN MINER ERAL AL ............................... ................................................................ .................................................................. ....................................27 ...27 21.. FUNDAM 21 FUNDAMENTAL ENTAL PARA PARAMETER METERSS FOR FLOTATION ........ ............... .............. ............... ............... ............... ............... .............. ............... ............... .............28 ......28 22. DEVELOPMENT OF LAB L AB METHOD M ETHOD FOR FLOTATION FL OTATION TESTING TESTI NG ....... ............... ............... .............. ............... ............... .............. ...........29 ....29 23. FLOTATION OF DISINTEGR ATED ORE IN AIT AITIK IK ............... ...................... .............. ............... ............... .............. ............... ............... .............. ............... .........30 .30 24. IMPACT OF OF SULPHUR AND COPPER CONTENT ON COLLECTOR REAGENT NEED AT AITIK .............................................................................................................................31 25. PURI PURIFY FYING ING CONTAMINATED CONTAMIN ATED WATER WATER THROUGH FREEZING FREEZ ING ....... .............. ............... ............... .............. ............... ............... ............32 .....32 26. FUNCTIONAL PROCESS IMAGES ................................................................................................................33

2

CONTENTS Working at boliden boliden ...... ............. .............. ............. ............. .............. ............. ............. ............. ............. .............. ............. ........4 ..4 Map .....................................................................................................5 Ideas for master master`s `s degree exploration: ex ploration: ..................................................... 6 1. EX EXPLOR PLORATION ATION .............................. .............................................................. ................................................................. .................................................................. ...................................................... .....................66 2. PROC PROCESSING ESSING ROUTINE TO HANDLE DISTURBANCES FROM FRO M POWER LINES, WIND TURBINES TUR BINES AND MAIN ROADS IN BOLIDEN’S EM GROUND SURVEYS .........................................................................................7 3. PETROPHYSICAL PROP PROPERTIES ERTIES AND INDUCED POLAR IZATION OF SANDS SANDSTONES: TONES: IMPLICATIONS FOR MINER AL EXPLOR ATION ............. ..................... ............... .............. ............... ............... .............. ............... ............... .............. ............... .........8 .8 Master’s degree project projects s in mining engineering engineeri ng......................................... .........................................9 9 4. SUGGE SUGGEST STIONS IONS FOR AI AITI TIK K OPEN�PIT MIN MINE E .............................. ............................................................... ................................................................. ................................ 9 5. AUTONOMOUS MIN MINE E............................ ............................................................. ................................................................. ................................................................. ......................................... ........12 12 6. ROADS IN UN UNDERGROUND DERGROUND MIN MINE E ............................. .............................................................. .................................................................. ............................................... ..............13 13 7. MET METHOD HOD FOR TE TEST STING ING ST STR R ENGT ENGTH H OF FIL FILLL .............................. ............................................................... .......................................................... ......................... 14 8. WITHDR WITHDRA AWAL OF INTER INTERMEDIATE MEDIATE LEVELS DURING SUB�LEVEL STOPING AT LAPPBERGET ......................................................................................................15 9. VENT VENTIL ILATION ATION SIMUL ATION IN RENSTRÖM RENST RÖM MINE ..................... ............................ ............... ............... .............. ............... ............... .............. ...........16 ....16 10. DESIGN OF OF PLANNING PLANNI NG TOOLS AND CONTROL RULES FOR ROCK TR ANSPORT IN KR KRISTI ISTINEBERG NEBERG .......... ................. .............. ............... ............... ............... ............... .............. ............... ............... .............. ............... .......... 17 11. OPTIMI OPTIMISATION SATION OF LOGISTICS FLOW FOR ORE ORE TR ANSPORTS AND INBOUND IN BOUND DELIVER DELI VERIES IES ....... ............... ............... .............. ............... ............... .............. ............... ............... .............. ............... ............... .............. ............... ............... .............. .......... ...18 18 12. REDUCED NITR NIT R ATE DISCHARGE FROM EXPLOSIVES EXPLOSI VES UNDERGRO U NDERGROUND UND ......... ................ .............. ............... ..............19 ......19 13. DESIGN OF MAJOR BLASTS BLAS TS �SLOT DESIGN� .............................. .............................................................. .............................................................. ..............................20 20 14.. OTHER SUGGESTIONS 14 SUGGE STIONS FOR MASTER’S MAS TER’S DEGREE PROJECTS IN ENGINEER ENGIN EERING ING ....... ............... ............... ...........21 ....21 Master’s degree projects in process engineering ....................................22 15. DESULPHU DESU LPHURI RISATION SATION OF TAIL TAILINGS INGS ................................ ................................................................. ................................................................. .........................................22 .........22 16. OPTIM OPTIMISATION ISATION OF REGRINDING REGR INDING IN A FLOTATION F LOTATION CIRCUIT ....... .............. ............... ............... .............. ............... ............... ............23 .....23 17.. LE 17 LEACHING ACHING OF PY PYRR RRHOTI HOTITE TE ............................. .............................................................. .................................................................. ......................................................... ........................24 24 18. PUR PURIFIC IFICATION ATION OF ACIDIC MIN MINE E WATER ................................. .................................................................. ............................................................... .............................. 25 19.. FIN 19 FINE E PARTIC PARTICLE LE FLOTATION .......................................................................................... ......................................................... ............................................................... ..............................26 26 20. FLOTATION FLOTAT ION OF TEL TELLUR LURIDE IDE MIN MINER ERAL AL ............................... ................................................................ .................................................................. ....................................27 ...27 21.. FUNDAM 21 FUNDAMENTAL ENTAL PARA PARAMETER METERSS FOR FLOTATION ........ ............... .............. ............... ............... ............... ............... .............. ............... ............... .............28 ......28 22. DEVELOPMENT OF LAB L AB METHOD M ETHOD FOR FLOTATION FL OTATION TESTING TESTI NG ....... ............... ............... .............. ............... ............... .............. ...........29 ....29 23. FLOTATION OF DISINTEGR ATED ORE IN AIT AITIK IK ............... ...................... .............. ............... ............... .............. ............... ............... .............. ............... .........30 .30 24. IMPACT OF OF SULPHUR AND COPPER CONTENT ON COLLECTOR REAGENT NEED AT AITIK .............................................................................................................................31 25. PURI PURIFY FYING ING CONTAMINATED CONTAMIN ATED WATER WATER THROUGH FREEZING FREEZ ING ....... .............. ............... ............... .............. ............... ............... ............32 .....32 26. FUNCTIONAL PROCESS IMAGES ................................................................................................................33

2

Master’s degree projects pr ojects in the environment .......................................... ..........................................34 34 27.. ROOT PENETR 27 PENETRATION ATION IN PROTECTI PROTECTIVE VE AND SEA SEALING LING LAYERS IN TAILINGS PONDS NO LONGER IN USE ..............................................................................................34 28. INV INVENTORYING ENTORYING OF THE FUNCTION AND LONG� LONG�TER TERM M EFFECTS OF VEGETATION ESTABLISHMENT ESTABL ISHMENT WIT WITH H DIGESTED SLUDGE ....... .............. ............... ............... .............. ............... ............... .........35 ..35 29. METHOD M ETHOD FOR MA MAPPING PPING OUT NIT NITROGEN ROGEN FLOWS ............................. ............................................................. ................................................ ................36 36 30. EV EVALUA ALUATION TION OF OF ALTERNATIVE SEALING LAYERS AS R EGARDS OXYGEN PENETRATION ................................................................................................................................37 31.. OPTI 31 OPTIMISATION MISATION OF PHYSICA PHYSICALL PROPERTIES OF SEDIM SEDIMENTATION ENTATION PONDS ...................................38 ............................... ....38 32. PHYTOREMEDIATION ...................................................................................................................................40 33. EVALUA EVALUATION TION OF VEGETATION ESTABLISH ESTABLISHMENT MENT AT WAST WASTE E ROCK LANDFILL LA NDFILLSS WI WITH TH HELP OF DIGESTED DIGES TED SLUDGE ........... ...................... ..................... ..................... ..................... ..................... ..................... .................... ..............41 ....41 34. CRE CREATION ATION OF NEW INDUSTRIA INDUSTR IALL AREA AR EA IN GARPENBERG GA RPENBERG ....... .............. ............... ............... .............. ............... ............... .............. ...........42 ....42 Master’s degree projects at Rönnskär ...................................................43 35. SURV SURVEY EY OF RÖNNSK RÖNNSKÄR’S ÄR’S WATER WATER USAGE ............................... ................................................................ .................................................................. ................................. 43 36. PURIF PURIFYING YING DECOPP DECOPPERISE ERISED D ELECT ELECTROL ROLYT YTE E .................. .......................... ............... .............. ............... ............... .............. ............... ............... .............. ..............44 .......44 37.. THE EFFECT OF CHLORI 37 CHLORIDE DE CONTENT IN ELECTROL ELECT ROLYT YTE E ON THE SULPHUR CONTENT IN CATHODE COPPER C OPPER ........ ............... .............. ............... ............... .............. ............... ............... .............. ............... .............45 .....45 38. LEACH L EACHING ING OF GA GASS CLE CLEAN ANING ING DUSTS ............................. .............................................................. .................................................................. .......................................46 ......46 39.. EVALUA 39 EVALUATION TION AND IMPLEMENTATION IMPL EMENTATION OF COPPER COPPER CONVERTING CONV ERTING MODEL ....... .............. .............. ...............47 ........47 40. GR GRA AVIM VIMETR ETRIC IC SEPAR SEPAR ATION OF SMELTED SLAG, MATT MATTE E AND SPEISS AS A FUNCTION FU NCTION OF THE SLAG’S PHYSICAL PHYSICA L AND CHEMICA C HEMICALL PROPERTIES ................... ........................... .............48 .....48 41.. INCREASED PRACTICAL AND THEORETICAL UNDERSTANDING OF 41 OF ANTIMONY ANT IMONY DISTR IBUTION DURING DUR ING CONVERTING CONV ERTING ......... ................ ............... ............... .............. ............... ............... .............. ............... .............49 .....49 42. WASTE WATER WATER PURIFICATION PURIFIC ATION REGARDING REGAR DING NICKEL AND ANTIMONY ANT IMONY ................. ........................ ............... .............50 .....50 43. OPTIMIS OPTIMISATION ATION OF STEP STE P 1 IN I N DECOPPERIZATION DECOPPERIZ ATION PLANT PLA NT .................... ........................... .............. ............... ............... .............. ..............51 .......51 44. ASSAY ASSAYING ING OF INCOMING I NCOMING MATERI MATE RIAL AL AT SAMPLING SA MPLING PLANT PL ANT ....... .............. ............... ............... .............. ............... ............... .............. .........52 ..52 45.. PROD 45 PRODUCTION UCTION OF ANT ANTIMONY IMONY FROM INTERM INT ERMEDIATE EDIATE PRODUCTS .......... ................. ............... ............... .............. ...............53 ........53 46. EX EXAMINE AMINE THE EXISTANCE OF R ARE ELEMENTS IN INTERMEDIATE PRODU PRODUCTS CTS AT RÖNNSKÄR RÖNNSKÄ R ....... .............. ............... ............... .............. ............... ............... .............. ............... ............... ............... ............... .............. ............... ............... .............. ............... ............... .............. ...............54 ........54 47.. INV 47 INVEST ESTIGATION IGATION OF OF THE IMPACT OF OF PH ON ARSENIC PRECIPITATION AT RÖNNSKÄR RÖNNSKÄ R WASTE WATER TREATMENT TR EATMENT PLA PLANT NT ....... ............... ............... .............. ............... ............... .............. ............... ............... ...............55 ........55

