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By D. Harrington, C. W. Owings

Each year at least one and in some years several explosions are reported as having resulted from firing of mudcapped shots in coal mines; undoubtedly a number of small or local explosions occur that are not reported; in addition there are numerous accidents, some of them fatal, attributable to this reprehensible blasting practice. It is surprising that so few explosions and other accidents from this cause occur since the practice of firing mudcapped, Even in gassy "adobe," "dobe," "sand blast," or "bulldozed" shots is widespread. mines where general blasting is safeguarded by being done with permissible explo- sives, rocks or bowlders frequently are blasted with mudcapped shots of dynamite; even if permissible explosives are used, this type of shooting is dangerous. The usual method of preparing a mudcapped shot is to place the explosive, either in loose or cartridge form, with the detonator or "cap" on top of a piece of rock or coal and cover it with several handfuls of moist clay, loam, sand, or When the shot is road dust; in many cases there is no covering of any kind. fired a dense cloud of dust, together with an intensively hot fleme, are thrown into suspension, and if the dust is explosive or ignitable an explosion or igni- tion is likely to result practically simultaneously. The presence of gas greatly increases the explosibility of the dust, as well as the probability of an ignition. Every shot, of any known explosive, fired in a coal mine without having the charge properly confined in a drill hole and tamped with incombustible stemming to the collar of the hole, is capable of initiating an explosion that may cause the death of every man in the mine. Attention has recently been directed to this unsafe practice by an explo- sion resulting from a flagrant disregard of safe blasting practices in one of our The mine had been idle for several years most productive coal-mining regions. and was being prepared for reopening on a different system of mining. Six to 10 inches of bottom coal had been left in place during former mining operations, but in the new system it was felt desirable to remove the bottom coal left in certain parts of the mine. Instead of drilling holes in the coal, loading them, and fir- ing in the usual safe manner, five or six charges of dynamite were placed on top of the coal in each of several rooms; and while the men were at the mouth of the

Aug 1, 1929

? CAGER, CAGE RIDER, CAGE TENDER, SHAFT MEN All of the above job titles are variously associated with the handling of men and material at hoist stations. Generally, these classifications of personnel are involved with riding cages with personnel and in hoisting supplies into the mine. Job titles and activity description will be defined in the respective chapters. ? FLOW CHART SYMBOLS [Vertical Transportation Horizontal Transportation Storage Operation Delay ]

Jan 1, 1975

By G. R. Hopkins

The petroleum-refining industry established a new record in fuel efficiency at refineries in 1936, when 597,000 B. t. u. of heat were required to refine a barrel of crude oil, compared with an average of 615,000 B. t. u. in 1935 (see fig. 1). The principal factor in the "indicated gain in fuel efficiency at refineries in 1936 was an increase in crude runs of 11 percent over 1935. A large part of the heat utilized at refineries is consumed elsewhere than under stills, or in ways quite independent of crude-oil distillation. In other words, as the operating ratio (crude runs divided by capacity) for refineries increases toward the maximum of 100 percent, the fuel requirements show progressively smaller increases and the average E. t. u. consumption per barrel of crude refined declines.

Jan 1, 1938

By Jerry E. Olson

In 1988, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied additional areas, encompassing 11,303 acres, on the east and west sides of the 20,727-acre Badlands study area (Olson, 1987) in order to evaluate their identified mineral resources. The Badlands study area additions are located in Crook and Deschutes Counties, OR, about 10 and 18 miles east of Bend, OR. No mineral resources were identified. The additional areas studied are underlain by Tertiary-and Quaternary-age basalt flows which are largely covered by a veneer of sand and silt. No mines, prospects, mining claims or mineralized areas occur within or near the Badlands study area additions. Slab lava of marketable grade and quantity was not found in either area. None of the study area is of current interest for geothermal resources, but the eastern study area addition has been leased (1984) for oil and gas.

Jan 1, 1989

By S. G. McAnally

This is one of a series of papers describing mining and crushing methods and costs at cement plant quarries throughout the United States and deals directly with the methods employed and costs obtained at the Reliance quarry of the Giant Portland Cement Co. at Egypt, Pa., although it is more or less descriptive of the methods used throughout the Lehigh Valley cement district. Systems of transportation vary according to local conditions, such as proximity to the mill, depth of quarry floor with relation to the mill level, etc. Methods of prospecting differ mainly in the type f drills used. Systems of storage, crushing, and grinding vary chiefly in the types of units. ACKNOWLEDGMENTS Most of the information regarding the early history of the Lehigh cement district was obtained from the History f the Portland Cement Industry of the United States, by Robert W. Lesley, the first president of the Portland Cement Association. The writer is indebted also to Charles Clader, Giant Portland Cement Co. quarry superintendent, for valuable information regarding present and past methods and equipment.

