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By J. Sohn

The most promising near-term alternative to fuel cell driven vehicles is probably Hybrid Electric Vehicle (HEV or EV) technology. HEV technology combines the best characteristics of fuel-driven engines, electric motor drives, and energy storage components. It is designed with a combustion engine that functions as the primary power source, and an electric power storage system that functions as the secondary power source. The presence of the secondary power source allows designers to size the combustion engine for cruising power requirements. A new energy source for HEV or EV market will become lithium ion batteries (LIBs) in the near future. LIBs for HEV or EV has large scale about more 10,000 times than small size one for IT devices in order to achieve high electric density/capacity and high efficiency, etc. In those reasons, physical treatment of the batteries is more difficult for stable dismantling in comparison with the smaller one. Hybrid vehicle sales will grow by nearly 400 percent during the next seven years, according to a new report from analyst firm ABI Research. By 2013 hybrids will make up 6 percent of annual U.S. auto sales. The traction battery pack will become air-cooled LIBs which consists of several modules of Li ion battery and connected in series/parallel configuration to provide about >450 VDC, >150 kW peak power, and >80 Ah capacity. As the use of these batteries tends to increase significantly for the next years, it is relevant issues that development of new recycling methods as well as optimization of existing processes to treat spent LIBs for HEV have being addressed in order to obtain sustainability. In this study, physical treatment containing stable electrical discharge of spent LIBs for HEV was carried out for recovery of valuable metals from the batteries. Also In order to increase the yield of valuable metals through physical treatments such as electric discharge of spent batteries, crushing, and classification, we also focused on the recovery of cobalt from +8 mesh fraction due to its large portion in crushed intermediates.

Jan 1, 2010

By John H. Clark

This paper outlines new technological improvements in underground trackless equipment for the metal mining industry with emphasis on maintenance related developments for Load Haul Dump machines. Also new developments on other types of equipment are covered including drills, road headers and electric LHD's.

Jan 1, 1983

By Kevin J. Ashley

Coal is deposited at a mine site in several thin seams which outcrop in rolling hills and dip at about 8° to the northeast. The deposit is located in the northeast area of the State of New Mexico in the Southwest of the United States. A drilling program was undertaken and was quite irregular. Not all of the seams appear in all of the drill holes. Some of the holes did not go deep enough, while others were drilled below the outcrop of some seams. Occasionally a seam would pinch out and not be seen in a drill hole. Also, the outcrops of the seams are buried in many places by several feet of alluvium. All of these factors make correlation of the seams between drill holes difficult. The drawing of cross sections in three directions and at many locations across the mining area have been necessary to assure the accuracy of the input data.

Jan 1, 1982

By D. A. Elgillani

Oxidation potentials have been measured in the presence of various concentrations of cyanide, ferrocyanide, and ferricyanide and ethyl xanthate at various values of pH and related to flotation response. Eh-pH diagrams are constructed and show that the formation of surface ferric ferrocyanide is probably responsible for depression when cyanide is added. The influence of cyanide in the depression of pyrite with xanthates as collector has been the subject of many investigations (1,2,3,4,5,6), and from these studies several theories on the mechanism of depression have evolved. Wark and Cox (7) and Gaudin(8) have suggested that the depressing effect is due to a competition of cyanide ion with xanthate ion for the surface. Cook and his colleagues (9,10,11) have explained this phenomenon in terms of competition between hydrocyanic acid and xanthic acid. Sutherland (12) has shown that both of these theories describe accurately the relation between pH value and cyanide addition at constant collector addition but fail to describe the relationship, between pH value and the amount of collector required to cause flotation. Taggart(12) suggested that depression in these systems is due to the formation of a reaction product between ferric ion at the pyrite surface and ferrocyanide ion derived from solution. Majumdar(4,6) has attempted to prove this hypothesis by measuring the contact angles of pyrite in the presence of 25 mg/liter ethyl xanthate and different concentrations of potassium ferrocyanide and ferricyanide. In all cases the contact angles were quite high up to pH 10; these results indicate that pyrite should not be depressed by either potassium ferrocyanide or ferricyanide. In view of these facts, Majumdar has assumed that the compound Fe(CN)2 forms at the surface.

