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By B. W. Gandrud

[This report presents the data of one of a series of investigations of the washability of Alabama coals as indicated by float-and-sink tests mode by the Bureau of Fines at the Southern Experiment Station in cooperation with the University of Alabama and Alabama coal producers. The Klandyke mine, operated by the Blocton Mining Co., is about 1 mile eat of Vest Blocton, Bibb County, Ala., floor the southwestern, extremity of the Cahaba coal field. The Bureau of Mines already has published three reports that deal with the, washability of Cahaba coals - one a washability study of the Clark bed at Marvel4/ one on the tabling of fine coal from the Thompson and Woodstock beds5/, and the third a washability study of the Henry Ellen bed at Acmar6/.]

Jan 1, 1939

By Donald O. Capstick

The U.S. Bureau of Mines conducted an inventory of the prospects and mineral resources in the Scodies RARE II area (No. 5212) in 1982. No mineral production is recorded from the area, and no mines are being developed. The Scodies RARE II area is comprised primarily of light colored granodiorite with minor inclusions of mafic granitic rocks. Late stage differentiates of magmas resulted in quartz veins and pods. Metasedimentary rocks which have been mineralized in some parts of the Sierra Nevada were not observed within the study area during this investigation but small inclusions have been reported.

Jan 1, 1983

By Francis E. Federspiel

Silver and gold are the principal metals in the study area; they occur in quartz veins or silicified portions of shear zones. In some deposits, lead, antimony, zinc, and molybdenum are associated with gold and silver. A uranium-bearing buried stream channel lies near the southern boundary. Since 1850, more than 300 lode claims and relocations have been recorded mainly in the southeast corner of the study area (fig. 1). Complete mine production records are not available; however Clark (1977, p. 28) reported less than $300,000 of gold and silver were produced, mainly from the Exchequer, IXL, and Pennsylvania Mines. Other mines in the area probably yielded are before 1900, but early records are not available.

Jan 1, 1981

By R. L. Rough, W. K. Overbey

The Bureau of Mines obtained samples of oil - reservoir rock from wells in Ohio , Pennsylvania , and West Virginia as part of an investigation of the susceptibility of petroleum reservoirs to secondary - recovery techniques . Illustrations and tables showing the geographic and stratigraphic sequence of the cored reservoirs and 40 tables of detailed lithologic descriptions of the reservoirs are presented . Information relevant to geologic surroundings , oilfield history , coring and well logging operations , and reservoir core analyses are referenced throughout the report .

Jun 1, 1970

By Loren R. Anderson

Traditionally, an evaluation of the safety of slopes has been based on computing a safety factor against failure. In computing the safety factor, the geometry of the slope, the soil parameters and the pore pressures are treated as deterministic quantities even though they are known to be random variables. A pseudo-three-dimensional probabilistic slope stability model has been developed that treats shear strength as a random variable. The model uses the probability of a slope failure as an assessment of slope reliability. The model can accommodate zoned embankments of soil in which the strength is described by the Mohr-Coulomb strength envelope. Autocorrelation functions are used to describe the spatial correlation of the strength parameters, c and tan ø. Model error can also be included in the analysis. The model has been applied to an existing tailings dam and to several hypothetical examples. These examples are presented to illustrate the influence of the choice of the soil strength variability parameters on the probability of failure. The results show that the critical failure surface based on the minimum safety factor is not necessarily the failure surface that will yield the maximum probability of failure. The analysis of the tailings dam shows that variance reduction can be large and that the model error is the dominant source of uncertainty for the embankment analyzed.

