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By E. R. Palowitch

Coal wasted with mine refuse represents losses in overall recovery of merchantable coal to the mine operator and a concomitant reduction in domestic reserves of available coal. Fraser, Kelley, and Graham3/ in studying the available coal in mine refuse in the Pittsburgh district of western Pennsylvania have estimated that at least 1 ton of mine refuse is produced for each 10 tons of merchantable coal and that 20 percent of this mine refuse might be recovered as salable coal by mechanical cleaning. SUMMARY This investigation dealt with the mechanical recovery of coal from wine refuse by a dense-medium washery employing pulverized mine rock as the dense medium and operating at a rate of 175 tons per hour. Two types of mint refuse were tested: Freshly mined and that .which had been mined 2 years before and piled on a waste dump.

Jan 1, 1955

By Richard J. Leary

The inputs of capital and labor to support future iron ore production were developed by the Bureau of Mines from projections of iron demand and estimates of capital and labor requirements. Trends in technologic change and the organization of production were analyzed. Labor requirement schedules for iron ore mining and beneficiating were constructed from aggregate inter-temporal trends and 1970 cross-sectional analysis of mines and mills. A sup-ply schedule of the capital requirement for mine-mill-pellet plants was developed from U.S. and Canadian experience. The structure of demand for iron to the year 2000 was examined as well as the availability of resources. Projections of capital and labor requirements to 2000 were constructed under two international patterns of iron ore supply to the United States. The most likely model is for a continuation of the 70 percent United States-30 percent foreign shares, expanding at an average 2.0 percent growth rate to 2000, and supported by a cumulative gross capital investment of $3.8 billion constant 1967 dollars and a labor force in the United States of 29,800 by 2000. The information content of projections is discussed, and the possible effects of international forces on supply are considered. A generalized methodology for estimating capital and labor requirements in other mineral industries also is included.

Jan 1, 1975

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 A. L. Engel

[Thi;. re:9ort presents re3ults of investigations of problema a3signed as ore-testing projects to the Ore-Dressing Section, t.fetal1urgica.l Div:biion, of the Bureau of Ii.fines at the .fississippi?Valley E>"'1lcrimcnt Station in rtolla, Ho., durine the fiscal year ended June 30, 1940.]

Jan 1, 1941

By P. M. Daling

This report, sponsored by the U.S. Bureau of Mines, presents the results of an examination of available safety assessment methods and their applicability to the mining industry. Standard safety analysis procedures were evaluated for relevance to the mining industry and mine operators' needs. The major safety concerns and needs of mine operators were identified through telephone contacts and a visit to a mine site. Safety assessment methods recommended for use by the mining Industry were also Investigated for potential adaptability to a user-interactive computer system. Several methods were determined to be immediately transferrable to the mining industry; these techniques are described in a user's handbook produced as part of this project. The handbook gives detailed instructions on appropriate application and utilization of these methods. Other techniques will require further development before they can be effectively transferred to the mining industry. These methods, their advantages, disadvantages and resource requirements are described in the final project report. Recommended system safety analysis techniques facilitate an evaluation of total mine system safety and a determination of safety-related interactions among systems within a mine. The application of these methods to the mining industry could result in reductions in both the frequency and the consequences of mine accidents.

Jan 1, 1983

By T. W. Smelser

This Bureau of Mines report presents a review of underground testing, test results, and design guidelines of steel-fiber-reinforced concrete (SFC) mine support (cribbing) developed at the Spokane Research Center. The objective of the work was to verify, in field applications, the performance, economics, and acceptance by the mining industry of the SFC supports and establish design guidelines for their use underground. Results indicate superior performance, favorable economics, and enthusiastic acceptance by the mining industry.

Jan 1, 1983

By J. E. Chilton

The Bureau of Mines has developed a portable flammable gas detecting system for estimating the flammable gas concentrations in a mine containing one or more combustible gases at concentrations up to 100 vol pct. With this portable detecting system, mine rescue or recovery personnel can quickly determine if they are working in a potentially explosive gas atmosphere and either leave the area or make appropriate changes in the fresh air ventilation of the mine to render the area safe. The detecting system uses a commercial, intrinsically safe, flammable gas detector with a range from 0 to 5 vol pct methane (CH4). The flammable gas detector has a catalytic heat-of-combustion sensor that can detect all flammable gases that would be encountered in a mine including methane (CH4), ethane (C2H6), carbon monoxide (CO), and hydrogen (H2). To determine the mine gas concentration, the rescue worker dilutes a sample with fresh air carried within the detecting system. The concentration of the diluted sample is then measured with the permissable flammable gas detector. The actual mine gas concentration is calculated from the product of the indicated diluted gas concentration and the system dilution ratio using a pocket calculator or the nomograph on the side of the unit.

