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By James F. Neill, O&apos

Investigation of the Gilley fluorite deposit was based upon examinations made by several of the Bureau's mining engineers. Fluorspar was found in the dump talus of sloughed and water-filled trenches and shafts, and there were indications that faulting or other dynamic distortions favorable to deposition of this mineral in minable quality and quantity might exist. The inference was based upon a field study of the area and its comparison with fluorspar deposits in Kentucky. The proximity of this deposit to the iron furnaces at Gadsden and Birmingham was a factor that influenced its investigation, as the demand for metallurgical grades of this critical mineral is acute. The present supply for the district is obtained from out-of-State sources, and the value of any local deposit would be enhanced by the saving in freight charges. The Gilley fluorspar deposit is 17 miles east of Gadsden and 50 miles northeast of Birmingham, Ala. Mineral deposits occur as thin veinlets and small bunches of fluorite in upturned bode of siliceous limestone. The ore-bearing structure is a reverse fold, and the mineral deposit appears as a replacement along crumbled zone fractures of the contorted limestone.

Jan 1, 1950

By Charles L. Harness

Magnesia (MgO) has a variety of uses, and it has become increasingly important as a war material because of the imperative demand for refractories to line metallurgical furnaces, and because magnesia is used to make the in aircraft and other implements of warfare. Magnesia occurs as an integral part of nearly 60 minerals, but it is extracted commercially from only a .smaller number, of them. The present commercial sources are magnesite, brucite, dolomite, raw sea water, sea water bitterns, and well brines. Magnesia Raw Materials Magnesite magnesium, carbonate MgCO3, theoretically contains 47.8 percent MgO and 52.2 percent CO2. There are two varieties of magnesite, crystalline and cryptocrystalline (dense or amorphous). The latter type, though, not so plentiful as the former, is generally purer. It resembles unglazed write pottery in texture, whereas the crystalline variety is generally dark and granular, though the color may vary. The principal domestic deposits, of crystalline magnesite are near Chewelah, Stevens County, Wash. (which has supplied most of the magnesite mined in the United States), in the Gabbs Valley area of Nevada (near Luning); and in Llano County, Tex. Crypto-crystalline magnesite occurs principally in California. Magnesite occurrences have also been reported in several other States, including New Mexico, New York, New Jersey, Pennsylvania, Massachusetts, Vermont, and Maryland, but these deposits have not been developed commercially.

Jan 1, 1943

By W. W. Agey

Under terms of cooperative agreements, the Federal Bureau of Mines Inter-mountain Experiment Station assisted the General Services Administration (GSA) in operating the manganese-ore purchasing depots at Deming. N. Mex., and Wenden, Ariz. A resident metallurgist stationed at the depots directed sampling of the ore lots for assaying, took samples for amenability testing, calculated acceptances for payments to shippers, and served as technical adviser to the depot manager. The Intermountain Experiment Station at Salt Lake City, Utah, tested the amenability of the ores to determine how much of the manganese could be recovered in concentrates assaying a minimum of 40 percent manganese (Mn) and containing a maximum of 16 percent iron (Fe), 15 percent silica (Si02) plus alumina (AI203), 0.3 percent phosphorus (P), and I percent copper (Cu) plus lead (Pb) plus zinc (Zn). All chemical analyses of the ores and test products were done at Salt Lake City. In all, 567 ore lots submitted to the Deming depot were tested by flotation to determine their amenability to concentration into specification-grade material; 421 lots were amenable, and 146 were unamenable, primarily because of high copper content or excessive silica or iron in the flotation concentrate. Chemical analyses totaling 42,700 were made on the ores submitted to the Deming depot and on the products of the amenability-test program.

Jan 1, 1959

By Henry E. Blake

The Bureau of Mines has been engaged in a continuing research effort to develop processes for increasing the recovery and utilization of fluorine from low-grade resources. This current research has shown that over 98 percent of the fluorine in phosphate rock is extracted when the ore is treated with excess phosphoric acid in the presence of water vapor at 150° to 180° C. More than 80 percent of the fluorine can be recovered as fluosilicic acid, which can then be converted to commercially useful hydrogen fluoride or fluorspar by previously developed Bureau processes. Extraction of P205 from the ore was about 98 percent in batch tests and 90 percent in semicyclic tests.

