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By Louis A. Turnbull

An investigation of coal deposits near Cerrillos Santa Fe County, N. Mex., was undertaken 14 the Bureau of Mines in 1943 as part of a general program to determine sources of metallurgical coal for western steel plants. Almost all of the coal used for metallurgical purposes west of the Continental Divide Is mined from the Lower Sunnyside bed in, Carbon County,, Utah. Coke used in western steel plants that is produced from Lower Sunnyside a coal is weaker, structurally, than coke used elsewhere in this country. For this reason, western coal operators and steel manufacturers are anxious to develop new areas of coking coal of better quality then the coal produced from the Sunnyside bed. The objective of investigations of western coals was to (a) develop additional reserves of coking coal to supplement proved reserves in the Sunnyside bed. and (b) develop; if possible, reserves of coal with coking quantities superior to those of Lower Sunnyside

Jan 1, 1951

By C. V. Jude

This U. S. Bureau of Mines (USBM) report presents results of stress analyses and field observations to investigate the effects of elevated trench drifts on the structural stability of rock mass zones surrounding a production draw drift in a mine utilizing a mechanized load-haul-dump (LHD) trench undercut panel caving system. A two-dimensional boundary-element mine stress model was developed to predict the locations and extent of damaged rock mass zones surrounding draw drifts where adjacent, parallel trench drifts are either elevated or not elevated above the LHD production draw drift level. A Mohr-Coulomb shear-failure criterion was obtained directly from in situ borehole shear test data. Hock-Brown shear-failure parameter values were computed from borehole-shear and triaxial test data. A procedure is described to estimate these parameters when a rock mass rating (RMR) value and triaxial data on intact samples exist, and no borehole shear test data exist Results indicate that trench drifts, elevated to the level equal to the height of the LHD production draw drift, would not minimize material damage nor significantly enhance the stability of rib and crown pillar zones surrounding production draw drifts in the mechanized LHD trench undercut caving panel investigated at this mine.

Jan 1, 2010

By Anthony E. Szczuka

Two facets of surface mining were studied: feasibility of using training simulators to increase productivity of haulage trucks, front-end loaders, and shovels; and improving the efficiency of dragline operations with a computer-aided analysis of dragline usage and the addition of an on-board operator display. Training costs per student were estimated based on current training practices. Training objectives were derived from task: analyses of haulage trucks, front-end loaders, and shovels. The cost effectiveness of training simulators was determined. A computer-aided analysis defined the critical performance parameters. An on-board operator's display is recommended to improve operator efficiency.

Jan 1, 1976

By P. D. Lindahl

[A cost/benefit analysis was conducted by comparing the industry cost to protective structures on low-coal face equipment with the benefits paid for injuries/fatalities considered preventable by the use of these structures. Th industry costs were based on estimates by OEM's and rebuild shops for install protective structures on new and rebuilt face equipment. The accident benefit was based on evaluations performed by the USBM Accident Cost Indicator Model. Industry wide population data were developed on low-coal face equipment and injuries/ fatalities preventable with protective structures. The results of the analysis are to be used as a tool by USBM in determining the feasibility of continuing development of cab and canopy technology for low-coal equipment.]

Jan 1, 1983

By R. D. Saltsman

Under contract with the Federal Bureau of Mines, Bituminous Coal Research, Inc., performed a statistical study to find less expensive and time-consuming methods of monitoring the noncombustible content of coal mine dust. Calculations based on thermodynamic considerations verified the reasonableness of Federal rock-dusting requirements. The results of extensive sampling in southwestern Pennsylvania mines indicated that, at the 95-percent confidence level, the present system of sampling at 200-foot intervals may be replaced by sampling at 500-foot intervals, and that a 1-inch scoop floor sampler may replace the standard 6-inch scoop for floor sampling. Further field testing is recommended.

Jan 1, 1975

By J. A. Kost

A dust-control manual was prepared for use by mine operations personnel. The manual documents state-of-the-art control techniques, dust sampling, and use of personal protective devices. Content addresses advantages/disadvantages of control techniques, design and operating specifications, and implementation and maintenance guidelines. An indexed list of selected references is also included. In addition to the completed manual, this report documents work performed in the course of its preparation.

