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Objective: To enable mine operators and mine inspectors to make quick and accurate measurements of the explosible nature of coal and rock dust mixtures.

Jul 1, 2008

By A. A. Cochran

Methods of preparing small heats of steel containing radioisotopes were developed, and the techniques of stripping film autoradiography were used to detect and study the carbide and sulfide phases in titanium-bearing steels. Metallography had revealed areas of titanium sulfide and ferrite or pearlite adjacent to areas of titanium carbide and ferrite, and unidentified, irregular phases at the boundaries between these two areas. Sulfur 35 was used to deter-mine the extent of the titanium sulfide inclusions, and carbon 14 was used to delineate the titanium carbide phase. Individual radioactive areas were located with a resolution of approximately 10 microns. A general background exposure that was not correlated with microscopically visible phases was observed in the carbon 14 autoradiographs. The evidence from both sulfur 35 autoradiographs and carbon 14 autoradiographs indicated that the unidentified inclusions were sulfides rather than carbides. INTRODUCTION The use of radioisotopes to facilitate the work at the Rolla Metallurgy Research Center was expanded in fiscal year 1959 when the Bureau of Mines authorized the installation of an intermediate-level radioactivity laboratory. Before this time, sealed cobalt 60 sources had been employed for radiography, but no tracer work was done. The primary objective of the first experiments conducted in the new laboratory was to supplement physical metallurgy investigations of selected problems in steel research.

Jan 1, 1962

By Roy H. Poston

This paper sets forth the mode of ore occurrence, characteristics of ore and country rocks, methods of exploration, development, and. ore extraction, and the costs of underground operation at No. 8 mine of the St. Louis Smelting and Refining Works of the National Lead Co. located near the southern extremity of the Southeast Missouri lead district. The author acknowledges the assistance of E. T. Campbell, geologist, in the preparation of the paragraphs on the geology of the ores. HISTORY The first record of mining in St. Francois County, Mo., concerns more or less shallow semisurface "diggings" which were worked about the year 174-2. In 1864, however, the discovery of the disseminated deposits, the present source of lead, was made on property near the town of Bone Terre. Winslow has estimated the lead-ore production in this county prior to 1869 to be 59,526 tons.3

Jan 1, 1929

By R. W. Stahl

Gas accumulation and dust suspension are the major safety hazards in coal stockpiling and reclaiming operations. This report presents a schedule of safety precautions and plant design features devised by the Bureau of Mines to reduce danger from these and other sources.

Jan 1, 1965

By Hiram C. Draper

The Mining Division of the Bureau of Mines, in cooperation with the Obstacle and Demolition Branch, Engineer Research and Development Laboratories, Department of the Army, undertook some extensive tests to determine the effectiveness and limitations of using standard demolition-type shaped charges in underground Mining. The tests proved the shaped charge has no practical application in the functions of mining covered by this report. At an approximate cost of 0 per foot hole plus spall produced by the most efficient single shots with the M3 shaped charge, the cost is over 20 times that of producing a better hole with a rock drill. The concussion would prohibit its use in many mines, and the excess carbon monoxide gas liberated by the pontolite explosive would be an additional hazard when used underground.

Jan 1, 1948

By Ernesto Villaescusa, Andres Brzovic

Rock masses of the primary copper ore at the El Teniente Mine are very competent and massive. The rock mass contains almost no open discontinuities. Nevertheless, there is a high frequency network of small discontinuities coupled with widely spaced faults. A data collection campaign designed to characterize the rock structure was recently implemented. The results show that conventional analysis in terms of discontinuity frequency does not predict differences between two studied sectors. However, when an empirical definition of a weak discontinuity is applied, appreciable differences between the two sectors appear in terms of discontinuity frequency and predicted in situ block size distributions. These differences are in accordance with actual observations at the mine site. Due to the geological features of the primary copper ore, rock mass classification schemes cannot be readily applied to characterize these rock masses.

Jan 5, 2007

By J. A. Kosek

Work has been carried out under Bureau of Mines Contract HO 395132 to develop improved sensor cells for use in direct-reading detectors and diffusion exposure meters. A pumped CO sensor cell was developed which has a shorter response time, improved temperature cycle characteristics, and improved linearity and stability at high CO concentrations. Diffusion CO sensor cells have shown good response level stability and linearity up to 1000 ppm. In addition, a new sensor cell catalyst has been developed for NO2 sensor cells which has a much shorter response time and improved response stability characteristics.

Jan 1, 1982

By K. A. Johnson

Marshall and Bird have published the results of a cooperative investigation by the Bureau of Mines in which they developed a procedure for measuring the agglutinating value of coal.4 As stated in their paper, the procedure outlined was suggested by the early worn of Richters5 and Campredon,6 whose procedures were hurriedly modified to meet the need of an investigation then in progress. Since the publicatien of that paper, further work has been done in an attempt to show how the variables involved affect the concordance of the results, in order that such results may be obtained in different laboratories. Briefly, Marshall and Bird's method for determining the agglutinating value of coal consists in carbonizing an intimate mixture of 10 parts by weight of sand and 1 part by weight of coal in a porcelain crucible at a uniform temperature of 950° C. in a, vertical, cylindrical, electrically-heated furnace. After carbonization, the resultant buttons are crushed in a testing machine and the breaking strengths recorded in grams. The agglutinating value reported is the average breaking strength of 10 buttons. The coal for the test is prepared by crushing to pass a 100-mesh screen. The sand used as a diluent is sized between 40 and 50 mesh sieves with openings of 0.381 icon and 0.279 millimeters, respectively.

