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By L. R. Willmott

An ethanolamine purification unit for removing carbon dioxide and hydrogen sulfide from Firscher-Tropsch synthesis gas was installed at the Bureau of Mines synthetic liquid fuels demonstration plant at Louisiana, Mo. The unit was a surplus Radford Girbotol unit from the Missouri Ordnance Works modified for a capacity of 90,000 std. cu. ft per hour of synthesis gas at 450 p.s.i.g., operating pressure. The hydrogen sulfide loading of the feed gas was specified at 500 grains per 100 cu. Ft. The unit was designed by the Girdler Corp. and installed by the Koppers Co. Initial operations were conducted far 11 days in May 1951. Thereafter 7 additional runs were made, varying lo duration from 8 to 54 days. The last run was terminated on May 29, 1953, the total time the Plant wars in operation being 219 days.

Jan 1, 1956

By J. E. Murphy

The high-purity thorium metal was prepared by the Bureau of Mines from electrolytically produced thorium alloys. The thorium-chromium and thorium-manganese alloys were separated into the component elements by vacuum distillation. Chromium and manganese impurities remaining in the thorium metal after distillation at 1,850° C were <0.005 weight-percent. Removal of volatile impurities such as aluminum, calcium, magnesium, and lead was also accomplished.

Jan 1, 1969

By W. A. Cole

Underground mining methods at the Gray mine of Tri-State Zinc, Inc., are of special interest because of the low unit costs achieved through use of jumbos and loading equipment mounted un crawler-type tracks and of diesel trucks that haul from the stoping areas to the mill through inclined adits. The operating company, Tri-State Zinc, Inc., is a wholly owned subsidiary of Gold Fields American Development Co., Ltd., the latter being the American branch of New Consolidated Gold Fields, Ltd., a British-owned company.

Jan 1, 1957

By Charles H. Atkinson, Robert T. Johansen

Tremendous volumes of petroleum ( crude oil and natural gas ) at present cannot be recovered economically . The feasibility of using nuclear explosions for production stimulation therefore has been investigated . Data from underground nuclear tests conducted by the Atomic Energy Commission were reviewed , and the physical effects were evaluated for stimulating petroleum production . Calculations of the effect on ultimate recovery of increasing reservoir temperature with nuclear explosives showed disappointingly small increases . Production increases caused by fracturing of massive low- permeability reservoirs appear technically and economically promising . Petroleum reservoirs that might be converted from submarginal to commercial production are being located and evaluated as to potential reserves and as a location for a field test .

Jan 1, 1964

By R. A. Guereca

The Bureau of Mines conducted an analysis to determine criteria for steady-state, laminar flow boundary conditions for a coiled-tube gas viscosimeter by comparing experimental data from a thick-walled, stainless steel capillary in a horizontal, straight-tube condition, with similar data taken after the same capillary was formed into a helix. Overlapping volumetric f10wrates and pressure drops are covered for both configurations at pressure levels of 28, 225, and 1,000 psia at 3000 K. Friction factor, Reynolds number, and Dean number correlation plots show conditions where the coi1ed-tube flow deviates from straight-tube flow. The coiled-tube data indicate departure from Poiseui11e steady-state laminar flow at a Reynolds number close to 390 and a Dean number of about 15. Below these conditions and consistent with the data reported, Dean&apos;s circulation appears negligible. For the particular coil used, a conservative upper limit of 10 is chosen for the Dean number corresponding to an upper limit of about 250 for the Reynolds number.

Jan 1, 1967

By E. G. Valdez

Laboratory research demonstrated that ceramic wall and floor tile can be produced from electric furnace phosphorus slags composed of calcium silicates. Grinding the slag in a pebble mill, followed by magnetic removal of deleterious magnetite, produced a raw material that could be compounded and formed into wall tile by dry pressing, sintering, and glazing. The effects of process variables such as forming pressure and sintering temperature were investigated. Wall tile bodies produced by this method were comparable to commercial tile. The tiles were readily glazed to a smooth shiny finish and met ASTM Specifications C34-62 for structural clay load-bearing tile. The estimated cost of producing wall tile by this method compared favorably with the retail market value for similar wall tile. Addition of borax or other additives to the ground slag followed by dry pressing and firing likewise produced a commercial grade of floor tile.