Jan 1, 1981

This Bureau of Mines publication presents five papers given at a Technology Transfer Seminar on Metal Mine Fire Protection Research. Several seminars are held each year to bring the latest results of Bureau conducted and sponsored research to the attention of the mining industry as quickly as possible.

Jan 1, 1977

By W. P. Huleatt, Jr. Traver, Jr. Hazen

"Vanadium and uranium occur widely distributed throughout western Colorado and eastern Utah, and a few deposits have been found in northeastern Arizona and northwestern. New Mexico. The area in which it occurs includes approximately 10,000 square miles and is generally referred to as the vanadium region of Colorado and Utah.The majority of the deposits consist of replacement bodies and impregnations of rare minerals in the lower Morrison formation of Jurassic age. The ore bodies are flat, with irregular margins, and most of them conform to the stratification.The ""rim rock"" topography of the region includes many steep-walled canyons and plateaus, which afford an abundance of outcrops that have been responsible for most of the discoveries of mineralized areas. Delimitation of ore bodies within the areas is accomplished most effectively by core drilling from the surface.The deposits were discovered in 1899 and from 1911 to 1923 wore worked extensively for radioactive uranium ores, principally carnotite.The discovery and marketing of the richer and more cheaply mined pitch-blende ores of the Belgian Congo left the Colorado-Utah deposits without economic importance as sources of radium and uranium, and the region became inactive in 1923. After a period of comparative inactivity, the rising demand of the alloy-steel industry for vanadium renewed interest in the deposits, which were known to contain that metal. By 1938, vanadium production in the area had achieved respectable proportions, and new impetus was given to it by the United States’ entry into World War II in December 1941. In 1942, new treatment plants for vanadium ores were completed in Monticello, Utah, and Durango, Colo. In order to meet the requirements of these and other plants in the region, it became necessary to open new vanadium mines and prepare old onus for production.In an effort to stimulate mining, the Metals Reserve Company initiated a stock-piling program and appointed the united states Vanadium Corporation, to act as its purchasing agent.The extra production was expected to come largely from small, independent operators whose limited funds did not permit them to maintain development and exploratory programs. Study of conditions made it apparent that extensive exploration would be necessary to sustain production, and accordingly the Bureau of Mines initiated an exploratory drilling project on a cooperative basis with the Geological Survey. The principal objects of the work were to enlarge the known ore reserves of the area and, if possible, discover new ones. The results have been gratifying in both respects."

Sep 1, 1946

By R. K. Conrad

The Bureau of Mines conducted corrosion research to determine suitable construction materials for geothermal resource recovery plants. Weight loss, pitting and crevice corrosion, U-bend stress corrosion, and electrochemical polarization measurements were made on selected metals in brine and steam process environments produced from high-enthalpy hypersaline brine from geothermal well Magmamax No. 1 at the Salton Sea Known Geothermal Resources Area, Imperial Valley, Calif. Cadmium (and by extension cadmium coatings) and a 6061-T6 aluminum alloy were unsatisfactory because of high general corrosion rates and, in the case of aluminum, severe pitting Molybdenum and niobium (columbium) were resistant to general corrosion, pitting, and crevice corrosion, Copper alloys corroded at rates that may preclude their use in wellhead brine, The presence of iron accelerated the corrosion of the copper alloys Titanium alloys were resistant to general corrosion and stress corrosion cracking in all of the environments. They exhibited crevice corrosion in some of the brine and steam environments and Ti6A14V pitted in the brine environments. They exhibited passive behavior over a broad range of potentials. Exposure tests were conducted on a high-temperature polyphenylene sulfide thermoplastic (Ryton) in the same environments. A 40-pct-graphite fiber-reinforced Ryton composite deteriorated readily in wellhead brine and failed in all of the brine and steam process environments; Ryton coatings on 316L stainless steel were adherent and performed well.

Jan 1, 1983

By Robert H. Peters

This report presents findings from a Bureau of Mines study on barriers that may prevent miners from correcting and avoiding groundfall hazards. Such barriers stem from four basic types of problems: (1) inability to recognize groundfall hazards, (2) inability to correct groundfall hazards, (3) lack of motivation to search for groundfall hazards, and (4) lack of motivation to correct groundfall hazards. Data are presented that summarize the views of miners, section supervisors, and mine inspectors about the contribution of these barriers to groundfall accidents and what they think should be done to reduce the frequency of injuries sustained by falls of roof and rib. The report also includes a summary of miners' responses concerning their recent experiences with groundfall accidents, along with industrywide statistics on accidents and injuries caused by ground falls in underground coal mines.

