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By Wallace W. Roepke

Four bit designs, two conical and two radial, were tested in coal against a 60° conical reference bit to obtain data on orthogonal cutting forces and primary respirable dust generation. One conical and one radial design were modified by the Bureau of Mines for these tests. Results were mixed: One radial bit used substantially lower overall cutting forces and specific energy than the other bits and was the only cutter lower on energy and most forces than the standard 60° bit. How-ever, it generated more specific and total dust than any other bit. The four bits were also tested for incendivity, with a 90° plumb-bob bit as the reference. The frictional ignition tests were designed to simulate both trimming top rock and cutting such rock during advance on-sump. Results of these tests were also mixed. The radial bits were substantially less incendive than the reference bit and caused no ignitions in either top trimming or sump modes. Only the modified mushroom-tipped conical bit caused ignitions. Bits similar to this modified design should not be used on drum-type miners in gassy mine areas; in-stead, the other types of bits tested should be used to reduce ignition potential to a minimum.

Jan 1, 1983

By D. R. Mathews

Electrorefined vanadium was evaluated with respect to tensile properties and the effects of interstitial contaminants in the temperature range of 77° to 273° K. The yield strength of 18,500 psi and hardness of 63 diamond pyra-mid hardness (DPH) of electrorefined vanadium are approximately equal to that of iodide crystal bar vanadium. The ductile-brittle transition temperature was found to be below 77° K, but with 0.175 weight-percent oxygen or 0.10 weight-percent nitrogen, it increased to between 123° and 190° K. With carbon content up to 0.11 weight-percent, the transition temperature remained below 77° K. The yield strength of the interstitial-containing alloys can be expressed by: au = 7.5 + 480 (pct N) + 290 (pct 0) + 280 (pct C), where au is the upper yield stress in 1,000 psi at 273° K. Profuse deformation twinning occurred in the alloys tested at 77° K. However, twinning could be suppressed by dissolved oxygen or nitrogen in excess of 0.15 and 0.086 weight-percent, respectively. Carbon, even though present in excess of the solubility limit, did not affect twinning.

Jan 1, 1965

By H. C. Fuller

Submerged combustion and inverse solubility methods were investigated as promising alternative means for crystallizing manganese sulfate from solutions produced by leaching manganese ores with either sulfuric acid or sulfur dioxide. Evaporation of water from typical manganese sulfate solutions by sub-merged combustion techniques enabled production of a slurry containing 32 to 39 pct MnSO4.H2O crystals suspended in a saturated solution of manganese sulfate. Such a slurry required further processing by thickening or filtration and drying to produce crystals of MnSO4.H2O. In a second approach, semicontinuous processing of manganese sulfate solu¬tions by thermal crystallization under pressure effected a recovery of 94.5 pct of the MnSO4.H2O as dry free-flowing crystals. Treatment of a solution containing about 100 grams manganese per liter at 189° C, produced a "barren" solution containing only 1.9 grams manganese per liter. Calculations made on comparable manganese sulfate solutions show that the heat requirement of the thermal crystallization method was about one-third to one-fourth that of the submerged combustion method.

