06-Flacher-Holcim-vertical-roller-mills-for-clinker-grinding-with-Holcim.pdf

Strength. Performance. Passion.

Vertical Roller Mills for Clinker Grinding within Holcim Holcim Technology Ltd, D. Woldt, A. Flacher

Loesche Symposium 2014, 2014-08-24

© 2014

Agenda 1. Holcim Requirements on Cement Grinding Systems 2. Loesche VRMs in the Holcim Group 3. Grinding Systems and Cement Types 4. 5. 6. 7.

Comparison of Cement Grinding Systems Performance of Loesche Cement Mills Holcim Approach to ensure high VRM Performance and Reliability Focus of Holcim and Tasks for VRM Manufacturers

Loesche Symposium 2014, WOD, 2014-08-24

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Holcim Requirements on Cement Grinding Systems • Requirements on grinding system  

   

Achievement of required product quality Flexibility regarding changing market demands (cement types) High reliability and net availability Energy efficient system (kWh/t) Low maintenance and wear parts cost Simple installation and operation

• Trends in Holcim 



Large single VRMs with high flexibility and capacity Roller press systems (semi-finish and finish grinding) Carboneras LM 46 2+2


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Development of VRMs for Slag and Cement Grinding in the Holcim Group • First VRMs for cement grinding within Holcim were two LM 46 2+2 in Hon Chong plant, Vietnam, commissioned 1998

30 25 20 15 10 Overall 5

Loesche


2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

0 1997

Number of Vertical Roller Mills

35

Hon Chong LM 46 2+2

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Loesche Cement and Slag Mills in the Holcim Group No

Commissioning Year

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

1998 1998 2004 2004 2004 2005 2006 2007 2008 2009 2010 2010 2010 2011 2011 2013 2013* 2015 2016

Country Vietnam Vietnam Morocco Vietnam Spain France Morocco Canada South Africa India India India India Ecuador India Indonesia Philippines Indonesia Nigeria


Plant

Type/Size

Motor power kW

Cement (C) / Slag (S)

Hon Chong Hon Chong Fès Thi Vai Carboneras Dunkerque Settat Mississauga Roodeport Kolar Thondebhavi Dadri Nalagarh Bellary Kudithini Guayaquil Chanda Tuban 1 Mabini Tuban 2 Calabar

LM 46 2+2 LM 46 2+2 LM 46 2+2 LM 56 2+2 LM 46 2+2 LM 46 2+2 LM 56 3+3 LM 56 3+3 LM 53 3+3 LM 56 3+3 LM 56 3+3 LM 56 3+3 LM 56 3+3 LM 56 3+3 LM 56 3+3 LM 56 3+3 LM 46 2+2 LM 56 3+3 LM 70 4+4

2'800 2'800 2'200 4'450 2'400 2'400 5'000 4'600 4'000 5'400 5'400 5'400 5'400 5'100 5'600 5'200 3'400 5'200 8’800

C C C C S/C S C S C C C C C/S C C C C C C

* since 2013 in operation in the Holcim Group

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Loesche Cement and Slag Mills within the Holcim Group North America

Europe

1 x LM 56 3+3

2 x LM 46 2+2

Southeast Asia 3 x LM 46 2+2 1 x LM 56 2+2 2 x LM 56 3+3

Africa 1 x LM 46 2+2 1 x LM 56 3+3 1 x LM 70 4+4

Latin America

India

1 x LM 56 3+3

5 x LM 56 3+3

Status 2014


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Mill Systems used for Cement and Slag Production • Based on produced volumes in the Holcim Group 2013

Loesche LM

Ball mills

FLSmidth OK 32%

Vertical Roller Mills

54% 16%

57% 10%

29%

1% Horomills

Ball mills with pre‐grinding


Pfeiffer MPS

1% Polysius DOROL

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Cement Types and Slag produced with VRMs (Holcim 2013) OPC

Fly ash cement

(3’600 – 5’300 cm2/g)

26%

Composite Cement

24%

(3’400 – 5’700 cm2/g) 8% Slag cement

65%

11%

Limestone 16% cement

Multiple blend 43% cement

Slag

7%

Pozzolan cement

(3’200 – 6’200 cm2/g)


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VRM Performance compared to other Grinding Systems • Comparison is based on production of same cement type on three representative grinding systems (yearly figures 2012) • Multiple blend cement: 5’000 cm2/g acc. to Blaine, 1.8 % R45 µm, clinker 76 % • Grinding systems Closed circuit ball mill (cage rotor separator)


Ball mill with roller press pre-grinder

Vertical roller mill

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Comparison of Key Performance Indicators • The production rate index and overall equipment efficiency of the VRM system exceeds the performance of the other systems • Mean time between failures is similar to other grinding systems 220

