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By Lester G. Morrell

UPTREND in value of mineral production in the Commonwealth of Australia continued in 1963, again pacing the country's general economic growth rate. Increases occurred in output of most raw and processed mineral products, including bauxite, copper, iron ore, pig iron, steel, lead, zinc, cement, gypsum, pyrite, coal, and refined petroleum products. Although the economy of Australia has been traditionally based on wool and agricultural products, in recent years the country has become highly industrialized. Nearly one-third of the 3.6 million total civilian labor force is engaged in manufacturing. Employment in mines and quarries occupies 1.4 percent of the national labor force.

Jan 1, 1964

By Daniel C. Boteler

Data from 68 entrained-bed carbonization tests were treated statistically by the Bureau of Mines, and several useful relationships were developed among the major variables. Nine coals, ranging in rank from lignite A to high-volatile A bituminous, were carbonized in two entrained-bed carbonization pilot plants. The carbonizing reactors employed were vertically mounted cylinders, internally heated, refractory-lined, and 10 inches ID. The range of carbonization temperatures was from 825° to 1,600° F. Using a regression-analysis computer program, empirical equations were developed by which carbonization temperature, air-to-coal ratio, devolatilization of coal, char yield, and volatile matter content of product char may be predicted.

Jan 1, 1973

By H. C. Ko

Heats of solution of calcium carbon-ate (calcite) and calcium oxide in hydrochloric acid were determined by solution calorimetry. Combination of these two heats yields a value of 42.643±0.024 kcal/mole for the enthalpy of calcination of calcite at 298.15 K. Literature data on ?H°298.15 of calcination of calcite were reviewed and compared. Thermodynamic properties for the calcination process were calculated from 298.15 to 1,500 K using Gibbs energy functions. This research was undertaken by the Bureau of Mines as an effort to provide thermodynamic data for the advancement of minerals technology, energy conservation, and environmental preservation.

Jan 1, 1982

By P. G. Pigott

This investigation by the Bureau of Mines demonstrated that building bricks can be produced by the steam-curing process from various types of industrial mineral wastes. Wastes, utilized to produce bricks, consisted of copper mill tailings, roofing granule fines, asbestos fines, and zinc mill tailings. Bonding of the wastes with either Ca(OH)2 or portland cement resulted in building bricks that met ASTM specification C73-67 for grade SW and MW bricks when evaluated in accordance with ASTM designation C67-66 on sampling and testing of brick. An economic evaluation of the process indicates the total operating cost per 1,000 bricks is about $36.

Jan 1, 1974

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

C 2 Complete Hoisting Systems A Above Ground Installations A total of seven companies were identified who supply complete emergency escape hoist units for above ground installations The units have been designed predominately to meet the needs of coal mine operators to satisfy the requirements of the Coal Mine Health and Safety Act of 1969. The seven companies are as follows 1 Dover Conveyor and Equipment Co. 2. Coeur d' Alenes Co. 3. Connellsville Corp. 4. Scott Midland 5. W W Williams Co. 6. Equipment Corporation of America 7. Timberland Ellicott Table VIII contains detailed specifications and price information on each of these units. The units have a number of similarities

Jan 1, 1976

Measure tattling in cemented backfill when installation of bore-hole extensometers is not feasible. Problem To evaluate the amount of load that backfill carries during pillar recovery, information about how much the backfill settles after placement is often required. However, the composition of some backfills makes them difficult to drill and the installation of borehole extensometers almost impossible. Approach Bureau researchers have developed a vertical fill extensometer that can be cast in place as a stope is being filled. It consists of a baseplate, sections of steel pipe enclosed in loosely coupled polyvinyl chloride (PVC) pipe, and a top anchor assembly that contains a displacement transducer (fig. 1).

