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By Yael Miron

Coal mines that undergo self-heatings, and specifically mines that sustain both floor heave and self-heatings, would benefit from the use of sealants to minimize air ingress to susceptible areas. The U.S. Bureau of Mines (USBM) evaluated three sealant systems for this purpose, bentonite-water mixtures, silicate gel, and guar gum gel. The guar gum-based gel was the only sealant that possessed the desired properties of elasticity, ease of preparation, adaptability to the mine, and a long life. In addition, since the gel consists mostly of water, it could quench or cool nearby heatings. Optimal formulations were determined in laboratory tests, and then tested in the USBM Safety Research Coal Mine. Two for-mulations resulted in stable gels that lasted for at least 12 months in the mine. Semicontinuous preparation of gel using an eductor was evaluated and appears feasible. Although guar gum gel is expensive, selective use to prevent heatings in specific areas would be cost-effective, both in terms of productivity and enhanced mine safety.

Jan 1, 2010

By John T. Aydelotte, Martin J. Gavin

" Oil shale contains little or no oil as such , but it contains an organic material from which oil may be produced by destructive distillation" . This statement , or others conveying the same meaning, appears in many popular and techni cal articles on oil shale . It is based on the belief that the ordinary solvents of petroleum have but little action on the organic substances contained in oil- yielding shales , although on distillation these same shales may yield upwards of 50 gallons of crude shale oil per ton . A 50 - gallon shale thus yields by distillation 18.73 per cent of its weight as oil ( assuming the specific gravity of the oil to be 0.900 ) , although only a relatively small part of this can be recovered by extraction with such solvents as chloroform , carbon tetrachloride , and the like . In the course of certain experiments designed to determine the solubilities of different shales after they had begun to yield oil by distillation , it was found desirable to determine the quantity dissolved from certain unheated shales by various solvents , at or near the boiling points of these solvents . The method used and results obtained are presented below. These experiments were made in connection with the oil - shale investigations being conducted by the U. S. Bureau of Mines , in cooperation with the States of Colorado and Utah .

Jan 1, 1922

By Arthur L. Crawford, R. E. Head, Glen Burgener, F. E. Thackwell

"INTRODUCTION This report embodies the results of a detailed statistical microscopic examination of the ore and the mill products of the Silver King Coalition Mines Co., Park City, Utah.The study was conducted under the joint auspices of the United States Bureau of mines is cooperation with the University of Utah at Salt Lake City, Utah. The work was done in the cooperative Microscopic Service Laboratory, which was equipped by contributions from the following companies: Utah Copper Co., International Smelting & Refining Co., American Smelting & Refining Co., United States Smelting, Refining & Mining Co., Tintic Standard Mining Co., Silver King Coalition Mines Co., and Park Utah Consolidated Mines Co. The salaries and the other costs involved in operation of the laboratory were met by contributions from certain supporting companies. In addition to the regular personnel of the laboratory the Bureau of Mines contributed the part-time services of a microscopist-consultant to direct and assist with the technical work.ACKNOWLEDGEMENTSThe authors acknowledge the courtesies extended by the Silver King Coalition Mines Co., through its general manager, M. J. Dailey, in furnishing the various ores and products on which the study was made, together with general information concerning the problems encountered or recognized in connection with the milling of the Silver King ore."

