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By R. S. Dean

"INTRODUCTION The metallurgical research program of the Bureau of Mines has been somewhat disorganized, but generally advanced by the increased activities of the war period. The present report is for the purpose of summarizing the work of the Bureau in this field for the past 15 years and indicating its future plan.Fifteen years ago the Bureau turned from its pioneer work on the physical chemistry of steelmaking to an emphasis on raking a pure steel synthetically, rather than by refining, that is, :producing each of the steel 'constituents in the pure state and combining them by simple melting. Such a procedure permits the use of less high-grade ores, not only of iron, but of the ferroalloy metals, such as manganese and chromium,This program has led to extensive work on iron-ore concentration, agglomeration, reducibility of ores and agglomerates, direct reduction of iron ores and concentrates by a wide variety of processes; special refining processes for iron, the production of pure mangenese, chromium, and cobalt from low-grade ores by electrolytic processes, the production of ferrochromium, ferronickel, and ferronickel-cobalt from low-grade domestic ores, and the development of many special alloys to effectively use the new products.The status of the work in each of these fields and the future program of work, together with a bibliography of papers and patents by the Bureau staff on each of these subjects, are given."

Jul 1, 1946

By R. D. Leitch

"REASONS FOR AND PURPOSE OF WORKIn 1924 the United States Public Health Service was requested to undertake a special study of stream pollution. At that time the proposal that the United States Bureau of Mines take up the study was made by the Public Health Service because in point of training and experience the personnel of the latter was considered not to be as well, suited to this type of investigation as was that of the Bureau of Mines. H. Foster Bain, then Director of this bureau, promised to undertake the work, and, accordingly, field investigations were begun in the spring of 1925. The problems of mine-drainage wastes and of gas-house and coke-oven waste were investigated in the laboratory, and a method of treatment by sodium hydrate and benzol was found to be promising. The idea was obtained by A. C. Fieldner, chief engineer of the Bureau of Mines experiment stations, while in Germany in 1924, where he was shown a practical application of the process, but no information was obtained as to definite chemical or mechanical processes. Because of the then pending American patent application by the German firm, we made no attempt to develop our findings further. Shortly after, a similar method of treatment was developed in the United States, and since that time we have devoted our attention entirely to mine drainage. This paper is a presentation of some general facts and information gathered during the past five years on coal-mine drainage.SCOPE OF WORKAt the time our work was begun there was such a diversity of opinion on the whole subject and apparently so little was accurately known, that it was decided to undertake a basic study from which (1) certain definite information might be evident, and (2) what might be considered side issues of the original investigation would be suggested for subsequent study.A stream in a district thought to be representative of those in low to average sulphur bituminous coal fields and another in a high sulpbur district were selected for study, A fair (weber of factors entered into the tentative selection of these streams, the chief ones being their accessibility and freedom from other industrial or domestic pollution, besides, of course, the presence of mine drainage in these streams."

Apr 1, 1931

By Lynn L. Rethi

This U.S. Bureau of Mines report summarizes common obstacles found when attempting to implement health and safety strategies in small mines and small businesses in general industry. Recently, the U.S. Mine Safety and Health Administration focused much of its attention on addressing health and safety issues at small mines. Some of the more innovative interventions practiced by small businesses in general industry are discussed for consideration of their applicability to the mining industry. The most effective intervention strategy that was developed for small businesses is the Occupational Safety and Health Administration Consultative Program. The details of this program and other intervention strategies used by small mines and small businesses are presented.

Jan 1, 1995

By W. A. Haley

This is the second of a series of publications that describes the progress of mechanical longwall coal mining in the United States in which a German coal planer was employed.3/ Details of the equipment, a description of its operation, and the results obtained in mining the experimental panel were published in the preceding report. Experimental mining with the planer in the first panel showed an improvement in performance over conventional mining methods at the coal company's Stotesbury 11 mine. The work, which was begun on an experimental basis, soon proved successful, and the coal company purchased the equipment for continued use. Two panels, adjacent to the first, were developed and mined with the planer. Each of these panels was shorter than the preceding one because water seepage from a surface creek limited development. On completion of mining in the third panel, the planer equipment was moved by the cooperating company to a nearby mine operated in the same coal bed where a large area of coal suitable for planer mining is available.