3

WORKIN WOR KING G AT AT BOLID BOLIDE EN Boliden has a great need to recruit employees in the near future. Skilled and involved employees are a necessity in helping us to run and develop our operations. Within the upcoming five years, interesting jobs will be available in many of our approximately 200 (!) occupational categories. We need people with drive, creative thinking and cutting-edge expertise in different areas and we need a balance of experienced and new employees. Working Working at Boliden means that you are part of a group with greatly decentralised operations spanning many different countries. In many development areas, the work is carried out in project form or in small work groups. This creates the opportunity for exciting challenges for both specialists and leaders.

Master’s degree projects 2013 Performing your master’s master’s degree project and/or placement at Boliden gives you the opportunity to become acquainted with the industry and the company. Getting to know each other often leads to employment. You You are holding in your hands a list of suggestions for technical master’s master’s degree projects for students. An updated list is found at www www.boliden.com. .boliden.com. Some master’s master’s degree projects can be carried out in English. Different compensation terms apply depending on where you do your master’s master’s degree project. Please contact us for more information:

Janne Lindmark, Human Human Resources Department, Boliden Mines Emma Rönnblom-Pärson, Rönnblom-Pärson, External Environment, Boliden Mines Leif Båtsman, Work Environment, Boliden Mines Anders Forsgren, Forest Forest & Land, Boliden Mines Andreas Berggren, Minerals Engineering, Engineering, Boliden Mines Hans Årebäck, Exploration, Boliden Mines Staffan Sandström, Mining Engineering, Boliden Mines Marie Holmberg; Process Develop., Rönnskär, Rönnskär, Boliden Smelter

+46 (0)910-77 42 62 +46 (0)910-77 41 45 +46 (0)910-77 43 47 +46 (0)910-77 45 50 +46 (0)910-77 43 52 +46 (0)910-77 45 68 +46 (0)910-77 42 78 +46 (0)910-77 38 84

Boliden is a metals company with a focus on sustainable development. Scandinavian roots, global market. Our core competence lies within the fields of exploration, mining, smelting and recycling. Boliden has about 4,400 employees and an annual turnover of approximately SEK 40 billion. The stock is listed on NASDAQ OMX Stockholm, segment Large Cap and on the Toronto Toronto Stock Exchange in Canada.

Read more at www.boliden.com www.boliden.com

4

MAP

Mining areas Tara – – zinc and lead Garpenberg – – zinc, silver and lead Boliden area – – zinc, copper, gold, silver and lead Aitik – – copper, gold and silver

Smelters

Offices Stockholm – group headquarters Stockholm – business area Smelters Boliden – business area Mines Neuss – sales office LeamingtonSpa – – sales office

Kokkola – – zinc and sulphuric acid Odda – – zinc and aluminium fluoride Rönnskär – copper, lead, zinc clinker, gold, silver and

sulphuric acid Harjavalta – – copper, gold, silver, sulphuric acid and nickel smelting Bergsöe – lead alloys and tin alloys

5

IDEAS FOR MASTER`S DEGREE EXPLORATION:

1.

EXPLORATION

In the Exploration Department we offer Master of Science (MSc) projects in several themes and geographic areas. The Exploration Department includes three main divisions: Near-mine Exploration, Field Exploration and Geophysics: Near-mine exploration is concerned with locating new ore bodies close to Boliden’s existing mines and advanced exploration projects, including the Kristineberg, Maurliden, Renström and Kankberg mines in the Skellefte mining district (Västerbotten county, Sweden), Aitik mine (Norrbotten county, Sweden), Rockliden (northern Sweden), Garpenberg and Stollberg in the Bergslagen mining district (Dalarna, central Sweden) and the Tara mine at Navan (Ireland). Field Exploration is concerned with locating new ore deposits further away from Boliden’s existing mines. We are currently working in the Norrbotten mining province, the Skellefte District, Bergslagen and the foothills of the Caledonide Mountain chain (all in Sweden) and in the Dublin Basin of Ireland. In these areas, Boliden can offer MSc projects in the disciplines of geology, applied geochemistry and geophysics. However, we can not offer projects in all the various geographic areas in the same year. The details of the specific projects vary from case to case, but often involve field work, followed by laboratory work and interpretation. Geological field work comprises field mapping and/or geological logging of diamond drill cores or percussion drill chips. The Geophysics group works in all of the areas described above, carrying out geophysical surveys in the field and in deep drill holes using geophysical probes. The group also develops and tests new equipment. Geophysical MSc projects may include field geophysical surveys using electrical, electromagnetic, magnetic and/or gravimetric techniques and interpretation of geophysical data. The Boliden Exploration Department has in recent years also been involved in seismic reflection surveys in mining areas. If you are interested in carrying out an MSc project (examensarbete in Swedish) in the Exploration Department please contact: Geology:

Rodney Allen, Tel. +46 (0)225-362 45 E-mail: [email protected]

Geochemistry:

Rodney Allen, Tel. +46 (0)225-362 45 E-mail: [email protected]

Geophysics:

Bertil Sandström, Tel. +46 (0)910-77 41 08 E-mail: bertil.sandströ[email protected]

6

2. PROCESSING ROUTINE TO HANDLE DISTURBANCES FROM POWER LINES, WIND TURBINES AND MAIN ROADS IN BOLIDEN’S EM GROUND SURVEYS Background Boliden’s own developed electromagnetic (EM) ground survey has enabled the exploration department to search for and discover deposits that were, are and will be in production. Every year a large amount of EM ground surveys are performed. Therefore the method has a very high importance for exploration. Even though Boliden’s EM ground survey has been successful, the method is in continuously improvement. Measurements are disturbed by power lines, wind turbines and sometimes by main roads. Therefore there is a need to define a standard processing routine to handle noisy data, especially when interesting anomalies are located under the sources that cause the disturbances.

Description The master candidate would develop a mathematical and physical routine to handle the interferences. The proposed method will be tested with real data, including modelling and interpretation. The developed routine will be included in the processing of Boliden’s EM ground surveys when handling of disturbances is needed.

Contact person Geophysics:

Bertil Sandström, Tel. +46 (0)910-77 43 70, E-mail: bertil.sandströ[email protected]

Location: Boliden

7

3. PETROPHYSICAL PROPERTIES AND INDUCED POLARIZATION OF SANDSTONES: IMPLICATIONS FOR MINERAL EXPLORATION Background The Dorotea field is known for several sandstone-hosted Pb-Zn mineralizations in the Lower Allochthon of the Swedish Caledonides. This region has been shown to be particularly challenging for geophysical prospecting. Generally the only applicable method is the Induced Polarization (IP) method. Boliden has invested substantially in field IP measurements and is currently developing a multifrequency IP system. The IP response in sandstones due to different sources is still difficult to interpret, and the cause of anomalies is known only after testing with diamond drilling. Bedrock in the Dorotea area is very heterogeneous; sandstones and siltstones commonly contain clay minerals in the matrix. Pyrite is also common.

Description In this master thesis project, the candidate would investigate petrophysical properties of various sandstones in a laboratory and model the IP response that a Pb-Zn mineralized sandstone would give. The outcome of the thesis would greatly help the future exploration in the Caledonides and elsewhere. The ideal candidate is a geophysics major student, who has a good understanding of the physics of the electromagnetic fields and phenomena. Especially the geoelectric methods and the concepts of complex resistivity/ spectral induced polarization (SIP) should be familiar to them on a basic level. Boliden does not have a petrophysics labaratory, thus the candidate´s department needs to provide the instruments to measure SIP responses from the core samples. Also a supervising geophysicist with experience in the SIP method is expected. We encourage interested candidates to contact Boliden t ogether with their proposed supervisors.

Contact person Geophysics:

Katri Vaittinen, Tel. +46 (0)910-70 57 83, E-mail: [email protected]

Location: Boliden

8

MASTER’S DEGREE PROJECTS IN MINING ENGINEERING

4.