Jun 1, 1934

By Thys B. Johnson

The mine system analysis and evaluation study presented in this report was part of the U. S. Bureau of Nines' Tertiary channel project conducted under the Heavy Metals program. The Badger Hill pit, located on the west end of the San Juan Ridge area, near Nevada City, California, was the site of the Bureau's field work. The objectives of this study were: (1) Determine potential alternative mining systems for some of the large tertiary channel gold-bearing gravel deposits, and (2) Identify areas of technology where further investigation would be merited because of their potential inclusion in a mining system for such deposits, The study involved the development of a mineralized block inventory, an economic block inventory, determination of optimum ultimate mining limits and a preliminary economic mining system evaluation. Computer programs were developed and utilized for each of the study phases stated above. The sampling program conducted at Badger Hill by the Bureau Delineation Group together with confidential drill hole data provided by the San Juan Gold Co. formed the basic gold values and distribution information from which a deposit model was developed. The deposit was divided into minable block units and net economic values were assigned to each block for various configurations of both open-pit and underground mining methods based on cost and performance data provided by the various Bureau of Mines Research Centers. A number of controllable variables such as: (1) Mining method (open-pit and underground), (2) depth of mining cut, (3) production rate and (4) equipment type and capacity were evaluated. The prime measures of effectiveness on which the mining systems where judged were discounted cash flow rate of return and maximum utilization of natural resources. The analysis showed that underground mining of the Six-Mile Tertiary channel gold-bearing gravel deposit under consideration was uneconomical and did not permit maximum recovery of the resources within the channel. It was also apparent that mining the Six-Mile Deposit for gold alone is uneconomical or at best marginal at a gold price less than $80 per ounce. The analysis showed that the potential for an economic mining operation within the Six-Mile Deposit exists when the gravel resources of the channel are considered together with the gold. It was determined that the highest rate of return would be realized with a 20-year open-pit mining operation yielding 745,000 ounces of -gold and 55 million cubic yards of usable gravel.

Jan 1, 2012

By K. K. Kelley

This report contains heat-content values for hexagonal crystalline germanium dioxide between 298.15° and 1,350° K., and for germanium dioxide glass between 298.15° and 1,800° K. experimentally determined by the Federal Bureau of Mines. No similar data for these substances are to be found in the literature. The heat-content and corresponding entropy-increment data are presented both in tabular form and by equations. Free energy of formation values are estimated for germanium dioxide glass at 298.15° and 1,800° K.

Jan 1, 1961

By Guy A. Johnson

The Bureau of Mines, through research and development contracts with the FMC Corp., has developed and tested two automatic fire sensing and suppression systems for large haulage vehicles. This work was undertaken to enhance driver safety, to lessen substantial property damage from fires on large trucks, and to increase the vehicle operator's productivity. One automatic truck fire protection system protects both the engine compartment and brake rid areas, while the second system is used in the engine compartment and fuel tank area. Both systems have redundant fire-sensing capabilities and manual override controls. Upon sensing flames and/or heat, the systems suppress the fire with pressurized, E-C class dry chemical. Both fire protection systems are flexible in design and can be modified for use on other mobile minim' equipment. Prototypes of both systems have been subjected to long-term, in-mine validation testing and actual Eire tests on 100-ton-capacity trucks at the Puma mine near Tucson, Ariz., and the Erie mine at Hoyt Lakes, Minn. During the 4-month endurance test of the first system at Pima, an accidental flash fire occurred in the test truck while it was working in the pit. The system successfully sensed and automatically extinguished the fire with no injury to the driver and little damage to the truck.

Jan 1, 1975

By H. H. Schrenk

[A colorimetric method5/ for the determination of benzene in amounts as low as 0.001 mg has been developed recently at the U.S. Bureau of Mines Pittsburgh Experiment Station by the authors, with the assistance of chemical personnel fro a the Allegheny County (Pa.) Relief Works Division. The method is based on the direct nitration of either liquid - or gas - phase benzene, followed by neutralization, extraction with butanone, and final treatment with sodium hydroxide which produces a violet color. The color is matched with color standards of known values. Although the method is adaptable to many conditions the primary objective was a procedure that would be suitable for hygienic investigations. The development worth included a study of possible interference by chemicals that be present in those situations in which the method. would be employed. In this study it was found that a specimen of hexane prepared by the Gulf Research Laboratory, Pittsburgh, by fractionation of West Virginia natural gas gave positive result for benzene, whereas a specimen of pentane prepared in the same manner showed only a trace, and specimens of n -heptane and octane (2,2,4 trimethylpentane) supplied by Eastman Kodak Co. save a negative result. According to information obtained from the Eastman Kodak Co. the latter two compounds were highly purified, the n-heptene being prepared from line and the octane synthesized in the laboratory. On nitration of a larger amount of tae natural hexane a visible quantity, of needlelike crystals which resembled those of m-dinitrobenzene was obtained. The hexane from this nitration was recovered by distillation and again nitrated, but no crystals or colorimetric indication of benzene was obtained. This imitated that the specimen of natural hexane contained a substance which at least had the chemical behavior of benzene.]

