Search Documents

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 H. E. Peterson, W. L. Anderson

"INTRODUCTION The great demand for tungsten incident to the war has led to the exploration of a large number of low-grade tungsten deposits. To properly evaluate the low-grade deposits it is essential to have available a dependable method of analysis applicable to all types of low-grade tungsten ores. Results reported on the tungsten content of the ores have often varied quite widely and have led to confusion. The Bureau of Mines has been requested by Government lending agencies and by companies interested in the production of tungsten to publish a general method for the determination of tungsten in low-grade ores. To meet this need, the Bureau of Mines is herein submitting two methods for analysis that have been proved on a large number of tungsten-bearing ores various types in the Bureau of Mines laboratory in Salt Lake City. Also, a third method was developed that requires no cinchonine and has proved to be applicable on most tungsten ores. The cinchonine method is the generally accepted for analysis of tungsten ores. Very reliable results can be obtained by this method if certain precautions are taken, as outlined in this report."

May 1, 1943

By Raymond O. Dannenberg

The gas-combustion retort developed by the Federal Bureau of Mines at the Rifle Oil Shale Project near Rifle, Colo., is a continuous, gravity-feed retort. The heat required to convert the kerogen in the oil shale to liquid oil is generated by the combustion of product gas and carbonaceous residue remaining on the retorted shale after the kerogen has been converted to oil, gas, and residue. A study of the effects of the process variables on retort operation, product yields, and product properties is important to the successful solution of the problems encountered in the development of a satisfactory process. Statistical methods were used to design the experiments and analyze the effects of the rate of shale throughput, the composition of dilution gas, the height of the shale bed above the air entry, air-gas distributor design, shale size range, and the ratios of the flow rates of the various gas streams entering the retort to the rate of shale throughput.

Jan 1, 1960

By M. H. Kline, T. J. Ballard

"INTRODUCTION The Cranberry magnetite deposits occur in pre-Cambrian granite-gneiss in a belt extending from 3 miles southeast of Cranberry, N. C., to about 6 miles southwest of Magnetic City, Tenn. The belt forms a curve, elongated to the north, approximately 26 miles in length.The Bureau of Mines investigation has been confined to the eastern part of the belt, comprising the area from Fork Mountain, Avery County, N. C., to the Hcupscup Knob prospects in Carter County, Tenn.The deposits were worked at least as early as 1820. The Cranberry Iron & Coal Co. and its successors operated the Cranberry mine intermittently for about 50 years until 1930, when operations were abandoned.The magnetite rock is amenable to concentration. Numerous laboratory tests and pilot-mill operations have proved that a high-iron, and low-phosphorus concentrate can be obtained by fine grinding and magnetic, separation, the quality of the concentrate depending upon the extent of grinding. The principal objectives of the Cranberry project were threefold.The primary consideration for beginning exploration of the deposits was the need for developing additional deposits of high-grade iron ore during the war and for replenishing the war's depletion of iron-ore reserves for the peacetime economy. The emergency did not permit logical sequence bf development, and it was necessary to begin drilling before the geophysical survey was completed. The first drilling was begun at the Cranberry mine; and the holes were located from the geological data, coordinated with the position of the mine workings."

May 1, 1948

By H. B. Brunot

On April 26, 1949, the Bureau first approved a machine designed to replace the cycle of cutting, blasting, and loading coal by a single operation. This machine took the coal directly from the solid face and delivered it to transportation equipment. By January 1, 1955, 30 approvals for designs of machines of this type had been granted by the Bureau. In the main, this paper describes briefly the action of the various designs approved as permissible. In addition, the approval number, the date of approval, the voltage of the power supply, the number and character of the explosion-proof accessory parts, the size of the trailing cable, and the overcurrent protection at the outby end of the trailing cable are given for each design. Since no similar information has been published by the Bureau, it is hoped the material in this paper will be valuable in giving the mining public an organized look at the various machines of this nature that have been approved as permissible by the Bureau.

Jan 1, 1956

By W. W. Adams, T. D. Lawrence

"Despite the manpower shortage and other difficulties of operation in war time, the National Safety Competition of 1943 for the promotion of safety in the mineral industries of the United States was notable for having a larger enrollment of mines and quarries than in any other year except 1941 and 1942 since the yearly safety contests were inaugurated in 1925. The competition was also notable for having a larger number of man-hours represented by the competing companies than in any previous contest except that of 1942. The ratio of accidents and days of disability resulting from accidents to the number of man-hours of work performed was more favorable than in 1942; the accident-frequency rate was lower and therefore better than in 13 of the 19 years during which the annual safety competitions have been conducted, and the accident-severity rate was better than in 16 of the 19 years.The National Safety Competition is a yearly safety contest conducted by the Bureau of Mines, United States Department of the Interior. Companies that win first place in their respective group in the contest are awarded a bronze trophy, ""The Sentinels of Safety,"" which is provided by THE EXPLOSIVES ENGINEER magazine. Competing companies are segregated into six groups: Underground bituminous-coal mines, underground anthracite mines (in Pennsylvania), underground metal mines, underground nonmetallic-mineral mines, open-cut mines (without regard to kind of mineral produced), and open quarries (without regard to kind of stone produced). The bronze trophies are retained by the six winning companies for 1 year and are then transferred to the winners of the succeeding year's contest. On the pedestal of each trophy is engraved the names of the winners of the trophy. With the award of the trophies for 1943, therefore, the pedestal of each trophy bears the names of 19 winners."

