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By Arthur M. Hartstein

The Bureau of Mines through contract with Ultrasystems, Inc., obtained gram per gram data of products formed on thermal oxidative degradation of selected compositions, both under dynamic and static conditions. Four broad classes of materials were studied! Polyvinyl chloride compositions, neoprene compositions, rigid urethane foams, and variously treated woods. Whenever possible, comparisons between pure components and composites were attempted. Thermogravimetric and differential thermal analyses were performed to gain understanding of the processes occurring and to explore the feasibility of using these analyses as a method of material identification. The toxic products detected and quantitated included HC1, H2S, CO, S02, CS2,COS, HCOOH, CH3COOH, formaldehyde, acrolein, C 6H6, chloroprene, chloroethanol, benzyl chloride, aniline, and furfural.

Jan 1, 1974

By Walter W. Fisher

A kinetic investigation of copper cementation in a revolving drum was undertaken by the Bureau of Mines to explore the effects of a porous copper deposit attached to the iron surface and a fluidized slurry of copper particles surrounding the iron precipitant. The rate of cementation was found to be significantly enhanced by the increased cathodic areas provided by a porous copper deposit or the presence of a fluidized bed of copper particles contacting the iron precipitant. The cementation rate was found to be retarded by increased ionic strength, low pH, and the presence of oxygen. The cementation reaction was first order with respect to precipitant surface area. Copper cementation on iron is visualized to occur by two basic mechanisms. Precipitation may occur through a series of shorted electrochemical cells, whereby cupric ion precipitates on a growing cathodic copper deposit, or, deposition may occur via a fluidized cathode of copper particles contacting the ion precipitant.

Jan 1, 1976

By D. R. Douslin

This report describes an inclined-piston pressure gage that operates from a zero-pressure datum level. The gage is adaptable to accurate vapor-pressure measurements in the low and intermediate pressure range, 0.01 to 40 mm (mercury). Residual friction in the oil-lubricated piston-cylinder combination is eliminated by a unique oscillatory method that is free of end thrust on the piston and allows the full sensitivity of the gage to be realized. The axial component of the weight-to-area ratio of the piston is determined by measuring the angle of inclination with a goniometer that can be read to 1 sec. Accuracy of the gage proper is estimated to range from 0.001 to 0.012 mm from lower to upper pressure limits. Its highest practical sensitivity is about 0.0005 mm. As a test, the vapor pressures of ice and water were measured in the range -30° to +20° C.

Jan 1, 1963

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

TEST DECK – ALTMETER SURVEY WITHOUT PLTTMETER TEMPERATURE CCRRECTION DATA INPUT

Jan 1, 1977

Table 1.-Employment and injury experience at metal mines in the United States, by industry groups [ ]

Jan 1, 1967

By J. A. Holmes

As part of its investigation of methods of increasing the efficiency of fuel resources, the Bureau of Mines is continuing the study of the general problems involved in the economic use of fuels in gas pro- ducers that were carried on by the technologic branch of the United States Geological Survey. In the course of this study many inci- dental problems of prime importance have demanded consideration. Among them is the determination, under practically constant con- ditions, of the duration of gas-producer tests necessary to reduce the possible error to a minimum. A discussion of this proper length of test period forms the first part of this bulletin. An attempt to dispel some of the uncertainties that arise in an investigation or to account for some of the minor phenomena often necessitates a systematic and careful study of certain chemical, ther- modynamic, or physical laws, or a combination of these, which in turn may result in information or conclusions of great value. Fur- thermore, seemingly unimportant observations often prove to bear directly upon the design, construction, or manipulation of the machine under test. In attempts to improve the gas producer considerable attention has been given by manufacturers to such questions as fixing or isolating the combustible components of the tar, utilizing the waste heat of the producer for the generation of the steam required by the plant, apply- ing the suction principle to bituminous coal and other tarry fuels, and many allied subjects. Little study, apparently, has been given to the physical-chemical conditions most suitable to the formation of hydro- gen and of carbon monoxide, with a view to regulating the percentages of these gases in generators using fuels other than anthracite coal or charcoal. An attempt was made to introduce such investigations when the operations of the government coal-testing plant began at the Louisi- ana Purchase Exposition in St. Louis in 1904, but owing to adverse conditions these problems were abandoned until the plant was trans- ferred to Norfolk in 1907. The delay in beginning this line of inves- tigations, together with the short testing season at Norfolk, limit the second part of this report to preliminary physical-chemical studies, which, however, were sufficiently significant to warrant careful ex- amination pending more complete researches, which are being carried on at the station located in Pittsburg.