Jan 1, 1935

By L. D. Tracy

Many bituminous coal-mining companies have inaugurated extensive safety programs, but the failure to have approved or permissible equipment or safe practice in only one part of a mine has resulted in disaster. The necessity of using only equipment bearing the U. S. Bureau of Mines approval plate is emphasized by the fact that many accidents are the direct result of carelessness on the part of trusted employees using non-permissible equipment. A concrete example is found in the case of an explosion on October 26, 1926, in a mine in the Pittsburgh district, Pennsylvania. Story of the Explosion At about 10 o'clock on the night of the explosion an examination was made in No. 2 butt left and parallel off No. 14 north, and was found to be clear of dangerous accumulations of gas. (See figure). Several hours later a crew of two men brought a self-propelling rock-dusting machine within 50 feet of the face of No. 2 butt parallel before they examined for gas. The machine operator found an accumulation of explosive gas about 13 inches from the roof. He began to wave his arms thoroughly mixing the gas and air. Undoubtedly a highly explosive mixture was created, and as the men attempted to run the machine back to fresh air as explosion occurred.

Jan 1, 1927

By R. V. Ramani, A. S. C. Owili-eger

List of Numbers

Jan 1, 1974

By W. G. Bradley

THIS PAPER describing the quarrying, mining, and crushing of gypsum at the Blue Diamond mine, 11 miles from Arden, Nev., on the Union Pacific Railway, is one of a series on gypsum mining being prepared for and published by the Bureau of Mines. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total production costs might in some instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1932

By James V. Kelly

During the winter of 1946 and the spring of 1947, the Bureau of Mines conducted an investigation and drilling program in the vicinity of the village of Fairplay, Wis. Fifteen diamond drill holes totaling 2,457.6 feet of bore were completed. This work was part of a general study of the zinc-producing area of southwestern Wisconsin and had the particular purpose of investigating a structural trend, determined by the Federal Geological Survey, in an area some distance from known ore bodies or active mines.

Jan 1, 1948

By John A. Organiscak

Enclosed cabs are a primary means of reducing equipment operators? silica dust exposure at surface mines. The National Institute of Occupational Safety and Health recently performed a laboratory study to evaluate which factors on an enclosed-cab filtration system are most significant. The various factors evaluated were intake filter efficiency, intake air leakage, intake filter loading, wind infiltration, use of a recirculation filter, and the use of an intake pressurization fan. The result of this laboratory testing has shown that the two most important factors for an effective filtration system on an enclosed cab were the efficiency of the intake filter and the use of a recirculation filter. A higher-efficiency intake filter considerably increased the quality of the intake air that was delivered into the enclosed cab. It also was determined that air leakage around the intake filter notice-ably reduced its air cleaning effectiveness. The second key factor is the use of a recirculation filter, which was shown to improve the air quality in the enclosed cab by six to 12.7 times more than the intake filter alone. The reason for the significant improvement was that the cab air was constantly drawn through the recirculation filter, thus continually filtering the dust out of the air.

Jan 1, 2010

By Fred D. DeVaney

The Mesabi iron district of Minnesota has a potential production of over 50 million tons of iron ore annually. The large shipments of ore each year are gradually depleting the reserves, and if the present rate of production is to be maintained there must be a growth in the present available ore supply. Growth is a natural course. The growth of a city may be affected by the addition of city blocks or by the improvement of utilities necessary for its betterment. These may go on in the order named or concurrently. The city-block type of growth of the Mesabi has been tremendous, and the "betterment" type has followed in due course. Probably the former has reached its limit, and if so, more time will be allotted to the latter. It is not the intent of this paper to present either a eulogy of the wonderful mining methods or a history of the milling, but it is pertinent to say that if the lean-ore area continues to produce, the continuance will be more the result of further improvement of milling methods now well under way than of extension, of boundaries by the city block plan of growth. In an examination of the western end of the Mesabi district one finds sludge basins containing millions of tens of millable ore rejected by washing plants which were built for economy in operating cost and with little thought of conservation, and rich tailings piles of jigging plant rejects. In addition, there is an appreciable tonnage of bowl rake products so low-grade that it requires mixing with the best ore of the district to make it merchantable.