Aug 1, 1944

By LeRoy D. Loy

The disposal of excess overburden from surface mining can be accomplished by use of a reclamation technique entitled head-of-hollow or valley fill. This report attempts to assess current valley fill regulations and practices, identifies inherent benefits and deficiencies, and develops concepts to enhance fill technology.

Jan 1, 1978

By S. M. Runke

The pegmatite investigations at the Rapid City, S. Dak., Experiment Station during; the pact 3 years have been primarily a study of recovering beryl from nonlithium-bearing pegmatite rock by continuous-testing methods. Beryl concentrates containing 25 to 88 percent beryl were produced from rock that ranged in beryl content from 0.1 to 2.5 percent. The beryl recovery ranged upward from 70 percent but averaged better than 80 percent. Although promising results have been obtained with flotation methods for upgrading these concentrates to standard specifications, additional work is needed to improve and simplify the procedure. In addition, it was demonstrated that several potentially useful coproducts could also be recovered from pegmatite rock. The principal coproducts were mica, feldspar, and quartz. A heavy-mineral product also was made from pegmatites containing tin, tantalum, and columbium. The recovery if these minerals in products meeting the specifications of the commercial users has been reserved for future study. The investigations also included studies on extraction of beryllium from both high-grade beryl and flotation concentrates of medium beryllium content. The procedure investigated consisted of sintering beryl or beryl flotation concentrates with limestone, acid curing the resulting sinter with sulfuric acid to dissolve the beryllium, and water leaching to extract the beryllium. Over 90 percent of the beryllium was extracted by this procedure. Most of the optimum conditions and quantities of reagents were determined for dissolving the beryllium. As aluminum and iron also were taken into solution by the acid, further research is needed on methods of recovering high-grade beryllium salts from the solutions containing these elements.

Jan 1, 1957

By R. Hogg, Y. Lee, D. E. Rannels

"Lee, Yu-Chen, Richard Hogg, and D. Eugene Rannels. Extracellular matrix synthesis by coal dust-exposed type II epithelial cells. Am. J. Physiol. 267 (Lung Cell. Mol. Physiol. 11): L365–L374, 1994.—Although integrity of the alveolar basement membrane may influence progression of lung injury induced by inhaled particulates, little is known about direct effects of coal dusts on the alveolar epithelium or its extracellu¬lar matrix (ECM). Effects of dust on synthesis of cell and ECM proteins by type II cells (T2P) was thus investigated. Three coal dusts (anthracite no. 867; bituminous no. 1451 and no. 1361) and mine dust MIT-3, of respirable size, were studied as a function of dose and time over 3 days of primary T2P culture. On day 1, 750 µg/ml of 867 were required to increase relative synthesis of ECM proteins (ECM/cell). MIT-3, 1451, and 1361 were without effect. By day 3, 867 or MIT-3 increased ECM/ cell 60-100% at 300 µg/ml; 1451 produced modest, dose-dependent stimulation, whereas 1361 remained without effect. None of the dusts caused significant cytotoxicity. The results show dose- and time-dependent effects of well-characterized coal and mine dusts to modify partitioning of newly synthesized proteins into the ECM and suggest that coal dust exposure may modulate structure or function of the subepithelial basement membrane.basement membrane; cell culture; inorganic dust; lung injury; extracellular matrix deposition; pulmonary epitheliumCHRONIC EXPOSURE to coal dust may be associated with development of pulmonary fibrosis and consequent loss of normal lung function (see Ref. 26 for review). Al¬though the pathways of inorganic dust-induced lung injury are recognized to involve an inflammatory re¬sponse, the underlying pathogenic mechanisms are not understood in detail. Acute and chronic responses to dust exposure involve a variety of interacting cells of the immune system, including macrophages, T cells, and B cells, along with pulmonary fibroblasts. These responses reflect direct effects of the dust particles, as well as indirect effects mediated by soluble factors, including cytokines and eicosanoids (see Ref. 41 for review).Studies of pulmonary macrophages and fibroblasts following silica exposure suggest that dust-induced damage at the airway surface may involve cellular injury through oxidant-mediated pathways. Coal dusts and related inorganic particulates can activate the alveolar macrophage (42) to produce fibronectin (15) and cytokines, such as interleukin-1 or tumor necrosis factor (4) and/or other soluble products which act locally (29) to cause acute cellular injury and to initiate the progression of fibrotic lung damage (16). Type I epithelial cells are typically more susceptible than type II cells to oxidant injury. Type I cell damage and subsequent death leads to denudation of the subepithelial basement membrane (2, 21) and can be associated with leakage of plasma constituents from the pulmonary vasculature into the alveolar compartment (13)."