Jan 1, 1987

This volume contains a series of papers describing research conducted by the Bureau of Mines to develop or improve equipment and systems that satisfy the communication requirements of miners doing work related to rail, belt-conveyor, trackless, and hoist haulage systems.

Jan 1, 1977

By W. W. Graff

This paper describing the mining practice at Mine No. 5 of the Marquette range, Michigan, is one of a series being prepared by the Bureau of Mines on mining practices, methods, tend costs in the various mining districts of the United States. The top-slicing system of mining, has been used ever since the present operating company took control of the property in 1903, the main level and sublevel layout being chanced only as local conditions required and the use of mechanical equipment increased.

Jan 1, 1930

By Thomas P. Mucho

Cable bolts are emerging as the newest ?twist? for roof support in U.S. underground coal mines. For decades cable bolts installed in underground metal mines in the United States and Canada used cement-based grouts for anchoring. The cement anchoring process, because of the time and expense for installation, made cable bolts impractical for use in coal mines. Today, the introduction of resin-anchored cable bolts provides a system more consistent with tradi­tional U.S. coal mine roof bolting practices and requirements. Expecta­tions are that the utilization of cable bolts for a number of U.S. mining applications will expand, particularly in coal mining.

Jan 1, 1998

By Jeffrey A. Aldinger

This U.S. Bureau of Mines report presents an analysis of surface coal mining accidents involving mobile equipment for the years 1989 through 1991. Mobile equipment is defined as haulage trucks, front-end loaders, bulldozers, scrapers, and road graders. These five pieces of mining equipment accounted for 20 pct of all surface coal mine accidents and 41 pct of the fatalities. The general discussion of these accidents covers the accident causes, the primary activity of the accident victims, and other contributing factors. A more detailed analysis of accidents associated with each piece of mobile equipment is also provided. This report will provide mine managers and mine safety personnel with a better understanding of the hazards associated with mobile mining equipment. It identifies where improvements in mobile equipment safety can be made and those areas requiring additional safety emphasis, such as safety training, work procedure changes, or engineering changes to the equipment or work environment. The analysis was performed by a team of researchers using accident data and narratives provided by the Mine Safety and Health Administration.

Jan 1, 1995

By Felix duBreuil

The present sampling procedure for evaluating the rock dusting conditions in a coal mine is time consuming. This study considers means by which this procedure could be simplified. Surveys were conducted in six coal mines in Pennsylvania to determine the in¬combustible content of the deposited dust. Some 2,000 samples were analyzed and statistically evaluated. It is suggested that the mean incombustible content could be obtained with fewer samples and smaller samples without greatly increasing the sampling error.

Jan 1, 1972

By William Seymour, L. D. Schmidt

A preliminary survey of coke and steel plants conducted by the Bureau of Mines in cooperation with the Office of the Solid Fuels Administrator for War and with the advice of the Coke Production Committee indicated that production of pig iron could be increased. appreciably if present blast furnaces were supplied with a more uniform coke.4/ Nonvarying percentages of ash , sulfur , and fixed carbon in the coke , together with uniform physical characteristics , such as size , strength , and porosity , would aid the blast -furnace operator greatly in his trial - and - error methods of obtaining maximum production . With nonuniform raw materials he must employ certain factors of safety in operation , such as an excess of coke , an excess of limestone , and operation of the furnace below the maximum rate . Even so , he often has trouble from iron not being up to specifications , hot tops , high blowing pressures , furnace hanging up , etc. The more uniform his raw materials (of which coke is probably the most important) , the nearer to ideally can he run his furnace and thereby save raw material and increase production . One cause of nonuniformity of the coke produced by ordinary American plant practice is the prevailing lack of precise control of the bulk density ' of the coal charge in the byproduct oven . This report summarizes the available information on the subject of bulk density of crushed coal and its control . It includes brief reviews of some of the literature , some results obtained at plants visited by the authors , and results of a few preliminary tests made at the Pittsburgh Station of the Bureau of Mines .