Jan 1, 1911

By D. Harrington, B. W. Dyer

"One of the products of the activities of the United States Chemical Warfare Service is a simple device and method for nearly instantaneous determination of small quantities of carbon monoxide in air. Since the war, this device has been diverted to commercial uses, and is now being marketed in connection with rapid determination of the comparatively small but dangerous quantities of CO, which may be found in garages, in sewers, about blast furnaces, etc. Also, it probably has a definite field of use in both coal and metal mines in connection with fires and explosions, as well as in confined places after firing of explosives) the latter applica-tion being of especial importance in metal mining.The device as marketed is readily portable, being small and light enough to carry in a coat pocket of medium size. In operation, a sample of the air mixture is drawn into a small rubber bulb, then forced through a small glass tube filled with certain chemicals upon which CO has the effect of changing the original color from gray or white to shades of green, the deepness of the green determining the percentage of CO in the air. A color scale is attached for purpose of comparison and determination of CO percentage. Only a few minutes are consumed in obtaining the result, all work being done on the ground.The exact effect of minute quantities (up to 1/10 of 1 percent) of CO on the human system is somewhat uncertain, and much research has been and is being done to obtain definite data on this point. It is, however, definitely known that in air containing more than 1/10 of 1 percent CO men doing hard work are quickly and seriously affected. As the gas is tasteless, colorless and odorless, methods of determining the presence of both small and large quantities have been of much importance. Technical Paper 11 of the U. S. Bureau of Mines gives much data as to effect of CO on mice and canaries. It was found that mice show very little distress until the CO content is about 0.20 percent, but quickly succumb when that percentage is exceeded; canaries are somewhat more susceptible; they quickly show distress in as little as 0.15 percent 00, and soon collapse when that percentage is exceeded."

Jan 1, 1921

By D. Harrington, B. W. Dyer

"Two recent occurrences in Western metal mines in each of which 3 men were killed due to breathing fumes from explosives, have aroused keen interest among mining men not only as to the exact cause of such accidents, but also as to possible preventive measures.In sinking the forty five degree incline Marsh *haft near Burke, Idaho, on May 13, 1920, a round of holes containing about sixty pounds of 40 per cent gelatin explosive was blasted by the night shift upon leaving at 11:30 P.M. It was customary for the night shift to leave compressed air blowers open at bottom of abaft until the compressor was shut down slightly before midnight. Presumably this was not done on the night of the lath as the fumes were so heavy in the shaft bottom on the morning of the 14th that at about 8 o'clock, Superintendent Bergen and one of the shaft men, on reaching the shaft bottom, were overcome and fell from the bucket into the sump containing about six feet of water; and when two other men went down in the bucket a few minutes later to investigate, one also fell into the sump and the other was barely able to roach the shaft collar. The three bodies were later on recovered from the sump.At 400 P.M., June 10, 1920, at the Dominion Mine, Colville, Washington, a round of 11 holes containing about fifteen pounds of 60 per cent nitro¬glycerine explosive was blasted in a fifty degree raise about fifty feet above the main tunnel level by the shift going off for the night. in this mine it was the practice not to try to blow out the fumes until just before the shift went to work the next morning, Although no work was being done on the night shift, one of the raise men, curious to ascertain the effect of the shots, about 7:45 P.M., wandered into the mine (which was a tunnel only a few hundred feet in length), and was missed by one of his companions about an hour later. When three men tried to remove the body of the inquisitive miner, two of them were also overcome; ultimately these two and the first man were removed from the point at which all were asphyxiated, which was practically at the foot of themaise."

