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By R. W. Stahl

Methane, a highly explosive gas evolved during the coal-formation process, is one of the hazards of mining most difficult to overcome. It is retained between particles of coal and entrapped in strata overlying and underlying the coal beds to a degree dependent upon the permeability of the enclosing strata. Considering that methane might be encountered at any time during the mining of coal, attempts have been made through the years to minimize the sources of ignition at coal-mine faces, such as the introduction of permissible electric equipment, the prohibition of smoking and open lights, and the development of safer explosives. The sparks created when mining-machine picks contact sandstone or iron pyrites2/ constitute one source of ignition, always recognized as a possibility but never greatly emphasized in the United States until recently, when ignitions began occurring with rather alarming frequency and in widely scattered coal-producing areas.

Jan 1, 1956

By K. R. Dorman

To develop the potential of precast concrete sets as a support medium in underground mines, a three-piece precast concrete drift set was designed for a small opening and tested to destruction in an underground straining frame. Thirty-six tests were made with three sizes of members using three different loading conditions. In addition, 14 members were tested individually in the laboratory. Test results are compared with theoretical calculations. A cost comparison shows the use of concrete sets would be advantageous where conventional wooden timber requires excessive replacement.

Jan 1, 1968

By BUREAU OF MINES

This report is submitted in accordance with the provisions of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S.C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1953 has been divided into two separate publications. Each has been published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: R. I. 5043, Part I - Oil From Coal. R. I. 5044, Part II - Oil From Oil Shale. Identical in each report, the introduction summarizes research progress made in 1953 under the entire Synthetic Liquid Fuels program. A free copy of each of these publications may be obtained by a written request to the Bureau of Mines, Publications Distribution Section, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Apr 1, 1954

By W. J. Wenger

THIRTY-FOUR analyses of crude oils from the fields of the Four Corners Area of Arizona, Colorado, New Mexico, and Utah are presented and compared. The samples, taken from formations in four geological time periods, have high gravity and low-sulfur, -nitrogen, and -asphalt content. Generally, the oils are paraffinic in the low-boiling fractions, with increasing naphthenicity in the higher-boiling fractions. Oils from Cretaceous formations resemble other Cretaceous oils in the Rocky Mountains, but oils from Permian and Pennsylvania formations are unlike other oils of these ages in the Rooky Mountains. The differences in the oils are minor and cannot be used to distinguish between fields or between producing formations. With minimum special processing, the oils should yield large amounts of good-quality motor fuels. INTRODUCTION The only place in the United States where four States have a common junction is known as the Four Corners Area. This area (fig. 1) includes the northeast corner of Arizona, the southwest corner of Colorado, the northwest corner of New Mexico, and the southeast corner of Utah. It includes three major geological basins: The Black Mesa, the San Juan, and the Paradox. Major oil developments have occurred in both the San Juan and Paradox basins, but no discovery of commercial importance has been made in the Black Mesa basin.

Jan 1, 1960

By Harry V. Makar

As part of a continuing research program for conserving domestic mineral resources, the Bureau of Mines is investigating new and improved scrap identification techniques to improve sorted mixed scrap purity. This report focuses on various classes of wrought and cast copper alloys produced with recycled scrap. Based on a survey of the literature, principal alloys, such as the brasses and bronzes, are examined with respect to impurity elements and their effects on metallurgical behavior. Effects of elements such as lead, antimony, iron, chromium, and aluminum are discussed. The metallurgical effects described include hot shortness, fire cracking, and undesirable phase transformations.

Jan 1, 1985

By Thomas C. Atchison

The purpose of this Bureau of Mines investigation was to measure the amplitude and shape of the strain pulse and the size of the crushed zone produced in a granite by different explosives and to determine how these quantities are related to the detonation properties of the explosives. The reflection theory of rock breakage has shown that the amplitude and shape of the strain pulse incident at a free surface determine the fragmentation and volume of rock broken. Determination of the properties of an explosive that control the characteristics of the strain pulse produced in the rock will help in evaluating explosives for use in blasting. The investigation showed the different explosives produced a twofold variation in the amplitude of the strain pulse but little variation in the shape of the pulse. The explosives also produced a twofold variation in the volume of the crushed zone, but differences among the explosives were more accurately determined by strain-amplitude measurements than by crushed-zone measurements. The peak amplitude of the strain pulse and the volume of the crushed zone correlated with the calculated detonation pressure of the explosive.

