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By J. W. Horne, W. B. Shirey

"INTRODUCTION The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the noncondensable gases evolved when crude shale oil is distilled under pressure.Hydrogen sulphide is one of the components found in the complex mixture of gases produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills.The study required a complete extraction of all the hydrogen sulphide from the gas stream after it left the water-cooled distillate condensers and before the as stream entered the charcoal absorber for removing the light naphtha. In devising the method it was necessary to take into account a constant variation of velocity, pressure, and percentage of sulphide in the total gas stream coming from the still.Ordinarily, the quantitative determination of hydrogen sulphide in Gas is made by analyzing small samples taken at regular intervals. This estimation can be accomplished by use of the Bunte gas burette as modified by Tutriler,4 or by a similar method. In the industries where the flow of as is constant end of uniform composition, this practice is sufficiently accurate for plant control. For experimental work where many variables have to be taken into consideration, as in the case at hand, these methods are not applicable."

Oct 1, 1931

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. E. Back

A method has been developed in the laboratory for successfully treating titaniferous magnetite ore from the deposit at Iron Mountain, Wyo. The ore is roasted with 15 percent sodium carbonate to convert the vanadium to a water-soluble form and fix the soda for the subsequent electric-smelting step. Approximately 90 percent of the vanadium is recoverable in a product assaying 80 percent V2O5. The leached calcine is briquetted and smelted in a graphite-lined electric-arc furnace. Substantially all of the titanium is recovered in a soda slag, assaying 60 percent TiO2 and 2 percent Fe, which can be upgraded to 75 to 80 percent TiO2 by leaching with dilute sulfuric acid. The upgraded slag could be utilized for the production of titanium dioxide pigments or titanium tetrachloride. About 90 percent of the iron is recovered as pig iron, containing only minor amounts of vanadium, titanium, and sulfur. The high TiO2 slag compares favorably with slag containing about 70 percent TiO2 being produced by the Quebec Iron & Titanium Corp. at Sorel, Quebec. The data obtained from this investigation indicate that a feasible process has been developed for treating Iron Mountain ore, and larger-scale testing is warranted to develop engineering data for the ultimate utilization of this deposit as a source of titanium, iron, and vanadium. There are adequate supplies of basic raw materials, electric power, water, sodium carbonate, coal, and petroleum products within fairly short distances of Cheyenne and Laramie, Wyo., the nearest cities and probable plant- and labor-supply points.

Jan 1, 1952

By A. W. Khair, M. Ahmad, Gehi. L. D.

"This paper presents an analysis of the effect of the dynamics of bit wear on dust generation. Two surveys have been conducted in order to assess the mechanism and type of bit wear and to evaluate the impact of bit wear on the productivity of the continuous miners. Used bits were collected from the underground coal mines and these used bits were utilized in laboratory coal cutting. The effect of bit wear on dust generation has been quantified and its impacted on dust generation and ventilation system has been exemplified.INTRODUCTION Research has reduced the prevalence of Coal Workers Pneumoconiosis from 15 to 5 percent according to NIOSH reports (Breslin 1982). However CWP still have not been eliminated as a hazard to mine workers. To prevent coal workers from having black lung MSHA has established a very strict standard for coal mine operations (2.0 mg/m3 with silica content equal to or less than 0.1 mg/m3,). There are numerous coal operations still experiencing great difficulty with meeting the 2mg/m3 dust standard. Among these are the longwall sections and continuous mining sections. In order to meet the rising demand of energy and coal, the number of longwall operations and continuous mining operations would have to be increased. Thus a long term research commitment is required to develop basic solutions that are more generic and greater benefit to the mining and mineral industry.In continuous-mining operations, the miners are exposed to the dust produced during the fragmentation of the coal from the face plus the dust produced during loading and transferring of the coal. The fragmentation process generates most of the respirable dust. The amount of dust generated during fragmentation depended on the coal properties, cutting parameters and cutting bit configuration. Bit wear changes bit configuration, therefore, it also affects dust generation. Bit wear can be defined as the removal of material from surface as a result of mechanical action. In soft coal mines bit wear may not be a serious problem but in hard coal seams bit wear is very significant. In addition, as the good coal seams are depleted, the operators are mining thin seams and the seams with rock partings. During cutting these seams operators are sometimes forced to cut roof and floor rock or rock partings which result in more rapid wear of bits."