Dec 1, 1995

By Charles Will Wright

The purpose of this paper is to present briefly certain preliminary results of the study of mining methods by the United States Bureau of Mines; to show the relative importance of each method in terms of tonnages mined and man-hours consumed; to give to the mining engineers and particularly to the young student of mining a better understanding of the principal mining methods; and to indicate changes now in progress and to present suggestions for improvements in the art of mining. Questions of mine development and details of underground practice such as drilling and blasting, loading, hauling, hoisting, ventilating, pay systems and mine management are omitted, as these have been or will be discussed in other bureau publications.

Jan 1, 1931

By Walter W. Fowkes

Leonardite is a coallike substance, similar in structure and composition to lignitic coal and believed to be derived from lignitic coal by the process of natural oxidation. Leonardite is little known outside lignite-producing areas and has been developed commercially only to a minor extent. The higher oxygen content and less compact structure of leonardite, compared with lignite, make it undesirable as a fuel but indicate that it has potential as a source of chemicals and for other nonfuel uses. It is a convenient source of humic acids. The United States has a large natural reserve of leonardite; furthermore, it can be produced in the laboratory under controlled conditions. The significant elemental difference between leonardite and lignite is the oxygen content (leonardite, 28-29 percent; lignite, 19-20 percent). The higher oxygen content of leonardite is due entirely to a Larger number of carboxylic acid groups. This fact explains the 17-Cold increase in alkali solubility of leonardite. Spectral studies indicate that the material is mixed salts of humic acids.

Jan 1, 1960

By M. J. Ackerman

This study was undertaken to make a comparison between the cost of mining coal under roof bolt and under conventional timber methods of roof support. Studies were made at 14 mines in Pennsylvania, eastern Ohio, and northern and southern West Virginia. At each mine data were obtained for sections of the mine where the physical conditions, mining equipment, and mining systems were similar. Coal, recognized as one of the basic industrial fuels, is very competitive with other fuels, and management, in order to protect and enlarge its market, must be continually alert to find more efficient methods of production. Continuous production of coal is desired by all operators but never obtained. In mechanized mining the performance and production vary with operating time, which can be interrupted by many variable factors, such as condition of the roof, method of roof support, condition of equipment, water, ventilation, power, transportation, efficiency of operating crew, and supervision.

Jan 1, 1961

By G. E. McElory

"INTRODUCTION The subject of mine and tunnel ventilation has two broad aspects - (1) what atmospheric conditions to obtain in underground openings and (2) how to maintain the desired conditions efficiently. The first relates primarily to quantity requirements of ventilating systems, whereas the second relates more particularly to pressure requirements. Both, therefore, determine power requirements, which is the deciding factor in any system of mine or tunnel ventilation.Both divisions of the subject have received considerable attention from the Bureau of Mines since its inception in 1910 in the form of research, service, and correlation and dissemination of information. Numerous papers on various Phases of the subject have been published, of which a selected list, numbered and arranged in chronological order by type of publication, will be found at the end of this Paper. One of these, Technical Paper 705 (25) 2/ gives a complete bibliography of Bureau of Mines publications dealing with health and safety. As indicated by the selected list of publications accompanying this paper, the health and safety aspects have received most of the attention devoted to this work, chiefly because these have been dominant factors in Bureau policy, but partly because these aspects lend themselves to laboratory research and small-scale field studies. Although considerable attention has also been devoted to the engineering aspects of mine and tunnel ventilation, there has been, in the opinion of the author, who has been engaged on this phase almost continuously for the last 30 years, only sporadic recognition of the vital effect this phase of the work could have on improving health and safety conditions. As a matter of fact, ventilation activities have constituted but a very minor part of the total work of the Bureau of Mines, as, except for a few years in the nineteen twenties, there have been only a few short intervals when more than two or three men were engaged in field work and a similar number in laboratory research directly related to mine gases or mine air."