Jan 1, 1982

By W. P. Yant

Canister-type gas masks Pave become an essential part of the equipment of many industries, not only for use in .emergencies, but also in performing normal operations of industrial processes and procedures, particularly where ventilation is not practically or economically feasible. They are also used widely for enhancing safety of operations which previous to the development of gas masks had been performed in harmful atmospheres. Since the inception of industrial gas masks the Bureau of Mines has been actively engaged in endeavoring to increase the efficiency and safety of these devices, and this bureau bas become a source of advice to manufacturers in producing devices of good quality and to industry in the proper selection and use of these devices. In order to give first-hand information and keep current with the demands and needs of industry it is necessary to perform investigations from time to time. This report deals with tests of certain types of commercial gas-mask canisters for protection against mercury vapor.

Jan 1, 1932

By W. M. Dressel

In producing feed for a lead blast furnace, concentrates analyzing 70 to 80 pct Pb are sintered to produce a physically acceptable low-sulfur product which contains only about 50 pct Pb. Mixtures of PbS with varying amounts of SiO2, CaO, Fe 20., and ZnS were heated in an oxidizing atmosphere at 1,000° C; the products were cooled and examined to determine the problems involved in producing sinter with substantially higher lead levels. Microscopic and electron microprobe studies of the above products as well as experimental and commercial sinters indicate that sinters consist essentially of lead silicates, lead-zinc silicate, calcium zinc silicate, and spinel (ferrite). Lead oxide and lead sulfate areas appear to result from insufficient mixing of the materials prior to sintering. The data give an insight into the process and show that sintering results from a complex interaction of all constituents and that sintering is not simply a matter of diluting the mixture to control the oxidation of lead sulfide.

Jan 1, 1975

By Kenneth Trelewicz

This report describes the total effort that went into developing environmental test criteria for general mine instrumentation. The project was a two-phase effort. Phase I consisted of research and mine visits to develop an environmental profile for mine instrumentation. The profile was translated into general requirements and then into test requirements. A review of existing government and commercial specifications was performed to determine if they matched mine instrumentation test requirements. Finally, a set of environmental test procedures was developed for the testing of mine instrumentation. Phase II consisted of selecting and purchasing sample mine instrumentation and subjecting them to the previously developed tests. The purpose was twofold: (1) to evaluate the criteria developed for use as an instrumentation test document and (2) to determine the effects of the various criteria on a representative sample of both proven and newly developed instrumentation. The test criteria were then modified, based on the results of the testing, and are listed therein.

Jan 1, 1981

By James Westfield

This report covers the calendar year 1954 and has been prepared and submitted to the Congress of the United States in accordance with the provisions of Sec. 106(a) and Sec. 2l2(c) of the Federal Coal-Mine Safety Act (66 Stat. 692; 30 U.S.C. Sec. 451-483). Background The Federal Coal-Mine Inspection program was established to carry out the provisions of Public Law 49, 77th Congress, H. R. 2082, approved May 7, 1941. This act has since been amended to be known as Title I -Advisory Powers Relating to Health and Safety Conditions in Mines, under Public Law 552, 82d Congress, approved July 16, 1952, which also includes Title II -Prevention of Major Disasters in Mines. Public Law 552 is known as the Federal Coal-Mine Safety Act.

Jan 1, 1956

By William F. Hahn

The Bureau Of Mines recognized the desireability of illuminating working places in trona mines. This report describes two illumination system designs, their demonstration and evaluation on a Jeffrey 120HR continuous mining machine in an active working trona mine in Wyoming.

Jan 1, 1980

By Forrest T. Moyer

The safety record of the metal mining and milling industries in 1965 is reviewed by the Bureau of Mines. The overall injury-frequency rate of 23.77 per million man-hours was 5 percent lower than in 1964 and was the lowest annual rate in a statistical history beginning with 1931. The injury-severity rate of 3,521 days lost per million man-hours in 1965 represented a 5-percent improvement over 1964. However, the total of 3,825 disabling work injuries comprised 61 fatal and 3,764 nonfatal injuries, one and 92 more, respectively, than in 1964. At primary nonferrous smelters, refineries, and reduction plants, the injury-frequency rate of 8.97 per million man-hours in 1965 was 13 percent lower, but the severity rate percent higher than in 1964. these plants in 1965, 4 more of 1,173 days lost per million man-hours was 17 There were 12 fatal and 971 nonfatal injuries at and 28 fewer, respectively, than in 1964.

