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By J. Bruce Clemmer

[Gypsum is one of the most important nonmetallic c minerals, as is indicated by the fact that the United States consumed approximately 3,500,000 tons of natural and calcined gypsum in 1937. The building trades were the largest users required 2,520,000 tons of calcine for production of plaster, wall board, tiles, block, and various other insulating and building materials. The glass and ceramic industries and other manufacturers required an additional 126,000 tons. The balance was used in the uncalcined condition as retarder in Portland cement and or agricultural purposes.]

Jan 1, 1941

By C. C. Clark

This report presents the results of tests conducted by the U.S. Bureau of Mines to determine the transport characteristics of highly concentrated paste backfill mixes made from dewatered total mine tailings. The slurry concentrations of the mixes were all above 78 pct by weight with slumps ranging from 6.4 to 16.5 cm (2.5 to 6.5 in). Laboratory material property tests and full-scale pumping tests were conducted using pipe diameters of 102, 128, and 154 mm (4, 5, and 6 in) and a positive-displacement pump. The results indicated that the tested backfill mixes can be successfully transported as a stiff paste and identified the influence of and the interaction among the various mix and system variables.

Jan 1, 2010

Alabama ranked 19th in the Nation in nonfuel mineral value1 in 1994, down from 18th in 1993, according to the U.S. Bureau of Mines. The estimated value for 1994 was $576 million, a 2.5% increase over that of 1993. This followed a 3.5% increase in 1993 over that of 1992. The State accounted for a little less than 2% of the U.S. total. Nonfuel mineral production in Alabama consisted entirely of industrial minerals; no metals were mined in the State. Bauxite materials mined in the State are a natural mixture of bauxitic clay and bauxite having very low iron oxide content and are primarily used to make refractory (high temperature resistant) products, rather than in the production of primary aluminum. In descending order of dollar value, the top four mineral commodities produced in Alabama were crushed stone, portland cement, lime, and construction sand and gravel. These commodities accounted for almost 88 % of the State's total non fuel mineral value, while crushed stone and portland cement together represented almost 65 % of the total. In estimated mineral production for 1994, Alabama remained first in common clays and first of only two States that produced bauxite; third in lime, kaolin clays, and fire clays; seventh in portland cement and salt; and was one of the top seven States that produce bentonite clays. The State dropped from third to fifth in masonry cement. Production of talc and pyrophyllite resumed in 1994. Compared with 1993, the value of crushed stone, lime, construction sand and gravel, common clays, kaolin clays, fire clays, bauxite, and talc and pyrophyllite increased. Decreases occurred in portland cement, masonry cement, industrial sand and gravel, and dimension stone.

Jan 1, 1995

By H. H. Schrenk

One phase of Bureau of Mines work in health and safety is promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To insure that such devices will be. available, the Bureau has established schedules of minimum requirements for oxygen breathing apparatus,3/ gas masks,/ supplied-air respirators (hose masks, air-line, respirators, and abrasive blasting helmets, hoods, or masks),5/ and dispersoid (dust, fume, and mist)

Jan 1, 1943

By Lindsly. Ben E.

"The recovery or partial recovery of the oil remaining in oil sands after the usual methods of production have become unprofitable is perhaps the greatest problem in the petroleum industry today. The amount of this oil remaining in the sand is variously estimated by those familiar with the subject to be 25 to 90 per cent of the original content.2Lewis3 states, ""The estimate of 80 to 90 per cent of the oil left underground does not seem incredible.""It is estimated by the writer that approximately 91 per cent of the oil originally held in the Elliott pool, was still in the formation on January 1, 1924, and that it would take at least 12 years, at the 1923 rate of production, to further reduce this quantity by one per cent of the original content.The progress made in the oil industry during the past few years relative to the prevention of evaporation losses; to improvement in cracking processes, whereby the gasoline yield from many crudes has been doubled and trebled; to the increased recovery of gasoline from natural gas; and many other developments, remarkable as they are, can be applied only to that comparatively small portion of petroleum products which are raised to the surface. A device or process which would cut development costs to one-half would probably result in a much smaller profit to the oil industry, than the profit derived from an additional 10 per cent recovery of the total amount of oil in a pool. Various methods have been used and many others proposed, for the increase of oil recovery from normally depleted sands.In France, oil sands are being mined by means of shafts and galleries. In other places, notably the Bradford, Pennsylvania field, the yield has been increased by means of water flooding, wherein water is introduced into the sand to displace oil, and drive it to producing wells."

