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By T. Yoshida

The Ni-MH (nickel metal hydride) rechargeable battery was developed several years ago. Its higher electrochemical capacity and greater safety compared with the Ni-Cd rechargeable battery have resulted in very rapid Increase in its production. The Ni-MH rechargeable battery consists of Ni. Co and rare earth metals, so that recycling is important to recover these valuable mineral resources. In this study. a basic recycling process for used Ni-MH rechargeable batteries has been developed, in which the Ni. Co and rare earth elements are recovered through a combination of mechanical processing and hydrometallurglcal processing.

Jan 1, 1995

By Charles L. Mantell, George Ferment

This investigation determined the jeasibility of current-potential curves as an analytical tool for monitoving manganese electroicinning solutions for metallic impurities. Nine metallic impurities were studied: trickel, cobalt, silver, copper, zinc, molybdenum, catlmiun magnesium, and sodium. The individual effect of each metallic irzplrl,iLy on the standard point-izatiorr was determined for a range of 'concentration. Not all of Ihe impurities affected the polarization curve; correlation between transition current and cotrcetztration of impurity. Molybdenum had an uncorrelated effect on the polarization curie. The effects of binary mixtures of impurities were studied to see if the transition current of the mixture could be predicted. Interactions occurred between impurities which prei'etzted the pvecliction the transition current of tile rrlisLitr.e by additive laws. The polarization curve was shown to be sensitive to metallic impurities which affect the current efficiency of a manganese cell. THE application of current-potential curves in manganese electrowinning is not new but played an important part in the conversion of an inoperative large-scale pilot plant into a continuous comnercial operation.1"" The effects of trace metallic impurities in manganese electrowinning solutions on cathode current-potential curves,5-19 specifically nine impurities (nickel, cobalt, silver, copper, zinc, molybdenum, cadmium, magnesium, and sodium) were studied for a range of concentrations. Cadmium, magnesium, and sodium had no effect. Nickel, cobalt, silver, copper, and zinc yielded a correlation between transition current and concentration of impurity: molybdenum had an uncorrelated effect. Binary mixtures of impurities were studied to de-termine if the transition current could be predicted from the values for the individual constituents. Interactions between impurities prevented the prediction of the transition current of the mixtures by an additive law. The polarization curve was shown to be sensitive to metallic impurities which affected the rurrent efficiency of a manganese cell. The electrowinning of manganese relies upon maintaining a high-purity electrolyte. Purification schemes were developed to remove all of the heavy metals, the magnesium and calcium. Concentration limits have been established for single impurities. With high-purity electrolytes, favorable cell efficiencies are consistently obtained; but with impure solutions there is a reduction in efficiency. With the rapid rise to commercial prominence of electrochemical processes, there has been a lag in developing rapid methods for determining whether an electrolyte is sufficiently pure for efficient electrolysis. The most sensitive test for impurities is the behavior of the electrochemical cell. Impure electrolytes will cause a serious reduction in cell efficiency, and in many cases metal deposition will be prevented or reversed. The effects of impurities are not usually evident until after long periods of electrolysis, resulting in a disruption of the process. A method which could predict the behavior of an electrolyte in terms of cell efficiency prior to reaching the commercial cell is needed. Van Arsdale and Maier," Allmand and Campbell,a1'22 and others attempted to develop an electrochemical process for manganese,"3"29 but all met with some degree of difficulty. Jacobs et a studied the effects of metallic impurities in manganese electrowinning. Plant methods were based on a 2-hr plating in a small electrolytic cell. The final method was based on a 24-hr plating run, performed in a relatively large test cell. Here, current efficiencies were calculated with and without impurities in the electrolyte, and the critical concentration was established as the maximum amount of impurity that the electrolyte could tolerate before there was a serious loss in efficiency. The amount of impurity that could be tolerated decreased as the plating time increased, indicating deposition of the impurity. This test duplicated the conditions of commercial practire, and was sensitive to impurities. Small amounts of impurities significantly affect the hydrogen overvoltage at a metal surface, increasing or decreasing it depending upon the nature of the impurity. ockris established the limit for the onset of poisoning at 10-l moles per liter. The effects of impurities were studied by potential-time curves at a constant current density. The technique did not lend itself to rapid analysis in that several hours were needed to establish stable potential-time curves. Serfass and coworkers3' developed calorimetric and spectrophotometric techniques for analyzing for trace impurities. Our method4'" is based on current-cathode potential curves produced by continuously changing the cell voltage at a programmed rate. Starting with a clean stainless-steel cathode, the cell voltage was initially adjusted to yield zero current: the program was then started and the current was plotted as a function of the cathode potential. Fig. 1 is a typical current-potential curve. In initial region A the hydrogen-evolution reaction predominates and the polarization curve

