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By Neil B. Young

Carbonate minerals constitute a major fraction of the oil shale in Colorado's Green River Formation. Quantification of carbonate minerals is important for the characterization of oil shale, particularly because of their thermal activity in production of oil from shale. The carbonate minerals found in this oil shale are nahcolite (NaHCO3), dawsonite [NaA1(OH)2CO3], dolomite [(Mg1-xFx)Ca(CO3)2], calcite (CaCO3), and ferroan [(Mg1-xFex)CO3]. Although carbonate minerals can be removed by acid extraction from the balance of the oil shale, direct determination of carbonate minerals is complicated by the occurrence of the same cations in more than one mineral. A method for assigning the acid-soluble cations to the individual carbonate minerals was developed from two assumptions based on oil shale geochemistry: (1) Calcite and ferroan do not occur together, and (2) the ratio of iron and magnesium is the same in dolomite and ferroan. These assumptions were tested by the Bureau of Mines by applying the technique for assigning cations to 219 samples from the saline section of the formation. The reported carbonate mineral amounts were compared statistically with X-ray diffraction peak heights, verifying the cation assignment method.

Jan 1, 1975

By E. P. Youngman

The Siamese mining lew, which is cited as "The Sian Mining Act, 2461 (1919)," was enacted February 14, B. E. 2461 (A. D. 1919), corresponding to the ninth year of His Majesty's reign. This act replaces the Sian Mining Act of 1901 and repeals all edicts, decrees, laws, rules, and local customs relating to mining the terms of which are inconsistent with the new law. It shall in- clude all subsequent alterations or additions, as well as all rules issued by the Minister (of Land and Agriculture) already in force or to be brought into force publication in the Government Gazette to be deemed sufficient notice of any modifications or alterations. (Art. 1, 2, 5, 83, and 85.) Legislation passed recently amending certain provisions of the mining law for the purpose of controlling the sale of minerals is the mining amendment act, B. E. 2474, given August 21, 1931 (7th year of the present reign), which repeals provisions of the mining act, B. 3. 2461, and also all rules and regula- tions relating to mining that are inconsistent with the amending ect. Under article 25 of the mining amendment act, B. E. 2474, ministeriel regulations (of the Minister of Agriculture) were issued August 21, 1931. Further recent legislation, brought about by the agreement of the Siamese Government to become a party to the international tin restriction scheme (inter- national tin pool), is the tin and tin ore restriction act (Siam), B. E. 2474, which came into force on September 1, 1921, its purpose being to suspend the

Mar 1, 1933

By L. C. IlsLey

Cooperation between the United States Bureau of Mines and the Safety in Mines Research Board of Great Britain, continuous since 1924, has made possible this and other papers on safety subjects. Grateful acknowledgment is made to representatives of the Safety in Mines Research Board of the Mines Department for their assistance in arranging visits to several mine-safety stations, and to F. H. Wynne, Deputy Chief Inspector of Mines, Great Britain, for arranging visits to mines in Great Britain, Belgium, France, and Germany. During the summer of 1927 the writer had the privilege of visiting the mine-safety testing stations in Great Britain, Belgium, Germany, and France, in the order named. All of these countries have large coal mines, many of which are rated as gassy. Therefore, when the installation of electrical equipment is contemplated, each of these countries is confronted with the same safety problem as in the United States - the development of electrical equipment that will not ignite gassy mine atmospheres, should such atmospheres through neglect or accident surround the equipment. The means used by those countries in safeguarding gassy mines should therefore be of general interest to safety engineers in American coal mines, and it is proposed to give a brief survey for each of the four countries mentioned. The first of these surveys will cover conditions in Great Britain.