Jul 1, 1920

By Sivalingam Jeevan, R. L. McConnell

Ground check monitors may be made in several configurations. Each type has unique characteristics and provides different safety attributes when applied to different mine situations. In this paper, the monitor types are discussed in relation to the mine situations. It is shown that the selection of the monitor type can have a significant effect on the safety of the resistance grounded power system. The options are discussed, and the conclusion is drawn that only one monitor configuration can provide maximum safety. Unfortunately no monitors of this configuration are presently available. In addition, when the monitor capabilities and ground wire configurations are considered as a system, it can be shown that certain configurations will lead to maximum safety. This work was supported by U.S. Bureau of Mines grant G0144138.

Jan 1, 1979

By William L. Rice

Geochemical humus sampling techniques were used by the Bureau of Mines in investigating a potential large, low-grade gold deposit in the Orogrande district, Idaho. Conifer needle humus samples were processed by ashing and fire assay-atomic absorption analysis. An area bearing anomalous concentra¬tions of gold and silver was outlined by the geochemical method.

Jan 1, 1970

By L. C. Marchant

Results of detailed analyses of four cores from the Threemile Canyon area in the P. R. Spring tar sand deposit in Utah are reported by the Bureau of Mines. The cores were obtained by the Utah Geological and Mineralogical Sur-vey as part of a l7-corehole evaluation program in the P. R. Spring, Hill Creek, and Rim Rock tar sand deposits. Average properties of the oil zone in the Threemile Canyon area as deter-mined from these cores are as follows: Oil saturation, 67.4 pet of pore volume; porosity, 29.2 pct; permeability before oil extraction, 133 millidarcies; and permeability after oil extraction, 2,855 millidarcies. Average net thickness of the oil zone is 23.8 ft and average depth to the top of the oil zone is 189 ft.

Jan 1, 1974

By J. E. Zeilinger

This Bureau of Mines report describes the preparation characteristics of three samples collected from the Kidney seam, in the Northern Field of the anthracite region. Removal of the sink 1.70 specific gravity material from the samples collected would result in greatly reduced ash contents at yields in excess of 90 percent. The Kidney seam, in the locations sampled, proved to be a low-ash anthracite containing an unusually high percentage of float 1.45 specific gravity material.

Jan 1, 1970

By E. G. Valdez

The Federal Bureau of Mines, in cooperation with Ford Motor Co., investigated the recovery of polyurethane foam and other assorted plastics from the nonmagnetic reject of automobile shredders. Preliminary studies were con-ducted on a 1957 hulk augmented with additional foam and assorted plastics. The proposed flowsheet developed by the Bureau from the preliminary studies consists of a combination of screening, water classification, and gravity separation. The process was then tested on reject from two shredded 1972 cars. All of the foam and between 52 and 70 pct of the assorted plastics were recovered. The composition of the reclaimed foam concentrates ranged from 46 to 66 pct foam; the concentrates were hydrolyzed in laboratory tests by Ford Motor Co. to produce a reusable liquid mixture of polyether glycol monomers and toluene diamine.

Jan 1, 1975

By Rex D. Thomas

Concentration of the kerogen (organic material) in oil shale was accomplished by centrifuging after pretreating the oil shale with carbonic acid to remove the carbonates and pretreatment with sodium hydroxide (pH 11.5) to remove the claylike minerals. Analysis of the materials obtained showed that the concentrations of organic sulfur and organic nitrogen compounds were not affected by centrifuging. These compounds are evenly distributed in the kerogen and are not strongly bound to the mineral constituents. Organic oxygen compounds, however, were concentrated in the light fraction. These compounds are more closely associated with the kerogen and are not bound to the mineral constituents. Iron compounds other than pyrite apparently are closely associated with the organic material.

Jan 1, 1970

By Fred N. Kissell, Maurice Deul, T. D. Moore

Methane emission from two surface gob-degasification boreholes was measured by the Bureau of Mines. The investigation took place during mining of a 3,200-foot longwall panel in the Lower Kittanning coalbed in central Pennsylvania. The first hole was 500 feet from the start of mining, and the second hole was 2,200 feet. The first hole went on natural draft as soon as the longwall face passed it. This caused the methane flow in the return entries to drop 75 pct. In the 6 months required to complete the panel, the two holes emitted 69 MMcf of methane in varying percentages of concentration in air. In 3 years, the holes emitted a total of 150 MMcf of methane.