Jan 1, 1974

By C. Pritchard

John Marks said in his acceptance of the Hartman Award in 2008, "I guess that without the occasional complaint, your mine is probably over-ventilated" (Marks, 2008). Miners are seldom in this situation and spend much of the time trying to find enough air to keep an operation running. With examination, there are usually changes that can be made to increase the efficiency of ventilation systems. Mine ventilation air is a costly commodity, especially by the time it has been heated or cooled and moved to the bottom of the shaft and through the mine airways. Modifications that result in surplus mine ventilation air could bring financial and environmental benefits. Some issues mine operators have needed to address recently are increased airflow requirements to dilute diesel particulates in metal and nonmetal mines, to ventilate reserves that are deeper, hotter, and further away from fans and shafts, and to meet demands from increased production. This paper discusses successful methods to find additional usable air when there is no extra ventilation capacity. Most of the options presented in this paper are useful for metal/ nonmetal operations but some may be applicable to coal as well.

Jan 1, 2010

By L. C. IlsLey

"The maintenance of permissible equipment which is tested and inspected at the Pittsburgh Experiment Station of the United States Bureau of Mines is dependent to a surprisng degree upon the voltage at which the equipment is operated. The difficulty of maintaining 500-volt equipment is frequently brought to the bureau's attention, and it is quite possible that if the bureau had appreciated at the beginning the full hazard involved, it would never have undertaken the approval of equipment operating at voltages greater than 250 volts.In this connection, the following statement from State mine inspection departments and other sources are of interest as showing the general feeling in safety organizations with respect to voltages higher than 250. These statements, although obtained as a result of a questionnaire sent cut several years ago, still apply very well to present conditions.A. I have not had time to consider seriously the proposed change from every angle, but looking at it from a standpoint of hazard, feel that the danger would be greatly increased. I have always occupied the position that underground voltage on portable equipment should never exceed 250 volts.High voltage of course would mean smaller transmission lines, which would be more economical and no doubt would require in several instances smaller equipment; notwithstanding, if this statement is true, the writer is still favorable to low voltage on underground portable equipment.B. I believe 500 volts should be the limit on the best equipment ender the best conditions and that the U. S. Bureau of Mines should do all in its power to limit the voltage to 500 volts on permissible equipment, as any increase in voltage means increased hazard.C. I will refer you to a section of our mining law, entitled ""An Act to Regulate the Tine of Electricity in the Mines of the State of ----"" which reads in part, as follows: Trolley wires, or other exposed electrical wires, shall not carry a voltage above 275 volts.You may readily see by this that we are not permitted to operate mining machines under ground in -----, with more than 275 volts at the terminals, except that we are permitted to install transforming stations throughout the mines, after complying with certain regulations at the mine.However, as we have had to date, within the calendar year of 1925, six men electrocuted in the mines of the State, using a voltage of 275 volts, I am of the opinion that if this voltage was increased, the hazard would also be increased in proportion.D. I do not care to make a statement for publication: however, I am referring you to our mining laws. On page 27 and 28 you will find what the laws of -----¬require relative to the installation of electricity in the mines.""Hereafter where electricity is installed no higher than two hundred seventy-five (275) volts shall be used underground, except for transmission, or for application to transformers or other apparata, where the high-voltage circuit is stationary. High-voltage motors, and transformers, shall be installed in suitable chambers, built of fire-proof construction, and well ventilated, and shall not be placed on intake, or between intake and return air courses. All high-voltage lines lines and apparata must be clearly marked, to indicate their danger. Main and distribution switchboards for high voltage shall be made of insulating and incombustible material, such as marble or slate, and to be free of all metallic veins, or of material equivalent thereto. Same shall be installed in a dry place. All switches or other instruments used in connection with high voltage shall be installed on suitable switchboards, with at least a three-foot passageway in front and rear properly floored, and kept looked by a door at each end that can be opened from the inside without a key. With higher than medium voltage, there shall not be any live metal work on the front of switchboard, and the entry circuit must be protected by an oil breaker s"

Apr 1, 1932

By W. Ayvazoglou

A large number of organizations interested in the search for mineral deposits have adopted the magnetic method of geophysical prospecting, as it has proved to be the most simple, convenient, and rapid, and at the same time the least expensive in comparison with other methods. According to the last statistical data, about two millions square kilo¬ meters were explored in the United States by different geophysical methods. Ninety-six per cent of this area was prospected for oil and 4 per cent for minerals. Detailed exploration by means of the magnetometer has been carried out over about 85 per cent of this surface. The great advantages offered by this method resulted in the fact that the magnetometer was tried out in most places in which geophysical methods were applied. The main purpose of such e:rploration is to obtain the maximum knowledge valuable to the geologist; therefore good geological interpretation of the results of measurements is important. The possibility of drawing practical conclusions from a map representing the results of the study of the terrane depends greatly on the accuracy with which the measurements are made. The purpose of this article is to show the different sources of error by which the work of an operator may be affected and to discuss the means by which the carrying out of a magnetic survey may be improved.