Jan 1, 1967

By Hongbo Yang, Tongbo Zhang, Ting Huang, Jingshe Li, Fangfang Song

"Liquid core length is a very important parameter of the process of continuous casting, which directly reflects the cooling status in secondary cooling zone and solidification rate of the slab. In this paper, the billet caster in some steel plant in China was chosen as the prototype of simulating. A numerical simulating model for calculating the liquid core length of continuous casting billet was built by ProCAST software, which was verified reasonable and accurate by pin-shooting technique. Based on the model, the relationships between casting speed, casting temperature and liquid core length of casting billet were found, which was very practically useful for the workers on sit to improve casting billet quality. IntroductionContinuous casting process developed very rapidly because of the high metal yield, energy saving, and low-cost 111• And the quality requirements of continuous casting billet for customers became higher and higher with the fast development of economic121• Internal defect usually is the major quality problem for continuous casting billet[3•61 , which is influenced by the solidification process of casting billet, especially the solidification process of liquid core17•81 • So it is very important to study on the relationship between casting parameters and the liquid core length which means the distance between the crystallizer meniscus and the casting billet solidification end-point. In practical production process, the workers usually control the quality of casting billet according to the liquid core length."

Jan 1, 2013

By Kent D. Gastreich

As the number of prime surface coal mining sites diminishes with time and with the potential for increased coal demand, areas that were previously not mined because of their difficult mining conditions, marginal economics, and controversial environmental nature, will have to be considered if surface coal mining is to continue in the future. Such sites include areas near major rivers, streams, and lakes. The name most commonly given to these areas by regulatory agencies is "wetlands". The exact definition(s) to the term "wetland" will be discussed later in this paper. Most coal operators are now more than familiar with permitting requirements under the Surface Mining Control and Reclamation Act of 1977 (SMCRA). The SMCRA permanent regulatory program recognizes the fact that coal mining operations will periodically encounter streams, wetlands, etc. Although discussed in various sections of the permanent program regulations, the relationship of coal mining operations to wetlands is particularly evident in the performance standards regarding hydrologic balance and protection of fish, wildlife and related environmental values.

Jan 1, 1980

By S. H. Ash

THE INUNDATION of anthracite reserves in the Eastern Middle field of Pennsylvania affects the life of the anthracite industry in this field; it also influences the economic status of people, communities, and industries that depend wholly or in part upon anthracite for their livelihood. The trends of production and of employment in the anthracite-mining industry in this field are downward, and they probably will continue in this direction. The reserves have been depleted to the extent that the end of the active life of the industry as a. major economic factor is approaching. By removing the water in those pools where it can be done economically, the future of this industry may be extended somewhat.

Jan 1, 1950

By J du Plessis, W Marx

The FutureMine Collaborative Research Initiative has been successfully completed after three years of activity. The main objective of this initiative was to provide applications of research previously undertaken in the DeepMine initiative in terms of realistic solutions to problems facing gold mining operations as they reach for depths beyond 3500 m below surface. The FutureMine initiative was subdivided into four broad streams of technological expertise: rock engineering and seismicity; mining engineering and orebody management; software and communications and ventilation, cooling and refrigeration. This paper presents a summary of research output in this last area of expertise. Broadly, research in mine ventilation, cooling and refrigeration was directed in areas related to the recirculation of air, cyclical use of ventilation and cooling systems, air scrubbing technology, optimisation of chilled water reticulation, obtaining direct cooling at the workface, improving underground refrigeration systems through dry air-cooling and water heat rejection systems and a number of software simulation programs to be used in specific applications and as a tool assisting real-time monitoring of underground environmental conditions.This paper describes in broad terms the outcomes from this section of the research program and proposes ways in which some of these technologies may be combined synergistically in novel systems aimed at maintaining acceptable environmental conditions while reducing the impact on the profitability of operations.

Jan 1, 2005

By Michael R. Grubbs

The Bureau of Mines is currently developing methods for reclaiming the metal and mineral values contained in unburned urban refuse. One important phase of this research deals with recovering Mastic from shredded refuse using in electrodynamic separation process. The results of this study have indicated that mixed plastic concentrates analyzing 99.4 percent plastic can be consistently recovered from the light material fraction of shredded refuse, leaving a mixed paper traction analyzing 99.9 percent paper. Recovery of the plastic exceeds 99 percent.