Jan 1, 1987

This publication summarizes the Bureau's activities as part of a study of the Juneau Mining District (JMD) during the period 1984-1988. The objectives of the program were to identify the type, amount, and distribution of mineral deposits in the district, determine ore reserves, study beneficiation technologies for the ore, make feasibility studies, and address economic and legislative effects on mineral development. The JMD study was a cooperative study involving the Bureau and the Alaska Division of Geological and Geophysical Surveys (ADGGS). Over 30 employee-years were spent by the Bureau on this project. Bureau investigations in the JMD consisted of a district-wide investigation of industrial materials in addition to site-specific investigations of precious and base metals in five subareas. During the 4 years of the JMD study, more than 300 areas, mines, prospects, and occurrences were visited, which contain gold, silver, copper, zinc, lead, nickel, cobalt, tungsten, molybdenum, chromium, and platinum group metals (PGM). More than 59,000 feet of underground workings were mapped and sampled. More than 5,500 samples were taken; one diamond drilling program and three geophysical surveys were completed. An up-to-date and complete mineral data base for the JMD did not exist prior to this study. The JMD study, which coincided with a tremendous increase in mineral interest and activity in the district, has proven to be valuable to both the minerals industry and land management agencies. The discovery of two new mineral occurrences and compilation of data on known mines, prospects, and occurrences have aided industry activity in the region. The study enabled timely data to be available to land management agencies at the Federal, State, and municipal levels.

Jan 1, 2012

By M. H. Kline

The Great Gossan Lead in Carroll County, Va., is one of the largest undeveloped sulfide ore bodies known in the eastern United States. It extends for 16.7 miles along the western slope of the Blue Ridge Mountains (fig. 1). The various known segments of the deposit, extending from the southwest end to the northeast, are: The Great Outburst or Iron Ridge segment, Chestnut Creek, Copperas Hill, Sarah Ellen, Wild Cat, Cranberry, Dalton Hill and offset segment to the south of the Cranberry, Little Reed Island, Little Vine, and the Betty Baker at the northeast end. All of these segments have been explored or mined to various extents in the past for the iron gossan and secondary copper ore. The Great Outburst or Iron Ridge segment is now being mined by the General Chemical Division of the Allied Chemical & Dye Corp. for the sulfur and iron content of the primary ore. These deposits are becoming increasingly of Interest as a. large potential source of iron and sulfur owing to their proximity to Birmingham, where the burned cinder sells at a premium, and to the acid markets of the region.

Jan 1, 1949

By Forrest T. Moyer

The safety record of the coal-mining industry, both anthracite and bituminous, in 1966 was improved over that of 1965 in all general measures of injury experience. The improvement was more pronounced in the anthracite industry. The total of 10,679 disabling work injuries comprised 233 fatal and 10,466 nonfatal injuries, 26 and 692 fewer, respectively, than in 1965. The number of fatalities in 1966 was the lowest annual total since complete records were started in 1910. Similarly, the number of nonfatal injuries in 1966 was lower than in any year since 1930 when such data were first collected.