Nov 1, 1931

By George S. Rice, C. W. Owings

"Brattice cloth is an important material in coal-mine ventilation practically all coal mines use some brattice cloth, gassy mines a large amount. It is employed in three ways:Crosscut brattices.Curtains in haulageways.Line brattices in gassy mines.In each case brattice cloth is used to deflect part or all of a split of the mine ventilating current into or toward the face of a working place. As a general rule, its use in a particular location is temporary.A crosscut brattice should be employed only until a permanent stopping has been erected. Such a brattice is subject to little wear when in actual service, the chief damage occurring when it is taken down and put up again.When used for curtains on haulageways or haulage crosscuts to deflect the air current up into rooms or headings, the wear on brattice cloth is considerable, as mine cars, machines, and personnel constantly pass under the curtains which last only a few days or a few weeks in an active part of the mine. For such purposes tightly woven smooth cloth is desirable, so that it will not be easily torn. Curtains should not be used back from the working places, as they sometimes are, to deflect the main. split, as the leakage of air is too great. Doors should be used in such places."

May 1, 1928

By P. S. Lewis

Shortage of natural gas is reviving interest in low-Btu fuel gas made by gasifying coal in fixed-bed producers. The Bureau of Mines gasified strongly caking Pittsburgh bed coal over test periods lasting four days in an experimental gas producer located at Morgantown, W. Va, Mechanical stirring throughout the fuel bed was effective for keeping the fuel moving and this stirring made the operation successful; hence, the gas producer was named the stirred-bed producer. Nuclear density gages were applied as control instruments to indicate coal flow and fuel level, and to record the frequency and location of void spaces in the bed, The gas, of nominal 140 to 165 Btu/scf calorific value, could be burned in a boiler for generating steam.

Jan 1, 1972

By Lawrence W. Scott

This report presents several systems for continuously monitoring the quality of air in underground mines that are being developed by the Bureau of Mines. Underground stations measure methane, carbon monoxide and nitrogen dioxide concentrations, air velocity, and air temperature. This information is transmitted over a single telephone pair to central stations located on the surface. The central stations display alarms and the data is selectably displayed on digital panel meters.

Jan 1, 1977

By P. C. Good

Tungsten metal in fused form and of high purity was prepared by reducing tungstic oxide with redistilled calcium metal in a heavy-walled sealed reactor. Alloys of tungsten with vanadium, molybdenum) chromium, columbium, and tantalum were prepared by coreduction of mixed metal oxides in the same manner. This work was undertaken by the Bureau of Mines to investigate new approaches for preparing tungsten and its alloys in high-purity form. The standard method of producing tungsten metal has been the reduction of tungstic oxides by hydrogen. The resulting metal powder is compacted, sintered, and fabricated by powder metallurgy methods. Long experience in this field has resulted in the development of a technology that (by careful control of the variables such as metal composition, particle size, and sinterng technique) is well adapted to producing wire and the small shapes usually prepared from tungsten metal.

Jan 1, 1961

By A. G. Starliper

Laboratory studies were made to produce whiskers of tungsten over a wide range of operating temperatures. Hydrogen reduction of tungsten hexachloride in a vacuum furnace at temperatures from 2,7000 to 3,3000 C yielded a small quantity of tungsten whiskers, provided a low degree of supersaturation was maintained. Direct measurements of 3,000,000 to 4,000,000 psi were obtained for the ultimate tensile strengths of individual whiskers averaging 3 to 4 microns in diameter with average aspect ratios of 1,000. This compares with strengths of 300,000 to 400,000 psi for 13-micron-diameter commercial filaments.

Jan 1, 1968

By Raymond M. Stateham

Climatic conditions are compared with roof fall occurrence from April 1, 1972, to December 31, 1975, by the Bureau of Mines. These comparisons indicate that humidity has a strong influence on roof fall occurrence rates. Cubic regression techniques are used to develop best fit curves. Statistical analysis of these curves indicate that both are sinusoidal and exhibit positive correlation with each other. The sine waves have a period of 1 year with maximum and minimum inflection points in August and February.