Jan 1, 1959

By R. A. Beall, S. L. Ausmus

The development of a completely water - free expendable graphite mold material , useful for reactive metal castings , has been detailed . Mixing and curing variables have been evaluated both by physical testing of the material itself and by castings of titanium , zirconium , and hafnium . The blend of powdered graphite , cornstarch , dextrin , cereal binder , linseed oil , and Carbowax -4000 is a successful mix when mulled in a carbon dioxide atmosphere , and properly cured and fired . The primary advantage of this material is its adaptability to standard foundry techniques ; i . e . , core blowing and hand ramming . Temperatures in the curing and firing cycles do not exceed 960 ° C , and no vacuum firing is required .

Jan 1, 1964

By W. E. Young, D. T. Delicate

This study was made to present the mining methods and costs of a uranium mine typical of other mines in the highly productive Westwater Canyon member of the Morrison formation in New Mexico. Four mining methods have been used at the Section 23 mine: the retreat- room-and-pillar method, a sublevel-slicing method (also called top-slicing), the horizontal-cut-and-fill method, and a modification of the ring-drill method. The application of the methods at this mine and at other mines in the area should be of benefit to operators with similar problems. Ore bodies in the Section 23 mine are irregularly shaped and vary in size, in rock strength, in moisture content, and in uranium concentrations; different mining methods are required and mining costs are not constant. A 6-month period of operation at the Section 23 mine was analyzed and mining costs, not including amortization, depreciation, or Federal taxes, averaged about $6.80 per ton.

Nov 1, 1963

By Heine Kenworthy

"INTRODUCTION In 1930 the Shenandoah-Dives Mining Co. near Silverton, Colo., put into operation a newly erected, 300-ton selective flotation plant to mill complex ores from its nearby mine. The operation was a steady producer and was enlarged to treat 600 to 800 tons a day. In 1942 the company opened and started milling an area in the mine containing semioxidized ore. The valuable mineral content of this ore was considerably higher than in, the straight sulfide ore previously handled alone. The mixture of clean sulfide and semi-oxidized ore was difficult to treat; consequently, tailing losses, especially with respect to lead, were high. A few years later, in order to study the possibilities of obtaining higher recoveries by a modification of the mill flow sheet, a 1,200-pound sample of mill, feed, taken over a period of several days by the company, was submitted to the Mississippi Valley Experiment Sta¬tion for testing-. Although this sample proved to contain more than twice as much lead as the average yearly mill feed, the same problem of recovering the oxidized values was present.A résumé of the ore-dressing treatment used in the Shenandoah-Dives mill follows. After crushing, the ore passes through a ball mill, the minus 5-mesh discharge of which is distributed to three tables. A finished lead concentrate is made on the tables, and the table tailing goes to the classifier which is in closed circuit with the ball mill. The classifier overflow is treated -by flotation to obtain a bulk sulfide concentrate at a relatively coarse size. The bulk concentrate is thickened and reground to about 95 percent minus 325-mesh before flotation treatment to separate a lead-copper and a zinc concentrate. A typical monthly average showed that the table concentrate contained about 45 percent lead, 1 percent copper, 4 percent zinc, 12 ounces of gold, and 40 ounces of silver; that the lead flotation concentrate contained '35 percent load, 6 percent copper, 7 percent zinc, 3.5 ounces of gold, and 50 ounces of silver; and that the zinc flotation concentrate contained 2 percent lead, 0.5 percent copper, 60 percent zinc, 0.15 ounces of gold, and 4 ounces of silver. Recoveries in salable products were roughly b5 percent of the lead, 70 percent of the copper, 45 percent of the zinc, 85 percent of the gold, and b5 percent of the silver."

May 1, 1948

A list of permissible mine equipment approved by the Bureau of Mines before January 1, 1937, was published in Bureau of Mines Information Circular 6942.3/ Information Circular 7007,4/ published as a supplement thereto, listed equipment approved. Burin', the calendar year 1937. The present list includes most of the material liven in these two publications, as well as approvals that have been issued up to January l, 1940. Some equipment formerly listed has been omitted because it has become obsolete or is no longer actively marketed. The list now includes electrically-operated air compressors, coal drills, loading machines and conveyors, mining machine, mine ones, rock-dusting machines, room hoists, storage-battery gathering and haulage locomotives and storage-battery power trucks, mine telephones, junction boxes, electric cap lamps, flame safety lamps, electric hand and trip lamps, electric flood lens, flashlights, methane detectors, and single and multiple-shot blasting units. The appendix at the end of this circular lists trailing, cables that have passed tests prescribed by Schedule 2D. When equipment passes the inspections and tests prescribed by the United Status Department of the interior, Bureau of Mines, in published "schedules" or standards, it is formally approved as "permissible" for use in gassy mines, and the manufacturer is then permitted to mark it with an approval plate that identifies it as having been approved by the Bureau. The inspections and tests are designed to insure that each equipment satisfies the minimum requirements for safety in use. The Bureau's purpose in investigating equipment of this type and listing that

