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By Lance R. Barron

Over the past decade, the U.S. Bureau of Mines (USBM) has studied longwall gate road stability at four mines in the Book Cliffs and Wasatch Plateau Coalfields of Utah. These operations are characterized by multiple-seam mining, abruptly varying cover depths to 914 m (3;000 ft), and massive rigid, sandstone units in the main roof or floor. Such conditions encourage severe bumping, roof instability, and occasional floor heave problems.' Various gate road configurations have been employed to alleviate' these problems. Although the mines have comparable basic conditions, the lithologies and qualities of the immediate roof, floor; and seam ate different in each mine and often vary in a single mine. Gate road systems that mitigate hazards in one mine may prove inappropriate in another or for different areas of the same mine. This report relates the geology of the coalfields; describes the location, geologic setting, specific mining conditions, operating history, and the USBM field study and results or conclusions for each mine; summarizes the relative performance of the gate road systems; and emphasizes the need for site-specific geotechnical data to evaluate gate road conditions and performance.

Jan 1, 1994

By E. A. Rowe, G. H. Keith, B. D. Jones

An evaluation of electrowon tungsten powder was made by comparing its characteristics with conventional hydrogen - reduced tungsten powder . Electrowon tungsten powder was investigated with respect to particle size and shape , apparent density , flow rate , compressibility , green strength , and sintering characteristics . In addition , its chemical purity , absolute density , and purification by melting were determined . Significant findings were higher flow rates and better compressibility than hydrogen - reduced tungsten powder . However , the large particle size peculiar to the electrowinning process effectively prevented conventional sintering to a high- density material . The possibility of producing high - density material , using a new technique of hot swaging sheathed sintered - tungsten compacts , was demonstrated by the achievement of densities of 92 percent of theoretical .

Jan 1, 1965

By J. B. Rosenbaum

This report presents new findings and consolidates previously published data to provide a single reference containing a concise and comprehensive description of the Bureau's work on electrolytic chromium. Two separate systems for electrolytic-chromium recovery were developed, one designated as the oxidized system the other as the reduced system. The electrowinning of chromium metal follows the dissolution of chromium from the ore or from ferrochrome and its separation from gangue and metallic impurities. Chromite was first solubilized by pressure digestion at slightly elevated temperatures in an oxidized acid solution using Na2Cr2O7 as an oxidizing agent. Later it was found that a sodium-free electrolyte was preferable, using return-cell anolyte containing H2SO4 and Cr03 as the oxidizing agent. Gangue materials were separated from the soluble metallics by filtration; and, after the Cr+3 had been stabilized, the metallic impurities were separated as crystalline ammonium salts by vacuum crystallization.

Jan 1, 1957

By J. S. Berber

Bastnasite is a natural fluocarbonate of the cerium group and affords an abundant and high-grade source of the lighter rare-earth elements. As part of a broad research program in rare-earth element technology, the Federal Bureau of Mines directed extensive experimental work to separating and purifying the rare-earth elements in bastnasite. By the use of a combination of techniques--classical chemical, ion exchange, and solvent extraction--the processing of a bastnasite concentrate to obtain the individual rare-earth elements, or groups of elements, was accomplished. A bastnasite concentrate, containing about 60 percent rare-earth oxides, was sulfated with concentrated sulfuric acid to eliminate the carbon dioxide, fluorine, and silica. Calcination at 1,200° F. made the gangue matter insoluble, thus permitting the separation of the soluble rare-earth sulfates. Essentially 100 percent of the rare-earth elements were recovered by this procedure. Since the rare-earth sulfate solution contained only trace amounts of nonrare-earth elements, subsequent separation procedures were simplified.

Jan 1, 1960

By D. C. Seidel

This report describes generic procedures and equipment arrangements for conducting laboratory-scale hydrometallurgical and related waste-management experiments. It provides a starting point for personnel who have received or are receiving professional training, but do not have specific experience in laboratory procedures. With guidance, it also has application as a resource for technician training. The publication contains chapters on laboratory safety, feed-sample preparation, leaching, solids-liquid separation, and recovery from solution.