Dec 1, 1943

By Keith L. Harris

Economic activity in the United States picked up in the third quarter, according to the latest estimate released by the Department of Commerce. Real gross national product (GNP)--the Nation's output of goods and services--grew at a seasonally adjusted annual rate of 4.3%, or $17.6 billion, compared with a rate of 1.9% for the second quarter of 1985 and 1.6% for the third quarter of 1984 (table 1). The 4.3% rate is one percentage point above the preliminary estimate reported in the August/September issue of Minerals and Materials. Most of the upward revision was due to the change in business inventories and Government purchases, while the figure for net exports was revised downward substantially. The 4.3% growth bettered by 1.5% the average rate of growth in GNP from 1974 through 1984 and was 1.1 % above that of the period from 1975 through 1984 and 0.7% above that of 1980 through 1984. Of importance to the minerals industry was the $14.4-billion growth in personal consumption expenditures, $10.2 billion of which was for durable goods (especially domestically produced automobiles) and the growing residential investment. The net export deficit continued to grow, however, and investment in nonresidential structures, producers' durable equipment, and business inventories declined. Prices, as measured by the GNP fixed-weighted price index, increased at an annual rate of 3.1% in the third quarter, compared with 3.9% in the second quarter. The slower rate of inflation resulted mainly from a decline in energy prices, following second-quarter increases. Fourth-Quarter Prognosis Many of the economic data available for October and November indicate that the economy is growing modestly and will continue to grow over the next 3 to 6 months. The composite index of leading indicators, designed to predict economic activity within 3 to 6 months, rose 0.3% in October, the sixth consecutive monthly advance, according to the Department of Commerce. Six of the 11 available leading indicators were positive: Stock market prices rose, as did sensitive material prices, credit outstanding, and manufacturers' new orders for consumer goods and materials; initial claims for unemployment insurance decreased, and firms were getting slower delivery of goods. Four of the indicators were negative: Business formations, homebuilding permits, contracts and orders for plant and equipment, and money supply all declined. The average hours worked per week, already at a high level, remained unchanged.

Jan 1, 1985

By T. M. Barczak, S. C. Tadolini

Pumpable roof supports provide an alternative approach to secondary support in underground mining. Unlike all other supports that are either partially or fully prefabricated prior to being transported into the mine, the pumpable support is fabricated in place in the mine entry. This reduces the underground material handling efforts and thus the injuries historically associated with in-mine support construction. On-site fabrication also facilitates application of the support in areas that are inaccessible to transportation equipment such as scoops or rail cars, making it ideal for many bleeder applications. One of the main advantages of the pumpable support is that it fully bridges from the mine floor to the roof, thereby eliminating the requirement of “topping off” the support with wooden wedges or crib blocks that soften most other support responses. This report examines the development of modern pumpable roof support technology and provides a full description of the performance capabilities of each of the support products now on the market.

By D. E. Redmon

Exploration of hidden mineral deposits becomes increasingly important as known ore reserves are depleted. The primary objective in any exploratory program is to obtain enough reliable information to evaluate accurately the potential of the mineral deposit. Constant improvement in equipment and technique has established drilling as one of the most valuable methods of exploration. This paper presents the results of studies of several drilling methods currently used in the search for uranium deposits in sedimentary formations from surface drill sites. Also presented is a description of drilling with wire-line equipment from an underground location in metamorphic rocks. The studies were conducted in the Colorado Plateau area and in northwestern New Mexico and Wyoming. Statements of a general nature pertain to conditions or situations existent in those areas.

Jan 1, 1960

By W. L. Crentz

The Black Mesa coal field is part of the Hopi and Navajo Indian Reservation in Apache, Navajo, and Coconino Counties, Ariz. The field is in an isolated area with the nearest railroad 70 to 90 miles to the south. Travel is restricted by roads that become impassable during inclement weather. The area is a mesa and rises from 500 to 2,000 feet above the surrounding territory. Water is very scarce, and the nearest stream of any consequence is the Colorado River about 90 miles northwest from the center of the field. Coal beds are found in the Mesaverde formation of the Cretaceous age, but they are uncorrelated and range from subbituminous to bituminous in rank. Huddle2/ estimates the reserves of subbituminous coal in Arizona at about 15 billion tons, most of which is in the Black Mesa field. The geology of the field has been reported by Campbell and Gregory.3/ Coal production is small, and the output is used almost exclusively for domestic fuel in the Indian schools, missions, and trading posts.

Jan 1, 1955