Jan 1, 1931

By K. A. Fowler, L. W. Higley

Steels with an alloying addition of depleted uranium were studied to develop successful melting , casting , and fabricating methods ; to obtain data on mechanical properties ; and to determine the effects of this alloying element . Uranium in amounts up to 1.5 percent was added to steel - base compositions containing approximately 0.5 percent carbon , 2 percent nickel , 0.25 to 2.0 percent silicon , and 0.75 percent manganese in both vacuum- melted and air -melted heats . Radiation levels were monitored for all operations . Bureau of Mines research at the Rolla Metallurgy Research Center showed that uranium additions did not increase tensile strength ; that hot - shortness occurred during forging above 1,090 ° C because of the presence of a low melting point constituent of a eutectic type ; and although a measurable amount of radioactive contamination resulted from processing , the quantity was never large enough to require the work area to be identified as a radiation area .

Jan 1, 1964

By A. D. Garman

The mining ordinance of Costa Rica dates from 1830. In spite of the numerous attempts to enact a new ordinance , it has been so much amended and reamended during the hundred years of its existence either expressly or , more often , by implication , and sometimes by Executive Decrees of which the validity has been called in question - that in most cases no one but a lawyer thoroughly conversant with Costa Rican mining practice could properly advise with reference to it . The present attempt at a digest of these laws is based on the 1929 edition of Bolandi and Johanning - the only source available in Washington . Apparently this edition has no official character , and the editors themselves often made surmises although one would think that definite facts would be available in Costa Rica where it was published .

Jul 1, 1930

By John G. Kovac

A computer simulation has been developed to estimate the chances of a miner making a successful escape while wearing a SCSR. The model takes into account: (1) training in the use of SCSRs, (2) apparatus integrity, and (3) the oxygen cost of a mine escape. This Bureau of Mines report examines survival odds for a prototypical escape, and illustrates how these odds change when SCSR training is improved.

Jan 1, 2009

By D. J. Bauer

A solvent-extraction system employing selective stripping of a pre loaded organic phase was investigated for recovering Sm203 from a light-group rare-earth mixture. The samarium concentrated in the organic phase, and a >99-pct-pure samarium oxide product was obtained at 76-pct recovery in a 20-stage operation using di(2-ethylhexyl) phosphoric acid (EHPA) as the organic phase. The stripping agent was a 1.5-pct hydrochloric acid solution containing 200 g NH4C1/1.

Jan 1, 1972

By B. M. Stewart

Researchers at the U.S. Bureau of Mines conducted a long-term groundwater monitoring and site characterization program at an abandoned 10-ha, acid-producing, copper-gold tailings impoundment in north-central Washington State. The purpose was to investigate contaminant release and transport, and attenuation mechanisms in the tailings, sediments below the tailings, and gravels downgradient of the impoundment. This report summarizes the monitoring results and physical properties of the tailings, the sediments below the tailings, and the groundwater system associated with the tailings. Water samples from the vadose and saturated zones of the impoundment were analyzed for 15 constituents. Concentrations of the same constituents were determined in water samples up to 3 m beneath the impoundment and in the shallow colluvium and deep bedrock at 76, 335, and 550 m downgradient and 168 m upgradient. Constituent concentrations within the tailings are quite variable and are influenced by pH, depth of oxidation, grain-size differential (surface area), hydraulic gradient, groundwater mixing, and the presence of hardpan layers, carbonaceous material, and organic matter. Most of the metal constituents decreased to background or near-background concentrations in the farthest downgradient well.

Jan 1, 2010

By K. O. Bennington

The thermodynamic properties of synthetic acmite, NaFe3+Si206, were determined by the Bureau of Mines. The enthalpy of formation was determined by hydrofluoric acid solution calorimetry. The values of the standard enthalpy of formation at 298.15 K, ?Hf°298.15, from the elements and from the oxides, ?H°298.15, are ?Hf°298.15 = -615.87 ±0.71 kcal/mole, ?H°298.15 (from oxides) = -32.08 ±0.53 kcal/mole. Various experimental data were combined with other data from the literature to calculate all the related thermodynamic properties in the range of 298 to 1,263 K. The standard Gibbs energy of formation is ?Gf°298.15 = -575.8 kcal/mole.

