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By L. E. Schultze

Experiments were conducted by the U.S. Bureau of Mines to verify enhancements due to chloride and surfactant additions in the leaching system of chalcopyrite with ferric sulfate and sulfuric acid. A statistical experimental design was used and equipment was designed to eliminate contributions from changes in solution electrochemical potential during the course of the measurements. Results confirmed that chloride additions increased chalcopyrite leaching by as much as 94 pct over the electrochemical potential versus hydrogen electrode range of 630 to 750 mV at pH 1.7 and 50°C. Total iron concentration had no effect over the range of 1 to 5 g/L. The effect of surfactant addition was less well defined. While additions of LA 790 (a polyoxyethylene lauryl ether) resulted in increased copper leaching in several of the tests, the differences were too small to be statistically significant. No interaction effect could be verified.

Jan 1, 2010

By H. W. Kilau

The U.S. Bureau of Mines examined the wettability of bituminous and subbituminous coals before and after exposure to ambient air atmosphere, as part of an ongoing project investigating the coal-wetting abilities of surfactant solutions intended for the suppression of dust during coal mining operations. Exposure periods were generally 7 days or less, and the changes in wetting response were measured with a capillary penetration apparatus. Wetting solutions tested included a nonionic surfactant, two anionic surfactants, and pure distilled water. After exposure, higher ranked bituminous coals treated with nonionic surfactant solution and pure water showed increased wettability, but lower ranked subbituminous coals showed decreased wettability. With the anionic surfactants, the coals demonstrated opposite responses. The wettability changes appeared to be related to the coal moisture content. These changes may be amplified by specific, but incompletely understood, interactions between surfactant polar groups, absorbed water, and the coal surface.

Jan 1, 1989

After more than 20 years dependence on bituminous coal as a primary fuel for generating electricity, the Pennsylvania Power and Light Company initiated a one-year study on the economics of building an electric generating station using anthracite as a fuel. The study will be completed in December 1976. If the feasibility study so indicates, PP&L will consider installing four 400,000 kilowatt generating units for scheduled commercial operation in 1985. Each unit would consume up to one million tons of anthracite annually. Anthracite generally is more difficult and expensive to extract than bituminous coal, but it has a significantly lower sulfur content than the bituminous coal currently being used by PP&L, thereby eliminating the costs of installing sulfur emission controls at generating stations. Moreover, significant reductions in transportation costs may be realized because the utility's operating territory is situated in the center of the anthracite region in northeastern Pennsylvania. These advantages may indicate that the use of anthracite is more economical than bituminous coal to PP&L. ASBESTOS -Asbestos production in the U.S. dropped again in 1975 until it was just two-thirds of that in 1973. This was in spite of the very strong demand caused by the Quebec strike. The 7-month strike of the asbestos miners in Thetford Mines, Quebec cut off 55 percent of the normal supply of U.S. consumers. Apparent domestic consumption was less than 75 percent of that in 1974. The wage settlement will probably result in a 20 percent increase in asbestos prices.

Jan 1, 1975

By W. E. Wallace, B. L. Razzaboni, P. Bolsaitis, M. J. Keane

"Therma1 and chemical treatment of respirable size silica dusts samples is shown to induce marked changes in their hemolytic activity. The cytotoxicity of crystalline a-quartz (Min-U-Sil), and fumed silica (Cab-0- Sil) particles, as measured by a hemolytic activity protocol, is decreased by calcination and can be related to the dehydroxylation of the surface. The hemolytic activity of P-cristobalite particles of respirable dust si7.e was also determined and found to be lower than that of a-quartz. The change in the surface structure resulting from thermal treatment is detectable by photo-acoustic infrared spectroscopy and zeta-potential measurements. The absorption band in the 3200-4000 cm-1 frequency region of both Cab-0-Sil and MinU- Sil disappears upon heat treatment while a sharp band, identified with single silanol groups, at 3750 cm-1 increases in intensity. The zeta potential-pH profile, in the pH range of 4.0-7 .0, of the calcined, siloxane surfaced particles is more negative than that of material with a silanol surface.The cytotoxicity of the crystalline and fumed silica dusts was also found to be strongly dependent on particle size. Fumed silica of large surface area (small particle size) exhibits an initial increase in hemolytic activity upon calcination. This result confirms other experimental observations pointing to a particle size of maximum toxicity. INTRODOCTIONThe toxicity of silica and other mineral particles, as manifested by their role in inducing pneumoconiosis, fibrosis, silicosis and other pulmonary disorders is largely traceable to the characteristics of particle surfaces and to particle morphology. The great wealth of data on the physical and chemical properties of silica is still insufficient for a comprehensive understanding of the specific parameters to be associated with fibrogenic activity and, correspondingly, with the optimum means for characterizing and quantifying the toxicity of dusts, and the design of possible preventive or therapeutic methods.The great diversity of parameters that have been proposed and tested for correlation with cytotoxicity suggest that more than one mechanism may be involved in the fibrotic activity of silica particles. The crystalline structure of the material (more active tridymite versus less active crisobalite and passive stishovite), freshly formed surfaces and free radicals associated therewith, silicic acid adsorbed onto silica surfaces, the concentration of hydroxyl groups at silica surfaces, particle size and morphology, among other properties, have been investigated and found to conelate in tests of cytotoxicity."

