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By Frank J. Wiebelt

The Veta Chica and Cerro Colorado chromite deposits of the McGuffy Creek area, Siskiyou County, Calif. were selected as worthy of investigation by the Bureau of Mines in accordance with the Strategic Minerals Act of 1939. These were two of many chromite deposits examined by engineers of the Bureau of Mines during their extensive wartime mineral examination and exploration campaign. Exploration by the Bureau of Mines consisted of 2,234 feet of diamond drilling, surface trenching, and sampling during the months of May and June 1942.

Jan 1, 1949

By Kenneth J. Miner

Pittsburgh bed and Lower Freeport bed coals were tested in the U.S. Bureau of Mines two-stage froth flotation pilot plant, which utilizes a new flotation process to remove pyritic sulfur. The process consists of a first-stage coal flotation step to remove coarse, free pyrite and other refuse in the tailings. The clean coal froth concentrate is then repulped and treated with a coal depressant, a pyrite collector, and a frother to selectively float the remaining pyrite in a second stage. Results in the pilot plant were excellent, comparing well with those obtained in laboratory batch tests. That is, about 70 percent of the pyrite present in the Pittsburgh bed coal and about 90 percent of the pyrite present in the Lower Freeport bed coal were removed with excellent final clean coal recoveries.

Jan 1, 1973

By R. E. Lindstrom

A study of ion-exchange resin crosslinkage and eluant flow rate, resin-bed shape, and addition of separating ions to feed stock was undertaken to determine their effect on the separation efficiency of ion-exchange on bastna-site-rare-earth elements. Results show that 12-percent divinylbenzene (DVB) crosslinkage resin is detrimental to separation efficiency at flow rates over 2 to 5 ml./min./sq. cm.; whereas, separation with 4-percent DVB crosslinkage resin is relatively unaffected by flow rates between 2 and 10 m1./min./sq.cm.

Jan 1, 1959

By Eugene T. Sheridan

The 23d annual survey of the peat industry by the Bureau of Mines, United States Department of the Interior, revealed that 75 producers in 17 States re-ported commercial production of peat in 1956. Forty-seven producers reported humus production, 19 reported reed-sedge peat, 17 reported moss peat, and 1 reported muck. This total exceeds the number of active operations, but several producers reported recovering more than one type of peat. Fifty-five percent of the total production was reported as peat humus, 30 percent as reed-sedge peat, and 15 percent as moss peat. A negligible amount was reported as other types. More than one-fourth of the total output was raw peat with no preparation, other than having been air-dried. The remainder consisted of processed peat prepared for use by cultivation, shredding, or kiln drying.

Jan 1, 1958

By Sabri Ergun, Robert W. Smith, Victor H. Tiensuu

Factual geometries are considered for X- ray scattering studies of weakly absorbing materials by both reflection and transmission methods . These studies are usually made on slab specimens to obtain adequate scattered intensities ; however , the intensities are appreciably influenced by absorption of the X-rays in passing through the specimens . Conventional equations derived to account for this absorption are based on idealized geometries , but for polycrystalline carbons the use of idealized geometries leads to several percent error in the corrections to be made . Use of factual geometries substantially reduces this error .

Jan 1, 1964

By L. F. Willmott

Pulverized high-volatile A bituminous coal was gasified with oxygen and superheated steam in a pressure-gasification pilot plant equipped for slurry feeding. The minimum ratio of water to pulverized coal that could be pumped satisfactorily as a slurry was about 1 to 1. Heating this slurry produced a suspension of coal in superheated steam having a steam-to-coal ratio greater than the 0.3 to 1 proportion that is considered optimum for pressure gasification of pulverized coal. A steam separator removed enough steam to provide ratios down to about 0.5 to 1, but a 0.3 to 1 ratio was not achieved. Gasification of Sewickley coal produced a synthesis gas containing about 36 percent H2, 46 percent CO, and 13 percent CO2, Gas output, gas composition, and coal and oxygen requirements were Virtually the same as for a pilot plant equipped for fluidized-coal feeding. Typical results from the slurry-fed plant at 300 psig were carbon gasified, 95 percent; coal requirement, 34 lb/M (thousand) std cu ft CO + H2 produced; oxygen requirement, 365 std cu ft/M std cu ft CO + H2 produced. The results showed that the two feeding methods are equally satisfactory from the standpoint of gasification. A choice between a fluidized-coal gasification process or a slurry gasification process depends on considerations relating to the coal-feeding phase itself, including capital and operating costs, manpower requirements, safety, and flexibility of operation.

