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By Alex U. Miller

Since its beginning, the occupation of coal mining has been considered hazardous. It is true that there are hazards inherent in mining, but it is believed that most of them, at least, can be guarded against. Moreover, many man-made hazards can be eliminated by officials and workers adopting safer practices. Notwithstanding the hazards in coal mining, the fatal accident rate in the United States has improved. During the, period from 1911, to 1941, inclusive, the fatal accident rate varied from 5.35 to 2.22 per million tons of coal. With many handicaps during the war period, 1942-45, such as the lack of experienced manpower. and the, employment of untrained men, the increased average age of workers, and the shortage of equipment and supplies, the industry s ill further reduced its accident rate, so that it ranged from 2.30 to 1.724/ deaths per millon tons of coal. During 1944, 684,000,000 tons of coal was produced with a rate of 1.91, and during 1945, 631,000,000 tons was produced with a rate of 1.724/ deaths per millon tons of coal. The accident rate for 1945 was the lowest for the industry since records have been compiled.

Jan 1, 1946

By A. F. Cohen

When location guidelines are followed in choosing sites for fixed point velocity transducers for use in underground coal mine monitoring, mine air turbulence intensities <11% are generally expected at those sites. The objective of this Bureau of Mines investigation to determine the effect of turbulence intensities <11% on vortex shedding sensors and transducers. Measurements were made at velocity levels of interest for underground coal mine monitoring use (?200, ?500, ?1,000, ?1,500 ft/min). The effect of grid-produced turbulence intensities (2% to ?14%) on the output of vortex-shedding air-velocity transducers was less than ±10%.

Jan 1, 1985

By R. M. Jimeson

Pressure-drop measurements through beds of granular iron, lathe turnings, steel wool, and parallel-plate assemblies were made at linear velocity and gas-density ranges expected in the Fischer-Tropsch hot gas recycle process.4/ Equations relating pressure drop, linear velocity, gas density, and bed porosity were derived. The results indicate that the exothermic heat of reaction can be removed at a lower cost by using catalyst beds with high porosity. INTRODUCTION The Fischer-Tropsch hot-gas-recycle process requires a catalyst offering low resistance to gas flow as one condition to economic feasibility. Conventional granular or spherical catalysts used during early development of the process in Germany did not meet this requirement. Large pressure drops across these beds made the cost of recirculating the gas excessive. The Federal Bureau of Mines is investigating the process by using novel and unusual catalysts that offer little resistance to gas flow. Pressure-drop measurements across these types of catalyst beds are discussed in this report.

Jan 1, 1959

By Thomas J. Peters

In 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 34,310-acre Diablo Mountain (Additional) study area (OR-001-058), in order to evaluate its identified mineral resources and occurrences. The study area lies along the east shore of saline Summer Lake in Lake County, OR, about 145 miles southeast of Bend and 45 miles northwest of Lakeview. The climate is semiarid and temperate, and the study area is almost treeless. Geologically, the (Additional) study area is in a region of fault block-formed mountains and basins, characterized by interior drainage. The area is mainly underlain by unconsolidated Quaternary and Pleistocene lake and playa sediments, which may include subsurface evaporite mineral deposits and resources. Near the center of the eastern margin of the study area are an occurrence of dolomitic limestone of unknown extent, and an area of basalt outcrop totaling 1.5 square miles. A veneer of windblown sand covers about one-half the study area.

Jan 1, 1989

By John W. Sweeney

Shales and clays from Illinois were sampled, tested, and evaluated to determine feasibility of producing lightweight aggregate by rotary-kiln methods. Sampling procedures and the 1 ,,,y of the Pennsylvanian shale units are discussed. Chemical, X-ray spectrographic and X-ray petrographic analyses were run on the samples to determine if a correlation existed between chemical mineralogic composition and expansion. Preliminary expansion testing was conducted in a muffle furnace. Rotary-kiln tests were conducted in a 16- inch by 14-foot rotary kiln. The weight of the aggregate ranged from 27 to 59 pounds per cubic foot. Concrete cubes employing the aggregate were tested to determine the qualities of the concrete. Compressive strength of the concrete using the 7-bag of cement cement per cubic yard mix, after autoclave curing for 6 hours, ranged from 2,950 to 6,750 psi. No correlation was found between the chemical, X-ray spectrographic, and X-ray and petrographic analyses and expansion, Sixteen samples made suitable lightweight aggregates in the laboratory rotary kiln. The expansion temperature range of eight of the samples was extremely narrow, and difficulties would probably be encountered in processing these materials commercially.