Nov 1, 1995

By Andrew B. Cecala

As deeper seams are continually mined, methane liberation will continue to increase and must be monitored effectively. To effectively monitor and develop appropriate control technology, methane-liberation patterns must be known. The Bureau of Mines recently completed a study to identify specific patterns of face methane liberation during long- wall mining. Both of the longwall faces surveyed had high methane liberation rates. At one longwall face, most of the methane was liberated during cutting of coal by the shearer mining machine. At the second face, a significant portion of methane was emitted from the face and floor. An effective methane-monitoring system would be different for each longwall panel because of the differences in how the gas is released along the face.

Jan 1, 1985

By H. H. Schrenk, L. B. Berger, Robert L. Beatty

"INTRODUCTION Toxic oxides of nitrogen 5/ are formed or liberated in many industrial process and may constitute a definite hazard to the health of persons exposed to the atmospheres thus produced. Oxides of nitrogen occur in the gases involved in the use of explosives, in the gasoline products of welding operations in the exhaust of internal-combustion engines, in the vicinity of electrical discharges, in the combustion of nitrated materials, and in chemical process involving nitration or the use of nitric acid, Itis evident that oxides of nitrogen may constitute an occupational hazard in many industries, and therefore it is important that those concerned with the control of such hazards be equipped with a technique suitable for the determinations of oxides of nitrogen in the concentrations of,hygienic significance."

Feb 1, 1943

By John K. Alley, Robert C. Johnson

The primary objective of the research was to grow aluminum borate whiskers or fibers and to determine their properties . Molten salt bath and vapor deposition methods were used for synthesis . Whiskers exceeding 25 mm in length were grown . The best results were obtained by vapor deposition and most of the data presented were determined on whiskers produced by this method of synthesis . Three different aluminum borate compositions ( 4.8A1203 B₂03 , 3.8A1203 B203 , and 2.5A120, B203 ) were identified by X- ray and chemical analyses . The aluminum borates 4.8A1203 B20, X- ray diffraction pattern was indexed . Optical data were obtained on the three aluminum borates . In addition the following whisker properties and growth factors were determined : ideal atmospheric dewpoint for vapor deposition method , near 65 ° F ; temperature range of whisker formation , 1,000 ° to 1,400 ° C for the molten bath method of synthesis , > 1,000 ° to < 1,400 ° C for the vapor deposition method ; whisker growth rates by the vapor deposition method , maximum 12 mm per hour ; raw material vaporization , 50 to 60 percent of the fluoride lost in 1 hour ; tensile strength , maximum obtained 174,162 psi ; melting points , ranged from 1,675 ° to 1,795 ° C.

Jan 1, 1965

By A. L. Engel

In recent investigations of chloride Volatilization of gold at the Reno Station, it was found that the addition of small amounts of copper and NaCl to the charge brought about improved volatilization of the gold. The investigations described in this report were concerned with the recovery, in an aqueous medium, of fumes from chloride volatilization of gold. It was attempted to discover a suitable aqueous medium that would permit absorption, solution, or precipitation of all the volatilized gold immediately upon contact with the medium. A simple laboratory apparatus was employed to produce fumes by volatilization. To this furnace was attached an absorption train consisting of a series of chambers containing the aqueous medium, through which the fumes were drawn by suction. A satisfactory synthetic ore that contained metallic, gold in a quartz-matrix was made and utilized, enough. gold being present in a&apos; small amount of material to permit an accurate, metallurgical balance of the volatized values&apos; to be obtained in all the experiments.

Jan 1, 1949

By C. P. Bowie

[Frequent accidents in the transportation and. handling off petroleum and its more volatile products, serve as a reminder that this is indeed a hazardous undertaking and should always be conducted with due caution. On October 4, 1920, vapors in the held of the British tanks steamer G. R, Crowe became ignited and, caused an explosion which, it is reported, killed 5 men, injured. 40 others and endangered the lives of some 300 more. On November 10, 1920 the Morgan, Line freighter El Mundo was almost totally sot destroyed in New York harbor by fire caused by an explosion of gases in a fuel-oil tank. These two disastrous explosions emu emphasize the ever- present danger attending the use of petroleum products. This is also shown by the frequent occurrence of minor fires and explosions, caused by careless handling of baseline, which result in loss of life or serious injury to railroad employees, to oil-tank drivers, and to individuals in various walls of life. Statistics indicate that the lighter cuts of petroleum products, because of fire hazards, are dangerous, and are so considered by the railroad and other transportation companies. According o the Bureau of Explosives (Bar-eau of Explosives Report No. 13 p. 7) during 1919 transportation of gasoline in the United States resulted in 172 accidents, causing 2 deaths and 31 injuries, and a property loss to the extent of $687,966. Among the causes of ignition, an open light in the vicinity of the container stands out most prominently.]