Jan 1, 1954

By J. A. Rowland

Manganese-copper alloys containing 60 percent or more electrolytic manganese exhibit an unusual combination of high vibration damping capacity with good strength properties. Properties of the pure alloys were first studied in the laboratories of the Federal Bureau of Mines and have been described in a series of technical papers1/ published from 1941-49. The unusual characteristics of these manganese-copper alloys attracted the attention of research metallurgists and several additional investigations have also been reported in the literature.2/ The engineer, also, was attracted by the combination of high strength and high vibrational damping capacity possessed by these alloys. A wide field of application in structural and machine design was obvious. However, serious difficulties encountered in commercial fabrication of structural or machine components from the alloys retarded attempts at their practical utilization. For this reason the Federal Bureau of Mines, in cooperation with the United States Navy, Bureau of Ships, undertook a program designed to develop practical methods for fabricating a selected group of the high-damping alloys. It is the purpose of this paper to summarize a part of that investigation in a form suitable for use by the metallurgist interested in commercial fabrication of the alloys.

Jan 1, 1955

By Earl R. Maize

This is the first of a series of reports dealing with development of a method of strengthening bituminous-coal-mine roof. Later reports will describe the progress made with injecting high cohesive and adhesive bonding agents into bedding planes and mine tests of roof strata strengthened by the bonds formed. The concept of strengthening roof strata in coal mines by inserting steel rods in the form of bolts has been widely accepted by the coal industry. The benefits of increased production and safety derived from this type of roof support has more than justified the increased cost of roof bolting. However, not all coal-mine roof structure is amenable to this type of support, and failures occur owing to the heterogeneity and variable character of mine-roof strata.3/

Jan 1, 1957

By J. S. Browning

Laboratory and pilot-plant tests of spodumene-beryl pegmatites of the Kings Mountain, N. C., area resulted in development of a new and improved method by the Bureau of Mines for separating and recovering spodumene, mica, and beryl. The process was successfully applied to other domestic pegmatites and a spodumene flotation-plant tailing containing about 0.5 percent beryl. The method comprised soap flotation of the spodumene, using combinations of sodium fluoride and lignin sulfonate as conditioning agents to recover 80 to 85 percent of the contained lithia in concentrates assaying over 6 percent Li20. About 80 percent or more of the beryl was retarded in the spodumene tailing. The beryl subsequently was activated, floated, and cleaned in a secondary circuit to yield beryl concentrates containing 6 to 7 percent BeO. The tests also demonstrated that a good recovery of high-grade mica could be produced.

Jan 1, 1961

By A. F. Colombo

The differences in starch demands that occur between ore types subjected to the anionic flotation of calcium-activated gangue and the range of residual starch contents expected to give the best metallurgical response were evaluated on a batch and pilot plant basis. A phenol-sulfuric acid procedure was used to determine the residual starch contents in the iron ore slurries. Three pilot plant campaigns on samples from a group of orebodies located on the Marquette Range, Michigan, showed that in the rougher flotation pulp, a residual carbohydrate range of 25 to 100 ppm, which is equivalent to a 0.5 lb/short ton spread, yielded optimum results. Concentrates assaying at least 65 percent Fe and less than 6.0 percent Si02 and containing more than 80 per-cent of the recoverable iron were obtained. Both batch and continuous research indicated that starch adsorption is calcium modulated and relatively unaffected by the fatty acid additions employed. Residual starch level is not a critical control factor, but the addition must be adjusted to about 25 to 50 ppm residual starch and kept in this range for most effective utilization of the added tapioca flour.