Jan 1, 1962

By H. V. Makar

An aluminizing dross which is accumulating as a waste material in substantial quantities was tested for possible use as a steel deoxidizer. This material, consisting mainly of aluminum, silicon, and iron, was used to deoxidize laboratory-scale melts ranging from 7 to 100 pounds. Oxygen analysis showed that the aluminizing dross was effective in reducing oxygen levels in steel. A direct comparison with aluminum wire showed the dross material to be at least as effective. Under similar test conditions with 7-pound melts, 3 grams of aluminum reduced the oxygen concentration from 210 to 175 ppm, while 4 grams of aluminizing dross (equivalent to approximately 2 grams aluminum) reduced the oxygen concentration from 250 to 170 ppm. An additional 4 grams of aluminizing dross produced a final oxygen concentration of 140 ppm.

Jan 1, 1972

By N. E. Hanna

Experience with the current version of gallery test 4, in use since 1913 to evaluate the incendivity of permissible explosives in the presence of coal dust, has shown the procedure to have inadequate discrimination. Consequently the Bureau of Mines used the up-and-down method of statistical design to investigate the incendivity of permissible explosives in the presence of coal dust and gas. A suitable device was developed to measure coal dust concentrations in the air-gas mixtures and to disperse the dust in the gallery atmosphere. A proposed testing method which uses suspended shots in a predispersed coal dust-gas-air mixture was evaluated. The new method can discriminate between different explosives with respect to their incendivity. Maximum ignitibility of the coal dust cloud by permissible explosives occurred in the vicinity of 0.3 oz/cu ft. About 10% sodium chloride in permissible explosive formulations had a very significant effect in reducing the probability of igniting coal dust. Bundled charges were more incendive than column charges.

Jan 1, 1966

By Robert L. Grayson, Syd S. Peng

"An airborne dust study was undertaken at a Southwestern Pennsylvania underground bituminous coal mine by the Pennsylvania Department of Mines and Mineral Industries in 1964 for the purpose of making recommendations and requirements regarding compliance with health and safety aspects of The Bituminous Coal Mining Laws of Pennsylvania, approved by the legislature on July 17, 1961. The study was designed to accurately represent the airborne dust conditions of the subject mine. Sampling by midget impinger of specific worker locations throughout the mine was accomplished. Sample analyses yielded dust concentrations to mppcf, particle size determinations in cumulative per cent less than specified cut-off diameters, and determinations of free silica percentages in total dust samples. The data from this study is further analyzed, and the results are presented.INTRODUCTIONThe Bituminous Coal Mining Laws of Pennsylvania, enacted in 1961, prompted a study of respirable coal mine dust by the Department of Mines and Minerals Industry in 1964. In recognition of their obligation for ensuring the health and safety of bituminous coal miners, the department set out to characterize the airborne dust of mines throughout the commonwealth. The purpose of the studies was to make recommendations and requirements for compliance with the law and for control of airborne coal mine dust in Pennsylvania mines.One such study was undertaken at an underground bituminous coal mine operating in the Pittsburgh Seam in Southwestern Pennsylvania. The study was desig11ed to sample specific worker locations throughout the mine site and characterize the respirable dust relative to each of them. A midget impinger was used to gather respirable range dust samples during an 8-hour shift. Continuous miner operator, roof bolter, stoper bolter, loading machine operator, shuttle car operator, gathering motorman, mainline motorman, and rotary dumper jobs were sampled underground. In addition, barge mover, coal sampler, fine coal operator, heavy media operator, and boiler room attendant occupations were sampled on the surface. The surface sampling was over a 71-hour shift because of UMWA contract provisions."