Jan 1, 1930

By Francis Church Linxoln

"This property was explored as part of a general investigation of zinc-prodccing areas of southwestern Wisconsin at a time when an effort was being made to increase the production metals important to the Nation's war program. This report describes the work that was done and presents the data obtained.ACKNOWLEDGEMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the and that they make the greatest possible contribution to national security and economy. It is the policy of the bureau to publish the facts developed by each exploratory protect as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, P., G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director. Special acknowledgment is due Professor G. H. Pett, of the Wisconsin Institute of Technology at Platteville, Wis., Jack Tracy, manager of the Mifflin Mining Co., and J. M VanMatre, representative of the Defense Property, for their assistance in the work. Acknowledgment is also due to A. F. Agnew and A. V. Heyl, geologists of the Federal Geological Survey, for furnishing geologic interpretations and lithologic studies of the drill-hole sections. All drilling was done under the immediate supervision of Francis C. Lincoln and M. Howard Berliner, project engineers, Edward P. Barrett, district engineer, Minneapolis, and E. D. Gardner, regional engineer, of the Bureau of Mines."

Sep 1, 1946

By Janet Torma-Krajewski

Job tasks that involve exposure to work-related musculoskeletal disorder (WMSD) risk factors may impact both the risk of injury and production downtime. Common WMSD risks factors associated with mining tasks include forceful exertions, awkward postures, repetitive motion, jolting and jarring, forceful gripping, contact stress, and whole body and segmental vibration. Mining environments that expose workers to temperature/humidity extremes, windy conditions, and slippery and uneven walking surfaces also contribute to injury risk. National Institute for Occupational Safety and Health (NIOSH) researchers worked with powder crew members from the Bridger Coal Company to identify and rank routine work tasks based on perceived exposure to WMSD risk factors. This article presents the process followed to identify tasks that workers believed involved the greatest exposure to risk factors and discusses risk reduction strategies. Specifically, the proposed prill truck design changes addressed cab ingress/egress, loading blast holes, and access to the upper deck of the prill truck.

Jan 1, 2009

By John R. Duda

The Bureau of Mines is developing estimates of capital investment, operating cost, and selling price for underground mines producing bituminous coal by various mining methods. This study estimates the required capital investment, operating costs, and selling prices for two hypothetical mines designed to produce 1.5 and 3 million tons per year (MM tpy)3 by using a longwall system in conjunction with a continuous-mining system. The coal properties being mined are assumed capable of sustaining a 20-year product Lon period. Wages and union welfare payments used in this study are those in effect as of December 6, 1975, as set forth under the National Bituminous Coal Wage Agreement of 1974. Costs of materials and equipment are based on January 1976 Indexes. Initial capital investment is $33.8 million for the 1.5-MM-tpy mine and $61 million for the 3-MM-tpy mine. Capital requirements, including deferred investments, were estimated to be $52.5 and $94.2 million, respectively. These figures translate into total capital investments of $34.87 and $31.31 per ton of annual production. Assuming a desired 15-percent discounted cash flow rate of return, with Federal income taxes at 50 percent, the required selling prices would be $12.06 and $10.94 per ton for the 1.5- and 3-MM-tpy mines.

Jan 1, 1976

By Robert Stefanko

Test procedures for evaluating underground coal mine trailing cable splices are formulated. The tests are utilized to evaluate several trailing cable splices. The laboratory results are compared with actual field observations and experience. The results are utilized to define quantitatively the generalized terms of the 1969 Health and Safety Act. Recommended specifications and procedures for testing by MESA Department of Approval and Testing personnel are included. Failure points in splices are detailed and presented for use by a MESA training program and manufacturers attempting to improve product quality.

Jan 1, 1974

By D. Bienstock, J. H. Field, M. J. Lempel

A computer program is presented to perform the detailed and numerous calculations required for determining the interface temperatures and steady - state heat flow through a furnace wall composed of several refractories in layers . A method is developed that will allow the designer to determine the various thicknesses for each refractory layer to minimize either the total wall thickness or the cost of the wall per unit of area . A sample problem is presented and analyzed to illustrate the techniques involved .

Jan 1, 1964

By J. A. Eisele

The Bureau of Mines has reviewed the literature related to the recovery of A1203 (alumina) from coal ash. A small amount of unpublished data is also reported. Of the processes studied, the alkaline-sinter process is the most promising from a technical standpoint. However, owing to the high cost of processing coal ash, the dispersed location of powerplants, and the domestic availability of higher grade alternate materials, coal ash does not rank as a primary source material for replacing imported bauxite.