Jan 1, 1969

By R. A. Cattell

Progress of Bureau of Mines research related to oil and gas during the past fiscal year has been marked by the publication of more than 40 reports on the various phases of the work . These include papers dealing with the production of oil and gas , transportation of gas , chemistry and refining of petroleum , thermodynamic properties of hydrocarbons , and the processing and utiliza- tion of helium . As an additional service to Pennsylvania oil operators , a new suboffice was opened in Bradford , Pa . , during the year . With this addition , the work of the Petroleum and Natural Gas Branch of the Bureau of Mines is now conducted in two large stations , the Petroleum Experiment Station , Bartlesville , Okla . , and the Petroleum and Oil Shale Experiment Station , Laramie , Wyo . , and three field offices and laboratories at San Francisco , Calif . , Dallas , Tex . , and Franklin, Pa., and two suboffices, Wichita Falls, Tex., and the newly opened suboffice at Bradford, Pa. In addition, this Branch operates large-scale helium-production plants in Texas, Kansas, and New Mexico, and maintains ex- tensive helium-bearing gas reserves in Texas and New Mexico. All helium opera- tions are supervised from headquarters at Amarillo, Tex. A small headquarters staff is in Washington, D. C. A backward glance at the road traveled during the past several years by the Petroleum and Natural Gas Eranch of the Bureau of Mines brings out a general background for the events of the fiscal year 1949. Throughout the fiscal year 1945, the activities of the Branch were still mainly concerned with such war activities as making special field studies for the Petroleum Adminis- tration for War, finding ways of increasing rates of production, and supplying data pertaining to the manufacture of aviation and jet-propulsion fuels. A period of adjustment came in 1946, characterized by a turning from war to peace procedures and efforts to give wide distribution to technical facts ob tained in wartime research; also, there came a realization that the demands of war had broadened the horizons of research. This was emphasized in 1947, when a peacetime program was restored, based upon the long view of the Bureau's place as a research agency in oil and gas. Close attention was given to tech- nical detail in 1948, and emphasis was placed on maintaining a balance between the industrial need for technical knowledge and Governmental-research possi- bilities in the fields of (1) withdrawal of petroleum from natural deposits, (2) utilization of petroleum and its products, and (3) commercial utilization of helium. Studies of petroleum production and utilization and helium production and utilization are the normal functions of the Branch. These functions (sometimes expressed in different words) have been the mainstay of this organization since initiation of the work. The details of approach vary with changing conditions, but, fundamentally, the functions have been the same in both peace and war. The work of the past fiscal year has emphasized the advantages that accrue when Government and industry join in a wise use of technical and scientific knowledge gained through research. Outstanding evidence of the beneficial results of cooperative effort by the Bureau of Mines and various organizations is found in the following typical examples, the details of which are discussed in the body of this report. Working in close cooperation with operators along the Gulf Coast, the Natural Gasoline Association of America, and the National Association of Cor- rosion Engineers, the Bureau found, through field testing, that corrosion protection by means of chromates in high-pressure gas-condensate wells costs less than $1 per million cubic feet of gas produced. Laboratory experiments to measure the corrosion effects of carbonic and propionic acids on various steels and alloy steels gave data that will serve as guides in the selection of new. materials for the construction of well equipment to be tested by industry under actual service conditions.

Feb 1, 1950

By H. M. Cooper, R. F. Abernethy

Determination of the fusibility of coal ash consists in melting a pyramid of the ash to fluid under prescribed conditions . The conditions of the test are specified by the American Society for Testing Materials4/ and must be adhered to strictly if comparable results are to be obtained . The Society formerly specified a particular type of furnace , but with improvements in design of both electric and gas furnaces , it was decided by the Society to specify only essential details of the test . The Chairman of Committee D - 5 , Coal and Coke , of the American Society for Testing Materials suggested that the Coal Analysis Section of the Bureau of Mines conduct a cooperative investigation on the effect of furnace type and atmosphere upon fusibility of coal ash . The Coal Analysis Section enlisted the aid of a number of laboratories using the more common furnaces to cooperate in the investigation . Four types of gas furnaces burning natural and manufactured gases and two types of electric furnaces with different methods of maintaining a reducing atmosphere were employed . The results from the survey are tabulated herein , and some comparisons are made . There were not enough data from any particular furnace and atmosphere to make a reliable statistical analysis . However , definite tendencies are evident , and attention is called to them by direct comparison. in tables .

Oct 1, 1943

By J. Douglas Causey

No mines are active in the Hunter Mountain Wilderness Study Area (WSA), and no mineral resources have been identified in the WSA. However, the Monarch Mine has low potential for silver, copper, tungsten, and gold resources in quartz veins; the Shirley Ann Group and Sal Group have moderate and low potential, respectively, for silver, lead, and copper resources in skarn; claims overlying the Eureka Quartzite have low potential for silica resources; and the Tourmaline N1-4 Prospect has low potential for tourmaline resources in quartz monzonite. Copper, lead, silver, tungsten, molybdenum, wollastonite and garnet occur in skarn zones between monzonitic and carbonate units. Silver, tungsten, and copper also occur in quartz veins within monzonite. Known metallic mineral deposits are small, erratic and discontinuous. The J. 0. Mine, adjacent to the northeast corner of the WSA, may contain as much as 26 million tons of subeconomic wollastonite resources. The crest of an open pit to produce that resource would extend into the WSA. No information exists on geothermal potential because no exploration has been done in the area. No occurrences of energy minerals are known within the WSA.