Jan 1, 1966

By N. S. Dalal, V. Castranova, X. Shi, W. Wrr, V. Vallyathan

"SUMMARY Data presented here indicate that freshly fractured silica exhibits surface characteristics and biologic reactivity distinct from aged silica, and on this basis we propose that these surface features may lead to enhanced manifestations of lung Injury. Grinding of silica produces ~10"" Si and SI-O (silicon-based) radicals per gram of dust on the particulate surface which are characterized by an electron spin resonance (ESR) spectrum centered around g = 2.0015. These silicon-based radicals react with aqueous media to produce OH radicals, which are demonstrable using a DMPO spin trap. The concentration of silicon-based radicals in silica decreases with aging in air and exhibits a half-life of ~30 h, whereas its ability to generate OH radicals in aqueous solution decreases with a half-life of ~20 h. However, on storage in aqueous media, the concentration of silicon-based radicals end the dust's ability to generate OH radicals decrease significantly within a few minutes. Freshly ground silica is also more biologically reactive than aged silica, because freshly crushed silica activates a greater respiratory burst In alveolar macrophages than aged silica, i.e., storage of ground dust in air decreases silica-Induced superoxide anion secretion, hydrogen peroxide release, and NBT reduction by 25%, 68%, and 43%, respectively. Furthermore, compared to aged silica, freshly ground silica exhibits a greater cytotoxic effect on cellular membrane Integrity, i.e., a 1.5-fold increase in LDH release from macrophages, a 36-fold increase in hemolytic activity, and a three-fold increase in the ability to induce lipid peroxidation. Because acute silicosis is frequently associated with occupations in which freshly fractured crystalline silica of respirable size is generated, the present study suggests that fracture-generated silicon-based radicals may play a significant role in the pathogenesis of this disease. AM REV RESPIR DIS 1955; 133:1213-1218IntroductionOccupational exposure to crystalline silica can be associated with either chronic or acute pulmonary disease. Chronic silicosis becomes manifest 20 to 40 years after first exposure and is characterized by development of concentric hyalinized nodular lesions in the lung with the de-velopment of dyspnea over a period of several decades. Acute silicosis, on the other hand, is manifested by a rapid on-set after exposure and is characterized by the accumulation of an amorphous granular lipoprotein exudate in the airspaces and rapid development of respiratory disability within a few years (1-3).Information is growing concerning the etiology of chronic silicosis. Studies sug-gest that several mechanisms may be in-volved in the development of fibrosis. Lung injury may result from silica-induced release of lysosomal enzymes from alveolar macrophages (4, 5). In ad-dition, silica-induced activation of su-peroxide anion and hydrogen peroxide release from alveolar macrophages may result in oxidant-induced damage to lung parenchyma (6). Silica exposure can also result in the release of mediators from alveolar macrophages which enhance the proliferation of fibroblasts and the syn-thesis of collagen by these pneumocytes (7, 8)."

Jan 1, 1988

By Constantine C. Popoff

During 1946 several high-grade limestone deposits in western Washington were examined by the Bureau of Mines. This report presents the data obtained from investigation of the Sauk Mountain deposits in east-central Skagit County, Washington, The investigation consisted of transit and topographic surveys and sampling. The areas selected for sampling were first cleaned by blasting; channel samples up to 40 pounds Were cut where practical. Chip samples averaging 30 pounds were taken where channel samples could not be cut. A total of 21 samples in the Sauk Mountain area were taken and analyzed. The locations of the samples are shown in figures 2 and 4, and the analyses are listed in tables 1 and 2. This investigation is a part of a long-range program of general investigation of mineral resources for future industrial development of the Pacific Northwest. The Sauk Mountain deposits were investigated for the purpose of disclosing new sources of high-purity limestone, which could be mined and shipped at low cost to Seattle and other industrial cities in the Pacific Northwest.

Jan 1, 1948

By William W. Elmer

This paper, describing the mining method at the Black Butte quicksilver mine, is one of a series of papers being prepared by the U. S. Bureau of Mines on mining practices, methods, and costs in the various districts of the United States. It is presented to show the mining practice and costs in the successful treatment of low-grade quicksilver deposits. The operation discussed is an excellent example of w1-pat can be done in working a limited tonnage of low-grade ore under sound management. The Black Butte mine is situated at Black Butte, Lane County, in the southern part of the State of Oregon, 17-1/2 miles from Cottage Grove -- a station on the Siskiyou branch of the Southern Pacific Co. The Black Butte mining district lies in the foothills of the Calapooia Mountain Range, which connects with the Cascade Range on the east and with the Coast Range on the west. The elevation at '.lie reduction plant is 1,000 feet above sea level. The apex of Black Butte Mountain, or which the mine is situated, has an elevation of 2,700 feet. The district possesses exceptional natural facilities infrequently met with elsewhere for the mining and reduction of cinnabar ores. Several factors which contribute to the unusually low mining costs are:

Jan 1, 1930

By Richard D. Miller

The helium resources base of the United States was estimated by the U.S. Bureau of Mines (Bureau) to be 894.6 Bcf as of January 1, 1989. These resources are divided into four categories in decreasing degree of assurance of their existence: (1) helium in storage and in proved natural gas reserves, 282.4 Bcf, (2) helium in probable natural gas resources, estimated at 237.7 Bcf, (3) helium in possible natural gas resources, estimated at 263.1 Bcf and (4) helium in speculative natural gas resources, estimated at 111.4 Bef. These helium resources are further divided into depleting and nondepleting, with the helium in storage being in a classification. The depleting resources are those associated with natural gasfields that are, or will be produced for the natural gas they contain. Almost all of the helium in potential (probable, possible and speculative) natural gas resources is included in this classification. These depleting resources are estimated to contain 775 Bcf of the total helium resource base. Helium resources contained in nondepleting natural gas resources, i.e., those in shut-in, abandoned, or otherwise nonproducing natural gas fields, are estimated to total 84 Bcf There is 35 Bcf of helium in storage in the Federal Government-owned Cliffside Gasfield near Amarillo, TX.

Jan 1, 1990

By R. V. Higgins, A. J. Leighton

A computer program has been devised to calculate the reservoir performance of water floods of complicated well - spacing patterns . The method and program have been tested by calculating the waterflood performance of fivespot patterns using oils of different viscosities and the performance calculations agreed closely with laboratory results . The program on a high - speed digital computer will process the performance prediction in about 1 minute , which is very rapid for a prediction using so much fluid mechanics and nonlinear geometry . The program has been presented in such a way that one may use it as given and save the time required to write and " debug " one of his own . gram processes a complex reservoir analysis , many of the complicated steps are explained in detail , both for the fluid mechanics and the directions for the computer . The subtle features that originally delayed the application of the program to unusual combinations of permeability and viscosity relationships are incorporated and explained

Jan 1, 1963

By Forrest T. Moyer, J. I. DAVIS, JOSEPH H. SCHUSTER, E. K. ELSNER

The National Safety Competition conducted by the Bureau of Mines, United States Department of the Interior, is held each year for the purpose of promoting safety in the mineral industries of the United States. Since the program was inaugurated in 1925, twenty-three safety competitions have been held. This publication is a report of the results of the contests held in 1944, 1945, 1946, and 1947. The names of plants that have been awarded "Sentinels of Safety" trophies and Certificates of Achievement in Safety dur- ing these years, together with a summary of their achievements in injury prevention, are listed. Statistical data covering the injury experience of all plants entered in the annual contests also are included in this publi- cation. The injury statistics of these plants, arranged in the six groups of the competition, are the only data on injury severity at mineral operations available to the Bureau of Mines. Interest in the National Safety Competition has increased steadily. The number of participating plants has increased from 210 in 1925, the first year of the competition, to the record number of 494 in 1946. The widening scope of the competition means that a steadily increasing number of the mines and quarries in the United States are participating in a program that will supplement their other activities in promoting safety. Safety competitions have long been recognized as instrumental in stimulating and holding the interest of employees and officials in accident-prevention work. During the years covered by this report, conditions in the mineral industries of the United States were hardly conducive to setting records in accident prevention. During the war years, handicaps were especially severe- loss of skilled employees to the armed forces or to higher-wage war industries, greater production by a smaller force of workers, relatively high rates of labor turn-over, the longer workday in effect through 1944 and 1945, and difficulties in obtaining repairs and replacement for badly worn machinery. Even the immediate postwar period has brought no abatement of the tremendous pressure upon the mineral industries for greater production. Although there was a decrease of 18 in 1947 from the record enrollment in 1946, these oper- ations worked 160,525,025 man-hours, the greatest number of man-hours of exposure to mining hazards in any year of the contest except 1942. Despite the accelerated pace at which the mineral industry worked during the 4 years covered by this report, participants in the National Safety Competition have achieved creditable performances in the promotion of safety. In fact, the injury-severity rate in the enrolled plants in the 1947 contest was 7.315 days for each thousand man-hours worked, the lowest by far in the history of the National Safety Competition. The injury-frequency rate of 42.155 for each million man-hours of exposure to mine hazards in 1947 marks a favorable trend downward from the rate of 50.577 in 1946, which was the