SUGGESTIONS FOR AITIK OPEN-PIT MINE

Boliden’s open-pit mine in Aitik currently produces about 36 million tonnes of ore and the same amount of waste rock with an extremely low average content of approx. 0.2% Cu. To make the mining profitable, there must be thorough content control and effective utilisation of mine resources. Important elements behind this are modern machines, effective maintenance and effective production planning and control. In upcoming years, there will be opportunities to perform master’s degree projects in a number of different areas. Some examples are found below, but this is not an exhaustive list. Other relevant ideas will be gladly considered. In most cases, a large part of the project can be performed in Aitik and Boliden. Computers and tools for studying different aspects are available in Aitik and in Boliden, but data/tools can be copied to local computers if the scope permits this. Depending on the focus, the work can be presented as a report, proposal for continued work, computer models or prototypes. These master’s degree projects should be considered as suggestions that can be used as the basis for discussion.

Geology The open-pit mine in Aitik has a basic design, but this can be influenced continually by new data, particularly from geology and rock mechanics. Ore is a financial concept governed not only by the grade, but also by the properties of the rock and the degree to which it is affected by blasting. The properties of the rock, particularly grindability and fragmentation, affect the cost of processing the ore while grade affects income. To optimise production and ore base, the block model of the mine can be supplemented with grade data from production drilling, historic throughput data from concentrators, Measure-While-Drilling (MWD), rock type mapping and fragmentation data. Currently, it is mainly drill cutting samples from production holes that are used to improve the block model. But, there are ideas to supplement with several other methods to improve the data. Possible projects: •

Improved geological models and data based on both exploration and mapping/sampling in the mine

•

Utilise on-line sampling from drills

•

Utilise MWD (Measure-While-Drilling)

•

Combine explosion models with fragmentation and throughput

•

Modelling of older waste rock dumps that may contain ore quantities historically considered waste rock. Modelling will require retrieval of data on the “ore’s” original position, which can be obtained from older mine maps and/or trucks’ GPS positioning in the 2000s.

Rock mechanics The rock mechanics work in Aitik is used to create a basic design. Historically, this has been based on geology and information on rock conditions, such as strength and structures, as well as on the geohydrological situation and the affect of blasting damage on the possibility of shaping the slopes according to plan. Parts of this work are performed on a running basis. For this reason, any master’s degree project is best described based on the current situation. Possible assignments can be defined in the following areas: 9

•

Methods for continually monitoring slope stability

•

Slope stability

•

Geohydrology for impacting slope stability through water lowering

•

Slope design

•

Follow-up of blasting results when blasting against remaining slope

Maps, GIS and open-pit mine design Nowadays, it is possible to measure the mine through traditional measurement, laser scanning, 3D photos, aerial photos, etc. By using modern measurement methods in combination with GIS and various background data, it should be possible to generate good data for decision making and planning for rock mechanics and others in the form of crack maps, content models, quality maps for height maintenance, etc.

Planning and control To double the production tempo without having to double the number of loaders, etc., machine utilisation must be improved and production disruptions minimised. This can be achieved through methods such as optimising the mining plan for anywhere from the upcoming day to a few weeks in advance. The mining plan must be updated continually to account for ongoing production and disruptions. In 2008, Aitik implemented a production planning tool for this purpose. A possibility to further improve optimisation and facilitate planning is to refine the process with production plans based on simulations or optimisation algorithms that support the production planner with suggestions.

Optimal fragmentation Blasting results depend on rock types, rock & blasting plans, etc. In addition, it affects loadability, loader wear and concentration results. Aitik has worked for a number of years to find the optimal combination, taking into account both costs for fragmentation and the impact of its results. There are a number of possible assignments in this area: •

Models for blasting and fragmentation, e.g. to divide the mine into domains.

•

MWD to determine rock properties during drilling.

•

•

Affect on loadability and loader wear. Flow model for material from the mine – crusher and through plant to trace how different fragmentations affect concentration results.

Production system, drilling In the area of drilling, testing is in progress with autonomous drills as well as automated on-line drill cutting sampling.

Production system, loaders Aitik will produce a total of 72 million tonnes per year using 4 large loaders. Well-planned and disruption-free production is required to be able to achieve this. There are a number of possible assignments in this area: •

Suggestions for how loading can improve measures on and around the loader. The project can be performed as an activity study with a focus on the work site.

•

Evaluation of operator training simulator.

•

Refer to the planning and maintenance sections. 10

Production system, transport For transport from loaders to the crusher or dump, Aitik has over 20 trucks that must be allocated optimally. This is handled in real time via the dispatch system MineStar based on the required tonnage from the respective loader. At present, autonomous trucks are in use in research trial projects abroad. There are a number of possible assignments in this area: •

Calculation models for optimising truck usage.

•

Optimisation of refuelling and preventive maintenance.

•

Potential of autonomous trucks in Aitik.

Maintenance Aitik’s open-pit mine uses 5 large loaders, 4 large drills, about 30 trucks and many smaller machines and vehicles, all of which require maintenance. There is a need for improved maintenance planning and follow-up methods. Several machines and trucks are equipped with onboard computers for motor monitoring, etc. that should be put to better use. There are a number of possible assignments in this area: •

•

•

Map out existing routines for a machine or machine type and describe what areas can be improved Develop calculation method for planning maintenance activities and r isk analysis. Here, risk analysis refers to assessing spare parts stock, early component replacement, etc. Develop methods/calculation models for assessing machine service life

Contact persons Mining engineering:

Production/Planning

Arne Renström, Tel. +46 (0)910-77 43 01, E-mail: [email protected]

Rock mechanics:

Per-Ivar Marklund, Tel. +46 (0)910-77 41 69 E-mail: [email protected]

Optimised fragmentation:

Fredrik Jonsson, Tel. +46 (0)910-70 51 43 E-mail: [email protected]

Aitik:

Geology Aitik

Greg Joslin, Tel. +46 (0)970-72 92 33 E-mail: [email protected]

Production planning

Erik Jänkänpää, Tel. +46 (0)970-72 93 66 E-mail: [email protected]

Production preparation/ drilling/blasting

Peter Palo, Tel. +46 (0)970-72 90 54 E-mail: [email protected]

Production loading

Daniel Bergius, Tel. +46 (0)970-72 90 83 E-mail: [email protected]

Maintenance manager, mine

Magnus Fjellström, Tel. +46 (0)970-72 92 73 E-mail: [email protected]

Location:

Gällivare 11

5.

AUTONOMOUS MINE

Boliden has initiated development of an autonomous mine – the first step towards the goal of no employees working at the mine face. We already use video-controlled autonomous loaders. In the upcoming years, we expect to gradually increase the use of autonomous mining in our mines.

Description A master’s degree project could be to participate in the evaluation of various machine designs and/or use simulation to calculate consequences and potentials of automation. Master’s degree project possibilities in this area will be adapted to current projects.

Contact person Mining engineering:

Production/Planning

Location:

Arne Renström, Tel. +46 (0)910-77 43 01, E-mail: [email protected]

Boliden

12

6.

ROADS IN UNDERGROUND MINE

Background Boliden mines have an extensive road system that requires resource-intensive and costly maintenance to maintain good road longevity. Road surfaces in the mine ramp systems quickly become worn and rutted from the heavy vehicle traffic. The worn and rutted road surface increases wear to vehicles, resulting in increased maintenance needs.

Idea Maintenance costs for roads and machines can be reduced by improving the quality of the road surface and the design of the road structure. Use of road material with good bearing capacity and the right distribution of granule size along with various hardening additives and a properly drained road structure can increase the durability of a mine road.

Objective The objectives of the master’s degree project are: Provide suggestions for how road surface quality can be improved and the best way to build a road based on prevailing conditions in underground mines •

•

•

Test road material properties Examine whether additives such as cement or fly ash increase the surface life of the road surface at a reasonable cost

Description The project is expected to consist of the following components: Literature studies. Methods for improving road surface quality, e.g. paving or hardening with cement. Road construction in mining environment with high moisture level, high inflow of water and heavy vehicle traffic. •

•

Sampling and measurement of ballast properties.

•

Test of methods to increase road durability.

Contact person Evgeny Novikov, Tel. +46 (0)910-77 40 91, E-mail: [email protected] Fredrik Jonsson, Tel. +46 (0)910-70 51 43 E-mail: [email protected]

Location: Boliden

13

7. METHOD FOR TESTING STRENGTH OF FILL Background In extremely flat ore bodies or where the ore is broad, Boliden sometimes uses horizontal cut-and-fill mining. With this method, chambers are mined next to each other without leaving a column between them. So as not to create large spans, the chambers are refilled with cement-stabilised hydraulic fill before mining of the adjacent chamber is started. The purpose of the fill is to support the walls and ceiling. The strength of a fill is primarily determined by the amount of cement in it. This amount should be sufficiently high that the fill remains vertical when the adjacent chamber is mined. A problem with this type of fill is that it often becomes stratified and the strength is therefore not uniform. The stratification is due to factors such as draining of the fill, separation in fill lines and the geometry of the mining chamber and makes it difficult to measure and evaluate strength. At present, we use an extremely simple method of inserting a knife into the fill at a number of uniformly distributed points and noting the depth of insertion. However, the results of this method are extremely dependent on the person performing it and do not actually constitute a true strength value of the fill. To optimise the amount of cement and measure improvements to fill quality, we want to find a better way to evaluate the strength of the fill.

Idea Different instruments for testing strength in soil clay and concrete are currently available on the market. The idea behind the master’s degree project is: •

•

Investigate whether any existing measuring instruments (with or without modifications) can be used to determine fill strength. Develop a method to describe the strength of the fill in a statistically reliable manner.