Jan 1, 1940

The Florida phosphate industry currently produces more than 80 pct of the total U.S. marketable output of phosphate rock. Because phosphate is one of three principal nutrients used in formulating a complete fertilizer, it is imperative that an uninterrupted supply of this material be available to meet the agricultural requirements of the United States while maintaining a viable phosphate industry which is competitive in world markets. As a result of an evaluation made by the Bureau of Mines, five areas were identified that affect the overall production and projected growth of the phosphate industry in Florida. These areas relate to the technological ability of the industry to comply with environmental regulations and performance standards by using the best available technology. The most significant technical problem facing the industry is the management of the clay fraction rejected during the beneficiation of phosphate ores. Other areas of concern are environmental restrictions and regulatory requirements, issues associated with mining and reclamation of wetlands, reclamation of other disturbed lands, and consumptive water use. Each of these areas is reviewed, with major emphasis placed on the current state-of-the-art processes for treatment and management of phosphatic clays.

Jan 1, 1983

By Paul Meadows

The Buckrange reservoir, Stephens field, Ark., is approaching the economic limit of production under present operating conditions. Over 100 million barrels of oil remaining in the reservoir will not be recovered by primary producing methods. The Bureau of Mines, in cooperation with the Arkansas Oil and Gas Com-mission, made the petroleum-engineering study presented in this report to aid operators in evaluating secondary-recovery possibilities in the reservoir and in planning secondary-recovery programs if their initiation is decided. The Stephens field, in Columbia, Nevada, and Ouachita Counties, Ark., is about 12 miles northeast of Magnolia, Ark., and 15 miles west of the Smackover field. Surface elevations in the area average about 240 feet above sea level.

Jan 1, 1956

Toward the goal of maximizing minerals and metals recovery from domestic resources, the Bureau of Mines, U.S. Department of the Interior, has conducted in situ corrosion studies at the Salton Sea Known Geothermal Resources Area (KGRA) in the Imperial Valley, Calif., to evaluate and characterize materials of construction for geothermal resources recovery plants. General-, pitting, and crevice-corrosion characteristics of 13 commercially available alloys were investigated for periods of 15 and 30 days in seven process environments expected to be found in typical geothermal resources plants. Stainless steel alloy 29.4, Inconel 625, and the Hastelloys G, S, and C-276 were the most resistant to general corrosion, did not pit, and exhibited little susceptibility to crevice corrosion. Stainless steel alloys 430, E-Brite 26-1, and 6X had low general corrosion rates, but pitted and were susceptible to crevice corrosion. Stainless steel alloy 316 L had a low corrosion rate, but corroded intergranularly, pitted, and was susceptible to crevice corrosion and to stress-corrosion cracking. Titanium-1.5 nickel and TiCode-12 had low corrosion rates, did not pit, and were not susceptible to crevice corrosion. Carbon and 4130 steels had high corrosion rates, pitted, and had high susceptibilities to crevice corrosion. The major scale-forming mineral on the corrosion samples in most of the process environments studied was galena mixed with lesser amounts of other minerals.

Jan 1, 1979

By Eugene H. Skinner

The U.S. Bureau of Mines conducted experiments on the use of lightweight concrete in the density range of 100 Ib/ft3 for liners in underground mines. Three test sections were completed: a monolithic, portal-type structure with integral walls and arch constructed aboveground; an underground test section constructed in a mine drift using plywood forms; and a second section constructed in a drift using an air-supported formwork. The lightweight concrete in the two underground test sections was placed using piston pumps and a slickline. Fiber reinforcement was added to the concrete in the mine sections without any apparent problems with either pumping or placement of the concrete. In another experiment, the Bureau and Hecla Mining Co., Mullan, rD, used lightweight concrete in the density range of 25 Iblfe to replace timber blocking in a raise preparation structure. Other experiments are described in which low-density, lightweight concrete blocks were produced for mine ventilation doors, stoppings, and barricades. Other mine uses reviewed include pillars and collapsing beams. An advantage of low-density concrete is that it will display up to 50% deformation at a constant yield stress. These hlllovative concepts in deformable concrete lining systems will aid mine operators by decreasing capital and maintenance costs, increasing the available space in underground haulageways, and providing productivity gains and improved resource recovery in the soft, caving, squeezing, or bursting grollnu conditions often found in deep mines.