Jan 1, 1968

By E. M. Hill, D. E. Walsh, J. T. Hollow, H. K. Lin

Fairbanks Gold Mining, Inc. (FGMI) began blending and processing True North ore at their Fort Knox mill on April 12, 2001.Gold extraction subsequently dropped from 88% to 71% during the last week of April 2001. 25% of the gold values remaining in the leach tailings were gravity recoverable free gold. Significant quantities of stibnite and arsenopyrite were also identified in the tailings. In laboratory bottle roll tests, the gold extraction from a composite of leach circuit feed collected during the same period was 72.6%, when leached at an average NaCN concentration of 0.16 g/kg. The extraction increased to 82.4% and 91.7% with 0.5 g/kg NaCN, and 0.5g/kg NaCN plus 0.075 g/kg Pb(NO3)2, respectively. A passivating layer surrounding liberated gold particles and resulting from sulfide mineral dissolution, likely contributes to reduced gold recovery, which can be substantially increased by the addition of lead nitrate. Lead species remain in the solid residues after leaching and were not mobilized using Meteoric Water Mobility Procedure.

Jan 1, 2003

By J. W. Mustard

The Macmillan Pass tungsten property (MacTung) is the largest known copper-tungsten, calcic, exoskarn deposit in the Western Hemisphere. Located on the border between the Yukon and Northwest Territories in northwestern Canada, the deposit crops out on Mt. Allen within the Selwyn Mountain Range. It was discovered in 1962 by a subsidiary of AMAX Inc. and has since been explored by 16,300 meters of surface and underground diamond drilling and by 800 meters of underground development. Geologic reserves are in excess of 30 million tons, grading slightly less than 1.0% WO3. Scheelite (CaWO3 ) is the main mineral of economic interest. Accessible by road, the property is not in production. Previously estimated reserves at MacTung have been unable to fully utilize all the geological controls on mineralization. In the past three years, however, an intensive program has been underway to improve our understanding of the deposit and to use the resulting information in a more precise way. This paper will discuss the key aspects of the geology as they specifically relate to reserve estimation and will demonstrate how these controls are being used in a geostatistical model of the deposit.

Jan 1, 1985

By P. R. Taylor

This investigation (Bowles, 1990) involves consideration of technology utilized by three separate fields of metallurgy and materials science: 1) The recovery of metals employing the use of solvent extraction, 2) The fabrication of materials using powder metallurgy, and 3) The use of composite materials in fabrication of engineering materials. The research considers each of the processes in order to realize the benefits of each. In light of the fact that materials have an intended use -it does seem plausible to simplify the process required between "mother earth" and final use. For instance, a primary copper producer that already employs a solvent extraction and electrowinning process could produce value added products directly. Part of the existing extractant flow could be diverted into a pressurized hydrogen stripping process in order to produce specialty composite powders. Innumerable methods have been employed for the recovery of metals; solvent extraction, the one considered in this study, was used due to the possibility of it providing a pure powdered metal. The use of solvent extraction in the recovery of metals has gained wide acceptance and its use proves beneficial in many applications (Ritchey and Ashbrook, 1984). Pressure hydrogen stripping of solvent extractants may provide the benefit of flowsheet simplification compared to conventional solvent extraction followed by electrowinning. It may also provide the benefit of direct production of high purity metal powder (Demopoulos and Distin, 1985).

Jan 1, 1992

By Gilbert Sauriol

The mining complex, which the Mines Gaspé division of Noranda Mines Limited has operated in Murdochville since 1954, includes open pit and underground mines, two mills, one leaching plant and a smelter. The under- ground mining uses predominantly a large scale room and pillar method, rooms 15 m wide, 30 m high and 300 m long being common. Ore production is effected by 4.5 m3 front-end loaders and 32-tonne trucks powered respectively by 225 and 325 kW diesels. Daily dust and gas readings show that air quality can be maintained at an acceptable level with much less ventilation than that normally specified. This paper emphasizes the point that air requirements should be based on Air Quality Standards, thus allowing an operation to benefit from favourable conditions or from improvements such as exhaust treatment, fuel alteration, etc.