Jan 1, 1929

By Jan M. Mutmansky

"When, in 1973, a limit was placed on the amount of dust in the coal mine atmosphere, restricting the average exposure of a coal miner to 2 milligrams of dust per cubic meter of air (mg/m'), skeptics in the United States and abroad Said the standard could never be achieved. They cited much more lenient standards already established in other countries and refused to believe that the United States could meet the world's most stringent requirements in mines where dust had never before been regulated. Yet 10 years later the goal had largely been achieved and miners were working underground in a cleaner atmosphere than ever before. It was a major achievement and a big stride in what had become a war on coal workers' pneumoconiosis (CWP), the black lung disease prevalent among miners in underground coal mines.Although the health hazards caused by working in a dust-filled mine atmosphere have long been recognized, the problem became particularly acute in this century with the mechanization and increased productivity of underground coal mining. The United States was much slower than some other countries to address the problem of respirable diseases among miners. While dust levels in South African gold mines were first regulated in 1912, in the United States it was only when 476 workers died of silicosis while blasting a tunnel through a mountain near Gauley Bridge, West Virginia in the 1930s that widespread public attention became focused on the plight of workers in dust-filled environments. Another 30 years passed before regulation of dust finally became law in the Coal Mine Health and Safety Act of 1969.With a stringent new standard imposed in all underground coal mines, the industry was faced With the daunting problem of reducing levels of airborne dust from perhaps 6.5 mg/m' to 2 mg/m', in an inherently dusty operation carried out in the close confines of underground passageways. Most of the coal dust is made by the cutting operation in which the continuous miner or longwall machine can produce several thousand milligrams of respirable dust for each ton of coal mined. Other dusty operations such as drilling holes for roofbolts, loading and unloading coal on shuttle cars, and the operation of conveyor belts contribute to the overall problem.Since the institution of the new dust control standards, a number of strategies have been adopted for reducing the coal dust in the mine atmosphere. These strategies involve engineering and design improvements that help lo prevent the generation of particles, keep particles of dust from becoming airborne, carry dust away from the working area, and isolate the dust from the workers in the mining operation. These procedures have been pursued vigorously by the Bureau of Mines, and many successful methods have been developed to reduce the mass concentration to which the workers are subjected. The mining companies were reluctant at first to confront the problems but after a period of trials and gradual improvement, they joined with others in the fight to reduce the dust concentrations in the working place."

Jan 1, 1990

By R. M. Gammell

"INTRODUCTION The Farmer prospect was examined by W. R. Green, an engineer of the Bureau of Mines, in June 1944. As a result, studies of this property were included in a general preliminary investigation of the Etevens County lead-zinc deposits by the Bureau in 1945. The exploratory work was designed chiefly to supplement the surface examination by determining the nature of the mineralization below the zone of oxidization. The results of the small-scale diamond-drilling program undertaken at the property are presented in the following report.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization our resources to the end that they make the greatest possible contribution to 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 preliminary examinations, performs the actual exploratory work and prepares the filial report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests."

Mar 1, 1947

By W. H. Kerns

The Simon & Coles manganese deposit in Sherman Valley, Bedford County, Pa., was investigated by the Bureau of Mines during the fall of 1942. Two churn-drill holes; 65 and 75 feet deep were bored, and 8 channel samples were taken. Manganese occurs at this property in the form of psilomelane and manganiferous iron as replacement of the red sandy shale of the Much Chunk-formation. Two cars of manganese ore had been shipped by the owners in 1940, of which one averaged 10.9 percent manganese and the other 21.3 percent manganese. One car of hand-sorted manganese ore that averaged-45 percent manganese was shipped in 1942.

Jan 1, 1948

By R. H. Sprute

This report describes Bureau of Mines laboratory test results in electro-kinetic dewatering and consolidation of metal-mine mill tailings from five mines in the Coeur d'Alene, Idaho, district. Classified (coarse) tailings, slimes, and unclassified material were separately tested. Tailings were placed in 0.3 ft3 plexiglass models, and dc potential was applied until dewatering ceased. Time-oriented measurements of water removal, changes in resistivity, and power consumption were recorded during the dewatering process. Moisture content and density of the dewatered material at test end indicated the method to be generally effective for all materials examined, but best results were achieved with well-mixed unclassified tailings.

Jan 1, 1974

By Oliver C. Ralston

Nonmetallic technologic investigations of the U. S. Bureau of Mines are headquartered at experiment stations in three widely separated localities of the United States. During 1936, the Nonmetals Division of the Technologic Branch was formally set up by combining the direction off the work of these three experiment stations under one administration. The New Brunswick (N.J.) station which in the past has been known as the Nonmetallic Minerals Experiment Station, is henceforth to be at College Park, Md., as part of the Eastern Experiment Station, and its principal activities will be related to the nonmetallic resources of the Eastern and New England States.