Jan 1, 1972

By B. J. Scheiner

Oxidation procedures based on the chlorine-hypochlorite system were investigated for improving gold recovery from carbonaceous gold ores. The oxidation pretreatment prior to cyanidation was accomplished by (1) addition of sodium hypochlorite to ore pulp, (2) by addition of chlorine to ore pulp, and (3) by generation of hypochlorite in situ by electrolysis of a brine solution used to pulp the ore. Gold extraction of 90 pct was achieved by cyanidation of carbonaceous ore that had been pretreated with 20 Ib per ton sodium hypochlorite at 50° C for 4 hours. Similarly, pretreatment of the ore pulp with 35 1b chlorine per ton at 24° to 30° C and 15 hours reaction time resulted in 89-pct gold extraction by subsequent cyanidation. Concomitant studies showed that electrolyzing the pulp prepared with a brine solution was equally as effective as electrolyzing hypochlorite and chlorine for oxidizing carbonaceous ore constituents that are deleterious to cyanidation. Gold extraction of 90 pct was obtained by electrolysis when 275 lb of are was treated at 200 amp for 7 hours in an 8-to 10-pct salt solution. Power consumption was in the range of 60 kwhr per ton.

Jan 1, 1972

By R. M. Santmyers

Umber and sienna, like ocher, are naturally occurring mineral pig- ments composed largely of clay permeated with hydrated iron (ferric oxide), but they differ from ocher in that they also contain hydrated manganese oxide. The presence of manganese accounts for their browner color. In addition to silica and alumina (clay) and the coloring oxides of iron and manganese, these pigments often contain lime, barium, and other metallic salts as impurities. Sienna most nearly approaches ocher in chemical composition, and the chief distinction is its physical character. It grades into ocher with de- creasing iron content and into umber with increasing manganese content. Sienna is translucent rather than opaque and is more of a stain than a pigment; as the iron oxide content is rather high (often 60 to 80 per cent), the color is strong and rich and varies from pure brown to reddish brown. This pigment raw sienna, terra di Siena, and Italian earth. is known under several names: Burnt sienna is a pigment of an orange-brown tint made by cautionsly calcining raw sienna. It is divided into two grades; American, and Italian burnt sienna. American burnt sienna is a reddish-brown pigment containing from 25 to 60 per cent iron oxide (Fe2O3). One grade, found in Pennsylvania, analyses as high as 80 per cent and is mown as double strength sienna. Italian burnt sienna is a pigment generally containing more iron than the American product, averaging 60 to 75 per cent iron oxide.3 American pig- ments of the same iron content differ materially in shade, having a Havana- brown color, whereas the Italian is more of a maroon. Italian siennas when tinted with 20 per cent of white, show a bluish tint, whereas American siennas yield a brownish or yellowish hue. Raw umber, also known as Turkey umber, Levant umber, and terra ombra, is a greenish to yellowish brown siliceous and ferruginous earth, containing a considerable proportion of one or other of the higher oxides of manganese, Mng04 and MnO2." It is similar in many respects to raw sienna except that it is much coarser and contains more manganese oxide. All umbers contain over 5 per cent of manganese dioxide. Like sienna, umber is a permanent pigment, not being injured by light or by impure atmospheres. Burnt umber (velvet brown, chestnut brown, etc.), results from the calcination of raw umber. The color is much richer and warmer than that of the raw umber. The colors are equally permanent and can be used in conjunc- tion with all other durable pigments.

Sep 1, 1931

By W. W. Agey

As a result of a field examination made during the Bureau of Mines intensive manganese program, three lots of ore were procured from the famous old Paymaster District, 7 miles from Midway Wells, Imperial County, Calif. This district is an old producer and shipped approximately 10,000 tons of 45-percent manganese ore during World War I. A 2-ton lot of ore was taken of a Bureau engineer from the exposure of a small fissure vein in conglomerate on the Turtle Group of claims; 1 mile east of the Pacific Coast Manganese Corp. claims. The vein material consisted of manganese oxides, calcite, and quartz in fairly coarse association.