Jan 1, 1990

By M. M. Tilman

A series of alloys was laboratory prepared by adding up to 4 weight-percent cobalt to the basic composition of type AM 350 (AISI 633) stainless steel. Aging curves were established for each alloy at 750° F, 850° F, and 950° F for lengths of time up to 100 hours. A series of annealed steels containing as much as 1 weight-percent cobalt was cold-rolled 50 percent and aged for 3 hours at 850° F. No improvement in hardness due to cobalt was observed in the steels transformed by heat treatment. Slight improvements in hardness were observed in the steels transformed by cold working.

Jan 1, 1968

By W. M. Weigel

Langley is about nine miles north of Augusta, Georgia., on the Sou them :l;.ilv1ay. According to the South Carolina. Geological Survey, tr.e district is known a.s tr. Horse Creek and Town Creek sub-areas of the Aileen or Savannah River Area f the South Ciil.Z'olina Coastal Plains. The geology and origin of the clays 3l"e Jscribea in a bulletin of the South Carolina Geological Survey (Series 4, Bull, l; "A Preliminary Report on Cl.:.ws of South Carolina.-), According to this report, i.he clays are sedimentary kaolins, in the Mid.dendor! and Hamburg series of the Cretaceous Age.

Aug 1, 1922

By A. J. Strazisar

The Bureau of Mines conducted a laboratory investigation to study the effectiveness of low-pressure steam and water spray in suppressing respirable dust at the tips of a saw-type cutting wheel. Suppression efficiencies were found to be proportional to the amount of the water or steam applied at the cutter tips. For equivalent water output rates, a maximum efficiency of approximately 80 percent was reached for both steam and water spray. Results from the steam and water spray tests showed an increase in suppression efficiency with an increase in particle size of 1 to 8 micrometers. The data indicate no advantages for using steam as a dust suppressant.

Jan 1, 1972

The Bureau of Mines believes that all coal mines are potentially gassy; for the purpose of administration in the prevention of explosions and fires, the Bureau recommends: That any coal mine wherein methane or other combustible gas can be detected in amounts as much as 0.27 of 1 percent or more by frequent systematic searches shall be classified as a gassy mine. Permissible methane-indicating detectors such as are given in I.C. 7110 or subsequent lists of Bureau approved methane-indicating detectors, or conventional methods of sampling and analysis of required accuracy may be used. The concentration referred to in the decision is percent by volume.

Jan 1, 1941

By T. J. Lutz, G. T. Homce

A standard Ford1 4600 agricultural tractor was converted to remote control to perform ASAE/SAE field upset tests (rear rollover and side rollover). This paper discusses the engineering process to develop a remote-controlled tractor in determining the critical parameters of operation, to choosing appropriate actuators, designing the circuitry to control them, installing the actuators on the tractor, testing the system for functionality and then conducting numerous overturn tests. The system uses off-the-shelf components for simplicity, replaceability, and economic concerns. The remote control system has withstood 21 tests to date with no failures and will continue to be used for at least three more years of testing.

1. Mining to prevent and control underground acid formation should begin with education imparted through: (A) Course work at mining schools to teach prospective engineers. (B) Training of engineers presently employed in the mining industry through appropriate mining extension courses. 2. Considerable need exists to devote more attention to: (A) Hydrogeologic studies of mining areas to enhance the planning of new mines and the abatement program of existing mines. (B) Additional research to explore methods of dewatering the strata associated with mining areas. (C) Further effort to develop sealants for preventing contact between water or oxygen and the acid producing material associated with the coal seam.