Jan 1, 1972

By Reamy Joyce

Conditions in underground mining are so variable that in approaching the problem of the economies effected by the use of pressure-treated mine ties and mine timbers, it is necessary to secure specific data for each mine. Facts must first be dug out to show the service life of untreated timber and the reason for its failure. Generally speaking, decay is the usual cause of failure, but in some mines mechanical destruction is an important factor. Occasionally the two causes combine to produce fail-urrs, and it is difficult to determine positively which factor is responsible. In making comparisons, it is always necessary to start with the cost in place and for this reason there must be accurate information covering the labor cost of installation and the labor cost of renewals. When treated timber is used, it is necessary to know the specifications for the treating process, whether the timber was painted, dipped, treated open tank, or impregnated under pressure according to standard specifications. It is also necessary to know the preservative used and the amount of the preservative that was retained by the timber after treatment. It is also well to know whether the timber was thoroughly air-seasoned before treatment or was green at the time it was treated. The kind of timber available, both untreated and treated, must be known and all of the factors listed above must be taken into consideration in the study of any problem. Variable Conditions A study was made recently of the untreated mine ties used by a bituminous coal company in two of its mines, which are about 20 miles apart. The mine ties were secured from the same sources for both mines. A careful check was made over a 10-yr. period on the life of untreated main-haulage ties, and it was found that in the mine where the haulage roads were on intake air the average life was approximately 5 yr., while in the other mine, where the haulage roads were on return air, the average life was 2 yr. A similar variability in untreated timber

Jan 1, 1940

By Reamy Joyce

Conditions in underground mining are so variable that in approaching the problem of the economies effected by the use of pressure-treated mine ties and mine timbers, it is necessary to secure specific data for each mine. Facts must first be dug out to show the service life of untreated timber and the reason for its failure. Generally speaking, decay is the usual cause of failure, but in some mines mechanical destruction is an important factor. Occasionally the two causes combine to produce fail-urrs, and it is difficult to determine positively which factor is responsible. In making comparisons, it is always necessary to start with the cost in place and for this reason there must be accurate information covering the labor cost of installation and the labor cost of renewals. When treated timber is used, it is necessary to know the specifications for the treating process, whether the timber was painted, dipped, treated open tank, or impregnated under pressure according to standard specifications. It is also necessary to know the preservative used and the amount of the preservative that was retained by the timber after treatment. It is also well to know whether the timber was thoroughly air-seasoned before treatment or was green at the time it was treated. The kind of timber available, both untreated and treated, must be known and all of the factors listed above must be taken into consideration in the study of any problem. Variable Conditions A study was made recently of the untreated mine ties used by a bituminous coal company in two of its mines, which are about 20 miles apart. The mine ties were secured from the same sources for both mines. A careful check was made over a 10-yr. period on the life of untreated main-haulage ties, and it was found that in the mine where the haulage roads were on intake air the average life was approximately 5 yr., while in the other mine, where the haulage roads were on return air, the average life was 2 yr. A similar variability in untreated timber

Jan 1, 1940

In the context of sustainable development, the Minerals Council of Australia (2010) states that 'investments in minerals projects should be financially profitable, technically appropriate, environmentally sound and socially responsible'. In other words, the business of mining can only be sustained if these criteria are met.   Science and technology plays a major role in all four of these criteria. This paper will present the technology and innovation emerging from the Minerals Down Under National Research Flagship which brings together CSIRO and more than ten of Australia's leading universities to work with industry to drive efficiency, productivity and environmental performance. This work is required if the Australian minerals sector is to thrive and continue to deliver national benefit in the face of increased global competition, declining ore grades, depleting ore deposits, increasingly constrained national resources (land, energy, water and people) and changing societal expectations.   Science and technology to reduce emissions and water use, discover greenfields resources, enable deeper mining operations and transform mineral processing are described. Technology is presented as an enabler of sustainability: a means to this end but not as an end in its own right.

Jun 1, 2010

By R. D. Yancich

A case study of longwall mining surface subsidence was performed at a mine in Southwestern Pennsylvania. The mine operated in the Pittsburgh coal seam which averaged 70-72 inches with 6-8 inches draw slate in the longwall location. The average overburden depth ranged from 625 8eet to 660 feet. Three adjacent longwall panels were studied and classified as Panel 1, Panel 2, and Panel 3. The following is information on each and can be seen on the General Mine Map (Fig. 1).

Jan 1, 1984

By Rolf Hindstroom

Outokumpu Mintec started development of the pressure filter in 1991, and the first unit was delivered to Tara Mines Ltd. Ireland in 1992. The filter replaced a conventional disc filter and a thermal dryer. The replacement of the thermal dryer has improved both environmental and working conditions. The filter is currently dewatering 80,000 tons per year of lead concentrate, producing a cake with less than 6 wt % residual moisture.