Jan 1, 1932

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Haiti has been prepared from the best available information in Washington, but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Sep 1, 1930

By Michael J. Sapko, Eric S. Weiss, Kenneth L. Cashdollar

A fundamental safety research area for the National Institute for Occupational Safety and Health (NIOSH) is to eliminate the occurrence of coal mine explosions or to mitigate their effects. One approach is to develop and evaluate new and innovative seal designs that provide increased explosion protection for mining personnel. The NIOSH Pittsburgh Research Laboratory (PRL) cooperated with HeiTech Corp. of Virginia, Barclay Mowlem Construction Ltd. of Queensland, Australia, and the Mine Safety and Health Administration (MSHA) in three separate research programs to evaluate the strength characteristics and air leakage resistance of numerous innovative seal designs and ventilation control structures for use in underground coal mines. For each phase of the program, various full-scale seals, stoppings, and an overcast design were constructed in PRL's Lake Lynn Experimental Mine near Fairchance, Fayette County, PA. The seals and stoppings were built in crosscuts and were subjected to explosions to evaluate their strengths. Four pumpable cementitious seal designs ranging in thickness from 610 to 915 mm (24 to 36 in) were evaluated in the first cost-reimbursable research program with HeiTech Corp. A simple wooden framework with brattice liner was used as a form to contain the cementitious slurry during the curing period. As the seal designs decreased in thickness, higher compressive strength cementitious grout was used. All four seals withstood an explosion pressure pulse of at least 138 kPa (20 psi) while maintaining acceptable air leakage resistance. In the second cost-reimbursable research program with Barclay Mowlem Construction Ltd. of Australia, several innovative seal and stopping designs and an overcast design were evaluated. Each of the seal designs and the overcast side and wing walls used one or more air-inflated vinyl bladder assemblies anchored to the mine roof and hitched into the ribs and floor. The air within these bladders was displaced with a high-strength cementitious grout. The overcast deck consisted of a 200-mm ('7.8-in) thick reinforced cementitious slab. This was the first time that an overcast structure had been explosion tested under full-scale conditions. All of the seals, stoppings, and overcast design passed the air leakage tests before being subjected to a series of explosions with static pressure pulses ranging from 14 to 475 kPa (2 tab 69 psi). Instrumentation measured seal and overcast wall displacement as a function of time. The 450-mm (1 7.7-in) thick seal in the 2.8-m(9-ft) high third crosscut withstood an explosion pressure of 170 kPa (25 psi), but failed during a later test, which generated a peak static pressure of 475 kPa (69 psi) at the seal location. A similar 450-mm-thick seal in the 2.1-m (7-ft) high second crosscut withstood three explosion tests, which generated peak static pressures of 195, 205, and 370 kPa (28, 30, and 54 psi) at the seal location. Next, the overcast design withstood four explosions, which generated static overpressures ranging from 16 to 47 kPa (2.3 to 6.8 psi). A third program at the request of MSHA evaluated the effectiveness of using pressurized grout bags (Packsetter bags) along the mine roof and ribs in lieu of floor and rib hitching for a standard-type solid- concrete-block seal. This program was initiated to address an urlusual geological mining condition encountered when building seals in entries where required rib hitching is not a viable option due to soft friable coal. Results showed that the use of these quick-setting grout-filled Packsetter bags pressurized internally to 300 kPa (44 psi) not only provides a seal that can withstand a 138-kPa static pressure explosion, but also provides a sealing option where rib hitching is not possible.

Jan 1, 2003

By Robin B. McCulloch

No producing mines are in the study area. Sample results indicate the only resources in the study area are low grade phosphate deposits associated with Cuyama Phosphate Mine (fig. 1). Within the study area, are more than 21.4 million tons of inferred subeconomic phosphate rock resources which would be reserves at an 80 percent higher phosphoric acid price; weighted average grade is 4.84 percent phosphorous pentoxide (P205). About 17.6 million tons of similar grade are outside the area to the northwest. The South Cuyama Oil Field, adjacent to the study area (fig. 1), produces petroleum from the Vaqueros Formation which underlies parts of the study area. Oil and gas potential was evaluated by U.S. Geological Survey. INTRODUCTION Location, Size, and Geographic Setting The U.S. Bureau of Mines conducted a mineral survey of the Fox Mountain RARE II area (No. 5120) during the summer of 1981. The area was examined to determine the presence or absence of mineral resources and reserves, and to estimate tonnage and grade where possible.