Jan 1, 1970

Objective To characterize the roof fall risk associated with underground limestone mining. Background During the first 5 years of this decade, more than one-fourth of the underground mining fatalities occurred as the result of fall of ground. The large openings in underground stone mines present limitations in observing ground conditions because of floor-to-roof heights ranging from 20 to 60 ft or more. Generally, the status of ground conditions in under-ground stone mines is based on observation and experience obtained during mining development. Some mines use monitoring instruments to gain information on roof conditions, but this practice is typically focused and localized to address issues in a particular area or section of the mine. The Roof Fall Risk Index (RFRI) described here provides a method of systematically characterizing the risk of roof falls to enhance the safety of mine workers. Approach As in many industries, a defective product signals the potential for failure. Similarly, defective rock or strata in an underground stone mine presents a potential risk. Assessing ground conditions relative to the concentration of defects observed provides a way to index or rate these conditions and the subsequent risk. Through observations at approximately 50 underground limestone mines in the United States, strata defects were categorized to develop a quantitative method for determining the RFRI. This method is specifically geared to underground lime-stone mines because strata defects are difficult to see and limited by the experience and knowledge of the observer. Overall, 10 defect categories were deter-mined: 3 that relate to geology, 4 that result from mine development, 2 that are indicative of the roof profile, and 1 that addresses moisture or water flow (see RFRI Chart 1). The defect categories are also weighted to reflect the conditions indicative of roof or strata movement or separation (categories 4 through 8). These weights are multiplied by the assessment value to determine the total category value. The benefit of using monitoring techniques to gain information on roof conditions is also factored into the RFRI for overall assessment of an area in the mine. Each defect category is assessed with a value of 1 to 5 based on parameters as defined in each defect category, with 5 indicating the highest degree or level of defect. The assessment value of 3 is also used when information on a parameter is unknown. The parameters for the defect categories are illustrated in RFRI Chart 2 for use in determining the assessed value. How It Works The RFRI provides a means to categorize the risk for roof falls in underground stone mines. The concept of this calculation is aimed at providing an indication of the level or degree of defect relative to the area of the mine examined. The RFRI for the calculation produces a distribution where RFRI values approaching 0 represent a stable condition and those ap-proaching 100 represent an unstable condition.

Oct 1, 2006

By H. B. Humphrey, J. J. Forbes

"In accident prevention, a study of statistical data is necessary to determine primary causes of accidents to devise means to eliminate causes at the original sources. Explosions in coal mines of the United States during the 10 years ending December 31, 1931, ranked third in the causes of fatal accidents; they constituted 16.2 per cent of all fatal accidents in bituminous mines and 8.4 per cent of all fatal accidents in anthracite mines. A study of coal-mine explosions in Pennsylvania, with approximately 160,000 men employed in anthracite mines and about 145,000 in bituminous mines or about 205,000 out of -the approximately 525,000 men employed in all coal mines of the United States, should give information of value to all persons endeavoring to reduce or eliminate coal-mine explosions. This circular reviews explosions of gas or dust or of both in the coal mines of Pennsylvania to show the hazard of gas and dust, to point out the influence of certain factors in causing explosions, and to emphasize the efficacy of explosion-preventive measures.The data published annually by the State Department of Mines and of the United States Bureau of Mines were used in compiling the tables of explosions. Through the cooperation of W. H. Glasgow, secretary, Department of Mines of Pennsylvania, and his assistants, many doubtful cases were clarified, so that as far as recorded the history is comparatively complete. Figures used in compiling some of the tables were furnished by W. W. Adams, chief statistician, demographical division, United States Bureau of Mines.Anthracite in the Wyoming Basin of Pennsylvania was used locally by gunsmiths in 1755, by blacksmiths in 1769, and as domestic fuel in 1808.Mining and shipments developed slowly between 1806 and 1812, but more rapidly after that.Early mining along the outcrops gave essentially no trouble from gas, but by 1870, when State inspection was established, explosions were frequent; ventilation was crude and accumulations of gas were generally ""brushed"" or burned out.Table 1 lists 1,232 ignitions and explosions of gas in anthracite mines from 1870 to 1932, inclusive, every one of which was accompanied by loss of life. Some details are given of 110 representative cases in which five or more lives were lost or in which it appeared that some violence was present.During the period 1870 to 1932, inclusive, gas explosions caused 2,213 fatalities, or an average of about two deaths for each ignition or explosion. Records are not available as to the number injured in these and in other explosions where no deaths occurred, but from a study of explosion reports it appears probable that the number injured exceeds the number killed. In the 110 cases described, 599 were killed and 294 were injured. As shown in Table 2, fatalities from gas explosions averaged 8.3 percent of the total fatalities in Pennsylvania anthracite mines from 1870 to 1931, varying from 6.0 percent in 1931 to 13.1 percent in 1927."