Jan 1, 1995

By David A. Newman

Barrier pillars created during mine development provide additional reserves during mine closure and can be the sole access to reserves previously abandoned because of mining height or out of seam dilution limitations. The safe and successful mining of barrier pillars requires a thorough knowledge of the magnitude and distribution of the vertical stress field in addition to the strength and physical properties of the coal, immediate roof, and immediate floor strata. Quantifying the vertical stress field is complicated by the combination of the overburden stress, abutment stresses transferred onto the barrier pillar from adjacent gob areas, and in multiple seam mining, stresses transferred from abandoned subjacent mines. These variables make the extraction and development of barrier pillar reserves a site specific consideration. Three case histories are presented in which barrier pillar development and extraction provides; i) an access point and the means to ventilate a large area of low seam reserves left by a prior operator after developing only the thicker areas of a multiple split reserve, ii) the means to increase total recovery of a deep, thick seam longwall reserve, and iii) opportunities for the development and retreat mining of a two mile long barrier pillar in thick seam reserves.

Jan 1, 1995

By J. W. Miller

From 1889, when the first railroad shipments of coal were made from McDowell County, W. Va., until today, the coals produced from the New River and Pocahontas groups have had a good reputation as premium low-volatile coals. Although there has been a large production from the Pocahontas No. 3 and. Pocahontas No. 4 beds, considerable reserves remain. This Bureau of Mines publication is one of a series appraising the Nation's coking-coal reserves by presenting data on the basis of which the practicability of upgrading marginal deposits to metallurgical standards can be determined. This study of the preparation characteristics of McDowell County coals is the second of the series to be undertaken in West Virginia. The Pocahontas No. 3 and No, 4 beds have not been included because their washing characteristics are well known.

Jan 1, 1954

By M. E. Lombardi

Discussion of the paper of AI. E. LOMBARDI, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 105, September, 1915, pp. 2109 to 2114. C. D. KEEN, Shreveport, La.-Did Mr. Lombardi include in his figures the purchase price of the property? M. E. LOMBARDI, Berkeley, Cal.-No. C. D. KEEN.-Suppose I pay $1,000 per acre for it, and in four or five years it is worked out. M. E. LOMBARDI.-That is a question of depreciation and must be added to my figures. MARK L. REQUA, San Francisco, Cal.-You say it cost $35,000 to $40,000 a year to maintain 1,000-bbl. per day production? M. E. LOMBARDI.-Yes, 1,000 bbl: a day would cost $40,000 a year to maintain.

Jan 12, 1915

By R. I. Jaffee, J. W. Roberts, D. N. Williams

DISPERSION hardening as an alloying process has aroused increasing interest in the past few years. This alloying procedure, in which an insoluble phase is dispersed randomly through a metal or alloy, is believed to be especially suited for the attainment of creep strength at elevated temperatures since the dispersed phase is metallurgically stable. Another advantage is that the physical properties of the matrix phase, such as electrical conductivity, remain relatively unaffected by alloying. These two characteristics resulted in interest in the applicability of dispersion hardening to copper and copper alloys. A study of copper alloys prepared by powder metallurgy methods has shown some strengthening from oxide dispersions.' However, powder metallurgy processing would not be economical for large scale production of dispersion hardened copper-base alloys. Therefore, the research described in this article was initiated to examine methods of forming dispersion alloys which would not require powder metallurgy processing. If powder metallurgy processing is to be avoided, a method must be found by which the dispersion material can be introduced into and dispersed through the melt before casting. When the dispersed phase is an oxide or similar nonmetallic, it is extremely difficult to form a satisfactory liquid: solid dispersion since successful mixing requires that the melt wet the dispersed phase. It is almost impossible to force a nonwetted particle beneath the melt surface. This difficulty can be avoided, however, if the oxide particles are produced in molten copper by reaction within the melt. The problem would then reduce to maintaining randomness until solidification. Four procedures were considered for producing an oxide particle within molten copper by reaction. In all cases, the intent was to react oxygen (0) with a reactive metal (X) to form an oxide (XO) within the copper melt. These reactions were as follows: 1) (Cu-X), + (O)g (Cu)1 + (XO)S [1] 2) (Cu-X)1 + (Cu2O)s (Cu)x + (XO)S [2] 3) (Cu-OK)1 + (Cu-X)1 (Cu)1+(XO)9 [3] 4) (Cu-OK)1 +(X)s (Cu)1 +(XO)s [4] The reactions were carried out in an 8-lb melt of 99.98 pct Cu maintained in the vicinity of 2200oF by induction heating. Where possible the amount of the reactants was controlled to give 1 to 5 vol pct oxide. Mechanical stirring during the reaction period was used to minimize agglomeration of the reaction product. The presence of a reaction product was determined metallographically by study of an ingot cast from the melt at the end of the reaction period. Reaction [I] was studied by dissolving aluminum in the melt followed by forcing oxygen through the melt. The melts became quite sluggish during the reaction period suggesting that A12O3 was formed. However, the reaction product rose out of the melt rapidly, possibly due to the flushing action of the oxygen stream, and little dispersed phase was formed. Reaction [2] was examined by dissolving aluminum, silicon, or nickel i; the melt and then adding Cu20 (melting point 2250F). This procedure was unsuccessful. Although Cu2O was easily stirred into cop-

