Search Documents

By L. B. Berger

Each winter brings its toll of deaths and serious accidents from the deadly gas, carbon monoxide. Newspapers carry warnings to the public of the dangers of this gas, and frequent now items retort the finding of persons dead or unconscious from the effects of carbon monoxide, yet these accidents continue. Either those warnings are not read, or they are unheeded by people who feel that "It can't happen to me." It can happen to you - carbon monoxide is no respecter of persons, as evidenced by items appearing daily in newspapers all over the country. Carbon monoxide has been a threat to human safety as long as man has used fire to keep himself warm and to cook his food. The burning of any fuel that contains carbon may produce carbon monoxide. This is true of solid fuels such as coal, coke, and wood; of liquid fuels such as oil, gasoline, and kerosene, and of gaseous fuels such as natural or manufactured gas. In the process of combustion the carbon in the fuel unites the chemically with tat oxygen of the air to form carbon dioxide (CO2), however, if the supply of air is not adequate, combustion is incomplete and carbon monoxide (CO) will be formed.

Jan 1, 1943

By H. F. Yancey

A relatively large proportion of the coal produced in the state or Washington, especially in the coking coal areas is of fine size; hence washing by means of coal-washing tables to reduce the ash content is commonly practiced. For this reason the program of research in coal washing conducted jointly by the U. S. Bureau of mines and the College of Mines, University of Washington, has given special attention to the mechanism of the separation of coal from its impurities as affected by the coal-washing table with the object of

Jan 1, 1931

By Benjamin C. Pollard

The location and production potential of a large block of strippable reserves in North Dakota were determined by using published data as a base and adding new drill hole data or other data contributed by companies that presently own or lease coal lands. Only beds exceeding 5 feet in thickness, under less than 120 feet of overburden, and in large blocks of 5 million tons or more were included in the estimates. All such reserves are in the Fort Union Formation of western North Dakota and are lignite in rank. Sixteen large blocks of reserves evaluated in this study are estimated to contain a total of 4.1 billion tons of strippable lignite.

Jan 1, 1972

By R. D. Haynes

Coal, gas, and oil in many geological formations of the Eastern United States are intimately associated but have traditionally been recovered independently of each other. Oil and gas wells, however, are often spaced sufficiently close to cause the subsequent loss of up to 50 percent of the recoverable coal in the form of pillars or barriers left for mine safety purposes. A long-range planning technique was devised for exploiting oil and gas wells simultaneously with the mining of coal to recover the maximum fuel potential of the formations. Planned plugging of oil and gas wells, determined partly from production predictions via decline curve analysis, is coordinated with a mine development plan to achieve maximum coal recovery and reduce overall production losses of gas and oil due to plugging of the wells.

Jan 1, 1973

By Young W. A.

The Eagle Silver mine is in the Rush Valley mining district, Tooele County, Utah, and is now operated by the Hampton Mining Co. The property, originally referred to as the Argent, is reported to have been one of the first discoveries in the district. The early operators mined ore to a depth of 850 feet, at which point the property was abandoned because of excessive water. During 1905 the Honerine tunnel was driven into the area approximately 1,800 feet below the collar of the Argent shaft. This tunnel served to drain the levels above and operations were resumed. Ore deposits in the Eagle Silver mine occur in the Galena King lime-stone, a 20-to 60-foot member of interbedded quartzite and limestone in the Oquirrh formation of Pennsylvanian age. This member has been faulted along the bedding, forming the Galena King gouge. Mineralization commonly occurs in or near this gouge area in a brecciated, highly altered, pipelike zone. The known ore shoots occur in association with the breccia pipe, commonly adjacent to cross faulting and porphyry intrusions. In general, two ore shoots have been mined on the upper levels of the mine, one lying to the east and the other to the west of the breccia zone. The Bureau of Mines diamond-drilling program was begun during the latter part of 1948 and completed early in 1949. Nine holes were drilled, aggregating 852.8 feet. Sludge and core samples from mineralized sections were analyzed in the Salt Lake City laboratories. A total of 87 sludge, 71 core, and 11 chip samples was submitted for analysis.