Oct 1, 1926

"For a good many years the Bureau of Mines and various state mining experi¬ment stations have endeavored to develop some method of utilizing the immense deposits of lignite in the United States. Work in relent year has indicated that the best method of this is to drive off the moisture and most of the volatile water from the lignite in some form of carbonizing apparatus leaving a residue high in fixed carbon and low in moisture and volatile matter, which by briquetting can be made into a high-grade fuel. The earlier forms of carbonizing equipment tried were complicated, costly to build and keep in repair, and could not be operated intermittently without being seriously damaged. During the year 1922, however the Bureau of Mines devised a very simple carbonizing oven which produces a uniformly well carbonized product. This oven is essentially a vertical shaft with means for supplying raw lignite at the top and discharging the carbonized limited at the lower end. Air in regulated amount is admitted to the shaft at two horizons, and a zone of combustion maintained through which the column of lignite passes. The lignite is thus carbonized by construction of its contained matter and a small proportion of its fixed carbon, leaving most of the fixed carbon in the carbonized product or ""char"". The degree of carbonization can be closely controlled by varying the volume of air supplied to the oven and the rate of travel of the charre down the shaft.The ""lignite char"" produced is a soft material resembling charcoal more than coal or coke, but somewhat harder than charcoal. A typical analysis is shown in the table headed ""Fuels,"" further on in this papers."

Feb 1, 1924

By A. Sainato, S. J. Schatzel, D. M. Hyman, J. C. LaScola

The Bureau of Mines determined the gas contents of 135 oil shale samples obtained from approximately 630 ft of core drilling. Drilling was done within a projected mining zone of the Cathedral Sluffs Mine, located in the Piceance Basin of western Colorado. Methane contents were determined by the modified direct method, which can measure the volumes of several gases released from or reacted with mine rock without destructive sample treatment. Over the duration of the test, nitrogen was largely unreactive, CO2 increased slightly, oxygen decreased markedly, and methane increased more than the total increase of all contained gases. The gas volumes were normalized per unit sample mass and are given in cubic centimeters per gram. Common time irzdices for test duration of 3, 40, and 125 days were used to compare methane desorption among samples. The means of the sample populations for these indices were 0.0316, 0.114, and 0.195 cm3/g, respectively. These quantities are lower than those reported in a Bureau emissions study at the Horse Draw Mine in the Piceance Basin. Oil shale samples that were gas enriched beyond the mean methane contents frequently contained bitumens and pyrite.

Jan 1, 1987

By Sarkis G. Ampian

Published optical microscopic and X- ray diffraction characteristics of the following compounds are critically evaluated and compared with Bureau of Mines data : Tricalcium aluminate , calcium monoa luminate , dodecacalcium heptaluminate , dicalcium silicate , tricalcium silicate , and sodium aluminate . A recommended set of definitive optical and X- ray diffraction characteristics is presented . These values are used to identify products of the lime soda sinter process for production of alumina . Polymorphism of gamma- , beta- , and alpha prime - dicalcium silicate is reexamined , and new data are presented on polymorphism of tricalcium silicate and sodium aluminate by high- temperature X- ray diffractometry . Polymorphism is not observed for tricalcium aluminate , calcium monoaluminate , and dodecacalcium heptaluminate . Bureau of Mines data indicating a stoichiometry of 12Ca0.7A10 for the phase 5Ca0.3A1 0₂ are discussed . A critical review of the literature concerning calcium dia luminate and sodium undecaluminate ( 8 -A10 ) is also included .