Jan 1, 1990

By David C. Uhrin

Two improved methods have been developed to transfer microfilmed mine maps to suitable base maps showing surface features. The methods provide for (1) positioning and orienting maps; (2) merging adjacent maps; and (3) plotting maps at a common scale. One method produces an overlay mosaic of mine maps using an Integrated camera-processor. This photographic method shows the details of mine workings and is most useful for specific limited-area projects. In the second method, outlines of mine maps are digitized, manipulated, and plotted as overlays using a computer. This computer method can plot mine outlines and spatially index large numbers of microfilmed maps. Microfilmed mine maps used in this Bureau of Mines study are on file in the Mine Map Repository of the Eastern Field Operations Center. The base maps are U.S. Geological Survey 7.5-minute topographic maps. The demonstration area is located in the New Kensington East and West quadrangles, Pennsylvania.

Jan 1, 1977

By Dwight L. Sawyer

To provide technology that can help decrease the dependence of the U.S. aluminum industry on imported bauxite, the main ore of aluminum, the Bureau of Mines is investigating the extraction of aluminum from abundant domestic reserves of kaolinitic clay. Miniplant studies of the continuous leaching of calcined kaolin with boiling 25-pct HC1 acid resulted in a 93- to 99-pct extraction of the acid-soluble alumina in the calcined kaolin feed. Data are presented for an acid leaching study carried out in three or four continuously stirred tank reactors (CSTR) in series, feed rates of 100 to 250 lb/hr of calcined kaolin, and total nominal residence times of 0.7 to 2.3 hr. A material balance for a 176-lb/hr calcined kaolin feed rate in a circuit consisting of three reactors, four classifiers, and five thickeners is given. Data provide detailed compositional and physical information for calcined kaolin, process liquors, and acid-leached residue solids.

Jan 1, 1983

By Annie G. Smelley

As a part of research conducted in its mission to effect pollution abatement, the Bureau of Mines, U.S. Department of the Interior, is developing a dewatering technique that allows for disposal of clay wastes, for reuse of water now lost with clays, and for reclamation of mined land. The technique utilizes a high-molecular-weight nonionic polyethylene oxide polymer (PEO) that has the ability to flocculate and dewater materials containing clay wastes. In laboratory experiments, coal-clay waste, potash-clay brine slurry, phosphatic clay waste, uranium tailings, and talc tailings were successfully consolidated. Coal-clay was te was consolidated from 3-. 6 to 57 percent; potash-clay brine slurry was consolidated from 3.8 to 35 percent; phosphatic clay waste from 15.6 to 49 percent; uranium tailings from 15.4 to 67 percent; tailings from talc production from 9.7 to 53 percent; and an acidic Ti02 slurr slurry from 1.68 to 30 percent.

Jan 1, 1980

By Steven W. Schmauch

The U.S. Bureau of Hines conducted e mineral resource survey of approximately 232,000 acres in part of the Humboldt National Forest, Nevada, during 1989. About 7S percent of the study area was covered with mining claims. About 1,800 samples were collected end analyzed for 16 elements. Geologic structure, including thrust faults, is the most important factor in the localization of mineral deposits in the study area. The Independence mine (formerly Jerritt Canyon), Big Springs, and Wood Gulch are the most well known active properties, all developed on large, low-grade, disseminated gold deposits. These deposits have produced almost 3 million ounces of gold and are known to contain more than 8 million ounces of gold. At least 10 barite deposits in the south end of the range have had significant past production and contain 0.2 million tons of resources. Numerous precious and base metal targets have been identified and in some cases quantified during this study.