Jan 1, 1965

By Alan J. Fejes

As part of its mine subsidence research program, the Bureau of Mines and the American Electric Power Co. cooperated on a study, conducted at the Price River Coal Co. No. 3 Mine, directed toward developing the capability to estimate the surface subsidence resulting from longwall mining in a geologic, topographic, and mining environment common to coalfields in the Western United States. Subsidence was monitored at the No. 3 Mine over two adjacent longwall panels. The subsidence study area was reduced when the two planned panels were reduced in length because of equipment failure and a mine fire. Subsidence was measured for 21 months. Subsidence continued for 6 months after mining had been completed. A maximum of 2.2 ft of subsidence occurred over the two longwall panels mined at an overburden depth ranging from 300 to 1,500 ft.

Jan 1, 1986

By J. W. Chester

The rapid depletion of zinc-lead ore reserves and the rising costs of exploration have been major factors in the decline of mining activities and explorations for additional reserves in the Tri-State mining district. There is a need to develop new or adopt known, improved exploration techniques that will appreciably lower the costs of exploration. Demonstration of the practicability of using improved techniques to indicate, rapidly and cheaply, mineralized areas or geologic structures where more intensive explorations are justified could stimulate the search for and discovery of additional ore reserves. Various operators in the Tri-State district have used geophysical surveys to some extent since 1928 to guide exploratory drilling. Some geophysical investigations have also been made in the district by the State Geological Surveys of Kansas (11)3/ and Missouri (8, 13) and by Federal agencies (16), with the objective of directing exploratory drilling to areas where geologic conditions favored ore deposition. Many factual data obtained have not been published. The investigations generally have not been broad enough to permit conclusive evaluation of the usefulness of the geophysical techniques in all parts of the district.

Jan 1, 1959

By Peter J. Clarke

Afghanistan&apos;s mineral industry continued to be dominated by the production and export of natural gas, although several mining and related industrial projects, all under the supervision of Soviet technicians, were in the planning stage in 1982. Afghanistan produced minor quantities of barite, cement, coal, fertilizer materials, iron, and lapis lazuli, all for domestic consumption.2 Large-scale projects being investigated were a copper mine and concentrating plant at Ainak, extensive mining of the Hajigak iron ore deposit near Kabul, construction of an oil refinery at Angot, increasing production and processing of natural gas, and implementing an intensive geologic prospecting and exploration program for areas of mineral potential. Afghanistan&apos;s gross domestic product (GDP) was estimated at $2.76 billion3 and has remained stagnant for the past several years. Total exports in 1982 were estimated at $700 million, only a marginal increase from the 1981 figure of $694 million. Exports of natural gas to the U.S.S.R. earned $385 million in 1982, representing just over one-half of Afghanistan&apos;s total exports. Natural gas revenues were down approximately 11% from the 1981 level, owing primarily to increased antigovernment activity in the northern part of the country.4 About 90% of the country&apos;s natural gas production was exported to the U.S.S.R.5 About 38% of Afghanistan&apos;s development budget had been earmarked for mining and industrial projects in 1982.6

Jan 1, 1984

By Charles Prasky

This report describes and appraises recent progress in the development of a differential sulfatizing process for recovering a ferrograde manganese oxide from low-grade manganiferous ferruginous materials in the Cuyuna range. Individual process steps were carried out successfully using a 20-inch-diameter shaft for continuous countercurrent sulfatization of the manganese, a multiple-compartment rotary drum for leaching the water-soluble manganese sulfate, a submerged-combustion evaporator for the recovery of monohydrate crystals of manganese sulfate, and a shaft furnace for the thermal decomposition of sulfate crystals for production of a ferrograde manganese oxide and a sulfur dioxide gas suitable for sulfatization of fresh are. Of the two general kinds of Cuyuna manganiferous materials--the carbonate slates and the oxidized ores--only the slates were studied at pilot scale.

Jan 1, 1963

By R. V. Higgins

A numerical method is presented to calculate the isopressure (isobar) lines and streamlines for an oilfield from the pressure distribution. A knowledge of these lines is useful in the study of the flow of fluids in underground reservoirs, especially for those containing gaseous and/or liquid hydrocarbons. This work was done primarily to enable determination of the shape factors needed in the calculation of petroleum reservoir performance. However, it has application for the flow of water in aquifers, or electricity or heat in odd-shaped geometry. Techniques previously developed were used to calculate the pressure distribution. From this pressure distribution, the isopressure lines were calculated accurately by the method presented in this paper. Then by successively projecting orthogonal lines from one isopressure line to another, the streamlines are determined. From the coordinates of the isopressures and the streamlines, the shape factors can then be determined by a published method. Computer methods are presented to calculate the streamlines and isopressures for any well-spacing pattern existing within a field with multiple wells. The method reproduces the flow net for several well configurations having extensive geometrical variations. Such information provides the petroleum engineer with data from which he can compute oil recoveries for different patterns and thereby maximize the recovery of hydrocarbons from the reservoir.