Jan 1, 1983

By Ralph W. Barbaro

In many parts of the country, electric utilities use spot market coal to make up the difference between the amount of contract coal and the total amount burned. The utilities involved will normally have a structured contract for those companies supplying that spot coal. These contracts will often involve a pricing schedule with bonuses or penalties for coal above or below the specified coal quality goals. Normally, penalties will be assessed on the sulfur, ash, and other coal quality variables. This paper deals with some aspects of the pricing schedule of one of the eastern utilities that buys coal on the spot market. This utility has a number of plants that a supplier can attempt to supply through bidding procedures. The existence of the pricing schedule gives the supplier a number of different options. To the single-mine producer, options are available to send the coal to any demand site and to clean all, part, or none of the coal. In other words, he can ship to a number of different sites and can send different coal qualities to each site depending upon the level of preparation. In addition, the options to deliver blended coal to any given site will provide an additional level of complexity to the problem.

Jan 1, 1983

By R. H. Snow

Although industrial size reduction methods have an energy efficiency of only about 1 percent, methods of size reduction have not changed much for many years. One reason for slow progress has been the oversimple viewpoint that a single law should exist to relate size reduction to energy input. Modern simulation methods decompose the grinding process into a grinding rate function (selection function) and a breakage function. The breakage function is difficult to measure, and it usually requires tracers if it is determined from milling experiments. Prediction of breakage functions from basic principles is one objective of this paper. In this study we focus attention not on the gross energy input to the experiment, but on the spatial distribution of stress energy within the particle. We are led to this viewpoint by experimental observations of a few previous investigators (Bergstrom2, Rumpf3, Axelson4) and our own observations. Oka and Hiramatsu recently used their calculations of stress within particles for prediction of breakage, but again they tried to correlate the size of the fragments with the total stress energy, rather than the approach we propose. We assume that the stress energy is stored in the interior of the particle as the load is increased, until the particle breaks. We assume that each element of the particle breaks into fragments of a mean size that depends on the locally-stored stress energy. The size distribution of fragments is the computed from maps of the stress-

Jan 1, 1972

By Basil W. Mercer

Increased emphasis on industrial pollution control has intensified investigation of waste treatment technology for methods of reducing the amount of pollutants discharged by industry. The mining and mineral processing industry can point to a record of considerable accomplishment in the field of wastewater treatment and reclamation because these operations are so frequently an integral part of the entire operation of an ore dressing facility. This is amply demonstrated by metal producers in the arid regions of the Southwest where water shortages require maximum use of available water. For example, the copper industry in Arizona during 1960 employed an estimated 184 billion gallons of water of which 87% was reused water. (1) Only 0.0003% was discharged to streams and the remainder was consumed by evaporation (8%) and seepage (5%). The most severe pollution problem facing the mining and ore processing industry today is that resulting from acid mine drainage. This problem is largely associated with the mining of coal although it occurs to a lesser degree with the mining of other materials. The degradation of streams by acid mine drainage in the vicinity' of the Appalachian coal fields has been widely publicized and a major effort is underway to determine the best means of correcting this situation. Other forms of pollution from mining operations are less well-known, but it is anticipated that improved or advanced waste treatment techniques will be required for segments of the industry to comply with new pollution control regulations. The current emphasis on redefining hazardous levels for heavy metals and various chemicals with regard to the total environment will in all likelihood lead to tighter discharge controls in some cases. It is the purpose of this paper to review some of the waste

Jan 1, 1971

By D. R. Kelland

A program has been carried out over the last two years to apply the technology of High Gradient Magnetic Separation (HGMS) to the problem of mineral beneficiation and specifically oxidized taconite iron ores. This program, supported by the RANN division of the National Science Foundation, has consisted of a laboratory program at the Francis Bitter National Magnet Lab- oratory at MIT and a pilot investigation at the Hanna Mining Company Research Laboratory. 1 The laboratory tests were conducted using several batch type high gradient separators and a continuous separator with a rotating matrix which was constructed at the beginning of the program. The high field magnets available at F.B.N.M.L. were used for investigations above 10 kG but most of the test work was performed in the range of this field value. Ore samples were contributed by several iron ore companies and consisted of oxidized taconites having goethite and hematite as their principal components.