Dec 1, 1949

By Charles M. McCulloch

This Bureau of Mines report discusses the principles of using computers to draw maps and plot geologic data of mining areas. The types of maps that can be drawn by a computer are reviewed, using as examples two separate areas where poor roof and gas emissions caused mining problems. Such maps can be used not only to help identify problem areas, but also to predict areas where problems could occur, thus giving mine operators time to work out solutions prior to mining. The average cost of a computer-drawn map for a mine property is less than $100, including computer time and man-hours for data preparation.

Jan 1, 1976

By R. G. Warncke, Stanley M. Walker

The United States Bureau of Mines was created by an act of Congress in 1910 as a governmental agency to work , on a national scale , toward reducing the huge annual loss of life in the production and processing of the Nation's minerals . From 1906 to 1910 , inclusive , nearly 2,500 miners lost their lives in 84 major explosion disasters , and more than 13,000 suffered fatal injuries from all causes in the coal mines of the United States . Also , conditions in the metal and nonmetal mines were proportionately hazardous during this period , and the total loss of life in all mines and quarries exceeded 3,000 annually and approximately 250,000 workers suffered serious injuries . Under these conditions it is readily understandable why Congress took notice of this " high cost of mining" , and from the investigations and hearings of the day emerged the Bureau of Mines charged with the prevention of accidents and the preservation of the health of all those engaged in the mineral industry; this has continued to be a most important part of the work of the Bureau . Throughout its existence the Bureau of Mines has had no legal authority of enforcement , except during war years , when enforcement necessary to the national security was given to it . The Bureau believes that persuasion , with factual evidence , is the proper and best way to obtain compliance with the safety suggestions made by its engineers and scientists . There is no panacea for accidents , nor will any single " approach " , instill safety consciousness in all workers , and without it accidents will occur --and occur again . To persuade men to work safely, numerous forms of appeal are required to reach the various temperaments of workers in many types of mines operating under diverse conditions .

Nov 1, 1949

By R. F. Tenney

This report has been prepared because little detailed information has been published on the production and use of anthracite producer gas for industrial-process and brick-kiln heating. To obtain this information, an investigation was conducted by the Federal Bureau of Mines in cooperation with a building-brick manufacturer (firing both periodic and tunnel kilns with anthracite producer gas) and with a manufacturer of anthracite-gas producers. In addition to a study of available plant records, 2 weeks was spent in systematic observation and measurement during regular operation of the Hazleton Brick Co. plant, Hazleton, Pa., in July 1953. This report presents the results of this investigation and a description of producer and periodic-kiln equipment, operating procedures, and labor requirements. A summary of the conditions of producer and kiln operation is given for the 2-week observation and for the 11 preceding months. The two 10-foot standard anthracite-gas producers consumed 301 tons of Rice and Buckwheat No. 1 anthracite, as delivered, averaging over 13,000 B.t.u. per dry pound during the 2-week period, with a producer hot-gas efficiency of 95 percent, at an average gas offtake temperature of 5400 F. The yield of gas5/ of 153 gross B.t.u. per cubic foot amounted to 140,000 cubic feet per ton of fuel as fired, or 73,500 cubic feet per kiln heating hour, which was sufficient for kiln requirements.