The method must be simple, quick and applicable in field conditions.

Objective The objective is to find a method that can be used to determine fill strength in the field.

Description •

Field studies of fill in Boliden mines

•

Literature study and description of existing instruments/methods for determining strength in the field

•

Lab tests of fill using different methods

•

Development of a statistically reliable measurement method in the field

•

Test of the method in the field

Contact person Daniel Sandström, Tel. +46 (0)910-77 42 26, E-mail:

Location:

Boliden

14

8. WITHDRAWAL OF INTERMEDIATE LEVELS DURING SUB-LEVEL STOPING AT LAPPBERGET Background Sub-level stoping is run simultaneously on several levels in Lappberget in Garpenberg. The mining of intermediate levels between the working levels occurs under difficult rock conditions due to greatly elevated rock stress. Stoping chambers above the intermediate levels are either filled with paste fill that has a specific strength and enables the intermediate level to be mined or filled with waste rock that requires that an ore level be left to prevent waste rock from caving into the stoping chamber. How do we maximise ore extraction in these intermediate levels? Another part of this master’s degree project involves describing how residual mining of the remaining ore columns at the bottom of the level Lappberget 1080 can be performed.

Idea Develop methods for mining the intermediate level when the stoping chamber above the intermediate level is filled with paste fill or waste rock. This includes, among other things, calculation of what strength the paste fill must have to be able to mine the stoping chamber up towards a paste-filled stoping chamber. Develop a mining plan for residual mining of the ore columns at Lappberget 1080.

Objective •

•

Create mining plans for intermediate levels in Lappberget, where stoping chambers above the intermediate levels may be filled with paste fill or waste rock. Develop a mining plan for residual mining of the ore columns at Lappberget 1080.

Description Through literature studies, investigate how intermediate levels are mined in sub-level stoping mines around the world. Utilise the mining experience available at Lappberget to understand the rock conditions at Lappberget (interplay between mining method, rock quality and stresses). Create drawings/plans that describe withdrawal of intermediate levels (geometry, reinforcement, fill technique, risk analysis, etc.). Calculate strength requirements for past fill when a stoping chamber is created under the fill. Residual mining of the ore columns at Lappberget 1080 is a special case that can utilise knowledge from the described work of withdrawing intermediate levels.

Contact person Anders Nyström, Tel +46 (0)910-77 43 85 E-mail: [email protected]

Location:

Garpenberg

15

9. VENTILATION SIMULATION IN RENSTRÖM MINE Background The ventilation system of the Renström mine is large and complex. The system must be redesigned as the mine will be deepened to the 1400-metre level while at the same time new areas will be opened above the 800-metre level. In 2011, studies will be conducted to examine how the new sections should be mined.

Idea With the help of ventilation measurements and map data, create an updated ventilation model in the Renström mine that can be used when dimensioning ventilation flows in the mine.

Objective The objective of the master’s degree project is to build a calibrated ventilation model in the VentSim Visual simulation program that the mine can then use when planning new production areas.

Description The project is expected to consist of the following components: Literature studies. Methods for measuring air flows and air pressure, calculating system friction plus the VentSim Visual manual. •

•

Measure the existing ventilation system.

•

Design and calibrate a simulation model

Contact person Fredrik Jonsson, Tel +46 (0)910-70 51 43 E-mail: [email protected]

Location:

Boliden/Renström

16

10. DESIGN OF PLANNING TOOLS AND CONTROL RULES FOR ROCK TRANSPORT IN KRISTINEBERG Background Kristineberg’s strategic plans will lead to a production increase to 800,000 tonnes of ore and preparation to make such production possible. A development project has been running at Kristineberg in several areas to achieve the intended production increase. Planning and control of rock transport in the mine is an area that has not yet been investigated and developed to the scope we feel is necessary.

Idea Improve planning and control of rock transport in the Kristineberg mine. The purpose of the master’s degree project is to monitor parameters such as stock levels and lead times for rock transport in the mines and to look at how to optimise these.

Objective •

Find simple tools for performing checks and standardise of the procedure for this.

•

Create simple planning parameters for optimised rock management.

•

Formulate control rules.

•

Implement the tools and procedure.

Description The project is expected to consist of the following components: •

Literature study. Suitable methods for analysing and determining planning and control rules.

•

Supplementary investigation and flow study for rock transport.

•

Development of tools and rules.

•

Implementation of the procedure.

Contact person Fredrik Jonsson, Tel. +46 (0)910-70 51 43 E-mail: [email protected] Thomas Theolin, Tel. +46 (0)910-70 51 53 E-mail: [email protected]

Location:

Boliden area/ Kristineberg

17

11. OPTIMISATION OF LOGISTICS FLOW FOR ORE TRANSPORTS AND INBOUND DELIVERIES Background The Boliden area consists of a concentrator and a number of mines (one open-pit mine and 3 underground mines), all within approx. 1000 kilometres of each other. The ore is mined in the mines and transported by truck to the concentrator. At the concentrator, the ore is dressed into a number of products (concentrate) that contain gold, silver, copper, zinc, lead and tellurium. Concentration is performed in campaigns, where one ore is dressed at a time. The lengths of the campaign vary from a few days to up to one month. The ore production in the mine with stock situation, ore transports, stock situation of the inbound delivery at the concentrator together with campaign planning are all associated with high costs that should be reduced and a certain degree of error management that should be avoided.

Idea An investigation of the logistics related to the mine’s ore production and stocking, aspects related to ore transports, the stock situation of the inbound delivery at the concentrator together with campaign planning. Create a dynamic simulation of the entire system to enable testing of different improvement suggestions.

Objective Lower costs for logistics related to ore management in the mine and concentrator. Avoid error management.

Description The project is carried out at Boliden’s office in Boliden and in the Boliden area. The work is preferably performed by an engineer with a background in logistics. A category B driving license is required as there is travel to and from the mines

Contact person Torbjörn Viklund, Tel. +46 (0)910-77 40 92, E-mail: [email protected] Malin Rosenius, Tel. +46 (0)910-77 43 42 E-mail: [email protected]

Location:

Boliden area

18

12. REDUCED NITRATE DISCHARGE FROM EXPLOSIVES UNDERGROUND Background Boliden uses nitrate-based explosives underground. Spillage of explosives during loading and explosives that do not detonate lead to problems with nitrate discharge from the mine and concentrator to the surrounding watercourses. Measurements performed in Garpenberg show that 50% of the annual total amount of nitrates comes out via pump water from the mine and 50% is released to the tailings pond after the concentrator. The water flow from the concentrator is five times higher than the drainage water from the mine, which dilutes the nitrate to such low concentrations that the water cannot be purified. The nitrate content in the mine drainage water is higher. Purification technology is in place here.

Idea Improved explosives handling and loading technique can reduce spillage of explosives. Improved ignition of the blasting drill hole can reduce the risk of the explosive being pressed dead, resulting in detonation failure. Improved water flushing of rounds of shot may be a way to move undetonated explosives to the mine’s drainage water, which increases the ability to use purification to reduce discharge of nitrates from the mine.

Objective The objectives of the master’s degree project are: •

Provide suggestions for improved handling and loading techniques.

•

Test whether electronic blasting caps reduce the amount of non-detonated explosives.

•

Investigate whether increased water flushing of blasted rounds increase nitrate levels in the drainage water.


Literature studies. Loading and blasting techniques. Methods to measure nitrate in water.

•

Planning and testing with electronic blasting caps.

•

Test of techniques to better wash nitrates out of rounds of shot.

Contact person Fredrik Jonsson, Tel. 0910-70 51 43, E-mail: [email protected]

Location:

Boliden area

19

13. DESIGN OF MAJOR BLASTS (SLOT DESIGN) Background For the most part, mines have complicated geological compositions in their respective ores. As a result, different slot designs are applied in various applications. There is often a local model that works from a production technology standpoint, but this is not always optimal.

Idea To investigate what improvements can be made, with a scientific and modelled slot, compared to the designs in use today.

Objective •

Describe the practical production benefits that can be measured/seen/perceived.

•

Suggest further design improvements.


Literature study. Experiences from other mines throughout the world.

•

Interviews and practical tests as regards different slot models used at different places.

•

Perform calculation models and work out design proposals based on retrieved information and material.

Contact person Fredrik Jonsson, Tel. 0910-70 51 43, E-mail: [email protected]

Location:

Boliden area

20

14. OTHER SUGGESTIONS FOR MASTER’S DEGREE PROJECTS IN ENGINEERING Background Boliden Mineral AB is a mining company with different mining methods and techniques. This enables Boliden to offer a wide variety of master’s degree projects.

Idea •

•

Investigation of shaft V’s truck transport Water management in the mines

•

Planning tools and methods (including activity control)

•

Drilling and blasting in the mines

•

RFID monitoring of different products (from mines to plant)

•

etc.

Objectives •

Describe any practical problems

•

Suggest appropriate solutions to these problems

Description The project is expected to consist of the following components: Literature study. Experiences from other mines throughout the world. •

•

Interviews and practical testing

Contact person Arne Renström Tel. +46 (0)910-77 43 01 E-mail: [email protected] Stephen Manning, Tel. +46 (0)910-77 40 06 E-mail: stephen.manning @boliden.com Fredrik Jonsson, Tel. +46 (0)910-70 51 43 E-mail: [email protected]

Location:

Boliden/Garpenberg/Gällivare

21

MASTER’S DEGREE PROJECTS IN PROCESS ENGINEERING

15. DESULPHURISATION OF TAILINGS Background The pyrite content in the Aitik tailings is a potential source of acid, if oxidised. At present, the pyrite is deposited together with the waste rock phase in the tailing pond. Because the iron pyrite content is not currently extracted from Boliden’s ores, it is led together with the waste rock phase to the tailing pond. Oxidation of the iron pyrite produces sulphuric acid. To minimise the risk of acidification of the tailing pond in Aitik, a desulphurisation circuit will be installed in the new concentrator currently being erected. In the desulphurisation circuit, the majority of the remaining sulphur content in the tailings is separated into a smaller product through flotation. This product will be led to a separate landfill site. Comparison of the results from continual pilot tests with the results of tests conducted with larger cells has shown that a considerably longer flotation time is needed in the larger scale to achieve the same degree of separation as in the pilot scale.