Jan 1, 1972

By R. S. Dean

In the early days, most smelters were erected in nonarable land and at some distance from settled communities. The movement of population, which resulted in many instances from employment at the smelters, has brought to most smelterman in the United States the problem of preventing damage to plant and animal life in the territory adjacent to the smelters by sulphur dioxide gas (S02). This problem has been met, broadly, in two ways: (1) By diluting and removing the S02 by means of air currents and (2) by converting the S02 to a liquid or solid compound of sulphur and disposing of the compound.

Jan 1, 1937

By R. S. Dean

In the early days, most smelters were erected in nonarable land and at some distance from settled communities. The movement of population, which resulted in many instances from employment at the smelters, has brought to most smelterman in the United States the problem of preventing damage to plant and animal life in the territory adjacent to the smelters by sulphur dioxide gas (S02). This problem has been met, broadly, in two ways: (1) By diluting and removing the S02 by means of air currents and (2) by converting the S02 to a liquid or solid compound of sulphur and disposing of the compound.

Jan 1, 1937

By R. E. Morgan, Barkleym J. F.

"INTRODUCTION Wood burned for commercial heat and power usually is waste material from some manufacturing process. The amount of it reaches substantial proportions. It is estimated that over 50 percent of the timber cut for lumber becomes ""waste"" in the process - sawdust, shavings, trimmings, slabs, and bark. Woodworking manufacturing processes also produce much waste. The incentive to use this waste has resulted in much development of wood-burning equipment to produce heat and power. To answer general inquiries received by the Bureau, this publication covering developments along these lines was written. There is included a bibliography of additional information on the subject.COMPOSITION AND BURNING CHARACTERISTICS OF WOODThe approximate composition of moisture-free wood is, in even figures:PercentHydrogen 6Carbon 49Oxygen 44Ash 1Total 100This composition corresponds to about C6H1005. Moisture is essentially always associated with wood. Green wood contains approximately 30 to 50 percent moisture; air-dried or seasoned wood contains 15 to 25 percent and kiln-dried about 8 percent. Exposed to the weather, wood absorbs and gives off moisture depending on weather conditions and water contact.""Dry"" wood ignites relatively quickly and readily gives off volatile matter when heated. Long flames and smoke easily occur during burning. The burning action is substantially retarded, however, by appreciable moisture content; ignition is more difficult. When the moisture content is more than about 70 percent, an auxiliary fuel is required to maintain combustion. One of the main factors in the problem of the satisfactory and smokeless combustion of wood is its moisture content."

Sep 1, 1950

By Fred R. Biggs

This report was prepared by the U.S. Bureau of Mines to present a brief history of the listing of Iron Mountain Mine as a Superfund site on the National Priorities List (NPL) and subsequent remedial actions. The mine area is located on 4,400 acres near Redding, CA, and includes underground workings, an open-pit area, waste rock dumps, and tailings piles. This property involves multiple sources of acid mine drainage (AMD) that are high in copper, zinc, and cadmium. The selected remedial actions, based on the Record of Decision of 1986, would partially cap the Richmond mineralized zone to reduce infiltration of clean water, divert clean surface waters away from contaminated areas, fill surface subsidence areas, and enlarge the Spring Creek debris dam to provide increased surge capacity. Site remediation efforts at Iron Mountain are well into the remedial design-remedial action phase. Costs to date for remedial action are $7.5 million. Details of activities and designs of remedial elements are presented and future activities discussed.

Jan 1, 1991

By Stella Sigler

This publication contains analyses and related source data for 153 natural gas samples from 16 States. Of the total samples, 149 were collected during calendar year 1993. The remainder were collected earlier, but releases granting permission to publish were not received until 1993. None of the analyses have been previously published in annual reports. All samples were obtained and analyzed as part of U.S. Department of the Interior, U.S. Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by mass spectrometer and chromatograph.