Jan 1, 1995

By John J. Baz-Dresch

Catalyzed diesel particulate filters (CDPF's) reduce the concentration of diesel particulate matter (DPM) and may reduce the emissions of carbon monoxide (CO) and hydrocarbons (HC) in diesel exhaust. Asamera Minerals' Cannon Mine first installed CDPF's in 1987, and currently has 12 diesel-powered vehicles equipped with CDPF's. The Cannon Mine and the U.S. Bureau of Mines collaborated to evaluate the durability and performance of a CDPF. One of the CDPF's used at the mine was periodically evaluated in the USBM's diesel emissions laboratory after 839, 1,584, and 2,881 h of in-mine service. The objectives of this report are to present results from the USBM's evaluation of this CDPF, to describe the Cannon Mine's experience and cost analysis of using CDPF's, and to make recommendations for the future use of CDPF's. CDPF's improve air quality at the Cannon Mine, but they frequently become plugged and are subject to excessive mechanical shocks and stress, shortening their useful life. Mine records indicate that CDPF's account for 0.8 to 4.9 pct of the vehicles' operating cost at the lVine. CDPF life to date has ranged from 1,671 h to more than 5,992 h. Laboratory tests of the CDPF determined that DPM removal efficiency decreased and regeneration temperature increased over time.

Jan 1, 2010

By F. W. Lane

Some months ago the Bureau of Mines began research of a fundamental character on sulphur in petroleum. In the course of this work, the usual qualitative test for sulphur in organic compounds1 was applied to certain oils that were believed to contain approximately 0.5 percent sulphur. No sulphur was found, and, as a check on the qualitative test, the oils were subjected to quantitative determination of this element by the oxygen-bomb method.2 The sulphur content of the oils ranged from 0.10 per cent to 0.50 per cent. This experience led to further trial of the qualitative test for organic sulphur, both on the oils mentioned above, and on common sulphur-containing organic substances. No difficulty was experienced in detecting the element in the latter, but with the petroleum oils the test, as usually performed, could not be relied upon to detect less than 0.60 per cent of sulphur consistently. The use of mechanically polished pure sheet copper for the detection of free sulphur, hydrogen sulphide, and perhaps other sulphur compounds has been recommended.3

Jan 1, 1927

By J. Koster

[In lQ jG thc E'lcct,ro:~(: L7.l :~u..-ic:ll S;%cti ?n of t?c :I. tcIl~tr,-;lcal 3:vi cioa, ?U~CE~U of lv!irtos, bc,~m an 9.ct iv.t In-:?*t ik7;5i GI of r.:ct.l-;c?;is for rccovcrin,; niclrel, cop?ir, an2 ?? cciou:; ~ot-1 c 1;-on or; :; of tile 3unl~crvi~.l~~ tiistrict in C1ni.k Coult:r, !Icl.r. ]

Jan 1, 1939

By J. F. McCoy

The quantitative determination of the mass rate of flow of methane in an underground airway is calculated as the product of the methane concentration and the air flow rate. Velocities are taken at several points and then averaged over the airway cross section to determine the total volume flow. Errors in velocity measurement thereby result in errors in total volume flow as well as the mass flow rate of methane. The purpose of this program was to evaluate existing instrumentation for measuring air velocities in the speed range under 2000 feet per minute; to evaluate the method for determining total air volume flow from the velocity measurements; to evaluate new techniques which may be applied to measuring air velocities; and to design a prototype instrument which represents the best technique based on the evaluation. The instrument should be: a. portable b. self-contained c. insensitive to dust, moisture and temperature changes d. safe for use in gassy mines

Jan 1, 1972

By Nils A. Eilertsen

This Bureau of Mines report describes the unit cost procedure for estimating direct development costs within a cave block in an undercut block caving mine. Costs of supervision, labor, equipment, and supplies are combined to build a unit cost for each type and size of mine development opening in the block. These costs are then combined to estimate the direct cost for developing a ton of ore. Operating data from several domestic metal mines are combined with a hypothetical mining system to illustrate the costing procedure.

Jan 1, 1975

By M. J. Spendlove

A progress report is presented on a research program in which an attempt was made to develop a practical sulfide-volatilization process for recovering tin from low-grade Bolivian ores. Shaft-furnace designs and operating techniques were studied in a series of experiments in which the objective was to sulfidize cassiterite to stannous sulfide, remove the stannous sulfide by volatilization, reconvert the stannous sulfide to stannous oxide, and collect the resulting fume. A shaft furnace was developed and operated in a final test in which many of the previous difficulties were surmounted. Since the supporting funds were exhausted at this point, the project was discontinued; recommendations for further improvements in furnace design and operation were made on the basis of interpretation of experimental results obtained in shaft-furnace experiments and other related studies.