Jan 1, 1937

By H. R. Babitzke, H. Kato, M. D. Carver

A number of columbium and tantalum alloys were investigated to determine their suitability for use at elevated temperatures . Columbium-vanadium , tantalum-vanadium , and tantalum-hafnium alloys , and also columbium- 10 wt pct titanium alloys modified with additions of 0.1 to 2 mole pct ZrO2 , TiO2 , ZrB₂ , TiB , ZrC, or TiC were prepared and examined . Workability , tensile properties , and oxidation resistance were tested . Of the columbium alloys studied , the columbium- 12 at . pct vanadium exhibited the best properties ; it compared closely with the columbium- 10 at . pct vanadium alloy studied in a previous investigation.

Jan 1, 1964

By J. B. Gayle

Both immediate and long-range economic factors are associated with blending anthrafines to produce metallurgical cokes, and they warrant careful consideration of the technology of carbonization of blends containing significant proportions of inert substances in general and anthrafines in particular. This situation has resulted in numerous publications dealing with various phases of the overall problem, particular emphasis being placed on the effects of inert substances on the yields and quality of cokes produced. Because relatively little attention has been given to the expansion behavior of coal blends containing inert substances, an investigation of this problem was undertaken using the Bureau of Mines sole-heated oven. Since experiments in the sole-heated oven do not measure wall pressures directly, a new method of interpretation of sole-heated oven data, which permits estimates of wall pressures, has been proposed.

Jan 1, 1955

By F. N. Kissell, R. J. Bielicki, J. H. Perkins

A sorption apparatus for measuring the equilibrium sorption isotherm and the rate of diffusion of methane from fine-sized coal was designed and constructed. Preliminary work that used Pittsburgh and Pocahontas No. 3 coal shows that the diffusion coefficient varies with pressure and that the fracture spacing in these two coals is substantially different.

Jan 1, 1972

By W. P. Diamond, B. M. Bench, C. M. McCulloch, Maurice Deul

As part of the Bureau of Mines methane control program, the Pittsburgh coalbed was studied in Washington and Green Counties, Pa., and in Marion and Monongalia Counties, W. Va., where this coalbed is now being mined at its greatest depth. The coalbed thickness appeared to be structurally controlled; the bed was generally thinner near the axes of anticlines and thicker near the axes of synclines. The overburden isopach shows a similar relationship. Most of the clay veins in coal occur in the synclinal troughs, generally under sandstone roof. Cleat orientations measured in 18 underground mines showed that face cleats are perpendicular to the axial trends of the folds, and the butt cleats are parallel to the axial trends, indicating structural control of the cleat. Measurement and analysis of surface joint orientations provide a method for predicting the cleat orientations of the coalbed, but linears measured from infrared photographs and photoindex sheets helped only to determine regional trends. The results of these investigations provide a geologic framework for rational planning for underground mine development to use the best available technology to cope with methane emissions, coalbed discontinuities, and related ground support problems.

Jan 1, 1975

By J. A. Eisele, D. J. Bauer, D. E. Shanks

As part of its effort to produce cell - grade alumina from clay , the Bureau of Mines investigated the hydrogen chloride gas - sparging crystallization of aluminum chloride hexahydrate ( ACH ) from aluminum chloride liquor , to provide information for optimizing the crystallization operation . Four parameters important in controlling the crystallization of the aluminum chloride hexahydrate and the concentration of impurities , particularly phosphorus and magnesium , in ACH crystals are ( 1 ) aluminum chloride concentration in the feed solution to crystallization , ( 2 ) hydrogen chloride gas flow rate , ( 3 ) temperature , and ( 4 ) concentration of phosphorus and magnesium also in the feed solution . Parameters 1 , 2 , and 3 affect crystal formation . The combined effects are very important because the phosphorus and magnesium concentrate in the crystals during the early stages of crystal growth . Aluminum chloride hexahydrate of cell -grade purity was crystallized from saturated aluminum chloride solutions containing less than 0.003 wt - pct P205 and 0.010 wt - pct Mg0 . Crystallization temperatures less than 60° C decreased crystal purity .