Jan 1, 1950

By Martin H. Stanczyk

The direct dissolution of a typical zinc sulfide flotation concentrate by elevated temperature and pressure leaching was investigated. The concentrate assayed about 55 percent Zn, 32 percent S, 6 percent Fe, and 1 percent Pb and contained minor quantities of copper and precious metals. The influence of various factors on the dissolution of the zinc in acidic and ammoniacal pulps when using oxygen as the oxidant was determined. The tests revealed that the sphalerite was difficult to oxidize. Complete dissolution of the mineral required vigorous and intimate nixing of the gaseous, liquid, and sold phases. The addition of pyrite or sulfuric acid to water slurries of the concentrate was required to obtain a high zinc extraction when leaching under acidic conditions. The quantity of pyrite and acid used was about 0.125 and 0.25 pound, respectively, per pound of zinc sulfide contained in the leach charge. In tests with acid, about 96 percent of the zinc was extracted from the concentrate in 1 hour at 200° C. when the oxygen partial pressure was 75 pounds per square inch gage or higher. Leaching with a continuous flow of air as the oxidant gave results that were almost as good as those obtained when oxygen was used, In tests with air fed through the autoclave at 320 liters per hour, 95 percent of the zinc was dissolved in 1 hour, Acid leach solutions assaying approximately 58 grams Zn per liter and containing Fe, Ni, Cr, and Cu impurities were produced in the better tests. The leached residue consisted essentially of red iron oxide together with substantially all of the lead and precious metals.

Jan 1, 1961

By ALICE V. Petar

Thallium is one of the rare metals that has come into commercial use within recent years . Its comparative scarcity , combined with a resemblance to the common metal lead , have retarded the development of uses for thallium . Although production is still measured in pounds rather than in tons , it is now finding application in a number of fields . Perhaps the earliest commercial use of thallium was as a constituent of optical glass of higher refractive power than similar glasses containing lead . One of the later applications to attract attention was the use of the oxysulphide in a sensitive electrical device similar to the selenium cell . The " Thalofide " cell , which was patented in 1919 , constituted for a time the most important outlet for thallium. During the next few years the limited use of thallium and its salts in other fields was insufficient to absorb an annual production of a few hundred pounds , and the price dropped from $ 16 or $18 per pound in 1922 to $ 5 per pound in 1924 . Beginning in 1925 several new uses were developed , especially as a poison for rodents and ants , and as a result the demand for thallium increased sufficiently to cause a recovery in price to the present level of from $12 to $15 per pound .

Jun 1, 1931

By H. F. Yancey

A relatively large proportion of the coal produced 1n the State of Washington, especially in the coking coal areas is of fine size; hence washing by means or coal-washing tables to reduce the ash content is commonly practiced. For this reason the program of research in coal washing conducted jointly by the U. S. Bureau of Mines and the College of Mines, University of Washington, has given special attention to the mechanism or the separation of coal from its impurities as effected by the coal-washing table with the object of increasing its efficiency. Previous work has evaluated the role of stratification the influence of size, specific gravity and respective shapes of particles in the feed, and the affect of hindered-settling classification of the feed prior to tabling.

Jan 1, 1931

By B. R. Mohal, F. F. Aplan, S. Chander

"ABSTRACTThe wetting behavior of coal has been determined in the presence of nonyl and octyl series of nonionic surfactants containing polyethoxy groups of different sizes. The wetting behavior was determined by a modified Walker technique and contact angle measurements. The results show that the wetting rate of coal varies with coal rank, structure of the hydrocarbon chain and number of ethoxy groups in the hydrophilic group of the surfactant. A close relationship has been observed between the wetting rates and the short-time advancing contact angles.INTRODUCTIONNonionic surfactants are used in many applications to improve wettability of solids. They can be used as dispersing agents [ 1 ] or dust suppressants [ 2-5 ] and to control the flotation, flocculation, filtration and flowability of particulates. This study was undertaken to study the effect of a series of nonionic surfactants on the wetting behavior of coal. Two series of surfactants, namely, ethoxylated nonyl and octyl phenols were used. The nonyl phenol series contains a linear hydrocarbon chain containing nine carbon atoms ( CH3( CH2 )8-C6H4,- ( OC2H, ) n, where n is the number of ethoxy groups) . The octyl phenol series contains a branched hydrocarbon chain containing eight carbon atoms ( ( CH3 ) 3CCH2C ( CH3)2-C6H4- ( OC2H4) n ).Initial wetting rates — modified Walker techniqueWalker et al. [ 6 ] developed a sink test to determine the wettability of coal particles. In this technique, coal particles are dropped individually onto the surface of surfactant solutions of different concentrations, and the most dilute concentration in which coal would sink ""instantaneously"" is determined. This technique is a variation of a procedure initially developed by Draves and Clarkson [ 7 to determine the effect of surfactants on wettability of cotton fibers. In this procedure commonly known as the Draves test, the concentration of a surfactant required to give a 'sink time' of 25 s is determined.Other investigators have used slight variations of the Walker method to study the wetting of fine particles [ 8-12 ] , by measuring the time for wetting a given amount of powder. There are differences in the manner in which the time of wetting is measured, however. Some investigators measure the time for the last trace of coal to disappear [ 8,11 ] whereas others determine the time for the vast majority of particles to sink [ 10 ] . Some investigators report a wetting rate [ 11 ] which is a value calculated on the basis of the time for the 'last traces of particles to sink'. The differences in choice of criterion for wetting can result in different values for wetting rates as illustrated in Fig. 1 which is based upon our measurements of the amount of powder wetted as a function of time. The procedure for wetting rate measurements is described in the next section. The technique in which time for disappearance of the 'last traces of particles' is determined gives the smallest value for the wetting rate, while the technique in which the time for wetting of the 'vast majority' of particles is determined will give intermediate rates. The terms 'last traces of particles' and 'vast majority of particles' are usually not defined explicitly and can lead to large differences in wetting rates measured by different investigators. Since our measurements show that the wetting rates for an assembly of powder decreases with time, we have used the initial wetting rates to compare the wetting behavior of coal in solutions of different surfactants."