Idea Establish which factors in particular limit the flotation rate of sulphur from the tailings and determine how these factors affect cell size and geometry.

Objective The objective is to find a model for dimensioning a full-scale facility based on the results of continuous pilot testing.

Description The project is expected to consist of the following components: Literature study – flotation kinetics, dimensioning of flotation cells. •

•

Modelling – mass balancing across a continual flotation cell.

•

Model testing in flotation cells of different sizes (parameter testing).

The majority of the work will be performed in Boliden’s office and laboratory in Boliden.

Contact person Jan-Eric Sundkvist, Tel. +46 (0)910-77 42 30 E-mail: [email protected]

Location:

Boliden

22

16. OPTIMISATION OF REGRINDING IN A FLOTATION CIRCUIT Background Grinding of mineral particles is a normal sub-process in our flotation circuits. We know that there are several cases in which grinding can be made more efficient. The problem is primarily showing what potential exists. This master’s degree project will contribute to our work to develop evaluation methods for this.

Idea The regrinding circuits are mapped out based on both their grinding results and how well they contribute to the flotation results.

Objective The objective is to map out a regrinding circuit for the Boliden plant and to provide suggestions for possible improvements.

Description The project is expected to consist of the following components: Literature study. •

•

Floating and grinding testing in laboratory scale.

•

Sampling from operating circuits.

•

Controlled full-scale testing.

The majority of the work will be performed in Boliden’s office and laboratory in Boliden.

Contact person Nils Johan Bolin, Tel. 0910-77 42 15 E-mail: [email protected]

Location:

Boliden

23

17. LEACHING OF PYRRHOTITE Background A deposit called Älgliden near Jörn in Västerbotten contains minerals such as nickel and cobalt bound to pentlandite. The pentlandite is intimately intergrown with pyrrhotite, which can be extracted with weak magnetic separation. In addition to nickel and cobalt, there is copper, gold and silver. It is not possible to produce a saleable nickel concentrate. Indicative leach testing shows that nickel and cobalt can be extracted through leaching. Destruction of the leaching solution and extraction of leached metals has not yet been investigated.

Idea To map out how the leaching solution should be handled to reduce costs through e.g. precipitation of iron sulphate and the manufacture of NaSH. Released metals must also be extracted from the leaching solution, e.g. through selective sulphide precipitation.

Objectives The objective is to find the best parameters for handling the large quantities of iron and sulphur that report to solution during leaching. Another objective is to examine how selective sulphide precipitation works for the relevant metal concentrations, in addition to considering other extraction methods.

Description The project is expected to consist of the following components: Literature study “Precipitation of iron sulphate”. •

•

Literature study “Selective sulphide precipitation of metals”

•

Model testing (parameter testing) of both iron sulphate precipitation and NaSH production in bench scale.

•

Model testing (parameter testing) of sulphide precipitation in bench scale.

The scope of the project may be big. It may therefore be necessary to set a narrower scope for the work than the description provided above. The majority of the work will be performed in Boliden’s office and laboratory in Boliden.

Contact person Jan-Eric Sundkvist, Tel. +46 (0)910-77 42 30 E-mail: [email protected] Paul Kruger, Tel. +46 (0)910-77 40 53 E-mail: [email protected]

Location:

Boliden

24

18. PURIFICATION OF ACIDIC MINE WATER Background/current situation Acidic water containing metal is generated through natural weathering processes in which sulphide ores are broken down. When acidic water is generated in underground mines or open-pit mines, it is usually called AMD (Acid Mine Drainage). Acidic water from waste rock dumps and other dumps of low-value material is usually called ARD (Acid Rock Drainage). At Boliden plants where AMD/ARD is found, purification is primarily carried out through neutralisation with slaked or burnt lime, where the metal content is precipitated as hydroxides together with gypsum. The properties of the precipitate obtained and the utilisation ratio of the lime additive varies with the composition of the water and the actual process design.

Idea Through a multi-step process, separate high-value metals such as copper and zinc from iron, arsenic, aluminium, manganese and other low-value metals. By optimising conditions in a multi-step process, obtain precipitation products with good dewatering properties while at the same time achieving a high utilisation ratio for the lime additive.

Objective For a given ARD, describe which types of precipitates can be obtained in a multi-step process depending on number of precipitation steps, pH, profile, standing time, type of alkali, process temperature, etc.


•

Perform thermodynamic calculations regarding solubility of metals vs. pH.

•

Model testing in continual mini-pilot facility.

•

Report writing.

The majority of the work will be performed in Boliden.

Contact person Johan Hansson, Tel. +46 (0)910-77 42 28 E-mail: [email protected] Jan-Eric Sundkvist, Tel. +46 (0)910-77 42 30 E-mail: [email protected]

Location:

Boliden

25

19. FINE PARTICLE FLOTATION Background The flotation process works most effectively with particles that are of a medium fraction size. At the concentrator in Boliden, grinding has been increased to reduce losses in the large particle size classes. Because of this, there are now major losses since fine particles do not float. It is both surface chemical and hydrodynamic effects that cause the particles to fail to float. To map out the hydrodynamic effects, two parallel floatation cells (operation scale) with good sampling capabilities have been installed in a floatation circuit at the concentrator. The surface chemical effects can be studied through laboratory flotation testing.

Idea By differentiating between hydrodynamic and chemical causes of fine particle losses during flotation, suitable improvement measures can be suggested and tested.

Objectives Establish causes of loss of fine “zinc blende” grains. Test suitable improvement measures.


•

Grinding and laboratory flotation testing.

•

Full-scale operational testing.

The majority of the work will be performed in the laboratory and at the concentrator in Boliden.

Contact person Nils Johan Bolin, Tel. +46 (0)910-77 4215 e-post: [email protected]

Location:

Boliden

26

20. FLOTATION OF TELLURIDE MINERAL Background/current situation Telluride is a common contaminant in copper concentrate and is extracted as a bi-product at the copper smelter. In Boliden, there is a find with unusually high telluride contents, primarily bundled in bismuth telluride. A special leaching plant has been built for the extraction of telluride from floatation concentrate. Flotation of telluride mineral has not been fully studied and further knowledge is necessary in order to optimise telluride extraction.

Idea By performing flotation studies in lab scale with different collectors and conditions, study how telluride mineral floats in order to increase knowledge. The flotation products are analysed in fractions where justified and are studied (in certain cases also mineralogically with Quemscan instruments).

Objective Improve the exchange of telluride to the flotation concentrate for ore from Kankberg.


Literature study.

•

Evaluate the results from different types of flotation tests.

•

Report writing.


Contact person Nils Johan Bolin, Tel. +46 (0)910-77 42 51, E-mail: [email protected]

Location:

Boliden

27

21. FUNDAMENTAL PARAMETERS FOR FLOTATION Background During the flotation process, air bubbles lift hydrophobic particles to the surface of a flotation device and the froth with the hydrophobic particles is separated to a froth trough for further transport to repetition, regrinding or finished concentrate. There are many parameters that determine how well the flotation process works on a specific ore. There are both chemical and device-related parameters. The distribution of bubbles in the flotation device and the quantity of bubbles on the surface are examples of two factors. Other factors include the hydrodynamics (turbulence) in the bottom or at the surface of the devices, the froth thickness and the distance of the floated particles to the froth removal edge. There are methods for determining the amount of air in the bubbles and the bubble distribution in the devices. A limiting factor for the capacity in a flotation device is the total surface of the bubbles and the speed at which they are transported through the pulp. The term can be summarised as “carrying capacity”, which was introduced in the 1980s when column flotation became more generally used and the limitation became more obvious than earlier.

Idea By finding methods for determining the capacity of a flotation device for a specific ore, it will be possible to specify certain design parameters with better precision. This applies in particular to the surface of the devices in relation to the design production capacity of the devices. Through this, it shall be possible to avoid limitations in new installations and enable the identification of any such limitations in the existing concentrators.

Objective Map out limitations in the capacity of devices for a few cases.


•

Sampling in operating plants.

•

Calculation of flotation parameters from sampling results.

The majority of the work will be performed in the laboratory and concentrator in Boliden.


Location:

Boliden

28

22. DEVELOPMENT OF LAB METHOD FOR FLOTATION TESTING Background/current situation Sulphidic mineralisations and ores are evaluated through methods such as flotation testing in batches at laboratory scale. Test results are evaluated by preparing a mass and metal balance of froth products and residual product. Results from testing on representative samples have been shown to vary between different laboratory workers. pH value, pulp density, air flow, additive levels of collector, presser and activator are normally given. Possible reasons for test result variations may be that the froth oil, water additives and the method in which the froth product is removed from the flotation device vary between different laboratory workers. This may mean that the percentage of pulp mechanically recovered to the froth product is dependent on the laboratory worker.

Idea By studying in detail and describing how different laboratory workers perform floatation tests, map out the reasons for the observed variation in the results. By determining the water content in the froth product, quantify the percentage of mechanically entrained pulp and thereby normalise the results for different laboratory workers.

Objective Improve repeatability in flotation test results.


•

•

Evaluate the results of different types of flotation tests performed by different laboratory workers on representative samples. Report writing.