Jan 1, 1988

By Alla D. Mah

Combustion energies of barium and strontium were measured by means of the combustion bomb calorimeter. The heats of formation obtained for the oxides were ?H298.15 = -139,060 ± 700 cal/mole of barium oxide (BaO) and ?H298.15 = -144,440 ± 400 cal/mole of strontium oxide (SrO). Tables containing heats and free energies of formation from 298.15° to 2,000° K were prepared.

Jan 1, 1963

By E. J. Schneider

In view of the growing commercial interest In the higher boiling fractions of low-temperature tar, a study of the literature has been undertaken to obtain as many data as possible regarding the properties of possible pure constituents. The following substances have been studied: THREE-ORTHO-XYLENOL (1, 2-DIMETHYL-3-HYDROXYBENZENE) Detection By the isolation of the silver salt of 1, 2-dimethyl-3-phenoxyacetic acid.

Jan 1, 1930

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 Jr. Driscoll

The thermoelectric properties of yttrium monoarsenide, yttrium monoanti-monide) and ternary materials from the Y-As-Se and Y-Sb-Te systems were investigated by the Bureau of Mines from room temperature to 1,000° C. The maximum calculated figure of merit for yttrium monoarsenide and yttrium monoantimonide was 2 x 10-5 ° C-1. YAs and YSb were semimetallic conductors with low Seebeck coefficients and electrical resistivities. The values of the Seebeck coefficient and electrical resistivity of the Y-As-Se and Y-Sb-Te materials were between those of the yttrium selenides and tellurides and of YAs and YSb, respectively. The maximum power factor calculated for the Y-As-Se materials was 2 X 10-5 watt/cm ° C2 which yielded an estimated figure of merit of 6 X 10-4 0 C-1. Most of the Y-As-Se compounds had high Seebeck coefficients and moderately low electrical resistivities. The Y-Sb-Te materials were degenerate semiconductors with power factors of 6 X 10-8 watt/cm ° C2.

Jan 1, 1967

By H. J. Heinen

The Bureau of Mines, investigated a cyanidation-carbon adsorption technique for extracting gold from arsenopyrite concentrates. Agitation leach experiments were conducted on 85-pct-minus-35-mesh gravity concentrates containing 21.8 oz gold and 6.4 oz silver per ton. Results obtained in leaching the concentrates showed that 96.9 pct gold and 90.7 pct silver extraction could be achieved in 96 hours of agitation. Gold and silver were recovered from the resulting pregnant solution by exposure to granular activated carbon in a countercurrent system. Carbon loadings of 2,556 oz of gold and 502 oz of silver per ton were achieved. These loadings are significantly higher than heretofore thought practical.

Jan 1, 1980

By Frank K. McIntosh

The Wood mine area was investigated by the Bureau of Mines in -1941 by a magnetic survey and a gravitational survey. Surface trenches were excavated, and diamond-drill holes were bored at the strongest anomalies developed in common by the two surveys. In the last century', several widely separated bodies of chromite with some magnetite had been exploited in a 'serpentine belt near its contact with schist. At one time this district held a virtual monopoly on the production of chromite. Known ore bodies now are exhausted. Owing to the relatively high specific gravity of chromate compared to normal rocks, a gravitational survey was run to determine which magnetic anomalies were worthy of diamond drilling. Linear feet of trenching totaled 1,710 feet. Ten holes were diamond drilled, which totaled 2,272 feet. The log of the drilling is shown in the text in a tabulation of drill-hole data.