Mar 1, 1989

By T. A. Sullivan

High-purity vanadium metal was prepared by electrorefining commercial vanadium in a molten sodium bromide, potassium bromide, and vanadium dibromide electrolyte. Variables investigated were operating temperature, current densities, electrolyte composition, and condition of the anode. The purity of the refined metal was in the range of 99.95 percent vana-dium. Iron and oxygen in the 50- to 250-ppm range were the only major impurities. Metal with hardness numbers of 50 to 60 in the Rockwell F scale was prepared from feed material with a Rockwell B hardness of 90. The arc-melted metal was highly ductile and could be cold-worked into sheet or foil.

Jan 1, 1965

By A. M. Evans, J. H. Soulé

"INTRODUCTION Deposits of iron ore in Cherokee County, Tex., have been worked at various times in the pact, and the ore has been smelted in small local blast furnaces.Recently it was proposed to establish a charcoal blast furnace with a wood distillation plant to produce charcoal for fuel and byproducts. Financial assistance from the Reconstruction Finance Corporation was sought by George Easley and associates to enable them to purchase, move, and erect the furnace and build the required accessory plants. The furnace was to be moved from Pembroke, Fla.In August 1941, the Bureau of Mines was asked by the Office of Production Management to check the development work of Easley and associates and to ascertain (1) the iron-ore reserves, (2) the cost of mining ore and delivering it to the blast furnace, and (3) the grade and character of the ore. The Bureau of Mines was advised, while the investigation was in progress, that approximately 1,000,000 long tons of measured reserves would be sufficient to demonstrate the feasibility of operating the properties.Although deposits of iron ore are widely distributed in Cherokee County, only the Pryor Mountain, Banks and Cherokee, J. P. Acker, and Citizens State Bank tracts were sampled thoroughly by the Bureau of Mines. The iron-ore rights on these are owned by the New Birmingham Development Co., the Cherokee Development Co., or by individuals. Options to lease the ore rights were obtained by Easley, who obtained options on the Hawes Peach Orchard and Bradford tracts, also, which were examined only cursorily by the Bureau."

Aug 1, 1947

By Terry L. Muldoon

The Bureau of Mines conducted an investigation to quantify microphone response variations that could result when the microphone is worn by a worker, as with a personal noise dosimeter, and to suggest an optimum placement and orientation of the microphone for noise exposure measurements. Previous studies have shown no significant variations in a diffuse field. This investigation, therefore, was conducted in the free-field conditions of an anechoic chamber using an anthropometric dummy as a subject, and broad band noise as the acoustic stimulus. This investigation established that, in a free field, the wearer's body does significantly affect microphone response; the response variations are a function of azimuth, and location and orientation of the microphone. Results suggest that locating the microphone on top of the subject's shoulder, oriented parallel to the body axis, should yield data comparable to that obtained using a sound-level meter.

Jan 1, 1973

By Roy L. Grant

The Bureau of Mines investigated the up-and-down method with factorial designs to determine if shorter, and therefore less costly, trial sequences could be used. Although sequences of 50 trials are usually recommended, sequences of 20 trials were arbitrarily chosen for the experiments with permissible coal mine explosives described in this report. These explosives were fired from a cannon pointed into a flammable natural gas-air atmosphere at the Bureau of Mines Explosives Research Center gallery to ascertain their safety properties. The investigation demonstrated that the shorter sequences led to useful conclusions with a reduction in cost of the experimental program.

Jan 1, 1967

By H. W. Brandt

A field test was designed to inject a specially formulated two compound epoxy resin into the roof rock ahead of a working face to cement fractures and formation interfaces at the Westmoreland Coal Co., Winding Gulf Div., Eccles No. 5 Mine, Eccles, West Virginia. Five 30 foot long X 2 inch diameter, hold were drilled at an angle of 15° above the plane of roof line front the face of a working entry. The epoxy resin compounds were pumped through a proportioning unit and mixed in-line before being discharged into the drill hole under treatment it injection pressures up to a maximum of 450 psig. When the coal face was advanced an anomalous failure of the roof rock occurred in the treated section. Further testing was suspended until the cause of the failure could he determined. The polymers were tested, under confined conditions, in 2 inch pipe columns. Extreme temperature and pressure (up to 2400 psig) rises were recorded as they cured, It was concluded that this pressure source fractured the rock and caused the roof failure. The entire program was terminated after it was determined that the heat rise and resultant high pressures could not he controlled chemically or mechanically.