Jan 1, 1969

By Rose L. Ballard

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are the tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is ordinarily termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1983

By F. N. Kissell, C. M. McCulloch, Maurice Deul, J. R. Levine

The methane content of virgin bituminous coalbed can now be measured accurately in the field with exploration core samples from vertical boreholes. The gas content of the coal per unit weight can be used either to design a mine ventilation system or to determine if degasification of the coalbed will be necessary before mining, and to determine the gas resources in the coalbed. The equipment necessary to conduct the test costs less than $50. The gas content of the coal in place in the ground is determined by summing the gas lost from coring, gas measured during desorption, and the residual gas in the coal. Upon removal from the borehole, the core sample is placed in an airtight container and desorbed for several weeks until the desorption rate is below 0.05 cm3/g for 5 consecutive days. The gas lost from the core while it was being cored and the residual gas are estimated by a new graphical method. The amount of gas remaining depends upon whether the coal is friable or blocky. Friability appears to relate to the depth of the sample below the surface, fixed carbon percentage, Hardgrove grindability index, and proximity to tectonic disturbance. Friable coals emit nearly 96 pct of the total gas during desorption whereas a blocky coal emits only 60 pct of its total gas. Coalbeds that are ill defined as to their blocky or friable nature must be tested in the laboratory for unambiguous analysis.

Jan 1, 1975

By H. D. Kline

This paper describes the methods of mining and washing brown iron are in 1957 at the Sawyer mine, leased by Wayne County Mining Co., and the Fore mine, leased by Four Mining Co., both in southern Missouri; it is one of a series prepared by the Federal Bureau of Mines on mining and milling methods and costs in various districts of the United States. The Sawyer mine is in Wayne County, about 10 miles north-northeast of Williamsville (fig. 1); the Fore mine is in Howell County, about 20 miles southwest of West Plains (fig. 2). Both are open-pit mines from which the crude are was upgraded by washing and hand-sorting to produce are of grade and quality suitable for sale to operators of iron and steel furnaces. The operations described are typical of many others that produce or have produced marketable brown iron are from small sedimentary deposits, several hundred of which outcrop on the crests or hill sides of southern Missouri (fig. 3). The 1957 production of marketable brown iron are by 40 separate operations in the southern part of the State was 281,427 wet long tons, valued at $1,637,243. Production from the Sawyer mine that year was 17,000 dry long tons of washed are, and from the Fore mine, 20,816 dry long tons.

Jan 1, 1960

By Mohan K. Wali

This report, the first in a series of 13 reports, provides a summary of 11 major topics on which individual reports have been prepared. These major topics are: (a) Nature of coal mine spoils, topsoils, and unmined soils; (b) influence of macro- and microclimate on (c) plant production on spoils and topsoils; (d) prediction of aboveground biomass from plant cover; (c) mineral composition of plants; (f) controlled environment studies on plant growth response; (g) microbial communities (h) water chemistry and organism diversity of catchbasins; (i) vegetation and soil development on abandoned, and (j) topsoiled sites; and (k) viability and diversity of seed bank. Based on these investigations, general conclusions and some recommendations are presented.

Jan 1, 1982

By W. R. Hardwick

This paper describes mining methods and practices of the Chino Mines Division, Kennecott Copper Corp., Grant County, N. Mex. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A similar program was conducted from 1928 to 1939, which helped to improve the efficiency of mining operations. The primary purpose of the program is to promote development and conservation of our mineral resources by disseminating technologic information on methods, practices, and related features in mining mineral deposits. It is expected that the program will: (1) Promote efficiency in operating mines; (2) assist operators and engineers in evaluating and developing new mineral deposits; (3) provide data for engineering curriculums in mining schools; and (4) furnish performance and cost data for revising engineering handbooks and for inclusion in engineering textbooks.