Location:

Boliden

29

23. FLOTATION OF DISINTEGRATED ORE IN AITIK Background There are large quantities of marginally disintegrated ore in Aitik that was previously considered unprofitable to process. With higher metal prices and lower operating costs, it is now probably profitable to treat such ores. The marginal ore was mined to enable the mining of richer ore. Since the marginal ore has been stored for long periods of time partially by soil, it is unfavourable from an ore dressing perspective. When opening a new open-pit mine, the top stopes often consist of somewhat disintegrated marginal ore with soil mixed in. At Aitik, there are plans to process the marginal ore, and with plans of opening a new open-pit mine, there is a strong motivation for investigating methods for improving the process results for such cases.

Idea It is suspected that disintegration and the inclusion of soil consumes an unusually large amount of collector reagent. Disintegration means that the amount of lime added to raise pH increases greatly.

Objective Map out how the flotation process works for disintegrated ore and soil mixture with different flotation parameters. The primary focus of the study will be on the consumption of collector reagent, but there will also be a study of the impact on other parameters, such as the addition of lime. There may also be methods to counteract e.g. the effect of soil being mixed in. These should also be studied.


•

•

Literature study. Testing in lab scale with different mixtures of soil and on marginal ore with different disintegration properties. In this context, it is desirable to find a method to determine the degree of disintegration of the ore samples. If possible, perform operational testing if interesting methods can be found.

The majority of the work will be performed in the laboratory and concentrator in Boliden and Aitik.


Location: Boliden and Gällivare

30

24. IMPACT OF SULPHUR AND COPPER CONTENT ON COLLECTOR REAGENT NEED AT AITIK Background The consumption of collector reagent for a specific flotation is dependent on factors such as the surface size of the minerals to be made hydrophobic. Disintegration and soil mixture are other factors that affect reagent consumption. Today, there is ratio control of reagent added vs. throughput tonnage so that there is a fixed addition in grams per tonne. A more advanced control involving grinding, copper content and perhaps even sulphur content could give the results more stability, if the given hypothesis is correct.

Idea Ratio control of collector reagent addition against not only tonnage, but also the copper and sulphur content of the ore involved, as well as the degree of grinding, should produce a more stable process with better total exchange.

Objective Map out how the flotation process works at different copper and sulphur contents in the ore and at different degrees of grinding as a function of the collector reagent addition.


Literature study.

•

Lab-scale testing of different ore samples and with different degrees of grinding.

•

Operational testing may be difficult as ore contents cannot be affected, but this can be considered e.g. to study the effect of grinding.

The majority of the work will be performed in the laboratory and concentrator in Boliden and Aitik.


Location: Boliden and Gällivare

31

25. PURIFYING CONTAMINATED WATER THROUGH FREEZING Background Acidic water containing metal is generated through natural weathering processes in which sulphidic ores are broken down. When acidic water is generated in underground mines or open-pit mines, it is usually called AMD (Acid Mine Drainage). Acidic water from waste rock dumps and other dumps of low-value material is usually called ARD (Acid Rock Drainage). Contaminated neutral and slightly alkaline process water is also found in the vicinity of the concentrator. At Boliden plants where AMD/ARD is found, purification is primarily carried out through neutralisation with slaked or burnt lime, where the metal content is precipitated as hydroxides together with gypsum. The University of Cape Town and Delft University of Technology have spent the past several years developing a water purification method called Eutectic Freeze Crystallisation. With this method, contaminated water is cooled down to a temperature where dissolved salts crystallise out and sink to the bottom while the ice that has formed floats to the surface and can then be separated from the concentrated salt solution.

Idea Investigate whether natural freezing can be a method for clearing metals and sulphate out of contaminated mine water. Or whether it could be a pre-treatment step of a subsequent purification process while pure water in the form of ice is produced.

Objective By cooling contaminated water to different temperatures, determine the actual distribution of a number of contaminants between the three phases – ice, precipitated salt crystals and mother liquor.


•

Lab-scale testing on different water qualities.

The majority of the work will be performed in the laboratory in Boliden.

Contact person Johan Hansson, Tel. +46 (0)910-77 42 28, E-mail: [email protected] Jan-Eric Sundkvist, Tel. +46 (0)910-77 42 30, E-mail: [email protected]

Location: Boliden

32

26. FUNCTIONAL PROCESS IMAGES Background Several million tonnes of ore are dressed in Boliden’s concentrators each year. There are several steps involved in ore dressing – crushing, grinding, flotation and dewatering. Currently, all control is handled via one single control system for the facility, where all process data is also collected. Process data is then presented to the operators via process images and alarm lists. As the amount of gathered data increases, it becomes more and more difficult to present the information to the operators in a clear manner.

Idea Create process images that are more function-oriented and in layers to give operators a better overview of the status of the process.

Objective Concrete suggestions and guidelines for how process images should/shall appear at Boliden so that operators have maximum benefit from the system.

Description The project is expected to consist of the following components: Literature study and supplier contacts •

•

Interviews and testing (if relevant)

The project is carried out at Boliden’s office in Boliden and at one of Boliden’s concentrators if necessary.

Contact person Mikael Walter, Tel. +46 (0)910-77 42 58, E-mail: [email protected]

Location: Boliden

33

MASTER’S DEGREE PROJECTS IN THE ENVIRONMENT

27. ROOT PENETRATION IN PROTECTIVE AND SEALING LAYERS IN TAILINGS PONDS NO LONGER IN USE Background During reclamation of former mining areas, so-called qualified moraine covering is used to prevent oxygen penetration and thereby disintegration of the mine waste. In general terms, a qualified moraine covering means that a sealing layer of approx. 30-50 cm compacted moraine is laid out to prevent oxygen penetration. This is followed by an approx. 1.5-2 m thick protective layer of non-compacted moraine. This protects the sealing layer from damage from ground frost and root penetration. In the final stage, vegetation is established in the area with grass as well as spontaneous establishment of bushes and trees.

Idea Inventorying of one or more of Boliden tailings ponds or waste rock deposits undergoing reclamation, including a survey of root penetration from bushes and trees. An analysis of whether root penetration could affect the results of reclamation measures and what plant communities could be accepted.

Objective The work shall result in an evaluation of root penetration linked to different plant communities as well as suggestions of guidelines in choose plant communities/vegetation method based on what type of reclamation is being performed.


Literature studies

•

Field studies/inventorying

•

Evaluation

The work will be performed primarily at the Boliden offices in Boliden as well as out at some of the reclaimed Boliden mines.

Contact person Anders Forsberg, Tel. +46 (0)910-77 45 50 E-mail: [email protected]

Location: Boliden

34

28. INVENTORYING OF THE FUNCTION AND LONG-TERM EFFECTS OF VEGETATION ESTABLISHMENT WITH DIGESTED SLUDGE Background During reclamation of former mining areas, digested sludge is sometimes used during the final stage to add organic material and nutrients to speed up the vegetation process and to also reduce the risk of erosion. At present, there are no guidelines for how sludge is to be used during reclamation, what thickness it should be laid out and how it should be laid out. Physical stability problems have been obsorved in some sludge layers established on slopes. Also oxidation on sludge can be relatively fast and should be taken to consideration in planning.

Idea Documentation of measures performed in the areas in which Boliden established vegetation with digested sludge and follow-up of land profile and long-term effects.

Objective The work shall result in evaluation of performed measures and suggestions of guidelines for laying out digested sludge as a vegetation establishment layer. The guidelines must contain recommendations for quantity/thickness of the sludge as well as a method of laying it with the aim of being able to establish vegetation quickly while at the same time being stable in the long term, with as little nutrient (nitrogen and phosphorous) leakage as possible. Sludge on slopes can create physical stability issues and should bee studied seperately from sludge on even surfaces. Study can even include estimation of remaining sludge quantities on areas after time period that has passed since establishment.


Literature studies.

•

Field studies/inventorying

•

Evaluation

The work will be performed primarily at the Boliden offices in Boliden as well as out at some of the reclaimed Boliden mines.

Contact person Päivi Picken, Tel. +46 (0)910-70 57 73 E-mail: [email protected]

Location: Boliden

35

29. METHOD FOR MAPPING OUT NITROGEN FLOWS Background Mining involves use of a great number of explosives containing nitrogen. This results in elevated levels of nitrogen of different fractions in the mine water pumped up. There have been several investigations and compilations of nitrogen flows out of mines, but it is difficult to compare data between the mines as the result of differences in basic data.

Idea Review of previously performed mappings and suggestion for general method for mapping out nitrogen flows in the mine, concentrator, industrial area and tailing pond. The results may vary depending on where in the mine sampling occurred and what nitrogen fractions are analysed.

Objective The study shall result in a method that describes the frequency, testing points and nitrogen species in the different flows of the mining industry. It must be possible to use this as a standard method within the industry. The created model shall be verified with a number of samplings.


Literature studies

•

Collection of measurement data

•

Evaluation

The work will be performed primarily at the Boliden offices in Boliden as well as out at some of the active Boliden mines.

Contact person Erik Spinnel, Tel. +46 (0)910-70 57 55 E-mail: [email protected]

Location: Boliden

36

30. EVALUATION OF ALTERNATIVE SEALING LAYERS AS REGARDS OXYGEN PENETRATION Background Reclamation of mine areas no longer in use is possible with qualified dry covering. The material most often used as sealing layer is packed moraine. The sealing layer is intended to reduce oxygen penetration and water transport. There is a need to develop new materials that are suitable for use as sealing layer in qualified dry covering.

Idea Testing and evaluating different materials (e.g. GLS, ash, Mesa line or other suitable material) and/or material that can be mixed into the moraine to obtain a better sealing layer. The work can also involve evaluation with a filter layer installed and with no filter.