Jan 1, 1949

By O. C. Blade

The oil fields of Arkansas, all situated in the southern part of the State, have played an important part in the development of petroleum production in the northern coastal plain region of the Mid-Continent area. From the first discovery of oil in southwest Ouachita County in 1920 to December 31, 1930, a total of 480,167,5604/ barrels of crude petroleum has been produced from' this region. Development of the Arkansas fields proceeded rapidly after 1920. The El Dorado field was discovered in Union County in 1921. Drilling in Ouachita County resulted in the discovery of the Smackover field in 1922 and subsequently in the development of the whole southern area. To November 31, 1938, 6,4595/ producing wells had been drilled in 25 fields, aggregating 53,7356/ acres of proved territory in 6 counties. Peak annual production for the State was reached in 1925, when 80,823,7007/ barrels was produced, resulting largely from flush production from the Smackover field, which rose td an average of 444,9508/ barrel daily during that year. During 1924, 1925, and 1926 Arkansas ranked fourth9/ among the oil-producing

Jan 1, 1940

By W. A. Calhoun

"INTRODUCTION A letter from S. D. Strauss, vice president of Metals Reserve Company, Washington, D.C., dated May 22, 1945, to the chief of the Metallurgical Branch, Bureau of Mines, in Washington; includes the following: Because of the present critical shortage that exists in the supply of corundum required by certain industries in war production, the Reconstruction Finance Corporation, Mr. W. C. Keeley, Vice Chairman for Metals and Minerals, War Production Board, has recommended that the Reconstruction Finance Corporation though Metals Reserve Company, proceed with preliminary mill testing of the corundum ore in Gallatin County, Montana, and that the results of that testing be transmitted to the War Production Board. If the results of the testing work are considered satisfactory, Metals Reserve Company will then provide for the actual mining and milling of the ore for the production of corundum concentrates.Pursuant to the above stated recommendation by the War Production Board, Metals Reserve Company desires to make -use of the facilities of the Bureau of Mines testing plant at Rolla, Missouri, for conducting sink and float and other concentration tests on representative samples of the Montana corundum ore. Two, and possibly three samples of ore are to be tested which will have an aggregate weight of approximately 50 tons."

Dec 1, 1947

By Murray Jacobson

Data obtained by the Federal Bureau of Mines on the dust explosion hazard in air are presented for 220 samples of agricultural products. Information is given on ignition temperature of dust clouds and layers, minimum explosive concentration, minimum electrical energy for ignition, explosion pressure and rates of pressure rise, amount of inert dust required to prevent flame propagation, and, in a few instances, the permissible oxygen concentration in an atmosphere to prevent ignition by spark and by heated surface. The effects of particle size and source of sample on explosibility are shown. The relative ignition sensitivity, severity of explosion, and overall explosibility of the materials are characterized by empirical indexes. This report contains Ma obtained by the Bureau in laboratory studies on the explosion hazards of agricultural dusts. Recognition of the dangers will encourage adoption of adequate measures to prevent ignition and explosion during preparation, processing, and utilization of the materials. Agricultural products constitute one of the largest groups of materials used in America. More than 260 million tons of various grains, much of which now exists in dust form, was grown in 1958.6/ Over 600,000 tons of the annual production of 200