Jan 1, 1994

By John O. Atkins

[Experiments were conducted by the Bureau of Mines on five types of simuated lunar rock (dacite, tholeiitic basalt, vesicular basalt, pumice, and uluth Gabbro) to study the effects of various simulated lunar environments n their strength and deformational properties. Specimens were tested in an ltrahigh vacuum (UHV) system at pressures ranging from atmospheric down to 0-11 torr and at temperatures of -130°, 20°, and 135° C. All tests were onducted with a servocontrolled testing machine. Rock specimens tested at 0° C in UHV exhibited significantly higher compressive strength and Young&apos;s odulus than those tested at 20° C in atmospheric pressure. The magnitudes f increase are related to the porosities and permeabilities of the rock pecimens; high porosity and permeability allow better outgassing and thus nprove surface cleanliness in UHV. The compressive strength generally ncreases but Young&apos;s modulus decreases as test environments change from 20° C i UHV to 135° C in UHV. No significant difference was observed in the iysical properties measured at 20° C in LTV and -130° C in UHV. Anisotropy i strength and Young&apos;s modulus exist both in UHV and at atmospheric condi¬&apos;.ons with the same symmetry pattern. The orientations of the principal axes iy, however, change from the atmospheric to UHV condition. The results idicate that rock fragmentation in lunar environment will require more ergy than that at 20° C in atomospheric pressure.]

Jan 1, 1974

By C. E. Jordan

The Bureau of Mines is conducting research into the pneumatic recovery of coarse mica and has used this method to produce mica concentrates that contain more than 90 percent mica. This research is being carried out pursuant to the Bureau&apos;s objective to develop technology that will help maintain an adequate supply of minerals and metals to meet national economic and strategic needs. Researchers used a Bureau-designed system of crushers, screens, and zig-zag air classifiers to concentrate coarse liberated mica particles from mica-bearing materials. This pneumatic system was used to concentrate four mica ores from Arizona, North Carolina, and South Dakota and three waste tailings from Alabama, Georgia, and South Dakota. Using these samples, it was demonstrated that plus 65-mesh size mica can be effectively recovered by the pneumatic method. Not only were the concentrates high in mica content; it was also demonstrated that this method can be used to recover up to 78 percent of the mica that was originally contained in the samples. Because it is a dry concentration method, the pneumatic beneficiation technique may be advantageous in areas where water resources are limited.

Jan 1, 1980

By L. C. IlsLey

The last previous Bureau of Mines publication relative to details of permissible methane detectors (Bulletin 331, published in 1930) describes detectors of four different types, namely flame, combustion, catalytic, and a combination Weatstone-bridge and catalytic type in which catalytic action at the surface of a platinum filament when in methane causes a change in the temperature and resistance of the filament, thus unbalancing the bridge circuit and giving a reading proportional to the methane concentration. Three detractors of the latter type have been approved since 1930. A brief description of each follows: U. C. C. Detector Approval No. 902, covering the U. C. C. indicating detector, as described in Bulletin 331, was extended. January 27, 1930, to cover important changes in design that permit checking the calibration of the detector at any time whether in gas or fresh air. Essential features of the detector are shown in figure 1.

Jan 1, 1937

By Duvall Wilbur I.

This is the second report to be presented on th application of stress analysis to underground Mining problems. In part I2/ of this investigation the stress distribution around single openings in unidirectional and hydrostatic stress fields was analyzed. Relationships between maximum stress concentration and size and shape of openings were determined by the photoelastic method. In most cases the results were verified by mathematical methods This report considers the stress distribution in pillars formed by two or more openings in a. unidirectional stress field. Relationships between stress concentrations and size and shape of pillars are developed. Applied to mining, results snow how estimates may be made of the stress distribution in pillars, what factors cause high local stresses, and how local stress concentrations may be reduced by proper design of mine openings. The photoelastic method was used, as in Part I, to study the stress distributions, and, whenever possible, the results were verified mathematically. A description of the photoelastic method and equipment is .given in Part I.

Jan 1, 1948

By Henry E. Perlee

In a Bureau of Mines study two-dimensional mathematical equations were solved that describe the transient thermal response of a rock dust particle in a cloud of similar particles in a gas flame&apos;s preheat zone subject to a radiant field from the approaching flame. The description includes both radiant energy absorbed and emitted by the particle and thermal conduction inside the particle and into the surrounding gas environment moving relative to the particle. Two situations were studied; in one the radiant energy incident on the particle is converted to thermal energy at the particle surface, and in the other the radiant energy is converted to thermal energy uniformly over the volume of the particle. The result of the study showed that for a 10-µm-radius particle, a 200-mg 1-1 loading density, and a flame approach velocity of 30 m sec-1, the particle temperature rise was twice that previously calculated by Singer and Cook based on the model of Essenhigh and Csaba. It was further established that under the conditions examined a rock dust particle temperature never increases more than about 200 K before crossing the flame front.

Jan 1, 1976