150 Net availability index

Mean time between failures 210

Production rate index

130

Net overall equipment efficiency 200

120

MTBF in h

NAI, PRI and OEE in %

140

110 100 90 80

190 180 170

70 160

60 50

150 BM

PG+BM


VRM

BM

PG+BM

VRM

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Specific Electrical Energy Consumption • VRM system is most efficient but shows highest energy consumption of mill fan (high air flow rate and pressure drop) Spec. electrical energy consumption in kWh/t

60

Multiple blend cement: 5’000 cm2/g, 1.8 % R45 µm

55 50

100 %

101 %

45 40 71 %

35 30

Auxiliaries Separator Fan

25

Pre‐grinder

20

Mill

15 10 5 0 BM Loesche Symposium 2014, WOD, 2014-08-24

PG+BM

VRM © 2014

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Comparison of Mortar Strength • Cement quality of VRM system is comparable to the other systems 55

Mortar strength in MPa

50

Multiple blend cement: 5’000 cm2/g, 1.8 % R45 µm

45 40 35

1d

30

3d

25

28d

20 15 10 5 0 BM


PG+BM

VRM

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Maintenance Cost (7 Year Period) • Long term comparison of maintenance cost from 2004 to 2010 including wear parts replacement CAPEX show benefit of Vertical Roller Mill 120

Maintenance cost in %

100 80 60 40 20 0 BM

PG+BM


VRM

Dadri LM 56 3+3

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Loesche VRM Performance compared to other VRMs • Comparison is based on performance of three representative mills in 2013 Plant A

Plant B

Plant C

Loesche

Competitor 1

Competitor 2

5'000

3'750

2'300

Limestone Cem.

Limestone Cem.

Pozzolana Cem.

cm2/g

4'250

5'650

4‘300

% R45 µm

3.3

3.1

6.3

%

61.6

67.3

60.8

Mill manufacturer Mill type

LM 56 3+3

Installed motor power

kW

Cement data Cement type Product fineness

Clinker


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Loesche VRM Performance compared to other VRMs • All three VRM types show excellent performance at similar level • Every mill type has particular advantages and disadvantages regarding process and operation as well as reliability and maintenance 40

Spec. electrical energy consumption in kWh/t

35

Limestone cement Limestone cement 4’250 cm2/g,

5’650 cm2/g,

3.3 % R45 µm

3.1 % R45 µm

30

Puzzolana cement 4’300 cm2/g, 6.3 % R45 µm

1,2 0,9

25

0,8

20

7,5

9,9

8,6

Fan

15 10

Separator Mill

16,4

18,8

17,6

Competitor OK 36‐4 1

Competitor 2 MPS 4250 BC

5 0 LM 56 3+3 Loesche Symposium 2014, WOD, 2014-08-24

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Holcim Approach to ensure Vertical Roller Mill Performance • In order to achieve a high performance of a VRM system following areas need particular attention: 

Feed uniformity and particle size distribution



Reliably and effective metal detection and extraction system



Optimized mill process especially concerning air and material distribution



Mill operation and control



Automatic mill protection system



Preventive maintenance



Wear part strategy and management Dunkerque LM 46 2+2


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Holcim VRM Protection and Reliability Concept Holcim strategy to improve the process and reliability of vertical roller mills and to avoid gearbox failures. Started in 2006 with following main fields:

Interlocks / Stop of mill operation Protective Actions / Mill stabilization Control loops / Normal operation

• Regular process and maintenance trainings • Online monitoring system • Automatic protective actions * • High level mill control • New drive concepts for large mills (multiple drive concept)

* (WO2009087558) METHOD FOR PROTECTING MILL DRIVES ON VERTICAL ROLLER MILLS AND VERTICAL ROLLER MILLS Loesche Symposium 2014, WOD, 2014-08-24

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Holcim Wear Part Experience • The most common root causes for failures are:  breakage due to foreign metal  poor casting quality  inadequate rewelding • The increase in specific electrical energy consumption with worn grinding tools is around 1 to 2 kWh/t.


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Holcim Wear Part Strategy • Ceramic inserts for sold out markets to reduce production loss due to downtime

• Rewelding in case grinding tool contour significantly impacts the production rate


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Focus of Holcim and Tasks for VRM Manufacturers • Process 

Reduction of specific air flow rate



Reduction of pressure drop



Operation at minimum water injection





Operation at lowest specific electrical energy consumption High level control to optimize production rate and operating costs

Air flow & pressure drop

Auto mode

Water

Energy


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Focus of Holcim and Tasks for VRM Manufacturers • Maintenance 

Easy maintenance



Wear part strategy with best TCO



Gearbox reliability


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Focus of Holcim and Tasks for VRM Manufacturers • Design 

High flexibility regarding cement types



Compact grinding system



Larger single units


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06-Flacher-Holcim-vertical-roller-mills-for-clinker-grinding-with-Holcim.pdf

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