Objective The work shall result in evaluation of the material used. The work shall be monitored with measurement of oxygen penetration in the sealing layer and the material’s permeability. Lab testing can be designed to be a good reflection of reality, i.e. so that the thickness of the sealing layer and covering layer is applied based on field conditions.


Literature studies

•

Collection of measurement data

•

Evaluation


Contact person Andreas Uneé, Tel. +46 (0)910-70 56 22 E-mail: [email protected] Päivi Picken, Tel. +46 (0)910-70 57 73 E-mail: [email protected]

Location: Boliden

37

31. OPTIMISATION OF PHYSICAL PROPERTIES OF SEDIMENTATION PONDS Background Liming with sedimentation is a common water treatment method when handling acidic water in the mine areas and in some cases used for operations that have been closed down. Development of water management now often has a chemical focus. However, it is also important to study physical factors, particularly the physical properties of precipitation ponds at simple liming facilities. The flow can easily take a shortcut in the pond. In such cases, the sedimentation and volume of the pond are not used effectively. A pond short circuit flow with correctly adjusted flow can significantly improve water quality at the outlet. It may also be a cost-effective way to improve water management.

Idea Review of example pond’s/ponds’ effect at present: Is practical standing time as it should be based on pond volume? •

•

•

•

Is flow type optimal or should the flow pattern be manipulated? Where in the pond sediment settles Considering short circuiting and turbulence

Valuation of simple methods that could optimise use of pond surface and pond volume, e.g. booms and curtains. There can also be an evaluation based on the geometry of the pond. Pond geometry refers to e.g. length/curtains ratio, falling, rising or level bottom, etc. The study may involve field measurements and field evaluations, laboratory testing (if there is access to test instruments) and/or computer simulations. The study shall be based on the water quality and particle characteristics, lime dosing and flow/flow facilities of one or more existing ponds.

Objective •

Simple and cost-efficient addition for ponds (that does not prevent maintenance).

•

Future suggestions for planning efficient ponds (best output/volume principle).

Description The project is expected to consist of the following components: Alternative 1 •

•

Literature studies/state of the art Measurement data collection and characterisation of example pond/ponds, including water quality/particle characteristic.

•

Laboratory testing of different pond alternatives with standard flow with standard water (recently limed)

•

Evaluation, improvement suggestions for example pond

38

Alternative 2 •

•

Literature studies/state of the art Measurement data collection and characterisation of example pond/ponds, including water quality/particle characteristics.

•

Computer simulation of different pond alternatives

•

Evaluation, improvement suggestions for example pond

The work will be performed primarily at the Boliden offices in Boliden as well as out at one of the active Boliden mines or other liming units. If access to a test laboratory or simulation laboratory can be organised, some of the work can be performed at this organisation’s premises.


Location: Boliden

39

32. PHYTOREMEDIATION Background Phytoremediation involves remedying contaminated land, water and air with the help of plants. It involves the plant’s function in conjunction with toxic metals, e.g. the plant’s ability to accumulate, detoxify and bind heavy metals (e.g. in the root zone). Some plant specifies are more tolerant to metals than others. Some can even be described as metal-accumulating plants.

Idea Boliden’s current list of metal-tolerant and metal-accumulating plants shall be evaluated and updated. Practical opportunities for using phytoremediation should be tested in the industrial areas of the mining operations. Preliminarily, the method is expected to be best for side areas, where metal levels are not particularly high (only slightly contaminated or borderline). A master’s degree project could cover no more than the establishing year. For this reason, it is a good idea to choose one-year/quick growing species for the degree project. Another alternative is to base the study on the naturally occuring plants already established in the area.

Objective •

•

Supplemented list of plant species that are suitable for phytoremediation in wet conditions and location-specific recommendations (wet areas, large areas, open areas, etc.). This part is covered by literature study. Suggestion of method to use for phytoremediation of mildly contaminated former industrial areas.

Description The project is expected to consist of the following components: Literature studies and compilation of existing information and recommendations •

•

Planning and creation of small test area and preparation (on study of a naturally vegetated area)

•

Evaluation



Location: Boliden

40

33. EVALUATION OF VEGETATION ESTABLISHMENT AT WASTE ROCK LANDFILLS WITH HELP OF DIGESTED SLUDGE Background Reclamation of waste rock deposits is handled in stages during the life of a mine. The reclamation method used at the Aitik mine consists of a 1-metre thick moraine covering, which is laid out in two batches. Each batch consists of one 0.5-metre layer of moraine that is compacted. The moraine layer is then covered with 30 cm of digested sludge in order to improve the soil. To further improve vegetation establishment, the entire surface is sewn with grass seeds. The first areas of the landfill underwent reclamation in 2004 and the final area was completed in autumn 2011.

Idea The aim of the master’s degree project is to obtain understanding of the vegetation distribution in the treated areas. We need help to inventory what plant species are found in the treated areas, the degree of coverage and root depth. In addition, we should also look at how these parameters change over time and whether there are differences between slopes and plateaus as growth sites.

Objective The project shall result in evaluation of vegetable establishment and a picture of how things are today as well as what can be expected in the future. Focus should lie on the growth succession, whether the roots go down into the moraine layer, and how long it takes before a treated area is covered by vegetation.

Description The project is expected to consist of the following components: Inventorying at waste rock deposit T5 in Aitik, Gällivare. The inventorying should include plant species, vegetation coverage and root depth. The inventoried areas should be found both on slopes and on plateaus and in areas of different ages (time since digested sludge was laid out). Inventorying results should be supplemented with a literature study based on the results of similar testing to see what we can expect in the future.

Contact person Camilla Esberg, Tel. +46 (0)970-72 92 40 E-mail: [email protected]

Location: Gällivare

41

34. CREATION OF NEW INDUSTRIAL AREA IN GARPENBERG Operations in Garpenberg are currently undergoing expansion and facilities are being built above ground. To create a welcoming environment for employees and visitors, a plan for the appearance of the future industrial area must be developed based on geographic conditions and the new buildings.

Contact person Malin Söderman, Tel. +46 (0)225-360 92 E-mail: [email protected] Jenny Gotthardsson, Tel. +46 (0)225-369 30 E-mail: [email protected]

Location: Garpenberg

42

MASTER’S DEGREE PROJECTS AT RÖNNSKÄR

35. SURVEY OF RÖNNSKÄR’S WATER USAGE Background Rönnskär uses large quantities of fresh water and sea water. The water is used for the processes, gas cleaning and cooling. The spent cooling water is returned to the sea and the water that has been in contact with the process is treated in an efficient water treatment plant before being sent to the sea.

Idea Rönnskär needs to survey how water is being used. This survey shall include documenting each process’ use of fresh water and sea water and how water is treated after use. The survey will be used as the basis for suggestions on more efficient use of the water. The purpose is also to ensure that contaminated water is handled in an environmentally responsible manner.

Objective Literature studies focusing on Rönnskär’s water management •

Via questionnaires and site visits, survey the water going in and out of each plant as regards flow, type, temperature, content, etc.

•

Optimisations that could reduce water consumption

•

Suggest changes that lead to increased re-use of water

•

Based on the survey, review whether existing drawings are correct

•

Investigate whether spent water goes to the right drainage system

Description The majority of the work will be performed at the Rönnskär plant in Skelleftehamn. Contact person Kristoffer Renström, Tel. +46 (0)910-77 37 22 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

43

36. PURIFYING DECOPPERISED ELECTROLYTE Background Purifying decopperised electrolyte from copper prior to nickel evaporation. At present, a great deal of copper is lost via the nickel sulphate product as we cannot reduce the copper content more due to the risk of AsH 3 formation in the process used today.

Idea Through literature studies and lab testing, see whether it is possible to further purify the electrolyte before evaporation and NiSo precipitation.

Objective To reduce the amount of copper in decopperised electrolyte.

Description The majority of the work will be performed at the Rönnskär plant in Skelleftehamn.

Contact person Mats Holmlund, Tel. +46 (0)910-77 33 23 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

44

37. THE EFFECT OF CHLORIDE CONTENT IN ELECTROLYTE ON THE SULPHUR CONTENT IN CATHODE COPPER Background There are indicators that the chloride content of the electrolyte affects how much sulphur contaminates the cathodes, possibly in combination with other impurities in the electrolyte.

Idea Through literature studies and scale experiments, investigate to what degree the chloride content of the electrolyte affects the sulphur content in cathode copper.

Objective To reduce the amount of sulphur in cathode copper.


Contact person Mats Holmlund, Tel. +46 (0)910-77 33 23 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

45

38. LEACHING OF GAS CLEANING DUSTS Background Process gases contain dust that is precipitated in gas cleaning equipment. The precipitates contains both valuable metals and impurities. At present, there are two methods of processing the precipitates. Precipitates with a low level of impurities are recycled to the smelting process. Precipitates with high levels of impurities are treated as hazardous waste.

Idea Through use of various leaching processes, it could be possible to separate impurities from the valuable metals in the precipitates. The valuable metals could be recycled to the process while the impurities are treated as hazardous waste.

Goals: •

Reduced amount of hazardous waste.

•

Better yields (metal).

Objective •

Literature studies

•

Leaching trials, where possible leaching processes for the various types of precipitates are investigated.

•

Report writing


Contact person Kristoffer Renström, Tel. +46 (0)910-77 37 22 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

46

39. EVALUATION AND IMPLEMENTATION OF COPPER CONVERTING MODEL Background At the Rönnskär plant in Skelleftehamn, about 200,000 t onnes of copper are produced from ore concentrate and recycled material each year. One of the main steps of the copper production process is called converting. Copper converting means that iron and sulphur are oxidised with oxygen-enriched air that is blown into a smelt. As assigned by Boliden, Luleå University of Technology has developed a software tool that lets the user perform thermodynamic modelling of the converter process. This model is intended for use in testing different process scenarios theoretically so that the actual process can be optimised as regards impurity distribution, efficiency, etc.