Jan 1, 1992

By Harry W. Campbell

A mineral survey conducted by the U.S. Bureau of Mines in 1983 identified no mineral resources in the Beaver Meadows, Blind Horse Creek, Chute Mountain, Deep Creek/Battle Creek, and North Fork of Sun River Wilderness Study Areas (WSA's). A prospect east of the Beaver Meadows WSA has low potential for lead resources. Sand, gravel, and limestone occurrences are numerous in the WSA's; however, similar or better quality materials outside the areas are abundant and more accessible to potential markets. Impure coal and titaniferous-magnetite occurrences are near the WSA's, but are not known to occur within these areas. In 1983, there were 7,025 acres leased for oil and gas within the five WSA's; no current mining claims were in or near any of the WSA's. Evidence of mining activity was found at only one prospect in the WSA's. It is inside the Deep Creek/Battle Creek WSA; no resources or resource potential were identified at this prospect.

Jan 1, 1984

By A. F. Robertson

"INTRODUCTION This report is supplemental to R.I. 4178 and deals with the work accomplished between June 15, 1945, and September 7, 1945, on the Mitchell-Hodge mine, Grady mine, Albea and York property, and Cuzzort property.ACKNOWLEDGMENTSIn its program or exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigcal Branch, O. C. Ralston, chief, analyzes samples and performs benefication tests.Acknowledgment is due Mitchell H. Kline, chief, Raleigh Division, Mining Branch; Abraham L. Fox, acting chief, Raleigh Division, Metallurgical Branch; and Rowe McCrae, district engineers, U.S. Bureau of Mines, Gainesville,"

Jan 1, 1946

By Craig C. Hustwit

A pilot-scale treatment study was conducted on a copper-zinc bearing metal mine drainage using a pipeline treatment system called the In-Line System (ILS). The objective of this U.S. Bureau of Mines study was to determine whether the ILS could be extended from the treatment of coal mine drainages to the treatment of metal mine drainages. Hydrated lime (Ca(OH)2), quick lime (CaO), and caustic soda (NaOH) were used to neutralize the drainage. A novel reagent slurry of Ca(OH)2 and type C fly ash was also evaluated. Except for Ca(OH)2-fly ash slurry, treatment performance was evaluated for all reagents at pH values of 7,8,9, and 10. The Ca(OH)2-fly ash slurry was evaluated at a pH of 10. All reagents tested neutralized the metal mine drainage and substantially reduced the dissolved metal concentrations. It was concluded that the ILS could be useful in the treatment of metal mine drainages.

Jan 1, 2010

By Donald P. Mickelsen

The raining and quarrying trends data shown in this report were reported to the U.S. Bureau of Mines (USBM) by mining and quarrying companies on the Mine Information Supplement survey, as well as by mineral producers on 58 annual USBM production and consumption surveys covering 59 nonfuel mineral commodities. The 1993 data presented in the tables of this chapter, were processed for the first time using the USBM Automated Mineral Information System. Domestic mining of nonfuel mineral materials totaled 3.7 billion metric tons in 1993, including 2.2 billion tons of crude ore nun& or quarried and 1.5 billion tons of mine waste and ore from development. This \vas an overall increase of 11% over that of 1992. These data do not include construction sand and gravel which until 1993 has been surveyed biennially. Starting in 1994, construction sand and gravel and the stones, which were also surveyed biennially, will be surveyed annually.

Jan 1, 1993

By L. C. IlsLey

Minin,g Qr col-cu.ttint till:I chines are 1?;\i9ng the _m9t wideiy .used de1sses ()f mining equipment.· These 1T:.i:1Chines ,.--re practicaily t-tl\·operc1_ted eiyher_by compressed .iir or by electric. ·motors. According to &.ta• compiled _ from the 122. issue COAL CATALOG\JE. OJMEINED WITH; OOAL "FIELD 'pf!:fC'TOTl1, bf 7,088. mnes from which reports were obttiined there -are 3895 mines that u.se coal-cutting eql;lipmen:ts,, 'f'hi report lists 20,031: r.ct:lchines, 17,&75 being operated by·elct:i.c.m<;>_tors··:r;id :the remtiinder by compressed i.r motors,· ,-. · ', .. . · .. ··, .. _ ,· .,, .. .. . . . . . : ; "'l t:: On tl.Ccou-nt .. of the wide· use of coc:11-cutting -.:i"cliine_- any Stat!;ls have issued regulationa as "to their operation dnd be to safety precautions that.should be observed J especially in gaseous mines.

Oct 1, 1922

By William K. Tolley

The U.S. Bureau of Mines (USBM) is investigating hydrometallurgical processing techniques to recycle metals from semiconductors and other advanced materials. Cadmium and tellurium were recovered from mixed CdTe/CdS scrap produced in the manufacture of thin-film photovoltaic devices. Selective cadmium dissolution was achieved using oxygen-pressure leaching in dilute sulfuric acid. Leaching the scrap for 90 min at 110° C in 2.2NH2S04 under 400 psig 02 yielded 97% Cd extraction; however, cadmium content of the residue ranged between 4% and 7%. Soluble iron was added to the lixiviant to catalyze oxidation of the CdS component. Tellurium and sulfur remained in the leach residue primarily in the elemental form. The iron and tellurium were removed from the cadmium-rich leach liquor by adjusting the pH to 5.3. The cadmium was recovered as cadmium sulfate crystals by evaporating the solution. Alternative leaching and purification schemes are discussed.