Jan 1, 1974

By Scott W. Hazen

This report describes exploration for lead-zinc ores at the Madonna mine between 1945 and 1953 by the Utze Lode Co., the Bureau of Mines, and the company with Government financial aid under the Defense Production Act of 1950. The Madonna mine yielded silver, lead, and zinc with a net smelter value of over $5,000.000. from 1882 to 1924. The mine was inactive from 1924 to 1942 when the Utze Lode Co. acquired the property. Possibilities for finding ore in the mine, especially at depth, were considered favorable. The Utze Lode Co. began rehabilitating the Madonna mine in 1945. An exploration program, which consisted of winze sinking and drifting, failed to produce commercial are.

Jan 1, 1956

By Ernest W. Loya

The Bureau of Mines has developed a computer program for calculating the composition of gravimetric primary standard gas mixtures. The Fortran IV program applies corrections due to buoyancy variations of the cylinder and inaccuracies of the balance weights. The program also determines the statistical error due to the sensitivity and precision of the balance and applies the analytical error of the weighed gases.

Jan 1, 1985

By R. Lindsay Mundell

In the first half of 1990, lessening of cold war tensions was welcome. But Iraq's invasion of Kuwait in August led to the Persian Gulf War in January and February 1991. The subsequent oil shock contributed to a dampening of the U.S. economy, and the U.S. gross national product rose only 0.9 % to $5,463 billion (U.S. billion = 109). The buildup of military forces in the Persian Gulf area focused greater attention not only on petroleum but also on other strategic materials. The U.S. Department of Defense continued to review stockpile goals and upgrade several mineral materials. In addition, the U.S. Bureau of Mines continued to maintain the standby Emergency Minerals Administration. After the Defense Production Act, which authorizes priorities, allocations, and supply expansion, lapsed on October 20, 1990, the Selective Service Act of 1967 became the authority to ensure that orders of the Armed Forces and defense atomic energy programs were given priority treatment.

Jan 1, 1993

By T. F. Tomb

Past experience has shown that the penetration characteristics of the 10-mm nylon cyclone used on approved personal sampling equipment are significantly different from those determined in the laboratory using a nonpulsating flow source. The Bureau of Mines has developed and recommended a modification to presently approved equipment that will alleviate this difference. However, as a result of this modification, a new relationship for converting respirable dust concentrations measured with approved personal sampling equipment to equivalent concentrations as measured with an MRE instrument will have to be established. This Bureau of Mines report describes the underground sampling program conducted to establish a new factor for converting respirable dust concentrations measured with personal sampling equipment, modified with a recommended pulsation damping device, to an equivalent concentration as measured with an MRE gravimetric dust sampler.

Jan 1, 1973

By Michael E. Henderson

The U.S. Bureau of Mines (BOM) constructed the Hydraulic Transport Research Facility (HTRF) to investigate the hydraulic parameters relating to the transport of coarse coal. To achieve these goals in a timely and efficient manner, the Bureau contracted to Boeing Services International (BSI) the responsibility of operating the HTRF and providing technical support. This data report is a summary of the testing and data results for the period 22 November to 10 December 1982. The testing covered herein is for coarse 2-in by 0 (minus 50 mm) Pittsburgh Seam coal in a 6-in (150 mm) pipeline, at velocities ranging from 5 to 20 ft/s (1.5 to 6.1 m/s) and at concentrations ranging from 15 to 45 pct by weight.

Jan 1, 1986

By H. R. Shell

To obtain a better understanding of the crystallization of fluoride containing amphiboles from melts, an investigation of the range of stability between fluoramphi-boles and other minerals was conducted by the Bureau of Mines. This study has shown that the stability of fluoramphiboles is strongly influenced by both fluoride concentration and isomorphic replacement. Over 150 reactions were made with different compositions and reaction conditions. substitutions attempted and the phases that formed when the composition was crystallized by cooling from the melt are discussed. The attainment of equilibrium in these multicomponent systems is not claimed. Many ions that would be expected to enter the amphibole structure instead resulted in crystallization of phases other than amphibole. Those compositions that resulted in a high yield of acicular fluoramphibole by crystallization from the melts are shown in table 2. The fluoramphiboles obtained from melts typically had an acicular crystal habit and a hardness of 6 to 7 on the Mohs' scale. Although many had relatively high length to cross section ratios, none were fibrous; it was concluded that the possibility of synthesizing a fibrous fluoramphibole from a melt was low. However, many compositions can be crystallized into a tough, hard, impact-resistant mass of interlocking acicular crystals.