Jan 1, 1965

By Raymond W. Hiteshue, Sam Friedman, Robert Madden

Experiments were made in a semicontinuous unit to provide engineering data for designing experimental continuous systems . These systems would be used to study the hydrogasification of hvab coal and char (from lowtemperature carbonization ) to high - Btu gas . In experiments at 800 ° C and with a coal residence time of several seconds , yields of hydrocarbon gases increased from about 2,000 scf / ton of maf coal at 250 psig to 7,000 scf at 1,000 psig . With 15 minutes residence time , yields increased from 8,000 scf/ton of maf coal at 250 psig to 17,500 cubic feet at 1,000 psig . In all cases , small quantities of heavy oils were produced along with the gaseous hydrocarbons . Production of oils could be minimized with a corresponding increase in gaseous hydrocarbons by increasing the retention time of the volatiles within the hot zone . Yields of gaseous hydrocarbons from char were slightly greater than from coal under similar conditions . Although the hydrogasification reaction is very pressure dependent , substantial quantities of coal (40 to 60 percent ) could be reacted to gaseous hydrocarbons at pressures as low as 50 psig provided reaction temperatures were increased to 1,200 ° C. It was also demonstrated that a hvab coal could be hydrogasified continuously without incurring agglomeration . This was achieved by dispersing coal in a relatively large reactor with concurrent flow of hydrogen . At 1,000 psig and 800 ° C , it was possible to react about 35 percent of the coal and to produce a gas containing up to 52 percent methane .

Jan 1, 1964

By Joseph Chalmers

[Stimulative methods of production, whereby the total recovery of oil from natural reservoirs is increased, have come into considerable prominence during the past 15 years. In many oil-producing areas properties considered ready for abandonment by ordinary producing methods have responded to some form of stimulation, and their economic lives have been extended. The stimulative method having widest application is the injection of air or gas into the reservoir formations through selected input wells and is commonly referred to as the ?gas drive." As a result of the many successful "gas-drive" operations operators are depending more and more upon this method for increasing the ulti¬mate recovery of oil from their properties. A number of factors influence the efficiency of different gases as propulsive agents in recovering oil from sands. Gases of high density and viscosity shrew a tendency toward a slightly higher efficiency than those of lower density and viscosity. The solubility of the gas in the oil also affects the efficiency of oil recovery. Not only does dissolved gas decrease the viscosity of the oil, but dissolved gas that expands from solution in the oil tends to increase the effectiveness of a "gas drive." Interfacial tension between the oil and the gas and its effect upon the recovery of oil by gas injection are factors of which little is known. Dr. A. G. Loomis5 expressed the opinion that interfacial tension probably plays a minor role in the recovery of oil, except under conditions that produce a gas-oil foam. In connection with the above physical properties that influence the action of a pressure medium, control of the injected volume of the pressure medium is perhaps the major factor. The rate ofg;as injection determines to a great extent the amount of slippage and the resulting efficiency of the operation. The importance of volume control is realized when one considers that frequently it is the only factor that is under complete control of the operator.]

Jan 1, 1930

By Jack R. Woodyard

Scientists at the U.S. Bureau of Mines are studying iron aluminides as possible substitutes for stainless steels to reduce the Nation's dependence on imported strategic and critical materials. In a Bureau investigation on the mechanical properties of Fe-28Al, it was found that the material's machining properties were significantly improved at slow tool and feed speeds. Machining techniques normally used for brittle materials failed or were costly. Further experiments using a 5-in (12.7-cm) mill cutter with carbide inserts, operating dry at minimum machining speeds, produced visually smooth sample surfaces with no tool damage. As a result of these experiments and a review of published data on hydrogen embrittlement of iron aluminide under tension, non-water-based (e.g., sulfur-based) lubricants were chosen for production machining. Four-flute, 3/4-in (19-mm) carbide end mills were used at slow speed under lubrication. This latter procedure reduced tool wear and breakage by a factor of 2. Machined surfaces and specimen cross sections were analyzed by scanning electron microscopy to detect microcracking. Tensile tests gave the expected yield and ultimate strengths, indicating that no degradation by low-speed machining occurred. This study extends this work to show that the alloy can be machined at higher speeds using high-speed steel end mills, and that water-soluble cutting oil is a suitable lubricant and coolant.