Jan 1, 2010

By Harry W. Campbell

U.S. Bureau of Mines investigation; identified no mineral resources or evidence of mining activity in the Sheep Divide RARE II area. A deposit 10 mi (16 km) southwest of the area contains copper and silver minerals in the Triassic Wild Sheep Creek Formation which probably underlies basalt lava flows covering the study area. Abundant basalt in the area can be crushed and used as aggregate, but suitable deposits closer to markets are widely available No sand, gravel, coal, oil, gas, or geothermal resource, were Identified. INTRODUCTION Location and Access The Sheep Divide RARE II area [10 mi (16 km) west of the Snake River] encompasses 7,100 acres (2,800 ha) of the Hells Canyon National Recreation Area in the Wallowa-Whitman National Forest. Enterprise, Oregon, is located 23 air mi (37 (m) west of the area. Peripheral access is provided by the highway from Joseph to the community of Imnaha, Oregon, then south to the study area by the graveled Upper Imnaha Road (fig. 1).

Jan 1, 1983

By K. P. Wang

Mining and metallurgy have had a long history in China, and resources there have always been considered promising. Under the People&apos;s Republic of China (PRC), a remarkable industrial renaissance is underway that should further gain momentum in the years ahead. Rapid development of minerals have not only brought the PRC prominence in industrialization, but also in world affairs. Chinese mineral developments, especially petroleum, have been increasingly in the news. Oil and gas may have great potential, but a very large coal industry is already in existence. The steel industry ranks fifth or sixth in the world. The PRC is also prominent in fertilizer, cement, and salt production. The export metals are well known. Also, the country is buying heavily in nonferrous base metals. The need to know and the intense interest in the subject have prompted this study. The world significance of Chinese minerals is pointed out. The history of growth and PRC&apos;s mineral supply position are reviewed. Evaluations are made of policy considerations and regional and technical factors affecting mineral development. PRC&apos;s mineral trade and efforts to obtain equipment, supplies, and know-how are assessed. Specific reviews are made of major mineral sectors, including coal and power, oil and gas, iron and steel, nonferrous metals, industrial minerals, and fertilizers and chemicals. The overall outlook is summarized.

Jan 1, 1975

By S. J. Broderick

[Xuge d-mp heap co:lt:.ini9: tilcu?:na3s of tons of cad ~eP~se 2r3 a failiar sight in coal-mininc regior@:. T5ey reprecei~t considergole economic 1083, are very l.u.,si~hC,ly, ?:ld t?ke un m-lch vaL-x3le qace. Cor.sequentl;r thelr remcval i~ geatlyr dezir36, ax2 my ret-sn t?-at c,m be obtained would be er;pecic.llj .a~elconre&apos; t.7 the cod ir.S..r; kry. T?.e vaste rk.t~ri..tl conpl-ises large pieces of slr.t.e, hi~h-2s&apos;. bore c~al., luqs cf cle:., ,ad finer refuse conin,= fro3 the vrtskery, Tilt 1:zshcr:r refilsn contnins sone yood coal. Rig coal and the &apos;better p~lcs of bore ere the zat~rla2.s ~15:;~itiered in this in- vest ig:?.tion. 7% Il~avter frnctions of the w~~sherjr ref;lw aizd tts large 2ieces of slcte ?,".:I rgck contilin 1it:lei ccai-i-bcna.c~o~s caterial ad are vir- tu<dly worthiess nc, rz:. ::atcrin!. for .*=irin,= zct,iv?*teb cCvb~n. 13 the 3irniingh.m district, i13br.12, a-c.ju",P p?rcccn",f the c3sl r?.ir?ed is washed, ,md in tkis c?i.;trict nlz:~c rcfilce ecc;:?:lletcs ~t the r%tg of 1 to 2 million .! tons 2 yew.]