Jan 1, 1964

By Harmon E. Keyes

Many organizations, including the Bureau of Mines, have made intensive studies of the application of leaching methods to relatively small low-grade disseminated deposits of copper ores, containing both oxide and sulphide minerals. One of the principal difficulties has been to obtain a solvent that could be made at a low cost and would effectively dissolve the copper minerals. Another drawback has been the high initial cost of a plant and the refined type of mechanism ordinarily required by standard practice for carrying out the leaching cycle. The Bureau of Mines has attempted to develop a cheap and efficient solvent that would especially meet the requirements of smaller plants. (See Bibliography.) It has been known that dilute ferric sulphate-sulphuric acid solution is an excellent solvent for most copper minerals, such as chalcocite, bornite, and oxidized forms, but not for chalcopyrite and certain silicates. A method of producing this solution from sulphurous products and waste liquors was developed by the bureau and tried successfully on a test-plant scale at the Southwest Experiment Station in cooperation with the department of mining and metallurgy, University of Arizona, Tucson, Ariz. However, this work did not involve the actual leaching of ores with the solutions thus produced or the cyclic use of the iron solutions in the regenerator cell. Except for certain laboratory tests, in which known impurities were added, no data were available to show the effect on regeneration if accumulations of impurities were built up in the leaching circuit.

Jan 1, 1930

By Larry Gsellman

This report presents the results of a benefit/cost analysis of the Bureau of Mines' Coal Extraction RCD Program for the period FY 1977 through FY 1982. The analysis is an update of the analysis performed on the Coal Extraction R&D Program for EY 1975 - FY 1980 and presented in a MITRE report, MTR-7225, published in May 1975. Major changes included: new production scenarios and an update of R&D cost estimates.

Jan 1, 1977

By Henry Kreisinger, WALTER T. RAY

General statement.-The briquetting tests conducted by the technologic branch of the United States Geological Survey had their beginning in the testing of coals and lignites at the Louisiana Purchase Exposition, St. Louis, Mo., in 1904. Briquetting tests were made at the fuel-testing plants at St. Louis, Mo., and at Norfolk, Va. Similar tests to be made at the experiment station of the Bureau of Mines at Pittsburg, Pa., form an essential part of investigations looking to the determination of the fuel value of the coals and lignites belonging to or for the use of the United States. The tests have comprised (1) the manufacture of briquets to determine the adaptability of different coals and lignites to the process and the merits of different binding materials; (2) physical tests to establish the fitness of the briquets to withstand weathering, transportation, and handling; and (3) steaming tests to prove the calorific value of the briquets in boilers of different types used by the Government, and, by comparison with the raw coals, the benefits to be derived from briquetting. Details of the tests have been issued in other publications. list of Government publications on fuel testing and briquetting is given at the close of this volume. Tests at Norfolk.-The fuel tests conducted at Norfolk included a detailed investigation of a number of Virginia and West Virginia coals that are bought by the United States Government for the Navy and for use in constructing the Panama Canal, and are extensively used by the merchant marine, manufacturing plants, and railroads. Through a cooperative arrangement with the Navy Department steaming tests of the coals were undertaken to determine the relative merits of the same coal when burned raw or as briquets in marine boilers. Preliminary arrangements were made between Joseph A. Holmes, then expert in charge of the technologic branch of the United States Geological Survey and now director of the Bureau of Mines, and Rear-Admiral Charles W. Rae, Chief Engineer of the United States Navy. The tests were made on board the U. S. torpedo boat Biddle, designated for the purpose, beginning December 6, 1907, and ending January 27, 1908. The coal used in these tests came from the Sewell and Beckley beds in the New River district of West Virginia. With the particular equipment used in the tests both coal and briquets were far. from smokeless; consequently the data of this bulletin are applicable only by analogy to parallel operation with a coal more nearly smokeless, but nevertheless applicable with much reliability. The possibilities of coals of different composition are indicated by the data to be published in a bulletin of the Bureau of Mines, wherein the present authors describe a number of tests in which only a very slight amount of smoke was emitted while burning raw coal from the Pocahontas No.3 bed, West Virginia, and briquets made therefrom at rates of combustion very much higher than any rates used in the torpedo-boat boiler. At a combustion rate of 120 pounds of the Pocahontas briquets per square foot of grate surface there was scarcely any smoke. It was the original intention to make a set of preliminary steaming tests alongside a dock (which tests furnish material for this bulletin) and to finish with a set of running tests at sea; but the running tests were never made, for lack of time and men.