Jan 1, 1920

By F. N. Kissell, C. H. Elder, C. M. McCulloch

The applicability of the "direct method" for determining the methane content of virgin coalbeds was tested. Preliminary results indicate that the direct method, when applied to exploration cores, can be successfully used to estimate coalbed gas content and also approximately predict the total gas emission from a prospective mine located in the coalbed at the exploration site.

Jan 1, 1973

By H. B. Brunot

The United States Bureau of Mines under provisions of Schedule 2C4 issues approvals covering complete operating units such as loading machines, room hoists, and storage-battery locomotives. Certain manufacturers design and build entire machines. Other manufacturers purchase a part or all of the electrical accessories from manufacturers of electrical equipment and make up permissible units by assembling them. Before the assembler purchases electrical accessories for use in such contemplated units he may require certain information from the accessory manufacturer as to whether the particular accessories are suitable for assembly in his proposed permissible outfit. To aid accessory manufacturers in marketing their product, a provision was incorporated in Schedule 20 whereby tests might be made on individual accessories and reports rendered as to the suitability of a given accessory for use in permissible assemblies.

Jan 1, 1935

By R. W. Van Dolah

An important function of stemming used to confine explosives in shot holes in underground coal mines is to minimize the chance of ignition of firedamp or coal dust by the detonation products. Until 1952, the Bureau of Mines approved only the use of fireclay or similar incombustible material for stemming permissible explosives. At least 2 feet of stemming were required except in holes less than 4 feet deep; in such short holes the stemming was required to be half the depth of the hole. Over the years, several special stemming devices have been proposed in the United States as substitutes for fireclay. Many economic and safety advantages were claimed for these devices, but only one approved device has been marketed in this country. Bureau requirements for stemming explosives in coal mines were modified at that time to permit the approved stemming device to be used as a substitute for the required fireclay.

Jan 1, 1961

By H. H. Schrenk

The Bureau of Mines midget impinger dust-sampling apparatus was described first in 1937.4/ Two supplementary reports5/6 were published in 1938. These reports are now out of print. The material published previously is combined in this paper to make information on this device available for distribution. The impinger was developed by the Bureau of Mines in cooperation with the United States Public Health Service in 1922. The underlying principle of this instruments is based on impingement land wetting, of the dust particles by drawing air through a nozzle at high velocity onto a smooth surface under a bubbling column of liquid. The dust particles are retained in the liquid. The apparatus has been used widely and permissible limits of dustiness have teen established in the United States on the basis of results obtained with this device in correlation with medical studies. However, it has been criticized for its bulk, weight, and power requirements.

Jan 1, 1939

By R. H. Nielsen

A new, cheaper precipitation scheme has been developed to produce purified zirconium oxide, Technical-grade sulfuric acid is used to precipitate a basic zirconium sulfate from a hot dilute hydrochloric acid solution. With close control of temperature, pH, and zirconium - sulfate ratio, excellent purification and complete zirconium recovery can be attained. The process has been successfully applied for 3 months and has proved to be a more satisfactory procedure than the ammonium phthalate process used previously. INTRODUCTION The Northwest Electrodevelopment Laboratory of the Federal Bureau of Mines has developed and improved the Kroll process for the production of pure ductile zirconium and hafnium. metal. Since 1946 over 1 million pounds of zirconium sponge metal has been produced, mostly high-purity material for the Atomic Energy Commission

Jan 1, 1956

By Alla D. Mah

The work described in this report is part of a Bureau of Mines research program for obtaining heats of formation of inorganic oxides, carbides, and nitrides by combustion calorimetry. The heats of combustion of molybdenum subnitride (Mo2N) and chromium subnitride (Cr2N) were measured. The data were combined with previous determinations of the heats of formation of molybdenum trioxide and chromium sesquioxide to obtain the heats of formation of the two subnitrides from the elements at 298.15° K. The corresponding free energies of formation were estimated. The heat data were compared with those of nine previously studied nitrides.