Jan 1, 1961

By R. Karl Zipf, Z. T. Bieniawski

"SummaryAs part of an effort.to understand the mechanics of fine fragment formation in coal, which is important in studies of respirable dust due to mining, fracture toughness measurements and the strain energy density (SEO) theory were applied to calculate the crush zone size under a cutting tool in coal. This · zone is the major source of fine fragments in the 1 to 10 µm size range. The model used in these calculations is a boundary element program containing a failure criterion based on the SEO theory. The boundary element program calculates linear elastic stresses at numerous points in the coal material ahead of a cutting bit. These stresses arc then input to a subroutine called critical ftaw length and orientation (CFLO) which uses the SED theory to determine the CFLO for a small crack at the boundary element stress computation point. The extent of crushing is based on earlier postulates about . the role of inherent flaws in a fragmentation process. To form 1 to 10 µm fragments requires firstly a local stress strong enough to activate flaws with a characteristic length less than 1 to 10 µm and secondly, a flaw density sufficient to provide an average spacing between flaws also on the order of 1 to 10 µm. The locus of active lO µm ftaws represents the maximum possible extent of fine fragmentation in the 10 µm or less size range assuming that a sufficient inherent flaw density exists. The approach offers a first order approximation to the extent of crushing under a tool tip. The size and shape of the crush zone volume is affected by the attack angle and geometry of the tool.IntroductionFine fragment generation in the 1 to 10 µm size range under the action of a generic coal cutting tool may be explained on the basis of fracture mechanics which suggests two major sources of fine fragments: first in a crush zone near the tool tip and second by shear fracturing. along major macrocrack surfaces (Zipf and Bieniawski, 1988a). In this paper, fracture toughness measurements and the strain energy density theory are used to calculate the crush zone size. This zone represents the major source of fine fragments in the 1 to 10 µm size range and understanding the mechanical factors controlling its size represents a first step toward using fracture mechanics to characterize the ·tendency of various coals to produce undesirable fine fragments."

Aug 31, 1989

By W. A. Selvig

[THE BUREAU OF MINES receives many requests for information regarding the low-temperature carbonization properties of American coals. This report presents in collected form the results of Fischer-Schrader bench-scale, low-temperature carbonization assays at 500° C. made by the Chemistry and Physics Section at the Pittsburgh station of the Bureau of Mines. Most of the assays were made of coals tested in connection with a survey of gas and coke-making properties of American coals,4 which was started in 1928 by the Bureau in cooperation with the American Gas Association. Other coals were assayed in connection with miscellaneous investigations. Since 1930 about 400 samples of coal were assayed from nearly every coal-producing State, Alaska, and British Columbia, Canada. The results of the tests on about two-thirds of the coals are scattered through more than 50 separate publications. This paper summarizes the data in the published reports as well as all unpublished data obtained to January 1, 1956. The report also includes a detailed description of the procedure used in making the assay.]

Jan 1, 1957

By John W. Frey

This paper presents one of a series of digests of foreign mining legisla- tion and court decisions which is being prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Trinidad has been prepared from the best information available in ashington 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 Rogers F. Davis

This publication has been prepared to supply manufacturers and industrial users a listing of mobile diesel-powered equipment and subassemblies approved and certified by the Bureau of Mines for use in nongassy noncoal mines and tunnels. This revised and supplemented listing supersedes an earlier publication2 released in 1963. Testing of diesel-powered equipment is one phase of the Bureau's program of health and safety that concerns approval of electrical and diesel equipment designed to prevent explosions, fires, shocks, or toxic hazards in underground mines, when such equipment is used and maintained properly. Manufacturers submit machinery and component parts to the Bureau for study of their design, safety features, and use. Equipment must pass exacting tests and must meet strict requirements established through research and experience and outlined in the Bureau's permissible schedules before the Bureau approves it for safe use in mines.

Jan 1, 1968

By F. W. Hoertel

Tungsten from the hydrogen reduction of WF was vapor - deposited to coat MERM (Material Evaluation Rocket Motor ) graphite and rhenium- lined graphite nozzles . These nozzles have surface configurations that preclude the conventional fabrication of high- density- tungsten liners . Operation at 550 ° C produced selectively placed uniform coatings of specified thicknesses at near theoretical density . An acceptable coating could not be deposited on a beryllia nozzle because of an undesirable side reaction between the substrate and one or more of the products of the reduction reaction .

Jan 1, 1964

By W. A. Stickney

As part of a Bureau of Mines program to investigate recovery of manganese (Mn) from low-grade materials, laboratory studies were made of four samples of mill rejects: Three from Montana and one from Peru. These studies demonstrated that certain mill-waste products can be a potential source of manganese. Both manganese oxide and carbonate minerals were recovered by flotation in an acid circuit with a fuel oil-tall oil emulsion as collector. Sintering) required to prepare a physically acceptable product, also was used as a method of beneficiation. In addition to being low-grade, some of the samples presented problems of intimate mineral association and complex textures.

Jan 1, 1960