Jan 1, 1982

By R. V. Ramani, R. Bhaskar

"One of the primary means of control of health hazards from respirable contaminants in mine atmospheres is through design and operation of mines to meet mine health and safety regulations and recommended practices. A U.S. National Academy of Sciences study concluded that for significant progress in coal mine dust control, research should be directed more toward obtaining fundamental understanding of the origin, transport and characteristics of respirable coal mine dust. Theoretical and experimental studies on transport of dust · in mine airways, particularly coordinated efforts to validate theory with practice, are scarce. Some empirical models, developed on the basis of experimental data, are available but these models cannot be applied to new conditions. The purpose of this paper is to present the results of theoretical and experimental studies on the transport and deposition of dust in mine airways. This study is a part of an ongoing research project in the Generic Mineral Technology Center on Respirable Dust.In the paper, the assumptions of the modeling phase of the project and the development of a convectiondiffusion equation for dust transport in mine airways are outlined. The important aspect of the modeling effort is the capture of the deposition phenomenon. The experiments performed under controlled conditions in a typical mine airway, as well as under normal mine operating conditions, are discussed. The comparison of the model predictions with experimental results are made to identify critical areas of agreements and deviations. The implications of the findings and areas for further research and development are presented."

Jan 1, 1990

By J. H. Wiggins

The evaporation of crude oil without doubt causes one of the largest single losses to which the oil is subjected after it is taken from the ground. The few days during which crude oil is stored on the lease before being taken by the pipe line, causes an aggregate loss per year from evaporation estimated at 122,100,000 gallons of gasoline in the Mid-Continent field alone. This has a value, at 22 cents per gallon, of $26,880,000 and represents about 3 per cent of the total gasoline produced in the United States from all fields and all sources. The following table shows this in more detail:

May 1, 1920

By A. J. Forney

A high-Btu gas was made at the Bruceton, Pa., laboratories of the Bureau of Mines to demonstrate the feasibility of using the gas as a nonpolluting fuel for automobiles. The pilot plants at Bruceton were revised to combine the processes of coal gasification, gas purification, and catalytic methanation in one overall system. Tests in the Bureau's test automobiles at Bartlesville, Okla., showed the Synthane gas was less polluting than natural gas.

Jan 1, 1972

By N. S. Dalal, N. Leelarasamee, V. Castranova, K. Van Dyke, V. Vallyathan

"INTRODCICTIONSilicosis is the chronic fibrosing disease of the lungs caused by the inhalation of crystalline silica. However, inhalation of crystalline silica, may induce three distinctly different disease patterns; i.e., chrome silicosis, accelerated silicosis, and acute silicosis. These three disease patterns differ in their pathologic characteristics, clinical symptoms, onset of disease, and mortality. Many studies in the past have focused on the elucidation of mechanisms involved in the development of chrome silicosis. We recently reported that freshly fractured silica has surface properties that could make it more reactive with lung tissue than aged silica, and that this unique reactivity of freshly fractured silica may be involved in the pathogenesis of acute silicosis (Dalal et al., 1986; Vallyathan et al., 1988; Shi et II., 1988). Because freshly fractured silica could contain some moieties in an ""excited state,"" due to the breakage of silicon oxygen bonds, we postulated that the de-excitation of these moieties could produce light which could be monitored by a luminescence measurement technique. In addition, if this ""excited state'' of silica could trigger a greater biologic response by phagocytic cells, this activation could be monitored by a chemiluminescence technique in the presence of appropriate enhancers.This investigation describes for the first time the use of luminescence in the study of freshly fractured silica and its properties. Enhanced biologic reactivity of the freshly fractured silica with alveolar macrophages was monitored by the chemiluminescence technique.MATERIALS AND METHODSNative silica was obtained from the dust bank of the GenericRespirable Dust Technology Center, Pennsylvania State University, State College, PA, and ground for 3~ min in an agate ball mill. It was then sieved through a 20 micron mesh filter and used within 1 O min as fresh silica or stored in glass bottles for aging. X-ray energy spectrometry and X-ray powder diffraction studies on representative samples were made to confirm the mineralogic purity. All the silica samples were found to be 99 % pure with minimal detectable conlamination by metal ions."

Jan 1, 1990