Jan 1, 1960

By Jerry E. Olson

In 1984, the U.S. Bureau of Mines conducted a mineral survey of the Black Rock Desert Wilderness Study Area (WSA) (NV-020-620), which covers approximately 319,000 acres in Humboldt County, Nevada. About 90% of the WSA is underlain by Pleistocene desert playa sediments; the remainder is comprised of Jurassic-Triassic metamorphic rocks, a Cretaceous intrusive and Tertiary volcanic rocks. Most of the WSA is within a down-dropped fault block of the Basin and Range physiographic province. No mines or evidence of major exploration were identified within the WSA; but five claim blocks within or adjacent to the WSA and zones of anomalous character as defined by the Bureau of Land Management were examined. No mineral resources were identified, but anomalous gold, silver, and indicator element content of samples taken near Pinto Hot Springs indicate resources may exist. Lithium content of samples from near-surface sediments on the desert playa is too low for resources, out geologic conditions are favorable for higher concentrations at depth. Occurrences of zeolites are not considered to be of commercial interest. Approximately 27,000 acres are held under geothermal lease, and most of the WSA is of interest for oil and gas. No evaluation of these commodities was made by the Bureau of Mines

Jan 1, 1985

By David C. Scott

Between 1990 and 1991, the Bureau of Mines studied the mineral resources of the Kaibab National Forest to appraise the resources present and to determine the types of deposits, and their location. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Small amounts of copper with lesser amounts of gold and silver have been produced from limestone-hosted, strata-bound deposits in the North Kaibab and Tusayan Ranger Districts. In addition to these small metallic deposits, volcanic cinders, pumice, flagstone, and sand and gravel have been quarried in the Chalendar and Williams Ranger Districts. At least ten uranium-mineralized breccia pipes have been identified in the Tusayan Ranger District, One of these, the Canyon pipe, contains a high-grade uranium ore body with associated silver, copper, lead, vanadium, and zinc. The mine permit for the Canyon pipe has been approved and the mine shaft head frame erected.

Jan 1, 1992

By John Dasher

The impetus given to mineral dressing arid chemical engineering by the war has placed many persons without previous experience in positions where they are concerned with the size of solid materials they are testing. Many good textbooks cover this field in considerable detail but are more concerned with the "why" than with the "how" For beginners and those to whom size is not of primary concern, this brief circular has been prepared. Refer-

Jan 1, 1942

By Leonard Obert

Subsidence to surface occurs in a large proportion of underground mines. Preliminary to any indication of subsidence on the surface, there is usually a breaking up and sloughing of the cover into the mine opening which, in a period of time ranging from minutes to many years, progresses to the surface, This process is referred to as subsurface subsidence. In many mining operations, information regarding the process of subsurface subsidence is important, For example, if there are buildings or other improvements on the surface, or if the direction of the subsurface subsidence might threaten other underground workings--such as shafts--or if the subsidence might be progressing in a direction which would fall outside the anticipated subsidence limits, the problem could assume special significance.

Jan 1, 1961

By Charles L. Kimbell

In broadest overview, UN global industrial production indicators released and shown in table 2 suggest that the extractive sector of the world&apos;s mineral industry in aggregate registered a very slight upturn in 1991 relative to its 1990 performance. It also shows a continued rebound in the industry from the recessionary period of the mid-to late-1980&apos;s. These same indicators as calculated in late 1991, however, reflected a very minor downturn in extractive mineral industry operations between 1989 and 1990. This latter downturn represented a notable revision from the data reported in the immediate previous edition of this chapter, which suggested a tiny upturn. The apparent slight 1991 upturn in extractive sector industrial output generally was not mirrored in the performance of the processing sectors of the global mineral industry. Although the aggregate index for the chemicals, petroleum, coal, and rubber products manufacturers (see table 3) showed a notable gain in 1991, similar indices for nonmetallic mineral products and for base metals registered declines between 1990 and 1991. Examination of regional performance indices shows that the difficulties experienced in 1990 in maintaining output levels within the countries that formerly constituted the CMEA were reinforced by trends toward reduced gains in output levels, if not actual reductions in output, in several other areas. Generally speaking, the traditional developed market economy countries recorded downswings in overall industrial activity in 1991, particularly after midyear, whereas developing market economy countries logged gains. The developed market economy country downturns, however, were not nearly as significant as were the downturns recorded for the former centrally planned economy states - those that before 1992 were either constituent Republics within the U.S.S.R. or the latter&apos;s CMEA partners.

Jan 1, 1993