Jan 1, 1975

By J. A. M. Cano

Introduction Since the beginning of operations at the pellet plant at Ponta Ubu ES, Samarco Mineração SA has produced pellets for direct reduction and blast furnace processes. Of the total amount of pellets produced from 1977 through 1993, 55 % are used in the blast furnace, about 45 Mt (49.6 million st). The principal components of pellet gangue are calcium oxide, magnesium oxide, silica and alumina. They should be added in adequate quantities to guarantee the mechanical resistance of the fired pellets under blast furnace conditions. Over the years, the pellets produced by Samarco had a silica content between 2.5% and 2.8% and varying binary basicity preferably between 0.8 and 0.85. On the other hand, the increasing amount of industrial waste in siderurgical plants caused by the increase of steel production has caused some countries to put into practice methods to reduce the volume of slag produced in the blast furnace. This paper's goal is to find an alternative for decreasing the amount of slag produced in the blast furnace. It is possible to decrease pellet gangue by decreasing the silica content to about 2%, leaving the metallurgical properties and quality of pellets unaltered. For this work, Samarco pellets were used with Si02 between 2.5% and 2.8%, pellets with high silica and pellets with Si02 between 2.0% and 2.3% low silica. Both were partially fluxed by the range of varying basicity CaO/SiO2 from 0.8 to 0.95 during production. Experimental tests on pilot scale Thhis work began in January 1986 in the pilot plant (pot grate, Fig. 1) at Samarco. Its goal was to obtain preliminary data that would indicate the bybility of the project. It also formed a solid base to extend the studies in tests on an industrial scale of production for blast-furnace pellets. The pot grate is a test furnace composed of a gas burner, a combustion chamber and a grate, connected by hot air ducts. The burner is fed by a mixture of LPG and air. It reaches high temperatures through oxygen injection. The combustion chamber heats the air that comes from the turbocompressor. This hot air flows through the ducts to the grate on which the pellet samples are fired. During updraft drying, downdraft drying, preheating, firing and afterfiring, the upward and downward direction of the air flow can be controlled by valves driven by pneumatic cylinders. The pot grate indurator was fully automated in August 1989. Positive and negative pressures measurements resulting from gas passing through the pellet layer, as well as temperature readings, are recorded in graphs in relation to time for all tests. The tests depend on the various steps carried out in sequence that can influence the results of the tests. Therefore, some criteria were adopted to restrict the number of variables in the process. This was done to facilitate the results of the analysis. The pellets were composed of concentrate, bentonite, hydrated calcitic lime and metallurgical coal, all regularly used in the pellet plant. The material balance of the pellets mix was determined from the chemical analysis of the components. Table 1 shows the chemical characteristics of the concentrate and the additives used in the pilot plant and industrial tests. The basicity has a marked influence on the metallurgical properties of the pellets produced by Samarco with a silica content between 2.5% and 2.8%. However, for pellets with low silica (about 2%), it was necessary to study the variation in the parameters of quality in a wide range of basicities to deliniate with precision a scope of work. A large variety of low-silica blast-furnace pellets were produced at the pilot plant with binary basicity varying between 0.8 and 0.95. After chemical analysis, those pellets were separated into five groups of different binary basicity (0.8, 0.84, 0.87, 0.90 and 0.95). Each was then split, one part for metallurgical tests in the laboratory at Samarco and another to be evaluated in a laboratory for metallurgical tests in Germany. It was agreed that the tests to evaluate the quality of the pellets in the two [ ]