Jan 1, 1958

By D. E. Pollock, Andrew B. Cecala

It has long been known that ventilation is a cost-effective method to lower respirable dust concentrations in all types of mining applications. The National Institute for Occupational Safety and Health has been working on a number of different research techniques that use ventilation as a critical component to lower respirable dust levels at surface and metal/nonmetal operations in the United States. This article presents five such research efforts. The first research area discusses how improving the ventilation flow patterns in an iron ore mill facility lowered respirable dust concentrations by 31 pct throughout the primary grinding area. The second research area examines how respirable dust levels were lowered at a dimensional stone shop by using air cleaning units suspended from the ceiling. A third area discusses how improvements in ventilation at underground limestone mines lowered respirable dust concentrations. The fourth area examines how improvements in dust filtration and pressurization systems significantly impacted the air quality in enclosed cabs of surface mining equipment. The last area presents a newly developed clothes cleaning technique. This technique uses an air spray manifold to blow dust from a worker’s clothing in an enclosed booth, which confines the dust for capture and removal by a baghouse dust collector. These research areas represent an array of different control technologies to lower respirable dust concentrations. Ventilation is an integral part of these control technologies.

By Virgil A. Marple

It was the purpose of this contract to conduct research in several different areas of instrumentation used to determine the quantity of respirable dust in the mining atmosphere. One area of research was in evaluation of instruments including several respirable dust monitors, several types of photometers, and a QCM cascade impactor. An instrument evaluation chamber was developed to aid in evaluating the instruments in a dust atmosphere. Another area of research was investigations into new instrumentation concepts, such as a virtual impactor/photometer instrument, a new optical device which can be used as either an optical particle counter or photometer, a new personal respirable sampler, which employs an impactor instead of a cyclone as a preclassifier, and the development of a new cascade impactor, which deposits the particles uniformly on the impaction plate. Another area of research included the use of many of these instruments in two field studies, including a silica sand plant and a tungsten mine.

Jan 1, 1981

By Ellsworth Y. Dougherty, Edwards F. Fitzhugh

"INTRODUCTION During the summer of 1945 the Bureau of Mines made approximately 200 miles of reconnaissance magnetic surveys in north-central Mirnesota. The survey started near the western end of the Mesabi Iron Range and extended into the area to the southwest, west, and northwest and also southward to the-northern limits of the Cuyuna Iron Range. The purpose of the survey was to data to assist exploration for iron ore in the region through:1. Supplying a relatively unit form network of traverses, by which and future surveys of localities in the urea ray be correlated. Suggesting localities in which more detailed magnetic surveys may be justified, and, Disclosing localities in which there is lass hope of obtaining significant results from further magnetic surveys.The instrument used was a Hotchkiss Superdip, and traverses for calibration and comparison were run with a Schmidt-type magnetometer. Field observations and work directly related thereto were carried out under contract by E. J. Lang-year Co., Minneapolis. Engineers of the Bureau of Mines planned, directed, and reviewed the survey."

Aug 1, 1946

By Francis E. Federspiel

In 1984 and 1985, at the request of the U.S. Forest Service, the U.S. Bureau of Mines examined the 87,720-acre South Boise Yuba study area (formerly known as RARE II Wilderness Recommended area I-4553) to evaluate mineral resources. The study area and additions are in Blaine, Camas, and Elmore Counties, 10, about 60 mi east of Boise. Granitic rocks of the Cretaceous age Idaho Batholith occupy the western two-thirds of the study area. A Tertiary age granitic complex has intruded, and broken into small blocks, Paleozoic age sedimentary rocks in the eastern third of the study area. Tertiary Challis Volcanics overlie both of these rock types. Principal mineralized structures are gold-and silver-bearing quartz veins and shear zones trending northwest to easterly in the Cretaceous granitic rocks. Copper, lead, and zinc are accessory metals in many mineralized structures.

Jan 1, 1987