NOVEL MINING METHOD
Novel methods are methods that work nontraditional principles, or exploit rare resources, and that are not yet widely accepted in practice. The difference between traditional and nontraditional methods is somewhat complex. Since classical methods evolve and modified, novel methods on the other hand may receive the acceptance that warrants their reclassification into one of the traditional categories. Take note that rapid excavation and automation are not mining methods but technology which could be both applied to a variety of mining methods, and that may be their greatest advantage.
RAPID EXCAVA EXCAVATION
Development of rapid excavation could be determined by the following: hardness of the rock time percentage of machine availability diversity of application rate of advance specific excavation rate cost of advance. !ardness of rock is an area in which some progress is being made. "ne of ma#or deterrents to applying rapid excavation in underground mining is the rather massive dimensions of the typical T$% with its trailing traili ng gear. ¬her ¬her important limitation of the T$% in mining pro#ect is the economics of conventional versus rapid excavation development. 'apid excavation has greatly improved mine development, particularly in the area of raise boring. 'aise borers for development of stoping operations are routinely used and have replaced conventional development in all but unusual circumstances. The most opportune area for research into rapid excavation procedures for mining is in specialty machines that can be applied to production mining as as development. The road header is one such machine that finds application in mining from time to time AUTOMATION & ROBOTICS
&utomation and robotics have been operated in mining for decades, but their execution basis has been long in coming. &dvances have been made in the last decade than any other realm of technology. This is because of gains and competitive economic forces and the growth in the use of computers and computer(guided systems. %echani)ation in mining began around *+-, about two decades later, the industry began to experiment with remote control application in continuous miners to remove the operator from the most dangerous area of the face and allow operation from a safer area some distance from the face, HYDRAULIC MINING
n hydraulic mining, a very high(pressure #et of water, steady or pulsed, fragments consolidated mineral or rock in place. Thus, it has application as a primary extraction or mining mechanism, although it is limited at present mainly to softer materials. /hen combined with mechanical action, hydraulic attack is an effective techni0ue in mining a variety of materials. !ydrailic mining utili)es the kinetic energy of a fluid #et to break and excavate material from the solid. ts effectiveness or cutting rate is primarily a function of no))le si)e, flow rate, pressures and power.
METHANE DRAINAGE
%ethane drainage, also called degasification, is the practice of removing gas in coal seam and ad#oining strata through wellbores, although operations may be conducted either from the surface or underground. Drainage is also similar to well production of natural gas, the principal constituent of which is also methane. Take note that methane drainage is an old method.
UNDERGROUND GASIFICATION &COMBUSTION
The idea of gasifying coal in its natural environment is rather old. %any 1uropean countries as well as 2anada and #apan have experimented with underground gasification, but only 'ussia has exploited the technology commercially to any extent. &dditional schemes for setting up a successful underground gasification operation include the use of directional drilling technology to connect the inlet and outlet wells and to involve greater coal volumes in the extraction process.
UNDERGROUND RETORTING
3nlike conventional petroleum, shale oil cannot be pumped directly from the ground. t must be processed by a techni0ue known as retorting, wherein the rock is heated to release crude shale oil, shale gas and water. 4rocessing can be
accomplished by mining the oil shale and retorting it on the surface, called ex( situ processing by using underground methods known as in(situ recovery or by a combination of the two methods. 2rude shale oil is upgraded to remove certain impurities, such as sulfur and nitrogen, and then further processed in an oil refinery to produce gasoline, clean diesel fuel, #et fuel and other petroleum based products. 1x(situ 4rocessing 1x(situ processing of oil shale has been practiced for over a century in various parts of the world. 4ro#ects based upon this approach have been operating for decades in 2hina, 1stonia and $ra)il. These processing facilities look much like any modern industrial complex.
5irst the oil shale is mined by underground or surface mining methods. n 2olorado and 3tah underground room and pillar mines were opened decades ago and are still in stable condition. $ecause of the strength of the oil shale beds, large stable rooms can be created supported only by pillars of oil shale and rock bolts placed in the ceiling. This contributed to the excellent safety record for these mines. This is very different than many underground coal mines that have small openings in relatively weak rock. 3nderground oil shale mines are more like subterranean 0uarries, and conse0uently large trucks, loaders and drilling e0uipment can be used in them to keep costs low. &fter oil shale is mined, it is reduced in si)e in machines called crushers, conveyed to the retorting plant, and converted into crude shale oil, water and shale gas. & number of well 6 tested ex( situ retorting technologies are candidates for commercial pro#ects, but none are operating at commercial scale in the 3nited States.
NUCLEAR MINING
The process of extraction of uranium ore from the ground. The worldwide production of uranium in 7-*7 amounted to 8,9+ tons. ;a)akhstan, 2anada, and &ustralia are the top three producers and together account for <= of world uranium production. 3ranium ores are normally processed by grinding the ore materials to a uniform particle si)e and then treating the ore to extract the uranium by chemical leaching. The milling process commonly yields dry powder(form material consisting of natural uranium, >yellowcake,> which is sold on the uranium market as 39"8.
3ranium from mining is used almost entirely as fuel for nuclear power plants. &s of ?uly 7-*, the price of uranium concentrate remained near a five(year low, the uranium price having fallen more than -= from the peak spot price in
5or both traditional underground and open pit mining, the rocks may have only a few percent @normally A-.9=B uranium in them. The uranium then has to be removed from the rock and concentrated. The milling process involves crushing and pulveri)ing the rock into very fine fragments and adding water to create a slurry. This slurry is then mixed with sulfuric acid or an alkaline solution to release the uranium from the host rock. Normally approximately + ( +8= of the uranium can be recovered from the host rock. 5rom this acid or alkaline solution, uranium oxide or yellowcake is precipitated. This is still not the purest form, and the uranium has to be sent to another plant to enrich it. The remaining rock slurry is pumped to a tailings dam. These tailings are exposed to the surface and heavy metals can be released into the environment.