May 1, 1933

By Edward F. Divers

A new nonclogging water spray system for continuous-mining machines has been developed under contract with the Bureau of Mines. This paper presents installation and operating guidelines for the system, which consists of improved and easily maintained machine-mounted hardware, including an inline Y-strainer, a hydrocyclone, a backup filter, and two quick-opening valves for flushing particulates from the strainer and hydrocyclone. Underground tests with continuous-mining machines have shown that when properly installed and maintained, the new sys tern virtually eliminates nozzle clogging and thus greatly reduces spray maintenance. The sys tern is relatively inexpensive and has been installed on typical continuous-mining machines for a total cost under $1,000.

Jan 1, 1976

By L. Cheng, M. S. Seehra, P. S. Raghoottama

The four major IR bands of a-quartz at 1080, 797, 693 and 488 cm-1 are studied at room temperature by FTIR-Photoacoustic Spectroscopy. Using Rosencwaig-Gersho theory, equations for the PAS signal q for the thermally thin and thermally thick cases are derived and it is shown how thin to thick transition occurs and leads to saturation as the sample mass is increased. For sample mass < 2 mg, q is proportional to sample mass thus defining the region for quantitative analysis. The dependence of q on the chopping frequency f is found to vary as q f-n with n ? 0.9 for quartz, in good agreement with the RG theory.

Jan 1, 1989

By H. C. Howarth

The preliminary tests referred to in this report wore made at the Bureau&apos;s Experimental Mine under the general supervision of G. S. Rice chief mining engineer, to determine whether rock dust way be used to extinguish or control mine fires. DESCRIPTION OF THE DUST USED The dust used for application by hand was made from draw slate taken from the Experimental Mine. This draw slate was crushed in a hammer-type crusher fitted with 1/16 inch by 2-inch slotted screens. A sizing test of the dust showed 96.5 per cent through 20 mesh, 69.4 per cent through 48 mesh, 46.2 per cent through 100 mesh, end 33.5 per cent through 200 mesh.

Jan 1, 1927

By A. C. Johnson

The Ellington manganese deposit in Reynolds County J Mo., had been known for some time; and limited exploration, consisting of test pitting and sinking a shaft 54 feet deep on the property, had been done by private interests. Late in 1941, the Bureau of Mines cleaned, deepened, and sampled many of the existing pits and dug and sampled 27 new ones. The shaft was unwatered and sampled, and several pockets of manganese ore were trenched to determine their extent. Samples were analyzed and beneficiation tests on 1 ton of the ore were made at the Rolla, Mo., station of the Bureau of &apos;Mines. Results of the investigation indicated that the deposit was small and low in manganese content.

Jan 1, 1948

By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and from the data developed to determine: 1. Which coals either as mined or after beneficiation by conventional preparation are chemically suitable under present standards for producing metallurgical coke. 2. Which coals require special and more intensive treatment in preparation than is now practiced. 3. Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation by present-day methods. This report is one in this county series that describes the preparation characteristics of the coals of Lee County, Va.

Jan 1, 1957

By M. E. Tyrrell

The purpose of the work leading to this report was two-fold: (1) To determine the properties of cemented tungsten carbide modified by the addition of one, two, and five percent of titanium diboride, and (2) to compare the properties of these mixtures when sintered, hot-pressed, and flash-welded (resistance-sintered). Minor additions of titanium diboride to mixtures of 94 percent WC and 6 percent Co decrease mechanical strength but increase oxidation resistance in proportion to the amount of the addition. One percent of titanium diboride increased the hardness by 2 Rockwell A units. Hot-pressing produced compacts with the highest density and the best mechanical strength, but losses of cobalt were high and grain growth was pronounced.

Jan 1, 1962