Jan 1, 1978

By George S. Rice

"It is well known that the lost coal left in the ground in mining, under such conditions that recovery is practically impossible, constitutes a large proportion of the coal in the beds worked. A recent estimate, in a paper on ""The World's Fuel Supply"" presented by Prof. L. P. Breckinridge, of Yale University, before the Annual Meeting of the. American Society of Mechanical Engineers, places the average loss in bituminous coal mining as one-third left in the ground.The bald statement that there is a loss of one ton of coal for every two recovered may seem to those not familiar with coal mining to imply inexcusable and wanton waste. Perhaps a better way of expression is in terms of total recovery rather than in terms of losses. Many mine superintendents and mine owners will readily concede that their total recovery may be only 60 to 75 per cent, but to state that they are wasting 25 to 40 per cent arouses antagonism. The suggestion is of willful waste, whereas the majority of the operators try to the best of their ability to get a high recovery under the adverse and complex conditions that confront them. These involve natural, commercial, and labor conditions, and the requirement in many cases of boundary pillars under railroads and buildings, which may be called for in the deed or lease, or in the absence of specific exemption in the deed or lease, the common law requirement that a surface owner is entitled to the support of the surface."

Apr 1, 1921

By Raymond W. Hiteshue, Henry H. Ginsberg, Paul S. Lewis

Coal was gasified in the presence of up to 3.57 million roentgens of gamma rays by the Bureau of Mines to determine whether the irradiation increased the gasification rate or yields of methane and hydrogen . High volatile A bituminous coal was gasified with steam at 500 and 1,500 psig and temperatures of 1,400 ° and 1,800 ° F ; five other coals ranging in rank from lignite to anthracite were gasified at 500 psig and 1,800 ° F. The average results of replicate experiments with and without radiation were compared for possible effects of radiation from 40,000 curies of radioactive cobalt . The irradiation had no gross effect on the gasification rate or on the yield and distribution of methane and hydrogen . It was concluded that gammaray irradiation produced no improvement in the technology or economics of coal gasification .

Jan 1, 1964

By D. E. Fogelson

In a factorial experiment, blasting caps were detonated in three sizes of shotholes in mortar with three types of stemming--dry sand, wet sand, and hydrostone. Free-surface displacement pulses were recorded with a capacitive-displacement gage at a distance of 15 inches. The effects of decoupling and the type of stemming on the amplitude and the duration of the displacement pulse were determined. Both the amplitude and the duration of the displacement pulse were significantly decreased by increasing the decoupling, but they were little affected by the type of stemming.

Jan 1, 1965

By N. S. Dalal, X. Shi

While it is known that vanadate and related compounds of pentavalent vanadium ( V (V)) exert potent toxic effects on a wide variety of biological systems, the underlying biochemical mechanism is still not fully understood ( 1- 3). One of the pathways is thought to involve the oxidation of NAD ( P) H. Thus, considerable effort has been devoted to finding the mechanism of NAD ( P) H oxidation by Vcvi (1-15). Erdmann et al. (5) first noted that vanadate stimulated the oxidation of NADH by plasma membranes and attributed this effect to a membrane containing NAD(P)H-dependent V(V) reductase. Later studies by Liochev and Fridovich indicated that endogenous superoxide ( 02 ) plays a central role in this reaction ( 4, 12, 13) . They proposed that NAD ( P) H dehydrogenases or oxidases produce 02, which causes VCV ) to stimulate NAD ( P) H oxidation via the following free radical chain mechanism ( 4, 12, 13) :

Mar 1, 1992

By Clark F. Grain

The monoclinic to tetragonal inversion of zirconium dioxide was studied by single-crystal X-ray methods, high-temperature X-ray diffractometry, and differential thermal analysis. The unusual features of the inversion, such as no definite transition Lperature, hysteresis, and athermal kinetics, were confirmed for powders who mean crystallite size was greater than 1,000 A. Samples of mean crystallite size below 1,000 A displayed classical kinetics, obeying a logarithmic rate law. A detailed mechanism based on Ubbelohde&apos;s theory of continuous phase transformations was proposed which is consistent with all the experimental facts.

Jan 1, 1965