Jan 1, 1948

By Byron E. Blair

This report describes procedures for using a high-speed camera to study blasting phenomena. Both quantitative and qualitative information can be obtained, provided that proper interpretations of the projected two-dimensional images are made. Geometrical relationships between object and image displacements are given in terms of horizontal and vertical angles of the camera optic axis with respect to the quarry face. Correction factors are given for obtaining true object displacements from image displacements in the camera film plane. The time of initial rock movement also is considered, and the control-ling factors of camera speed, scale factor, minimum increment of projection measurement, etc., are evaluated in terms of minimum time intervals. The high-speed camera and associated equipment are described, and field measurements and laboratory data analysis techniques are outlined. An analysis of a typical high-speed motion picture is made, and the application of the necessary correction factors is illustrated.

Jan 1, 1960

By Homer J. Ballinger

The Rex mine is one of several zinc deposits in Ozark and Howell Counties, Mo. It is the second of these deposits investigated by the Bureau of Mines in an effort to demonstrate reserves of sulfide ore underlying the shallow carbonate ores from which the district's major production has come. The initial investigation was made during 1945-46 on the Alice mine, Ozark County, Mo.21 The investigation reported herein was conducted during 1947. The Rex open pit is about 250 feet long, 100 feet wide, and about 25 feet deep (average). Three caved shafts are evident in the bottom of the pit, but the extent of the workings from these shafts is not known. The Bureau of Mines drilled five churn-drill holes in and around the Rex pit to test the grade and the vertical and lateral extent of the deposit. Two of the holes indicate notable zinc mineralization ranging from less than 1 to more than 10 percent metallic zinc, but largely in the oxidized condition.

Jan 1, 1948

By R. D. Brown

There are techniques for separating aluminum alloys from mixed scrap, but there are no efficient ways to separate wrought aluminum from cast aluminum. This Bureau of Mines report describes a novel technique for separating mixed aluminum alloy scrap into cast and wrought aluminum alloy fractions. The technique, which uses conventional heating, fragmentizing, and screening equipment, exploits differences in the mechanical properties of cast and wrought aluminum alloys at elevated temperatures. The cast alloys become brittle at high temperatures owing to intergranular melting of regions of eutectic composition. This melting begins to occur as the solidus temperature for each alloy is reached. Solidus temperatures for casting alloys generally range from 520° to 580° C, but are above 600° C for most wrought alloys. Thus, the casting alloys are easily fragmented while the wrought alloys remain ductile in the proper temperature range. Starting with a mixture containing approximately 80 pct cast and 20 pct wrought alloys, fractions of 100 pct cast and 98 pct wrought have been produced.

Jan 1, 1985

By Douglas F. Scott

This case study provides an example of how social marketing was applied to meet the needs of business customers. Federal regulations require that all companies develop a written program to track hazardous chemicals at their sites. The HazCom Writer, created by the National Institute for Occupational Safety and Health (NIOSH), is a software tool designed to help companies prepare their required Hazard Communications (HazCom) written plan and list all hazardous chemicals at the company's worksite. The social marketing goal was to provide a product for small- to medium-sized companies to use for federal HazCom rule compliance. The HazCom Wm'ter is a direct NIOSH response to customer and stakeholder needs (including the Mine Safety and Health Administration, the mining community, and Occupational Safety and Health Administration- regulated companies).

Jan 1, 2009

By D. J. Parker

This report is based on data collected in and about the Liberty mine of the Liberty Fuel Co. by D. J. Parker and W. W. Kessler on December 13 and 14, 1933. An important phase of an examination to determine the general condition of a mine with respect to safety is the collection of dust samples from rock- dusted areas. Definite conclusions, based on intelligent interpretation of the analyses of such samples, can be reached only when the general condition of the mine is known. A similar examination and report were made on this property in January 1930 by D. J. Parker and R. I. C. Manning. Since that time much has been done by the management to improve safety conditions in this mine. The changes made will be noted in the course of this report. The mine is in Spring Canyon at Latuda, Carbon County, Utah, and is served by a branch line of the Denver & Rio Grande Western Railroad about 7 miles long and connecting to the main line near Helper, Utah. The writer desires to express his sincere appreciation for the many courtesies and helpful cooperation extended by Superintendent George Schultz and Mine Foreman F. W. Koelling.

Nov 1, 1934