Jan 1, 1981

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Jan 1, 1965

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Jan 1, 1965

By Thomas C. Denton

The Old Reliable copper mine was first examined by Harlow D. Phelps , an engineer of the Bureau of Mines , in October and November 1942 , in compliance with a request from the War Production Board , which furnished copies of assay maps of the 100- and 200-foot levels and requested that they be check-sampled . The author and R. li. Grantham and W. D. Hughes , engineers of the Bureau , made a second and more detailed examination later , after a number of manways had been opened that were inaccessible when the first examination was made .

Feb 1, 1947

By A. E. J. Gallagher

This report summarizes the results of flotation studies conducted by the Federal Bureau of Mines on samples of extremely fine-grained lead-zinc sulfide ores. Samples from five ore deposits in the Pine Creek area, Coeur d'Alene district, Idaho, and one deposit in the Metaline district, Washington, were studied at the Albany Metallurgy Research Center to determine the recovery of sulfide lead and zinc by flotation. During the investigation it was found that flotation could be effectively applied to the selective recovery of exceedingly fine-grained lead and zinc sulfide minerals. Separation of galena and sphalerite was obtained on pulps ground through 1,600-mesh, in which most of the particles were smaller than 5 microns. Selectivity and recovery of minerals in this fine size range were enhanced by use of a chemical dye, diphenylthiocarbazone, as a galena promoter. Although unsuccessful on one ore, application of the dye in treatment of two other very fine-grained ores yielded lead concentrates containing over 62 percent Pb at recoveries in excess of 85 percent. More than 55 percent of the lead in these concentrates occurred as particles smaller than 2 microns.

Jan 1, 1961

By P. M. Gruzensky

A survey of the literature has been made covering the extraction of bismuth from raw materials, its separation from lead, and its subsequent refining. The use of aqueous, nonaqueous, and fused electrolytes in electrolytic refining is reviewed. This literature survey has been prepared preliminary to some proposed investigations concerning the electrometallurgy of bismuth, and, although an effort has been made to cover a majority of the applicable references, a critical review was not attempted and no assertion is made that this manuscript is exhaustive in nature. Titles of publications in parenthesis are translations from the language in which the reference was originally published.

Jan 1, 1954

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Dec 1, 1964

By D. L. Paulson

The Bureau of Mines studied the feasibility of producing copper matte in an electric furnace from blends of copper concentrate similar to those currently smelted in a gas-fired reverberatory system at an installation in Tacoma, Wash. A 800-kva electric-arc furnace was used to determine the distribution of constituents when arseniferous concentrates are being smelted in an electric-arc furnace. Test results from smelting 40 tons of materials indicated that electric smelting is more like a conventional gas-fired system than originally expected. Although gas composition over the molten bath is much different in an electric furnace, the secondary constituents such as arsenic, lead, zinc, and antimony behaved the same as in a reverberatory furnace. The results established that an electric furnace would be compatible with sulfur and particulate recovery facilities that are being used.

Jan 1, 1976

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 M. K. Quinn, N. P. Reddy, A. W. Khair

"An analysis of coal fragmentation due to the action of a continuous miner is presented. Underground coal cutting by a drum-type continuous miner was simulated in the laboratory using a specially designed unique automated rotary coal cutting simulator (ARCCS). The rotary coal cutter provided the versatility of varying the operating and in-situ parameters to provide information on the effects of generating 37 pm (0.0015 in) particles. In these tests, coal blocks with an approximate dimension of 50.8 x 35.6x 20.32 cm (20x 15x 8 in) were first subjected to confining pressures equivalent to in-situ conditions. The blocks were then cut by the rotary cutting head of the ARCCS, thus simulating the action of the continuous miner in underground coal mining. During the tests under a particular set of in-situ and operating parameters a number of other parameters such as (1) penetration of bit into coal, (2) penetration resistance (thrust and cutting pressures), (3) rotating velocity of' cutting head, and (4) acoustic emission activity in the coal block were monitored. During the test, all the cut products were collected for size distribution analysis. After each cutting cycle the fractured surfaces were photographed and a velocity survey was conducted using a sonic technique. At the end of each experiment the cutting paths of the bits in coal were photographed using a camera attached to an optical microscope.The results led to a better understanding of the mechanisms of the fragmentation process during coal cutting and the effect of operating parameters, in-situ conditions and coal type on the size distribution of the cut product:"

Jan 1, 1989