Jan 1, 1989

By D. F. Reed

As a part of a comprehensive survey of the Adirondack region, the Bureau of Mines, 1944 and 1945, conducted investigation of magnetic deposits at Dennemora, Russia Station, Redford-Clayburg, Standish, and the Ausable river region. Later in 1945, the Federal Geological Survey, started an aeromagnetic survey of the area and completed it in .1946. The Bureau of Mines extended its magnetic surveys in 1946 in the Redford-Clayburg area. In 1947 the Bureau of Mines .diamond-drilled throe holes in the Redford-Clayburg district. Clinton County has one active magnetite mine at Lyon Mountain and inactive mines at Palmer Hill and Arnold Hill, as well as along the Saranac River.

Jan 1, 1949

By R. W. Stahl

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to mineral industries' mines, quarries, and plants that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove that efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1963

By T. F. Curry, L. B. Berger, H. A. Watson, S. J. Pearce

The conduct of work at elevated air pressures , such as in caissons and in tunnel - driving in subaqueous strata , poses safety problems not encountered in mining and tunneling operations at ordinary atmospheric pressure . This publication discusses some of the problems involved and presents information on the following subjects : ( 1 ) Physiological effects of gases at elevated pressure . ( 2 ) Use of respiratory protective equipment in rescue or recovery operations in event of fire or other emergency in pressurized tunnels . ( 3 ) Effect of elevated pressure on performance of some gasdetecting instruments ; interpretation of the results . Various types of respiratory protective devices are discussed in relation to their possible use at elevated pressures , especially the 2 - hour , selfcontained , recirculating - oxygen - breathing apparatus , which has had wide use in the United States during rescue and recovery work in the mining industry . A modified procedure that eliminates the hazard of oxygen poisoning enabling the safe use of this apparatus at elevated pressures , up to 45 pounds per square inch , gage , and tests to verify its practicability are described . procedure involves control of the partial pressure of oxygen in the breathing

Jan 1, 1964

By Charles W. Perdue

This U.S. Bureau of Mines report considers, from a psychological perspective, the perceptual process by which miners recognize and respond to mining hazards. It proposes that if the hazard recognition skills of miners can be improved, mining accidents may be reduced to a significant degree. Prior studies of hazard perception in mining are considered, as are relevant studies from investigations of military target identification, pilot and gunnery officer training, transportation safety, automobile operator behavior, research into sensory functioning and visual information processing. A general model of perception is introduced, and selected concepts from the psychology of perception that are applicable to the detection of mining hazards are reviewed. Hazard recognition is discussed as a function of the perceptual cues available to the miner as well as the cognitive resources and strategies employed by the miner. The development of expertise in responding to hazards is related to individual differences in the experience, aptitude, and personality of the worker. Potential applications to miner safety and training are presented.

Jan 1, 1995

In 2006, a total of 2,113 coal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Coal mines comprised 14.2% of all mining operations. ? Bituminous mines comprised 92.5% (n=1,955) and anthracite mines 7.5% (n=158) of coal mining operations. ? Approximately 71.0% of all coal mines were located in three states: Kentucky (29.2%), West Virginia (21.8%), and Pennsylvania (20.3%).

Jan 1, 2008

By D. A. Larson

The Bureau of Mines conducted research to develop preliminary engineering data necessary if the cobalt-rich manganese crusts that occur in the Exclusive Economic Zone (EEZ) of the Hawaiian Archipelago are to be mined. The research was divided into the following sections: (1) physical, mineralogical, and chemical descriptions; (2) mechanical property testing, such as compressive strength, tensile strength, and a rippability index; and (3) mechanical cutting characteristics, including average and peak cutter forces, the specific energy, and cuttings size distribution. Section 1 utilized microscope, X-ray powder diffractometer, and electron microprobe analyses. Section 2 utilized standard mechanical property testing techniques. Section 3 utilized a converted planer mill with full-size coal cutters to fragment the crust and substrate samples. The manganese crust samples were mainly manganese and iron oxides and hydroxides with an average cobalt content of 1 pct and had a nucleus or substrate of rock or sediment. The significant results shown by the mechanical property and cutting tests are that the crust and all but two types of substrates (basalt and trachyte) are weak materials and easily cut with standard drag cutters. The crusts are generally comparable to medium hard coal in strength and in their resistance to cutting.

Jan 1, 1987