Jan 1, 1960

By L. H. Adami, E. G. King

The heats of formation of four sulfides --MnS ( alabandite ) , FeS ( hexagonal pyrrhotite ) , ZnS ( wurtzite ) , and CdS ( greenockite ) -- were determined by hydrochloric acid solution calorimetry . The heats of formation from the metals and rhombic sulfur at 298.15 ° K are , respectively , -51.01 ± 0.19 , -23.81 ± 0.24 , -45.86 ± 0.20 , and -35.70 ± 0.30 kcal /mole . The corresponding free energies of formation were calculated from the heats of formation and the pertinent entropy values .

Jan 1, 1964

By F. E. Brantley, D. A. Martin

Synthetic zeolites were tried as selective adsorbents for recovering sulfur dioxide from synthetic gases and gases produced from gypsum decomposition . Initial adsorption tests , using the synthetic gases , indicated that three of these compounds , having sulfur dioxide capacities of up to 29 grams per 100 grams of adsorbent , were satisfactory . Regeneration studies showed that over 90 pct of the sulfur dioxide desorbed from the loaded beds was of sufficient purity for direct liquefaction . However , all zeolites tested lost adsorptive capacity with repeated use . The zeolite determined to be the most promising in the preliminary synthetic gas tests was also evaluated for capability in adsorbing sulfur dioxide from gases produced by the thermal decomposition of gypsum . Despite small amounts of hydrogen sulfide in the gypsum decomposition offgas , good adsorption of sulfur dioxide was attained . The economic practicality of utilizing zeolites for sulfur dioxide removal from industrial gases was not evaluated , but the technical feasibility was demonstrated .

Jan 1, 1963

By A. W. Ambrose

"A need exists for men in oil-field production work who correspond to the mining engineer of a large mining property. Some oil companies prefer to call such an employee a resident geologist, resident engineer, or a petroleum technologist. He should perhaps be more correctly termed a petroleum production engineer. The duty of such a man is to apply his scientific and geologic training practically to oil-field development work.He should be, by education, a mining, civil, or mechanical engineer, with a knowledge of geology and chemistry. Upon completion of his education, such a man should spend several years in the oil-fields. There are two means of gaining proper experience. The first method is to work for an oil company in making a detailed study of each well, collecting data on the history and production, followed by a preparation of good records, from which well logs can be prepared. From the well logs, the geologic cross-sections, peg-models, and structure contour maps can be made. These allow a comparable, detailed study of each well, which is necessary to solve many of the problems. Along with this the engineer should visit drilling wells daily for collection of samples of formations and for a proper study of how they drill. He should form friendly relations with the drillers and production foremen. The second method of gaining proper experience is to start work as a roustabout, pumper, or on the pipe¬line gang, finally working up to a tool-dresser. After three or four years of such work, the engineer may be classed as a petroleum production engineer."

Jan 1, 1920

By Edward L. McHugh

The appraisal of mineral resources of the Challis National Forest, Idaho, by the U.S. Bureau of Mines, was made so that the mineral resources of the forest could be appropiately considered in land use planning. Information from this study is intended to tip the U.S. Forest Service to incorporate mineral resource data into forest plans The study was done in conjunction with the U.S. Geological Survey, which released a companion report on the geology and mineral potential of the Challis National Forest in 1989. This summary report is derived from a more detailed USBM Open-File Report (MLA 6-91) that includes descriptions of mines and prospects, commodity profiles, and development cost models. Since the 1860's mines within the Challis National Forest have produced mineral commodities worth more than $590 million at current (1989) commodity prices. Identified mineral resources have a gross value of about $2 billion at current prices, including 8 strategic or critical minerals. The U.S. Bureau of Mines study identified and described 723 active and inactive mineral properties within the forest. Mineral properties with identified resources were evaluate to determine their economic significance, and an assessment was made of the feasibility of mineral development. Of the 2,516,191 acres in the Challis National Forest, about 390,000 acres were classified as having mining development interest. Commercially important mineral production, mainly of molybdenum, gold, and silver from the Challis National Forest is likely for the foreseeable future.