Jan 1, 1941

By Jeffery M. Listak, Ernest A. Curth

"It took only 9 years from the first appearance of roof shields on the U.S. longwall mining scene to the present predominance of shield faces. An apparent consequence is the welcome downward trend in accidents related to failures in longwall ground control. The report addresses load prediction, the effects of shield geometry on support loads, factors contributing to ground control, and related techniques. The Bureau of Mines took an active part in the evolution of longwall mining, including developing one of the first shield faces in 1975, the first lemniscatetype shields in 1976, the Mine Roof Simulator completed in 1980, the first shields in steeply pitching coalbeds in 1981, and the first multilift working of a thick coalbed in 1982. The information offered in this state-of-the-art report will assist in establishing criteria for roof support selection. INTRODUCTIONIn terms of roof support technology, the introduction of shields in the seventies and eighties was a major step forward. Table 1 indicates the predominance of shield faces on the U.S. longwall mining scene and its apparent consequence, a welcome downward trend of ground-control related accidents.The rapid progress of longwall technology began in 1975 and is highlighted by a development leading from the caliper shield to the modern lemniscate type. Shields have been gaining preference over chocks since their advent to longwall mining in 1975. Safety and productivity factors favoring shields over chocks are--1. A sheltered working space requiring minimum cleanup work.2. Structural stability that allows advancing without delay even with brushing roof contact and, by controlling all lateral loads, removing the requirement for cumbersome leg restraint and restoration devices.3. Wide hydraulic range of mining height.The development of roof shields in the Federal Republic of Germany preceded and paralleled their rapid adoption by U.S. miners. In 1983, 87 pct of the total production in Germany came from shield faces (1).2 In Great Britain, the National Coal Board introduced the first shield support system in 1977 to initiate Advanced Mining Technology (ATM) and Heavy Duty Mechanization (HDM) programs; as of mid-1982, 44 shield faces were operating, or 7.5 pct of a total of 581 faces CJ_)."

Jan 1, 1985

By G. R. Hopkins

"Summary An apparent decline in fuel efficiency at refineries, which first became came evident in 1930 and continued through 1933, was checked in 1933 when the average amount of heat needed to refine a barrel of crude oil amounted to 660,000 B.t.u. This compares with an average requirement of 692,000 B.t.u. In 1932 and with a low of 639,000 B.t.u. in 1929. (See fig. 1.) The improvement in fuel economy in 1933 probably was closely related to the increase of 5 per cent in crude runs to stills. As much of the fuel burned at refineries is utilized for purposes other than under crude-oil stills and in relatively stable amounts, it is evident that a material increase in crude runs will usually reflected in a decrease in average fuel requirements. Another factor which has influences fuel economy at refineries in the past is the trend in cracking, a refining process requiring more than the average expenditure of heat. In 1933 production of gasoline by cracking increased slightly, but no appreciable rise in heat requirements resulted as an equivalent amount of fuel was saved in improved technique, particularly in the field of heat exchange.Since the beginning of the refining industry, the transition in fuels has been from solid to liquid to gaseous; in other words, the leadership was first held by coal, then passed to oil, and is now held by gas. In 1933, 54.7 percent of the total heat units generated came from gas, 39.0 percent from oil (including acid sludge), and 6.3 percent from coal and coke. The principal change in the relative importance of the various refinery fuels in recent years has been the rapid growth in consumption of refinery or still gas at the expense of all the other common fuels. Still gas owes its ascendency to its cheapness and availability, and probably it would have become the primary refinery fuel years ago if recovery methods had been perfected. The relative importance of coal showed a small increase in 1933, the first gain recorded since these surveys were inaugurated in 1925. The increase in use of coal was undoubtedly due to increased operations at plants using it,"

Feb 1, 1935

By Madan M. Singh

The use of fluid jets for industrial purposes has received considerable attention in recent years. The convening of The First International Symposium on Jet Cutting Technology1 in April 1972 devoted solely to this subject probably heralds the coming of age of this new science. It is interesting to note the emphasis in the conference towards the cutting of rocks, minerals, and soils, indicating the attention being devoted to excavation and mining. The use of water streams for mining of minerals is not new. It is well over a century since its first application.2 But its use in coal mining has been somewhat restricted over the years. In the past 30 years the U.S.S.R. has successfully used water for coal extraction, and these techniques have been examined in 15 countries in recent years. In the United States research on various aspects of the method has been conducted for over 15 years,3 but success stories from the Soviet Union,4 JapanS and Canada6 in the last 5 years has spurred greater enthusiasm. IIT Research Institute has done pioneering work in the 7-12 13-15 area of water jetting for rock and coal breakage. It has just completed an experimental study involving mining of coal with a 50,000-psi and 100,000-psi jet in a stripping operation14 under the sponsorhip of the U. S. Bureau of Mines (Contract No. HOll1789). As a complementary program the Bureau initiated a project to design a water-jet coal-mining machine (Contract No. H0133119). IITRI was a successful bidder on this competitive procurement.

Jan 1, 1974