Jan 1, 1996

By Elza Burch

Introduction The feeding to zero concept involves feeding 600 µm x 0 (28 mesh x 0) size raw coal to heavy media (magnetite) cyclones along with the +600 µm (+28 mesh) size coal. Traditional circuits employ desliming or removing the 600 µm x 0 (28 mesh x 0) size fraction and feeding the cyclones +600 µm (+28 mesh) size coal. The feeding to zero concept recirculates 600 µm x 0 (28 mesh x 0) fines in the circuit. At the same time, a portion of the fine material is continuously withdrawn and recovered. This, in turn, prevents a fines buildup. This concept eliminates desliming screens and secondary fines circuitry for recovery of 600 x 150 µm (28 mesh x 100 mesh) coal. The result is a very simple circuit. Feeding to zero at Island Creek Island Creek Corp. was the first involved with the new concept in 1976. The company needed a temporary plant for the 9.5 mm x 0 (0.4 in. x 0) raw coal at its Pond Fork mine, near Madison, WV, while a full-scale plant was being designed and built. At that time, the Childress Corp., of Beckley, WV, became interested in the feeding to zero concept. Island Creek awarded a contract to Childress to build a single cyclone modular plant, incorporating this feeding to zero concept. The plant was erected in three months. The Pond Fork modular plant proved successful in attaining the desired feed rate of about 63.5 t/h (70 stph), while maintaining good separating efficiencies and low magnetite consumption rates. The 9.5 mm x 150 µm (0.4 in. x 100 mesh) clean coal was recovered and the 150 µm x 0 (100 mesh x 0) size was disposed of to waste. The full-scale plant was completed about two years later and the Pond Fork modular plant was moved to Holden, WV. There, it was incorporated into the Holden 29 preparation plant as a separate circuit for cleaning -25 mm (-1 in.) coal. In 1976, a similar plant was installed in Virginia by another company. These two plants are believed to be the first two operational plants in the United States incorporating the feeding to zero concept. Island Creek subsequently contracted with Childress for an identical plant at the Coal Mountain operation in West Virginia. The plant operated for three years before the mine was closed. The unit was then moved to the Spurlock mine near Martin, KY where it continues to operate. The successful operation of the Pond Fork and Coal Mountain plants before and after relocation proved both the performance and moveability of this type of circuit when constructed in a modular fashion. Since the first two plants were built, Island Creek has incorporated the feeding to zero circuit in nine additional plants. A grand total of 33 cyclones have been installed using this concept. One is the Providence mine, near Providence. Providence preparation plant Island Creek contracted with J.O. Lively Corp. of Glen White, WV in July 1978 for the construction of the Providence preparation plant. The plant began operation in February 1979. The construction period was about halved by building the plant with modular design concepts. Prefabricated sections, floors, and sides were brought in as units and then bolted in place. The Providence plant has a good track record of processing coal at a feed rate of 454 kt/h (500 stph). Feed coal to the plant has an average ash content of about 18% and sulfur content of about 4.5%. It contains about 22% refuse. The coal product has an average ash content of about 8% and sulfur content is about 3%. Raw West Kentucky No. 9 seam coal is conveyed from a box cut in the Providence mine to a rotary breaker. The breaker is fitted with 74 mm-diam (3 in.-diam) opening breaker plates. Therefore, it is well suited for removing trash, roof bolts, wood, and pyritic balls that are common in Illinois Basin coal. The -75 mm (-3 in.) coal is conveyed from the rotary breaker to

Jan 8, 1987

By Anand Kumar, Debasis Deb, V. N. S. Prasad. M, A. K. Mishra

Shield leg pressure data from all shields and shearer locationwith time stamp from a mechanized longwall face are monitored and recorded in a surface computer. These data contain random noise due to power failure, leakage of legs, bad sensor reading and other maintenance or geo-mechanical problems. An algorithm is developed to detect mining cycle parameters such as setting and final pressures and duration of the cycle from these data for the analysis of periodic roof weighting phenomena. The intensities and persistence of periodic roof weighting are the vital information to the mine management to take judicious decision on longwall operation. The paper presents details of the algorithm which identifies 96% of mining cycles from the noisy data belonging to consecutive 5 months or 410 m of face advancement. Based on this analysis, 2 types of periodic roof weighting phenomena are detected, namely, (i) normal type—having peak intensity of 75 to 90% of yield pressure, interval of occurrences of about 10 to 15 m with persistence of 3 to 4 m and (ii) severe type—peak intensity over 90% of yield pressure, interval of 25 to 40 m with persistence of over 10 m. It is envisaged that these phenomena have direct relationship with main roof thickness, its overhung length and material properties.

Nov 19, 2020

By Steven J. Schatzel, Kayode M. Ajayi, Marcia M. Harris, Zoheir Khademian

Predicting rockmass permeability is critical in evaluating various engineering designs, including estimating gas inflow to a longwall mine in the case of a hypothetical breach in the gas well. This study conducted field permeability measurements to validate a geomechanical model capable of predicting rockmass permeability during longwall mining. A series of slug permeability tests were conducted in an active mine in Pennsylvania. A model of the mine was constructed in 3DEC numerical modeling software, and permeabilities were calculated. The modeling results agreed well with the pre- and post-mining permeability measurements, showing the applicability of this tool to evaluate gas well stability near mine workings.