Jan 1, 1983

By Robert N. Roby

"The Moffet-Johnston property was investigated by the Bureau of Mines with the object of determining the presence of ore reserves that might be utilized during the war emergency. Preliminary examination was made during May and Juno 1943, as a result of which the Johnston 'tunnel was cleaned out and repaired, the .mime was surveyed, and a small program of exploration was undertaken. This report describes the work performed and presents the data obtained.In its program of 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 each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts prelimi¬nary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs benefication tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.The chemical and spectrographic analyses were made at Reno, Nov., under the direction of A. C. Rico, acting engineer in charge, Rare and Precious Metals Experiment Station, Bureau of Mines. The ore-dressing tests were under the direction of Rollien R. Wells, metallurgist, at the Salt Lake City laboratories of the Bureau of Mines.The author acknowledges the cooperation and assistance of the lessee of the property, H.R. Hakes, who furnished nine reports and other information.The Moffet-Johnston property is in secs. 2 and 3, T. 3 S., R. 5 W., in the Tidal Wave mining district of Madison County, Montana.The portal of the Johnston adit is near the mouth of Bear Gulch, 9 miles northeast of Twin Bridges, Mont. It is reached by an improved dirt road that serves mining properties farther up Bear Gulch. The Moffet mine and the Mountain View shaft are now accessible from the Bear Gulch road over an access road recently completed by the U. S. Grazing Service. The Grazing Service road has also been supplemented by bulldozer trails built by the Bureau of Mines.An electric-power line extends from the Montana Power Co's substation at Twin Bridges to mines at the head of Bear Gulch and passes within 200 feet of the Johnston portal.The claims of the Moffet-Johnston property were located about 1900. A report by H. V. Winchel, consulting geologist, in 1904 indicates that most of the development on the Johnston adit was completed by that date. At the time of the Winchel report, the Moffet workings had just penetrated the first ore shoot (fig. 4)."

Sep 1, 1946

By Michel C. Frippel

This section of the Minerals Yearbook reviews the minerals industries of 27 countries: the 12 nations of the European Community (Belgium, Dermark/Greenland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, and the United Kingdom); 6 of the 7 nations of the European Free Trade Association (Austria, Finland, Iceland, Norway, Switzerland, and Sweden); Malta; the 8 Eastern European economies in transition (Albania, Bulgaria, Czechoslovakia, Hungary, Poland, Romania, and Yugoslavia); and the U.S.S.R. Western Europe Western Europe [loosely defined to include the 12 nations of the European Community (EC) and the 7 nations of the European Free Trade Association (EFTA)] is the single largest trading area and consumer of raw materials in the world. If Western Europe was at one time an important mining sector, it has now increasingly relegated the role of supplying minerals for its minerals processing industry to the more minerally endowed countries in North and South America, Africa, and Australia. In this regard, Western Europe is the most important determinant of raw materials consumption (and thus, indirectly, raw materials production). Western Europe has significant reserves of industrial minerals but has limited availability of metalliferous raw materials. It, therefore, imports significant quantities of the latter and ranks along with the United States and the U.S.S.R. in the production of refined metals. Nonetheless, there is an inherent tendency to underestimate the importance of Western Europe in the world of minerals, both as a minerals processor and raw materials buyer. The reason for this is that Western Europe is generally thought of on the basis of individual nations rather than as a whole. Viewed in this limited context, the United States, the U.S.S.R., and Japan appear to dominate the world economy. Viewed as one regional area, however, Western Europe includes the fourth (FRG), fifth (France), sixth (United Kingdom) and seventh (Italy) largest economies of the world, all bordering on one another. With the remaining 15 EC and EFTA countries, Western Europe has a land area approximately 40 % of that of the United States, exceeds the U.S. population by 50 % and has a gross domestic product about the same as that of the United States.