Jan 1, 2010

By R. J. Leary

This investigation was conducted to determine the effects of various rare-earth metal addition practices upon the macrostructure and the pattern of sulfur distribution in steel ingots. Heats of plain carbon steel were melted in a 1-ton, basic electric-arc furnace. Melts were treated with mixtures of rare-earth silicides, aluminum, and cryolite either in the furnace before tap or in the ladle after tap to determine the effects of this form of rare-earth treatment upon ingot macrostructure. Steels thus treated with rare earths in the furnace were characteristically free of the gross subsurface nonmetallics which typically result from conventional rare-earth treatments. Steel treated in the ladle showed only a few such nonmetallics, and practical techniques were developed for eliminating most of these. Results showed that furnace deoxidation was controlled by the concentration ratio of rare earths: aluminum. During casting, deoxidation was controlled by the concentration of rare earths. Oxygen contents equivalent to vacuum ladle degassing resulted from air-melt furnace treatments with the rare-earth mixtures described. Rare earths in steel inhibited the onset of equiaxed grain formation during ingot freezing, and also virtually prevented interdendritic segregation of sulfides.

Jan 1, 1968

By Yael Miron

Two recent unplanned detonations occurred during blasting operations in sulfide-bearing ores in a Nevada gold mine. Other premature detonations have also reportedly occurred at other Nevada, California, and Arizona operations within the past few years, with increasing frequency. Unplanned or premature detonations can be extremely hazardous to life and can cause extensive property damage. A miner was injured in one of these occurrences. This report, by the U.S. Bureau of Mines, is intended to acquaint personnel involved in such mining activities with the basic causes for these accidents. These causes include the exothermic oxidation of pyrite (FeS2) and formation of ferrous sulfate (FeS04), the exothermic and energetic reaction of the ferrous sulfate with ammonium nitrate-fuel oil (ANFO)-based explosives, and the associated elevated temperatures that can set off detonators and explosives in the boreholes. Recommendations for safe operation by the Mine Safety and Health Administration, the Bureau, and the mine involved with the recent incidents include monitoring temperatures in the blast holes, analyzing for sulfate and ferrous ions, and limiting the time between loading and firing in accordance with conditions in the blast holes. Other procedures for safe operations should fit specific conditions in, the mines.

Jan 1, 1992

By J. P. Hansen

The Bureau of Mines has investigated the S02 leaching of MgO from high-MgO-bearing Florida phosphate concentrates. The S02 was effective in leaching some of the MgO from three phosphate concentrates; flow rate of the S02 and leach time were major factors in determining the amount of MgO leached. Calcining the samples, then grinding to minus 200 mesh, and elevating the leach temperature gave only small increases in the amount of MgO leached. The research also showed that some of the MgO was so intimately associated with the phosphate mineral that it could not be removed by S02 leaching. This amounted to about 0.6, 0.7, and 1.0 pct MgO in three leached residues. The calculated heads for the three concentrate samples averaged 1.4, 1.1, and 1.5 pct MgO, respectively, before leaching.

Jan 1, 1985

By H. B. Brunot

The United States Bureau of Mines under provisions of Schedule 2C4 issues approvals covering complete operating units such as loading machines, room hoists, and storage-battery locomotives. Certain manufacturers design and build entire machines. Other manufacturers purchase a part or all of the electrical accessories from manufacturers of electrical equipment and make up permissible units by assembling them. Before the assembler purchases electrical accessories for use in such contemplated units he may require certain information from the accessory manufacturer as to whether the particular accessories are suitable for assembly in his proposed permissible outfit. To aid accessory manufacturers in marketing their product, a provision was incorporated in Schedule 20 whereby tests might be made on individual accessories and reports rendered as to the suitability of a given accessory for use in permissible assemblies.

Jan 1, 1935