Jan 1, 1955

By L. J. Froisland

Water classification and heavy-media sink-float methods were investigated for concentrating metallic junk automobile shredder rejects initially upgraded to about 75-percent metal content in an air elutriation system. An 8-inch-diameter water elutriation column with a feed capacity of 2.7 tons per hour was constructed and operated. The results obtained were compared with those produced by sink-float methods. Tests made on duplicate samples of an intermediate-grade metal product were successful in upgrading the metal con-tent from 75 percent to 98.7 and 99.1 percent with respective recoveries of 95.5 and 98.9 percent for the water classification and sink-float procedures. Tentative flowsheets for treating junk auto shredder rejects are outlined.

Jan 1, 1972

By W. W. Odell

Engineers interested in the manufactured-gas industry have witnessed p pronounced improvements in gas-generating equipment and marked changes in operating procedure during the past decade. In spite of these changes, however, the trend of development in the near future seems to be doubtful. Uncertainty exists mainly because no one can yet accurately calculate the number of years which will elapse before petroleum products become too expensive for, general use in making gas. Research in this field has been active, and the ultimate results are awaited with interest. Some engineers predict that in the future coking coal will be carbonized on such a large scale that coal gas will be used (straight or modified) for city distribution; others maintain that gas oil will be used in large quantities in the production of base gas; they believe that it will be economical to use oil even at appreciably higher prices. The question involves, among other; factors, consideration of initial and relative costs of equipment, flexibility of operation, salability of coke, cost of distributing different gases, and the relative value of by-products, It is common belief that for many years large quantities of oil will be used in gas-making, particularly in the generation of peak gas or that water gas will be used for the synthetic production of hydrocarbons to enrich additional water gas. In this paper interest centers in a discussion of the practicability of employing synthetic processes in view of reported investigations of the chemistry of the synthetic reactions. For many years it has been known that the chief components of water gas would react chemically under proper conditions to form methane. As long ago as 1903 a patent3 was issued in this country for a gas-making process which included the synthetic production of methane. More recently the studies of numerous investigators here and abroad have shown that besides methane it is possible to produce other paraffins, olefins, and additional, materials adaptable for enriching water gas or for other uses. The question arises: In what manner, if at all, can such processes be incorporated, as a part of the gas-making scheme in a city-gas plant?

Jan 1, 1928

By Otto Ruhl

The zinc-lead ore reserves of the Tri-State district of Kansas, Missouri, and Oklahoma, as of December 31, 1947, are estimated at a total of 66,100,000 tons of crude ore containing 2.18 percent metallic zinc and 0.38 percent metallic lead. The Bureau of Mines began estimating the reserves in October 1945 and completed the' work December 31, 1947. A total of 38,900 acres of land representing approximately 5 percent of the area of the district is covered in this report. The work was confined for the most part to properties developed or partly developed by drilling and underground workings, and to acreage sufficiently drilled out to indicate ore of enough tonnage to make a commercial undertaking. The acreage in which ore reserves exist is widely distributed in all three States. A map of the Tri-State area is shown in figure 1. The remaining 95 percent of the area is not necessarily nonproductive but represents, possibilities for future exploration and development of additional mineral resources when and if economic conditions or national necessity encourage such work. Of the total reserves, 41 percent are in Missouri, 38 percent in Kansas, and 21 percent in Oklahoma.

Jan 1, 1949

By Forrest T. Moyer, Nina L. Jones, Mary B. McNair, Virginia C. Berté

To keep the mineral and allied industries informed of trends in the causes of accidents, and to point out the need for corrective measures, the Bueau of Mines collects, analyzes, and periodically publishes health and safety statistics. This report includes data for 1963 on injury experience, with related employment statistics, at coal mines in the United States. These data are presented in tabular form under the following headings:

Aug 1, 1965

By W. W. Adams

"During the calendar year 1925 the Bureau of Mines received from the operators of several hundred mines and quarries complete accident records covering deaths, permanent disabilities, and “lost time” temporary injuries. Some of the companies, - those that participated in the National Safety Competition-also furnished information showing the number of man-hours of work performed during the year. With these two types of information it was possible to calculate the accident-frequency and accident-severity rates of the different plants. Complete and comparable reports of accidents and Man-hours of “exposure” were received from 34 underground metal mines, 59 underground coal mines, 15 underground mines producing other nonmetallic minerals, and 102 open quarries or open-pit mines. The figures in the table appended to this report show the accident severity rates and other data for each of the 34 underground metal mines and for the group as a whole. It is proposed to publish similar figures for the other classes of mines and quarries at an early date.The 34 metal mines listed in the table are situated in Arizona, Idaho, Kansas, Michigan, Minnesota, Missouri, New Jersey, New Mexico, Oklahoma, South Dakota., and Utah; they employed 5, 925 men, an average of 174 men per mine, including employees above-ground as well as underground. With but few exceptions, 50 men was the minimum number of employees in any mine. The total period of employment or “exposure” at the 34 mines was 14,612,607 man-hours, an average of 2,466 hours per man, or the equivalent of 308 work-days of eight hours for each employee. Accidents resulted in 15 fatalities, 9 permanent disabilities, and 1,950 temporary “lost time” injuries (causing disability exceeding remainder of shift). The fatal and nonfatal injuries represented 132,575 days of disability. Thus the accident frequency rate for the group was 135 accidents per million hours and the accident severity rate was 9.073 days lost per thousand hours of 1 “exposure”. The severity rates ranged from 0.227 to 88.653, while the ·range of the accident-frequency rates was from 16. 6 to 307 .4. In compiling the accident severity rates shown in the table, all accidents caused by explosives were weighted at twice the number of days actually lost, as one of the purposes of the National Safety Competition was to stress the prevention of accidents caused by explosives."

Sep 1, 1926

By Ivan F. Avery

OUTPUT of carbon black in 1959 increased in all producing States except New Mexico. The national increase was 20 percent. Domestic sales and exports increased 22 percent and 16 percent, respectively, resulting in a 21 percent gain in sales. Sales to the rubber industry, which purchased 95 percent of the domestic output of carbon black, increased 23 percent. Sales to all other major consumers also increased. Stocks decreased 82 million pounds during the year. [ ]

Jan 1, 1960

By Allen S. Smith

Analysis of the helium content of a natural gas presents more than the usual difficulties encountered in applying the thermal-conductivity method because of the relatively small amounts of this inert as present and the wide variation in the other constituents. However, the numerous advantages of this method and its adaptability to Continuously recording and control instruments make it worthy of consideration. A specific application of the method described yields quantitative results only when used with gas mixtures of known qualitative compositions which Vary within predetermined limits. Periodic analyses for the helium content of a producing gas well may be conveniently made by an absorption method, and a continuums analytical method is not necessary for this purpose. Natural gas containing 1.75 to 1.90 percent of helium produced from Government-owned wells is processed in the Amarillo (Texas) Helium Plant of the Bureau of lanes. The helium extracted in the plant is supplied to the Army and Navy, and the processed natural gas is sold to a commercial gas company. As complete recovery of the helium in the raw material is not economically practicable, the processed gas contains 0.1 to 0.3 percent of helium, depending upon conditions of operation. Production is checked against the helium removed from the gas, which before the installation of the thermal-conductivity apparatus was calculated from the analysis of a cumulative sample of the processed gas. As conditions of operation affect the residual helium content to a large extent, a composite sample was an uncertain index of the efficiency of the process.

Jan 1, 1934

By Elmer W. Pehrson

The recent establishment of an official price of 64.64 cents per ounce for silver by the President's order of December 21, 1933, has provoked discussion as to the effects of this move on the various metal-mining industries. To assist those of the mineral industry who are interested in this problem, the Bureau of Mines presents the following analysis of basic statistical data concerning; the relation of the silver price to the value of copper ores mined in the United States. The term "copper ore" as used herein includes all ores in which copper is the most abundant base metal paid for. In 1928, this class of ore contributed 98 percent of the total copper output of the United States.

Jan 1, 1934

By R. L. Rough

The Bureau of Mines analyzed rotary-coring-operations data to compare mud and air as coring mediums, and to compare core recoveries, penetration rates, and cost data for the respective mediums as part of an investigation of the susceptibility to secondary-recovery techniques of petroleum reservoirs in Ohio, Pennsylvania, and West Virginia. This report describes the rotary-diamond coring equipment and operations employed while coring 20 wells--10 cored using mud, and 10 cored using air. Data relevant to the draw works, rotary-table power, drill pipe, drill collars, core barrel, core head, mud pumps, or air compressors are tabulated. Average bit weight and rotary speed, core recovery, and penetration rates are listed for each formation cored. In general, core recoveries were better from the mud-cored wells, whereas penetration rates were faster for the air-cored wells. Coring costs were about the same for single-formation wells cored with either mud or air; however, costs increased considerably when multiple-formation wells were cored with air.

Jan 1, 1969