Jan 1, 1958

By Edward G. Cunney

Track in underground bituminous coal mines was investigated, and technology was taken from other industries in order to obtain information on conditions that impair the safety and efficiency of the track and to develop guidelines and useful information on the construction, inspection and maintenance of mine track. Volume 1 contains information on the investigations, observed track conditions, useful technology from railroads and other industries, derivations of track condition descriptors and recommended limits, conclusions, and recommendations. Volume 2, Guidelines, contains recommended standards and practices for mine track. It includes the relation of track conditions to safe speeds; descriptions and limits for measurable track features such as gage; descriptions of conditions for track components that are normally not measurable, such as subbase soils; construction requirements and techniques, inspection requirements and methods; and methods for managing and performing track maintenance work. As a research product, it does not repeat the summary or derivations. Volume 3, Inspection Handbook, summarizes recommended standards and procedures from Volume 2 and provides related information for' ready reference by inspectors in the mines. As a research product to be used in mines, it does not repeat the summary, derivations or references.

Jan 1, 1977

By W. W. Adams

The year 1937 was signalized by increased employment in the metal-and nonmetal-mining 4 industry of the United States. Measured by the number of men working, there was a 17-percent gain in employment compared with 1936. In total number of man-hours worked at all mines, the gain was slightly over 18 percent. Hazards connected with mining resulted in more accidents to the workers than in 1936, but the increase in number of accidents caused only a slight rise in the accident rate because of the much larger increase in the number of man-hours worked. In fact, the fatality rate per million man-hours of exposure was lower in 1937 than in 1936, but the rate for nonfatal injuries increased slightly.

Jan 1, 1940

By Russell R. Trengove

Bureau of Mines exploration at the property of the Tulare County Tungsten Mines was by core drilling from the surface from May 16, 1950, to July 13, 1950. The property is in the western foothills of the Sierra Nevada Range, 18 miles northeast of Lindsay, Calif. It has been in almost continuous production since 1942 and has produced 40,831 units of tungsten trioxide (W03) with a grade of approximately 67 percent. The work performed comprised a study of the geology, mapping the area, sampling the outcrops, and diamond drilling the area adjacent to the mine workings. Ten holes were drilled for a total of 1,824 feet. Ore reserves were found to be confined to tactite zones in a surface area approximately 250 by 400 feet and extending downward about 350 feet.

Jan 1, 1956

By Michael S. Wieland

This report investigates whether it is tractable and thereupon reasonable to remove the booster influences when ranking the toxic fumes of non-cap-sensitive mining explosives. The hazard potential is represented by relative fume toxicity RFT, the resultant influence computed from a formulated rule with a restricted set (tally) of fume components and multiplying constants. The RFT result is compared to the rule criterion that represents the worst case tolerable toxicity stipulated by regulations or otherwise. The typical nonstoichiometric booster composition can render notable unwanted influence on the RFT ranking results. Historically, the remedy was to shoot the booster separately and reduce the trial concentrations by the relevant subtractions. Unreal negative concentration results were noted on rare occasions, revealing the faulty nature of the reduction procedure. With thermodynamic reaction chemistry codes TDRC, on the other hand, the booster ingredients can be retained in or removed from the reactant tabulation, yielding reduction factors taken as the concentration ratios for the two circumstances. The underlying presumption regarding reduction factors is that the ratios of component concentrations with and without the booster ingredients when resolved theoretically ought to equal those rendered experimentally, when tractable. Upon rearranging the presumed relationship, the unadjusted fume concentrations divided by theoretical reduction factors yield the wanted readjusted fume concentrations, thereby removing the booster influence without generating unreal negative concentrations. The work principle from thermodynamics restricted by the constraint of zero-net interaction loss is utilized in conjunction with the TDRC to resolve the wanted (Z-state) fume spectrum. This circumvents the recognized difficulty with traditional hydrodynamic detonation theory that is related to the nonideal reaction characteristics of typical mining explosives. The tacit characteristic of the Z-state resolved from the non-trajectory work principle is that it can not be remedied or tampered with, unlike the traditional trajectory techniques where the reaction products can be readjusted by changing formula representations, nullifying specific reactions or otherwise manipulating the thermodynamic trajectory process. Though the work principle theory is an unfinished formulation, the Z-state results prove worthy enough for rendering trends and comparisons and reaching otherwise useful conclusions. Further refinements should yield more reliable fume spectra and indicate explosive composition readjustments that would reduce toxic effects within underground mines and the wider world environment.