Jan 1, 1978

By R. L. Hopkins

Fifteen alkyl cycloalkyl sulfides and three dicycloalkyl sulfides were synthesized to provide reference compounds in the search for these classes of sulfur compounds in crude oils. In synthesizing sulfides by alkaline alkylation the order in which the reactants were added was shown to determine the yield and purity of the product.

Jan 1, 1966

By L. C. IlsLey, E. J. Gleim, F. CRAVEN

Electrical apparatus and circuits began to be used in mines about 50 years ago. A search of the literature on mining reveals that in 1882, umping was being done by electricity in some aines of England. One account tells of a small electric locomotive being used in 1882 "to drive eight corves loaded with coal" in a mine near Dresden. In an account of his visit to some English mines, en American in 1892 mentions that he saw underground electric signals, lights, pumps, hoists, and one revolving- cutter-bar 19wall mining machine,. Among the carl electrical installa- tions in the United States was an electric locomotive in the Lykens Valley Coal Co. mine at Lykens Valley, Pa., in 1887. In 1889 the Sperry electric coal digger was being tried out. Tarce mining machines were placed in the Prospect mine, East Palestine, Ohio, in 1890. An electrical pumping plant was put in oneration during 1892 in the Woodward mine of the Delaware, Lacka- rahma & Western Railroad Co. Thus we Almost coincident with the proposed use of this new servant in under- ground workings, came the thought of making it safe in gassy mines. find an account of a design for a protected stationary electric mine lamp proposed by Edison in 1831. Enclosed-type motors rere developed in the United States and shiped to English collieries about 1903. From those early beginnings there has been continuous progress until to-day one finds hundreds of pieces of specially designed electrical apparatus distributed in American coal mines and in mines of nearly all important coal-producing countries. Along with introduction of this equipment grew the idea of the necessi- ty of government aid, in standardization. In most coal-mining countries to- day the governments either directly or indirectly have a considerable in- fluence in guiding the design of electrical equipment intended for use in Pasay mine

Jan 1, 1933

By Edward D. Thimons

The Bureau of Mines developed a stopping design that allows the stopping to be blown down by strong blast forces without incurring any permanent damage. Trials with the new stopping, dubbed the quick-fix blowout stopping, have been conducted in the Bureau's Safety Research Coal Mine at Bruceton, Pa., and in two New Mexico uranium mines. Results have been favorable in all cases. Compared with conventional brattice stoppings or wood bulkheads, the quick-fix blowout stopping is easier and less time consuming to install, is easier to maintain, and in most cases is just as efficient an air barrier. There is same indication that the shape of the stopping makes it more resistant to blast fore s than the fabric stoppings now in use.

Jan 1, 1976

By J. E. Chilton

Interim performance specifications are presented for carbon monoxide, methane, and air velocity transducers used in the Bureau of Mines intrinsically safe mine monitoring system. These specifications give quantitative values or qualitative descriptions of the transducers, including environmental parameters and monitoring system measurement and maintenance requirements as recommended by the Bureau of Mines. Commercially available transducer modules and prototype modules are listed together with selected characteristics.

Jan 1, 1983

By Natesa I. Jayaraman

This report describes recent improvements the Bureau of Mines made in the design of its shearer-clearer water-spray system for dust control on lonwgall shearer faces. The improvements were based on findings from a field survey of six mines and laboratory test results. The report in-cludes information on installation and use of the improved shearer-clearer system and describes a field installation and 3-week underground test of the system. The improved shearer clearer, like its predecessor, reduces dust concentrations in the shearer operator's walkway by splitting the airflow on the upwind side of the shearer and confining the dust cloud to the face side of the shearer. The improved shearer-clearer system utilizes more practical-mounting locations for the water sprays and requires less water consumption. In the underground test, the improved system maintained the clean-air split in the walkway up to 40 ft downstream from the shearer. To further improve dust suppression, cooling-water manifolds were relocated into the loading zone. The laboratory and underground tests showed that the improved shearer-clearer system and the techniques described can significantly reduce the respirable dust exposure of shearer operators from shearer-generated dust.

Jan 1, 1985

By Wilbert J. Huff

[This is the fifth of a series of annual reports of the explosives Division, Bureau of Mines, United States Department of the Interior.3/ It deals particularly with work done during the period July 1, 1939, to June 30, 1939. The writer and the respective unit leader to whom credit is indicated have directed the various studies outlined.]

Jan 1, 1940