Jan 1, 1911

By John D. Foulkes

An investigation is made into whether commercially available equipment can be used to engineer effective emergency warning systems for underground coal mines. Discussions with members of the Bureau and the Mining Enforcement and Safety Administration established that the preferred system should operate over the existing Pager Phone twisted pair, and broadcast an audio alarm. Applicable equipments such as voice band tone signaling equipment, alarm sounding equipment, mine telephones and complete alarm systems from over thirty manufacturers are listed. Factors affecting the range over which an alarm could be detected in representative mine situations were studied. These included (a) the subjective masking effects of typical background noise found in mines, such as that due to continuous miners (b) the attenuation of sound in mines (using both a theoretical and experimental results) and (c) the attention-getting qualities of different sound for miners. Audio alarm systems meeting the requirements can be installed and representative systems are described.

Jan 1, 1977

By A. B. Hooker

Gassy mines require daily inspections with methane detectors to test for the presence of methane. Although in many manes it may be sufficient to know that there is no methane present or that its percentage is below a certain amount, it is desirable and often necessary to determine definitely the percentage of methane at the working faces and in the various air currents. The Bureau of Mines recognizes two general types of portable methane detectors, namely; 1. Methane detectors by which the presence of methane may be detected and its approximate percentage estimated.

Jan 1, 1929

By C. P. Haller, S. J. Aresco, R. F. Abernethy

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash- softening temperature of ash, the free-swelling index, and the hardgrove grind- ability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instruc- tions issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the con- tractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal. The Government purchased approximately 5-1/4 million tons of coal in fiscal year 1953. In connection with these purchases, the Bureau analyzed 11,435 samples. These are published for the use of Government officials and the public. A series of publications has been completed on coal analyses by States, or, where production is small in any one State, by groups of adjacent States. In addition to analytical data showing composition and quality of coals of the States, the publications con- tain brief descriptions of the geological structure of the coal basins, typical mining conditions in the various districts, the principal economic data of the industry, and the relationship of mine or channel samples to delivered and tipple samples. The present publication covers many States but deals only with the analytical data of the coals. Previous publications in this series are: Bulletin 516, Analyses of Tipple and Delivered Samples of Coal (Collected During the Fiscal Years 1948 to 1950 Inclusive); Report of Investigations 4934, Analyses of Tipple and Delivered Samples of Coal (Collected During the Fiscal Year 1951); Report of In- vestigations 4972, Analyses of Tipple and Delivered Samples of Coal (Collected During the Fiscal Year 1952). Following are the Bureau of Mines technical papers published by States, with their numbers: Alabama, 347; Alaska, 682; Arizona, California, Idaho, Nevada, and Oregon, 696; Arkansas, 416; Colorado, 574; Illinois, 641; Indiana, 417; Iowa, 269 and 706; Kansas, 455; Kentucky, 308 and 652; Maryland, 465; Michigan, North Dakota, South Dakota, and Texas, 700; Missouri, 366; Montana, 529; New Mexico, 569; Ohio 344 (and Bulletin 499); Oklahoma, 411; Pennsylvania Bituminous, 590 (Supplement 645); Pennsylvania Anthracite, 659; Tennessee, 356 and 671; Utah, 345; Virginia, 365 and 656; Washington, 491 (Supplement 618); West Virginia, 405 and 626; and Wyoming, 484.

Jan 1, 1955

By E. L. Garton

Bureau of Mines routine crude-oil analyses of 88 samples from 60 fields are presented in this report. Similar analyses from other fields in California have been published in previous reports listed in the appendix, page 52. Yearly production of crude oil in California and the percentage of United States production represented by California production for 1948-54 are given in table 1. [ ] Analyses in this report are of samples from the fields listed in table 2, with production data for 1953, cumulative production through 1953, and year of discovery of each field. Information regarding the source and general characteristics of the samples is included in table 3 with a summary of analytical and computed data.

Jan 1, 1956

By Edward E. Johnson

The principal purpose of this study was the development of an engineering and economic model of a hypothetical large-scale open pit gold mining operation. The guiding concept in developing the model was the idea that, through study of a number of such models, it would be possible to evaluate a mineral property and to make reasonable estimates of the benefits to be derived from research in mining and metallurgy. The model by use of a computer is able to produce results easily and quickly when cost factors are varied. Cost factors may be varied as a result of assumptions of improved technology or of assumptions of assuming different approaches or methods to accomplish a particular segment of the mining or processing operation. The discounted cash flow rate of return was used to measure the effect of changes in costs or expected revenue. In this study, assumptions based on past processing practices were made in an effort to reduce costs of processing the ore These assumptions were: (1) Eliminating the low-grade cyanide circuit; (2) reducing the quantity of material to be processed by screening after crushing; and (3) using a combination of assumptions (1) and (2). All three assumptions resulted in reduced capital investment and operating cost that caused substantial increases in the rate of return.