Feb 1, 2024

By Yi Luo

Simulation of the multi-entry and multi-crosscut (MEMC) ventilation systems commonly employed in U .S. underground coal mines can be very tedious, due to the large number of crosscuts with stoppings to be represented in the network models. In order to reduce the amount of work needed to build the models, a common practice is to represent a number of crosscuts with one equivalent airway. However, this introduces certain errors into the simulation results. In this paper, algorithms have been proposed to simplify the ventilation networks of common MEMC systems encountered in panel development operations. The algorithms can be used to reduce a MEMC system into one airway with an equivalent resistance and to determine the airflow distributions in the system and the leakages through the stoppings.

Jan 1, 2011

By D. Tepavac, S. Simmonds

"The high virgin horizontal in situ stress field in the Sydney Basin and its impact on civil engineering projects is a well-known and accepted phenomenon found in significant literature (e.g., Pells, 2013). The prevailing high-stress effects depend on many factors — rock quality, tunnel orientation, proximity of geological features to tunnel crown, size and shape of opening, depth of excavation and stress magnitude. The behavior of the rock mass under high in situ stress conditions can cause stress fracturing and consequent dilation of the tunnel periphery, resulting in rock spalling at the tunnel crown/ invert or raveling of rock blocks on the tunnel sidewall. This type of failure is of a brittle nature and may create construction and safety risks during tunnel excavation, if it occurs behind the excavation face where ground support has already been installed. Therefore, the associated risks need to be managed during construction. This paper presents the design strategy adopted to mitigate these adverse tunneling conditions for the WestConnex Project to-date. Overview of the WestConnex M4 East and new M5 tunnel projectsWestConnex is one of the New South Wales government’s key infrastructure projects. This 33 km (20.5 mile) project aims to ease congestion and connect communities and is the largest integrated transport and urban revitalization project in Australia. It was a key recommendation of the State Infrastructure Strategy released in October 2012. It brings together a number of important road projects, which, together, form a vital link in Sydney’s Orbital Network. These road projects include a widening of the M4 east of Parramatta, a duplication of the M5 East, and new sections of motorway to provide a connection between these two key corridors. The WestConnex project includes a number of stages: Stage 1a: M4 Widening; Stage 1b: M4 East; Stage 2: New M5; and Stage 3: M4–M5 Link. The tunnel design referenced in this paper relates to Stage 1b and Stage 2 of the WestConnex Project (Fig. 1)."

Dec 1, 2018

By Richard J. Leary

At the 1976 Annual Meeting of AIDE, Alan Merson reminded his audience that economic' success comes to those who understand things as they are, rather than as they have been or what ideology says they should be (1). He went on to say that, measured by this standard, the mining industry is in trouble. The mining firms had recognized long ago the importance of effective lobbying in Washington and the state capitals. But, he pointed out, those methods are nearly worthless anymore in coping with many land use problems because the critical decisions are likely to be made at the local level. There the tactics are far different as are the relations of the decisionmakers to the parties before then. Furthermore, in his estimation the trend is to leave land use regulation largely to the local level of government. All who are concerned for access to land for mineral development will be benefited by reading Professor Merson's paper lie is speaking effectively about the context of decisionmaking for specific cases, the shape of things in the here and now. There is, however, a longer-tern set of considerations that if pursued will be likely to foster the creation of public support for mining developments. At that sane meeting I spoke on two foundations of the long-term relationships: namely, the growth in requirements for minerals implied by projections of increasing consumption; and a rationale for fostering mineral exploration and development. I mentioned in passing the social decisionmaking process for public uses of land (2). This paper is intended as a complement. The growth of requirements for Minerals and the rationale for development based on the Entropy Law will be only mentioned. The main concern will be on the process of social decisionmaking in the context of access to land for mineral development.

Jan 1, 1976

By R. W. Barbaro

The limitation of sulfur dioxide in power plant emissions dictates that sulfur in coal be reduced to the lowest possible level before combustion so as not to aggravate the emission control problem at the stack. For coal fired power plants, the methods in practice to achieve low sulfur coal include mining areas with relatively low sulfur. reducing sulfur in the mined coal through preparation techniques and blending high and low sulfur coals. A prerequisite to the successful implementation of any of these practices is the knowledge of the spatial distribution and the capability to predict sulfur values in a coal seam.

Jan 1, 1988