Jan 1, 1979

By T. F. Mitchell, Walter J. Long

"SUMMARYThis report is one of a series giving results of laboratory and pilot-plant investigations of the concentration of western manganese ores begun in December 1940. Data given summarize results of laboratory investigation of three samples of complex oxide manganese ores from the Madeline property, Lake View, and Victory claims, Clallam County (Olympic Peninsula), Wash. The samples represented an extremely intimate and complex association of manga¬nese oxide minerals with silica and iron.Owing to the complex nature of the ores, no effective concentration by ore-dressing methods was possible. No high-grade manganese concentrates were produced and the highest recovery at minimum accountable grade was only 55 percent on one of the ores tested.Since the Clallem County ores did not respond to ore-dressing methods, leaching processes were investigated, results of which are to be published in a separate report.INTRODUCTIONOre-beneficiation tests were conducted on three samples of manganese oxide ere from the Madeline, Lakeview, and Victory claims, Clallam County, Wash. The ores are extremely complex because of the unusually small size of manganese mineral particles, their mode of occurrence, and relationship to the gangue. None of the three ores was amenable to the production of high-grade manganese products by ore-dressing methods."

Dec 1, 1945

By Thomas A. Davidson

The Bureau of Mines Helium Field Operations has developed a method for determining the helium-3 CHe) content of natural gas and mixtures eontaining 0.5% to 100% helium. The helium is preconcentrated by passing samples through anhydrone, a liquid-nitrogen-cooled chareoal trap, and a titanium absorption trap. The mass spectrometer used to analyze the samples is tuned to 3He at mle ::=; 3.016. Hydrogen deuteride (HD+) interference is minimized by the titanium absorption trap and high instrument resolution. Sample measurements are compared with identically made measurements of a gravimetrically prepared primary standard. The method has a limit of detection of 0.15 ppb with a relative deviation of 13% below the 1~ppb level. The relative deviation is less than 7% for gases eontaining over 100 ppb 3He. The helium isotope ratios of natural gases from the Bureau's Tuck-Trigg Dome Red Cave, the Bush Dome Red Cave, and the Bush Dome Brown Dolomite Formations are distinguishable from one another and from the isotope ratio of crude helium produced from the Panhandle-Hugoton Gasfield.

Jan 1, 1990

By D. A. Stanley

The Bureau of Mines is investigating a method of dewatering flocculated fine-particle waste that involves treating the waste with a high molecular-weight polymer such as polyethylene oxide (PED) followed by dewatering on a static screen and/or in a trommel. Dilution of the polymer solution used for dewatering and use of the ion-exchanged form of the montmorillonite clay were found to be major factors determining the amount of polymer required to dewater clay-containing slurries. The amount of polymer, A, required to dewater ion-exchanged montmorillonite can be described by the equation, An = kC + b where n, k, and b are empirical constants and C is the concentration of the polymer solution used for dewatering. Clays that require large amounts of polymer for dewatering also dewater to a lower solids content. The concentration of the polymer solution is important because it affects the radius of the polymer coil in solution and hence its ease of transfer to a bridging configuration by shear. The constant, n, a function of the charge to hydrated radius of the exchange ion, relates to the strength of the bond between the polymer and the surface of the clay through a water bridge. The constant k is related to the hydrated radi-us for sodium or to the unhydrated radius for the other exchange ions.

Jan 1, 1986

By Jacqueline A. McClaskey

The U.S. Bureau of Mines (USBM) Information and Analysis Directorate collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U. S. economy. The USBM's data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), which placed the collection of mineral statistics on an annual basis. The most recent authority for the USBM survey activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress). This act strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1994

By IRENE AITKENS

The Mining Law of 1910 , with amendments of 1914 and 1928 , is at present in force in the Dominican Republic . The first and basic mining law of the Republic was passed in 1876 , and although numerous changes and amendments have been made from time to time , the new laws and amendments thereto have not changed the original or basic law materially . However , these enactments have materially changed the legal methods governing the exploitation of the mineral resources of this country and have added new regulations and requirements to those concerning certain specific minerals , etc. The original or basic law still exists as it was first promulgated to protect the rights of the Dominican Republic itself , the rights of the landowner , and the rights of prospectors in general . The Mining Law of 1876 remained in force , without amendment , until it was superseded by the law of May 25 , 1904 , an enactment modeled after the Mexican mining law and designed especially to encourage the investment of

May 1, 1931

By Robert L. Mentch

CADMIUM is one of the metals apparently destined to remain relatively scarce. The en tire supply of primary cadmium is recovered as a byproduct, concurrently with the treatment of ores of other metals. Development of the cadmium industry is attributed to metallurgical improvements in the zinc industry; output depends almost wholly upon zinc production. Cadmium is a metal of specialized uses where its superior performance has developed a strong, expanding demand. The supply, however, has been relatively unresponsive to price because of its byproduct nature. Cadmium's outstanding properties would assure it a manyfold greater market if more were available at lower prices.

Jan 1, 1958