Jan 1, 1961

By Matt Brandon

This case study demonstrates how integrating drone and GPS surveying with 3D modeling software creates more effective blast designs that address specific geotechnical challenges while improving safety and blast performance. In this case study an 80ft (25m) highwall experienced recurring slip plane failures exacerbated by a previously mined 40ft (12m) bench that removed back support, creating an unstable triangular rock mass. Previous blasting along this wall displaced the upper 40ft (12m) of material, opening geological discontinuities and causing progressive slope failures that compromised crew safety and blast effectiveness. High-resolution drone photogrammetry, GPS surveying, and laser measurements were employed to precisely map slip planes, bedding planes, and fault structures within the bench geometry. These geological features were imported into 3D design software to develop a shot pattern that strategically utilizes natural rock discontinuities rather than working against them. GPS-guided hole placement ensured accurate field implementation, while marking geological features on the surface of the bench provided visual references for the blast crew. The final blast design positioned the last row of holes to break preferentially along an existing slip plane while avoiding intersecting the next slip plane behind the blast. Explosive loading and timing sequences were adjusted based on the hole location relative to the 3D geological model to optimize fragmentation while maintaining wall stability. The optimized design improved highwall stability significantly, by reducing the slip plane failure mechanism that had previously compromised operations. Measurable improvements included enhanced highwall stability, reduced back-break, improved blast performance, and reduced safety risks for equipment operators and blast crews. Two subsequent shots using identical methodology were able to remove the rest of this problem area, confirming the repeatability and effectiveness of this integrated approach. This methodology demonstrates practical integration of surveying technologies with geological understanding to solve complex blasting challenges. Accurate 3D modeling of geological features enables blast designers to work with natural rock structures rather than against them, resulting in safer, more effective blasting practices. This case study shows the value of understanding the precise locations of geological features for optimizing blast design and provides a replicable process for addressing geotechnical challenges in blasting operations.

Jan 26, 2026

By W. E. Stephens, A. J. Boyce, D. Lowry

Paper presented at Mineralisation in the Caledonides, the Mike Gallagher memorial meeting held in Edinburgh, 27-28 June 1996. An integration of S isotopic, fluid and mineralogical data for granitoid-related mineralisation showed that the porphyry systems had a predominantly subcrustal magma source, but the inner magma pulse of two-mica granite in the Fleet pluton was derived mainly from reduced sediments. The porphyry-style mineralisation formed from boiling fluids at high crustal levels, with a moderately saline fluid percolating down to the upper veins as they cooled but not penetrating the deeper Talnotry deposit. Veins in peripheral greywackes have a significant magmatic component but also incorporated CO2-rich components and metals released by dewatering of host sediments in response to granitoid intrusion. The low grade of regional metamorphism resulted in the significant fluid input from country rocks which led to the more exotic mineral compositions, especially where argillaceous sediments were involved

Jun 19, 1905

By Tom Marttila

During the last few years, when a new tankhouse or a major modernization has been planned, automatic or semiautomatic crane and grab systems have at least been considered. It seems that in the future tankhouse managers for new, modernized and even old tankhouses will be looking for a proven and reliable system for automatically moving and positioning electrode loads in the tankhouse and in storage areas. In this paper, we will describe the Wenmec solution for automatic electrode handling. The advantages of automatic handling and very accurate electrode positioning will be discussed, and the way Wenmec has solved the problems in mechanical construction and in automatic, accurate and reliable positioning will be presented.

Jan 1, 1990

A summary of a proposal to develop a 20 000 tpa underground gold operation in a Forest Park. The environmental constraints are severe and affected the mine development planning and choice of mining method. The mine will use trackless methods to access the narrow 1.5 m ore shoots, and to mine ore by cut and fill methods. The use of Microscoop and CT 1700 HE electric LHDs for mucking, together with special drilling attachments for drilling, is central to efficiency and small Kubota diesel haulers will be used for carrying ore to surface.

Jan 1, 1986