Mar 1, 1950

By Charles E. McCarthy

Part 1 of this report is concerned with the electric-furnace production of calcium aluminate and iron alloy from a variety of siliceous ferruginous ores of aluminum. The furnacing research was directed, first, to determine the extent of the field in the CaO-Al2O3-SiO2 system, in which calcium aluminates with the optimum leaching characteristics are obtained; second, to produce suitable quantities of these aluminate mixtures for pilot-plant leaching tests; third, to investigate the physical chemistry of the reduction reactions during furnacing; and, fourth, to study the economics of the process. The third and fourth steps were not completed. Part 2 comprises another phase of the work and will appear as a second Report of Investigations. It deals with the extraction of metallurgical-grade alumina from the calcium aluminate slag produced in the electric furnace and includes the following steps: leaching, desilicating, precipitating, dewatering, filtering, and washing of the aluminum hydrate. No claim is made that the data are complete, nor has the chronological order of obtaining data been followed. Rather, it is emphasized that additional work is necessary if the full possibilities of the process are to be evaluated. and made available.

Jan 1, 1949

By John B. Knaebel

This paper is one of a series being prepared by the Bureau of Mines on mining methods and costs at various mines in the United States, Canada, and Mexico, and is a description of practice at the Edwards mine of the St. Joseph Lead Co. ACKNOWLEDGMENTS The cooperation and assistance of the officials of the St. Joseph Lead Co. in permitting publication of this paper and providing every facility for its preparation are gratefully acknowledged. Especial thanks are extended R. J. Mechin, manager, R. F. Mitchell, mine captain, and J. S. Brown, geologist, for their generous aid, and the assistance of W. H, Weijola, mine engineer in assembling some of the illustrations is deeply appreciated, The helpful suggestions of C. F. Jackson, principal mining engineer, U. S. Bureau of Mines, are gratefully acknowledged.

Jan 1, 1932

By Lloyd Williams

1. This investigation shows that the Poplar Creek is the most important bed in Scott County from a production standpoint. Although the Poplar Creek bed contains the largest reserve, the Big Mary has a larger recoverable reserve. Estimates of reserves also have been made for the Pewee, Red Ash, Windrock, Upper Pioneer, Jellico, and White Oak beds. 2. Known measured and indicated reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 143 million tons as of January 1, 1954. Of this total, 74 million tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By Forrest T. Moyer

Quarry accidents in 1963 caused 61 fatal and 3,468 nonfatal injuries which occurred at respective frequency rates of 0.31 and 17.91 per million man-hours of worktime. The fatality record in 1963 was better than in 1962 but was appreciably worse than in 1.961. For nonfatal injuries, the 1963 record was slightly worse than in 1962 but was better than in 1961. The injury--severity rate of 2,913 days lost or charged per million man-hours in 1963 was better than that of 3,046 in 1962, the first year for which such data became available. The average severity of all injuries in 1963 was 160 days lost or charged per injury, 15 less than in 1962. An average of 91,960 men were at work on active days in 1963 and these men had an aggregate worktime of 193.7 million man-hours during the year.

Jan 1, 1972

By Harold J. Bennett

The purpose of this study was to develop methods for the financial evaluation of mineral deposits. This includes the selection of the best alternative mining and processing methods and production rates. This was done by performing a financial evaluation through computer simulation using sensitivity and probabilistic risk analysis. The criterion used to measure the relative advantages of these investment and operating alternatives is the discounted-cash-flow rate of return. Included is a description of the theory and methods used in the probabilistic analysis approach, which is based on the premise that the expression of a range of values in establishing an estimate for a parameter is more realistic than the choice of a single value. Numerous simulations are made using randomly selected values of the input parameters resulting in a frequency distribution of the rates of return and their relative probability of occurrence. The sensitivity analysis method is described and combined with the probabilistic analysis to interrelate mineral reserves, capital investments, operating costs, and production rates. The ability to vary these input parameters on successive runs has permitted the selection of the best alternative mining and processing methods and production rates for a given mineral deposit. For illustrative purposes the evaluation of a mineral deposit was performed using three alternative mining and processing methods at three different quantities of resources and various production rates and prices. The computer program used in this analysis was written in FORTRAN II for maximum compatability and should run without modification on most computers having BK (8,000-word) core memory, a card reader, and printer (120 characters per line).

Jan 1, 1970

In 2004, data obtained from the Mine Safety and Health Administration (MSHA) indicated a total of 891 underground (6.2%) and 13,587 surface (93.8%) mining operations.

Sep 1, 2007

By D. W. Blaylock

I. The Lower Kittaning bed is the most important bed in Clarion County from the standpoint of present production, but the Clarion bed has the largest recoverable reserve. 2. Known measured and indicated reserves in all beds, based on a minim thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 1,210 million short tons as of January 1, 1952. Of this total, 790 million short tons is in beds 28 inches and mare thick. Areas in some beds were omitted from the estimate because available data relative to the bed characteristics are too wager for ding an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, they should be added to the total estimated reserves.

Jan 1, 1956