Idea The strengths and weaknesses of the model could be identified by following up a number of process cycles in full scale and then running a number of simulations in the software. It should be possible to find positive quality factors that can be tested in full scale.

Objective Upon completion of the work, a report is expected to contain an evaluation of the model’s potential for usage in Rönnskär’s development work, as well as comparisons between the model’s results and in situ results and recommendations for how the model can best be utilised. The extreme cases or optimisation attempts that are tested in the model shall also be reported with recommendations of continued simulation or full-scale testing.


Literature study of copper converting and the behaviour of impurities during the process

•

Simulations in the modelling software

•

Follow-up of the full-scale process and any full-scale testing

•

Report writing

The majority of the work will be performed at the Rönnskär plant in Skelleftehamn. Suitable education programmes include chemistry, metallurgy, physics and materials engineering.

Contact person Jonas Bäckström, Tel. +46 (0)910-77 33 12 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

47

40. GRAVIMETRIC SEPARATION OF SMELTED SLAG, MATTE AND SPEISS AS A FUNCTION OF THE SLAG’S PHYSICAL AND CHEMICAL PROPERTIES Background At the zinc fuming plant, the fayalite slag is processed in batches under greatly reducing conditions to separate the zinc and other volatile metals from the slag. Extraction is carried out for both financial and environmental reasons. The volatile metals are vaporised and reoxidised in the flow of process gas. The product follows with the gas that is transported, is separated in electrostatic precipitators and then undergoes further processing at a later stage. The slag is tapped to an electric furnace for gravimetric separation of slag, matte formed during the process, and speiss. The percentage of copper remaining in the slag after copper extraction is primarily distributed to the matte and speiss. The solubility of copper in the slag in question is relatively low and the copper losses that despite this occur via the slag are primarily due to incomplete separation of the phases.

Idea Effective separation of the molten phases can only occur if the physical properties of the slag are favourable. There are a number of theoretical models for calculating factors such as the physical properties of slags. These require data such as chemical composition, temperature, and oxygen partial pressure in the process gas. The aim of the master’s degree project is to evaluate a number of selected models for predicting physical properties and examine whether the calculated parameters have any influence on the effectiveness of the separation. Access to databases with necessary process data will be provided by Boliden, Rönnskär.

Objective The objective of the project is to evaluate whether existing calculation models can be used to investigate whether the phase separation is affected by: Chemical composition •

•

Temperature

•

RedOx ratio

Description The majority of the work will be performed at the Rönnskär plant in Skelleftehamn

Contact person Anders Öhrvall, Tel. +46 (0)910-77 34 21 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

48

41. INCREASED PRACTICAL AND THEORETICAL UNDERSTANDING OF ANTIMONY DISTRIBUTION DURING CONVERTING Background During converting, antimony is removed from the matte phase to the slag and gas phase. Compared to our competitors, very little antimony goes to the gas phase during the conversion. We require a basic theoretic followup of factors that affect the antimony desorption as well as a practical follow-up. Practical follow-up is done by sampling of exiting converter gas cleaning dust to see how different factors (oxide slag quantity, lead content in white metal, etc.) affect antimony distribution.

Idea To use theoretical studies to see what parameters affect antimony volatilisation most and perform sampling campaigns to see what happens in practice. Parameters that could affect antimony distribution: Antimony level in ingoing white metal •

•

Quantity of oxide slag

•

Composition of oxide slag

•

Temperature

•

Batch size

•

Blast

•

Blow time

Objective To increase knowledge and understanding of how antimony is distributed in the converter in order to optimise the flow of antimony through the smelter.

Limitations This project only covers the antimony distribution of the converter. The project could be expanded somewhat to include elements similar to antimony, such as arsenic and bismuth.


Contact person Dennis Furberg, Tel. +46 (0)910-77 37 52 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

49

42. WASTE WATER PURIFICATION REGARDING NICKEL AND ANTIMONY Background The Rönnskär plant has an efficient waste water treatment plant for impure water. Zinc, arsenic, copper, cadmium, lead, mercury, etc. are precipitated as sulphides. The sulphide sludge that forms is then recycled to the copper smelter. After sulphide precipitation the water undergoes lime precipitation at pH 11, where fluorine and remaining impurities precipitate. Both nickel and antimony are incompletely precipitated during sulphide precipitation. During lime precipitation, nickel precipitation is sufficient, but not antimony precipitation. A big disadvantage with the current lime precipitation is that a large amount of sludge is formed. An alternative lime precipitation method to a lower pH produces less sludge, but does not reduce nickel and antimony sufficiently.

Idea The aim of the master’s degree project is to suggest waste water treatment methods regarding nickel and antimony based on literature studies. Suitable methods for waste in the Rönnskär water treatment plant are then tested in laboratory scale.

Objective The objective is to suggest one or more waste water treatment methods for nickel and antimony that can be performed in the Rönnskär water treatment plant and achieve the following: •

<0.01 mg/l Ni

•

<0.1 mg/l Sb

Description The master’s degree project can be performed primarily at the Rönnskär plant in Skelleftehamn.

Contact person Peter Olsson, Tel. +46 (0)910-77 32 86 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84, E-mail: [email protected]

Location:

Skelleftehamn

50

43. OPTIMISATION OF STEP 1 IN DECOPPERIZATION PLANT Background The electrolyte in the tank house is purified in several steps – first with a copper crystallizer to remove copper sulphate and then with electrowinning in two steps. In step 1, most of the remaining, the copper is removed and in step 2 remaining impurities (except nickel) are removed.

Idea Adding inhibitors (sodium chloride, salt and bone glue) makes it possible to obtain a harder and more compact copper cathode in step 1.

Objective To obtain a higher current exchange in decopperzation plant step 1 through better and more compact cathode with fewer short circuits.


Contact person Marie Holmberg, Tel. 84 (0)910-77 38 46 E-mail: [email protected]

Location:

Skelleftehamn

51

44. ASSAYING OF INCOMING MATERIAL AT SAMPLING PLANT Background We are expanding our electronic waste recycling and need to investigate the possibility of analysing the incoming material for impurities as early as in the sampling plant.

Idea Analysis instruments are available on the market. Are there any we can use?

Objective To be able to sort incoming material by content


Contact person Magdalena Mattsson, Tel. +46 (0)910-77 33 42 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84, E-mail: [email protected]

Location:

Skelleftehamn

52

45. PRODUCTION OF ANTIMONY FROM INTERMEDIATE PRODUCTS Background Many of our intermediate products contain antimony. These are recirculated to the process. Is it possible to leach out the antimony and create a saleable product?

Idea Investigate the possibility of producing a saleable antimony product through literature surveys, lab tests, etc.

Objective Investigate the possibilities of extracting antimony as a product


Contact person Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

53

46. EXAMINE THE EXISTANCE OF RARE ELEMENTS IN INTERMEDIATE PRODUCTS AT RÖNNSKÄR Background There is a large number of elements in the raw material mix for Rönnskär processes.

Idea Investigate whether it is possible to extract rare elements through literature survey, analysis of our intermediate products and lab scale experiments.

Objective Map out the existence of rare elements and the possibility to extract these.


Contact person Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

54

47. INVESTIGATION OF THE IMPACT OF PH ON ARSENIC PRECIPITATION AT RÖNNSKÄR WASTE WATER TREATMENT PLANT Background Rönnskär has a central treatment plant that cleans process water, rain water, and rinse water from the Rönnskär industrial area. The water entering the plant contains large amounts of metals that must be removed before the water is released to the sea. In brief, the treatment plant consists of 2 different sulphide precipitation steps with subsequent lime and iron precipitation. Arsenic is precipitated in step 1. The pH of incoming water is normally between 1 and 2, but pH can vary. At present, pH is not adjusted before step 1. pH is instead adjusted after step 1.

Idea Experience has shown that arsenic is precipitated acidic. Precipitation is therefore performed before pH adjustment. But, how much is arsenic precipitation affected by pH changes to the incoming water? Would arsenic separation results be improved by adjusting the incoming pH values?

Objective •

•

Literature survey of sulphide precipitation of arsenic in acidic pH ranges Lab scale testing to investigate whether incoming pH values affect arsenic precipitation and, if so, find an optimal start pH value.

•

If an optimal start pH is found, investigate and, if relevant, test the possibility of performing this in full scale.

•

Optimise sulphide additions for stage 1


Contact person Kristoffer Renström, Tel. +46 (0)910-77 37 22 E-mail: [email protected] Marie Holmberg, Tel. +46 (0)910-77 38 84 E-mail: [email protected]

Location:

Skelleftehamn

55

EXAMPLES OF PREVIOUS MASTER’S DEGREE PROJECTS

•

Evaluation of sludge content meter for regulating chemical dosing at sanitary treatment plant plus investigation regarding new metal precipitation

•

Optimising zinc precipitation at Rönnskär water treatment plant

•

Mapping out of pump system in Kristineberg mine

•

Key indicators for energy efficiency

•

MPC Regulation of mill circuit

•

Optimal fragmentation

•

Early strength in shotcrete

•

Remote muck loading, production monitoring

•

Design of planning tools and control rules for rock transport in Kristineberg

•

Reduced nitrate discharge from explosives underground

•

Is synthetic fibre in shotcrete suitable in our mines?

•

Design of major blasts (slot design)

•

MIFO investigation

•

Mapping of biodiversity

•

Procurement master data 2.0

•

Procurement-driven cost measurements

•

Magnetite formation in fayalite slag and its effect on the zinc fuming process

•

Mechanisms for understanding and controlling sludge fermentation

•

Improved sorting and more rational handling of waste at the Rönnskär plants

56

BOLIDEN - MASTER Thesis - Examensarbeten-En

Recommend Documents