By Jack E. Fraley

Because of their noncombustibility, silicate and magnesium oxycements are desirable for sealing shale in underground coal mines. In this Bureau of Mines investigation, cement samples were cured and tested (nonstandard tests) for submersion to note resistance to dissolution (breaking into parts), which is an important property for a coating. Nonappreciable dissolution during 1 week of submersion was set for passing the test. Over half of the coatings passed the test.

Jan 1, 1977

By J. William Ganser

This paper is one of a series being prepared by the United States Bureau of Mines describing mining and milling methods and costs at cement-plant quarries throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs may in some instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1931

By W. P. Haynes, J. W. Mulvihill, G. B. Taylor, S. Katell

Capital and operating costs have been estimated for separating methane and hydrogen in gas - separating plants designed to produce 90 million scf per day of product gas containing a minimum of 90 percent methane . After a preliminary literature review of various separation techniques , three different processes --moving - bed adsorption using active carbon , oil absorption , and liquefaction -- were chosen for the cost estimates . Three different methane feed gas concentrations , 5 , 20 , and 50 percent ( cases 1 , 2 , and 3 , respectively ) , were chosen as representative methane concentrations for the separation estimates . Capital and operating costs were lowest for the moving - bed adsorption process in all three cases investigated . Operating costs declined from $ 0.24 to $ 0.06 per 1,000 cu ft of product gas , and capital costs declined from $47,490,800 to $7,411,200 as the percentage of methane in the feed gas increased from 5 to 50 percent .

Jan 1, 1964

By J. G. Kirby

According to the Bureau of Mines annual survey, there were 319 petroleum refineries in the United States as of January 1, 1957 capable of processing 9,123,674 [ ]-barrels of crude oil daily. This was the first time in eleven years that the total number of refineries increased. The crude throughput capacity of the refineries increased 491,284 barrels daily (6 percent) above the January 1, 1956 capacity. The East Coast and Texas Gulf Coast refining districts accounted for 60 percent of the additional capacity installed. Three new refineries were put into operation on the East Coast during the year with a total daily crude throughput capacity of 154,434 barrels while the other refineries in the district report a net loss in capacity, installing equipment capable of processing 140,000 barrels, but dismantling equipment with a capacity of 150,100 barrels. In the Texas Gulf Coast district, one new refinery with a daily crude oil capacity of 5,000 barrels was placed in operation in 1956 and 143,700 barrels of crude capacity was added to existing refineries. The capacity of the average refinery to process crude oil increased from 27,145 barrels daily to 28,601 barrels in 1956.

Jan 1, 1957

By H. R. Babitzke

To develop alloys suitable for use at elevated temperatures, columbium and tantalum were combined with tungsten, hafnium, vanadium, zirconium, and titanium, and the resulting alloys were evaluated with respect to fabricability, hardness, Electrical resistivity, strength at elevated temperatures, oxidation resistance, and bend transition. Of the 23 compositions tested, Cb-2OHf-5W-10Ti exhibited superior high-temperature properties. A recrystallized sample of this alloy was fabricable at room temperature, had a strength of 44,000 psi at 1,200° C, and had an oxidation rate of only 7.7 mg/cm2/hr at 1,000° C.

Jan 1, 1966

By J. D. Davis

On May 15, 1936, Congress authorized the Bureau of Mines to conduct certain studies, experiments, and investigations of subbituminous coal and lignite .4/ Appropriations were made in July 1937, and since that date an active investigation has been underway to complete the provisions of the act. Part of the investigation has included a comprehensive survey of the known properties of the lower-rank non-coking coals, and provisions were made to obtain more data on certain varieties. In line with this plan, a typically subbituminous coal was selected for an extended series o tests in the standard Bureau of Mines-American Gas Association unit,5/ at the Central Experiment Station. This particular noncaking coal was the first one of its rank that ha& been tested in the apparatus; for this reason the results are of particular interest because the testing apparatus was originally designed for use in studying the coke- and gas-making properties of coking coals. The test as described below has been developed by the Bureau of Mines since 1927 through a cooperative agreement with the American Gas Association.6/ Ninety to 180 pounds of coal is heated in a circular retort, 13 to 18 inches in diameter, at wall. temperatures ranging from 540°C. to 1,110°C. in 100°C. steps. All products axe collected and measured; their physical and chemical properties axe then carefully determined to ascertain the gas- and coke-making properties of the coal.

Jan 1, 1939