Jan 1, 1991

By G. B. Atkinson

The Bureau of Mines investigated a method for increasing the leaching rate of bulk superalloy scrap to facilitate recycling and recovery of critical metals such as Ni, Co, and Cr. Three superalloys were investi- gated, the cast-nickel-base superalloy IN-738, the wrought-nickel-base superalloy Rene-41, and the cast-cobalt-base superalloy Mar-M-509. Superalloys melted with 20, 30, 40, and 50 pct Al metal to form inter- metallic compounds were easily crushed to a convenient particle size and reacted rapidly with acid solutions which dissolved the metals. For example, leaching 1/2-in pieces of unalloyed IN-738 with excess 6N HC1 at 95° C for 2 h dissolved about 0.5 pct, while leaching 10 g of minus 20-mesh 30 pct Al-70 pct IN-738 with excess 6N HC1 at 95° C for 2 h dis- solved 96.2 pct.

Jan 1, 1983

By Richard P. Walters

This Bureau of Mines report reviews and assesses the technology for preparing electrodeposited coatings of the platinum-group metals from molten alkali metal cyanide baths. Methods are described for the preparation and purification of the cyanide electrolyte. Vacuum drying, fusion, and purity of the cyanide salts are discussed. Use of a sodium borosilicate test tube as a sodium-ion-conducting membrane for the addition of the desired platinum-group metal is described. The optimum plating parameters of potential and current density for Pt, Pd, Rh, Ru, and Ir coatings that result in the best deposits are given. A method for producing platinum-rhodium alloy coatings of predetermined composition is also described. The importance of careful substrate surface preparation is illustrated. While problems still remain with respect to coating porosity, careful application of the methods described permits the preparation of adherent, coherent electrodeposited coatings of the platinum-group metals.

Jan 1, 1984

By William M. Thornton

[Owing to the comparatively high freezing point of nitroglycerin (14, 15, 16, 17, 18, 23, 37, 38)3/ - 1.9° C. and 13.0° C. for the labile and stabile modifications, respectively, as determined by Hibbert (16) - manufacturers of dynamites have incorporated into the liquid portion of these composite explosives various substances capable of participating in an explosion, to depress the above-mentioned freezing point. Aromatic nitro-compounds, chiefly nitrobenzenes, nitrotoluenes, and nitronaphthalenes, have been used to a considerable extent (11), but such nitrosubstitution products have not proved altogether satisfactory, as has been shown clearly by Naoúm. (14). Consequently there has been a strong tendency in recent years to replace them with one or more of several nitric esters, among which the following (29, 35) have been prominent: Dinitrochlorhydrin (monochlorhydrin dinitrate); nitrosugars, for example, sucrose octanitrate (19); tetranitrodiglycerin (diglycerin tetranitrate); nitroglycol (ethyleneglycol dinitrate); and diethyleneglycol dinitrate (13, 46, 47). Of these, nitroglycol (33, 4l, 45, 48, 49, 65) is outstanding in importance. As the Bureau of fines is naturally interested in the analytical chemistry of the "explosive oils," it seemed desirable to bring together in this report the widely scattered experimental work covering the problem of differentiation that has appeared in various chemical and physicochemical publications.]

Jan 1, 1941

By Jr. Gabler

World resources of cobalt appear ample for the foreseeable future; however, political and economic events have caused concern over the availability and reliability of an uninterrupted supply. Because of this concern, the U.S. Congress requested that the U.S. Bureau of Mines initiate a study of the flow of cobalt in the economy that would delineate and quantify the production areas where metal values are lost. As a result, the Bureau has developed a computerized commodity flow model. A major attribute of this model is that it is amenable to updating as supply, demand, and/or production data change. This report follows the flow of cobalt through its metallurgical and chemical applications and highlights areas where significant losses occur due to downgrading, export, or disposal. The study indicates that about 4,300,000 lb of cobalt-bearing materials are lost each year, representing 24 pct of U.S. domestic demand.

Jan 1, 1990