Jan 1, 1976

By Michael J. Brnich

Since 1991, Pittsburgh Research Center (PRC- formerly part of the Bureau of Mines) researchers have recorded extensive interviews with 30 individuals who are experts in the area of mine emergency response. These individuals, who have an average of 35 years of mining experience and 29 years of mine emergency response experience, related stories and observations from events that they experienced during their combined 850 plus years in mine emergency response. The purpose of this effort was to gather information that could be passed onto both today?s and tomorrow?s mine emergency responders to train and guide them in handling future events.

Jan 1, 1997

Reduce spillage hazards and contamination when adding hydraulic nil to mining machine reservoirs. Approach An easily transported module, that delivers hydraulic oil directly into mining machines, was built and tested. How It Works The Hydraulic Oil Delivery Module is carried, from the oil storage area to the equipment needing oil, in the bucket of a scoop or other utility vehicle. Oil is pumped into the module reservoir from storage, or out of the module reservoir into the machine being serviced, through a long hydraulic hose. During long-term testing, the 115 foot long delivery hose made it possible to replenish the hydraulic oil in mining machines at the face with only limited interruption to the mining operation. (Figure 1 shows one! version of the module.) The compact Hydraulic, Oil Delivery Module consists of: an oil reservoir: a pump driven by a hydraulic motor; two high pressure, low volume oil lines, filters; and a low pressure, larger capacity delivery hose equipped with quick-connect-couplers. The high pressure oil lines are connected to the scoop's hydraulic power takeoff, which supplies the power to pump oil in or out of the module reservoir.

Jan 1, 1977

By Richard J. Bielicki

Poor mixing of methane and air at coal mine working faces causes fluctuating methane concentrations. If these fluctuations are large enough, methane levels can periodically exceed safe limits, even though the time average methane concentration may be satisfactory. Concentration fluctuations measured underground can result both from variations in methane emission rate and poor mixing. The present paper reports on a statistical analysis of fluctuations at a constant methane emission rate, that is, on fluctuations due only to poor mixing. A full-scale model of a working face was used. Both peak heights and elapsed times between peaks were evaluated. Good mixing was indicated by normal, Poisson, and exponential distributions while poor or incomplete mixing was indicated by log-normal or gamma distributions.

Jan 1, 1974

By Donald O. Capstick

A mineral survey of a 13,525-acre portion of the 21,875-acre Owyhee Canyon Wilderness Study Area in northern Nevada was conducted by the U.S. Bureau of Mines in 1984. Two samples from sand and gravel deposits in the study area contained minor placer gold typical of the Owyhee River area. The gold-bearing gravels are too low grade or of insufficient volume to support commercial placer mining operations. The sand and gravel deposits might have minor local construction uses.

Jan 1, 1986

By James P. Ulery, Stephen J. Kravits, William P. Diamond

This report presents results of a cooperative research project between the U.S. Bureau of Mines and Beth Energy Mines, Inc. Four coreholes (two before mining and two after mining) were drilled at a longwall mine operating in the Lower Kittanning Coalbed to obtain coal and rock samples from overlying strata to determine their gas content at various times in the mining cycle. The results of those tests indicate that 91 pct of the gas removed from the overlying strata came from coalbeds. Material balance calculations were made to compare the volume of gas produced both from gob gas vent holes drilled on the panel and gas removed by the mine's ventilation system with the volume of gas removed from strata directly overlying the panel to a height of 275 ft. This analysis indicates that only 40 pct of the total gas produced from the panel actually came from the strata directly overlying the panel. The remaining volume of gas production probably migrated to the Iongwall gob from overlying, and perhaps underlying, strata immediately adjacent to the panel and perhaps from greater distances downdip because of the establishment of a long-term pressure gradient in the study area.

Jan 1, 1992