Jan 1, 1993

By Alex C. Smith

This report describes laboratory studies conducted by the Bureau of Mines on the spontaneous combustion of U.S. coals. Approximately 11 pet of U.S. underground coal mine fires are attributed to spontaneous combustion. The relative self-heating tendencies of 24 coal samples were evaluated in an adiabatic heating oven. Minimum self-heating temperatures (SHT's) in the oven ranged from 350 C for a lignite and high-volatile C bituminous (hvCb) coal, to 1350 C for two low-volatile bituminous (lvb) coals. An empirical expression was determined predicting a bituminous coal's minimum SHT in the adiabatic oven based on the coal's dry ash-free oxygen content. Several factors that can affect the self-heating process were also evaluated. The self-~eating tendency of a coal increased when the coal was dried and exposed to humidified air, and was dependent on the particle size and oxygen concentration of the air. A new moderate-scale apparatus is described, in which the self-heating tendencies of larger coal samples, 3 kg, can be evaluated. The minimum SHT's of two coals were determined and the results were in good agreement with those found in the adiabatic oven. Finally, results of a test in the moderate-scale apparatus indicated a strong dependence of the self-heating rate of a low rank coal on the moisture content of the air.

Jan 1, 1987

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Joy Mfg. Co. loader. These instructions are based upon two actual install .at ions: one made in a mine on loader, model 14BU10-11AH, and one in the factory on model 14BU10- 11AH. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other loaders with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other loaders and can determine any necessary modifications if they are not.

Jan 1, 1973

This Bureau of Hines report on underground mine communications addresses methods and equipment to meet the communication requirements of working sections and places of coal and metal-nonmetal mines. A review of the status of trapped miner detection is also presented.

Jan 1, 1977

By John E. Conley

The great demand for metallic aluminum for the prosecution of World War II caused the consumption of bauxite, the common ore of aluminum, to increase greatly. Prior to the war, the domestic deposits 'of bauxite, which occur chiefly in Arkansas and less extensively in Georgia, Alabama, and Mississippi, supplied only: about 30 ,percent of the ore required for aluminum-metal production and approximately 40 percent of alumina for all purposes. Enemy activities during the war seriously interfered with shipment of bauxite from the normal peacetime source in Surinam, Netherlands Guiana, South America, and focused attention on the necessity for increasing production from known domestic deposits. Even in peacetime, the production of aluminum ore in the United States could not satisfy requirements. Field drilling and exploration by Bureau of Mines engineers resulted in the discovery of important tonnages of high-grade bauxite suitable for treatment by the conventional Bayer process, Although an ore containing approximately 55 percent Al2O3 and only 2 to 4 percent SiO2 is preferable, it was necessary to use ores containing up to 8 or 10 percent SiO2. Because of the lower recoveries of aluminum with increased silica content, the Reconstruction Finance Corporation, through the Metals Reserve Company, established a base price of $4 for a 50-percent Al2O3 ore, containing 13-percent silica, with a premium or penalty of 14 cents for each percent of Al2O3 over or under 50; each percent of SiO2 under 13 was awarded a 20-cent premium, and each percent over 13 suffered a penalty of 43 cents; all prices were on the basis of 1 long ton of ore, dry basis.

Jan 1, 1949

By D. S. Burgess

An investigation of the hazard of spillage of liquefied natural gas (LNG) onto water is described. About 2,000 gallons of LNG were consumed in various tests. The initial vaporization rate of LNG following spillage was found to be 0.037 lb/ft2 sec; when the spill was confined, this vaporization rate was moderated after about 20 seconds by the growth of an ice layer on the water surface; when the spill was unconfined, a coherent ice floe was not observed and the vaporization rate was essentially time independent. The maximum diameter (in feet) of the spreading LNG pool was found to be given by 6.25 Wo 1/3, where Wo is the weight of LNG in pounds, Downwind of a natural gas source, time-averaged methane concentrations were given in good approximation by standard air pollution equations. However, peak concentrations were as much as twentyfold higher than average, adding an additional factor to the assessment of hazard. The effect of layering by the cold vaporized natural gas was similar to the effect of a temperature inversion on normal gases in the atmosphere. Small-scale explosions were observed on pouring LNG onto a water surface; no single explanation seems pertinent to all of the incidents observed.

Jan 1, 1970