Jan 1, 1968

By Robert N. Roby

The Hornsilver lead-zinc property was examined by the Bureau in 1942 and again in 1944. A project was started on the property in April 1946 and completed in January 1947. Silver was first discovered in this district in 1883, and while complete production records are not available, it is known that a substantial tonnage of high-grade silver ore was shipped before 1887. All of the ore was mined from surface or near-surface workings. When the high-grade oxidized ore was exhausted, the district became inactive and remained so until the 1920's. In 1928 and 1929 some activity was shown in the district, but the Hornsilver mine was not reopened until November 1937. Between 1939 and 1946, the mine produced about 16,000 tons of ore of 531 ounces of gold, 283 ounces of silver, over a million pounds of load, and nerdy 2 million pounds of zinc. The property is now controlled by the Era Mining & Development Co., which has acquired the Last Chance and Ella groups of claims, in addition to the Hornsilver mine.

Jan 1, 1948

By C. V. Brennan

This paper, describing the various mining methods and practices at Britannia mines, Britannia Beach, British Columbia, is one of a series covering mining practices, methods, and costs in the mining districts of the United States and Canada. The Britannia property has been operated continuously for 30 years, and in that time many diverse methods have been used in exploiting the various types of orebodies worked. Under normal conditions mining methods include surface gloryholes, shrinkage stoping, shrinkage with powder drifts for primary breaking, horizontal cut-and-fill, horizontal and inclined square-setting, and timbered and open rills, the three latter systems being combined with close filling. The Britannia method of mining, a large-scale retreating shrinkage system usually combined with powder drifts for primary breaking, has been developed and applied here very successfully. Each block of ground as developed is studied as a separate problem, and the mining method, or combination of methods best adapted to the work in hand is applied thereto. Operating at, capacity, the series of mines produces 7,000 tons of ore per day.

Jan 1, 1935

By J. Fletcher Smoak

Consumption of abrasive materials in the United States decreased 23% in value from that of 1981 to $262 million, of which 53% was manufactured abrasive, 39% was industrial diamond (natural and synthetic), and 8% was natural abrasive. Production of natural abrasives, excluding industrial diamond, appeared to be stable when compared with that of 1981. Production of tripoli, a porous siliceous rock, increased slightly after decreasing steadily over the three previous years. The production increase of garnet, an abundant iron-aluminum silicate, was attributed to increased output from one plant that had completed an expansion program in late

Jan 1, 1983

By G. W. Elger

The Bureau of Mines investigated the conversion, at both laboratory and pilot plant scale, of a low-grade ilmenite to chlorination-grade feedstock that could substitute for imported rutile used to produce titanium tetrachloride. The concentrate was derived from the Tahawus, NY, lode deposit of ilmenite-magnetite in rock that contains anorthosite and gabbro. Charges of the ilmenite concentrate, containing 46.6 wt pct Ti02 blended with soda ash, were carbothermically reduced in an electric arc furnace, which separated most of the iron and left a high-titanium slag. However, the slag contained Ca, Mg, and Mn constituents that rendered the material unsuitable for continuous chlorination by causing plugging problems. After being ground and pelletized, the slag was reacted with S02 and air at 7000 to 9000 C, which selectively converted the harmful impurities to soluble compounds that were removed in a subsequent water or dilute HCI leach. In laboratory tests, the combined levels of harmful impurities were decreased from 5 to as low as 0.5 wt pct in leached slags. In pilot plant tests, leached slags sulfated at a rate of 10 lb/h averaged 85.5 wt pct Ti02 with pertinent impurity levels averaging 1.86 wt pct. The leached slag was successfully chlorinated in a laboratory fluidized-bed reactor at 9500 C to extract titanium as TiCI4.

Jan 1, 1986