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By Thomas E. Green

A gas volumetric method was developed for determining metallic aluminum at the 0.01-to 0.3-percent level in 100-gram samples of recycled glass. The method is based on the measurement of the change in gas volume produced by the reaction 2 Al + 2 NaOH + 2 H2O ? 2 NaAl02 + 3 H2 using a simple apparatus assembled from readily available glassware. Apart from sampling errors, the precision of the method is within ±5 percent. A minor modification of the apparatus would extend the method to larger samples or samples of higher metallic aluminum content. Metallic iron and metallic zinc do not interfere at the concentrations found in recycled glass recovered from incinerator residues.

Jan 1, 1971

By James J. Scott

Workshops were held in eight states during the period from December 12. 1975. through June 25, 1976, under U. S. Bureau of Mines Contract to the University of Missouri-Rolla. The workshops were designed to help define the Bureau's research and development priorities. At each workshop a summary of the current Bureau mine reclamation research was presented which was followed by identification of problems associated with mine land reclamation in the state where the meeting was being held. Discussions included the seriousness of problems locally and how the Bureau could best undertake research to assist the state in solving the problems identified. Participants included representatives of state agencies, educational institutions, and companies involved in surface mining. Attendance at these workshops totaled 201 persons who displayed a wide variety of opinions and ideas as to what should be done In government research and development efforts. A breakdown of these attendees is as follows: 91 state and Federal employees; 69 mine operators, equipment manufacturers and consultants; 33 educators and researchers; and 8 others representing such varied interests as environmental and conservation groups, news media and students .

Jan 1, 1976

By Richard A. Walker

This report describes the development and performance of a multi-level, multi-function Calibration Light Source designed for field-calibration of a group of specific photometers. The Calibration Source is capable of providing ±35% accuracy calibrations at all of the following levels: 0. 05 foot-Lamberts, 6 foot-Lamberts, 6 foot-candles and 20 foot-candles. The Source was found to provide constant light output to within 1% over 50 hours of lamp operation and for line voltage variations of ±25%. It is compact and light-weight (11 pounds), and can be easily transported and used by one man in normal office environments (without requiring a darkroom).

Jan 1, 1976

By Leonard F. Heising

Domestic production of Metallurgical-grade manganese has contributed such a small percentage of the United States industrial demands that areas known to contain large tonnages of low-grade manganese ore have been investigated by the Bureau of Mines to reduce this country's dependence on foreign ores. A major source of low-grade manganese is the Cuyuna iron range in Minnesota. The entire Cuyuna iron range is covered by an overburden of glacial drift that, in some places, reaches depths of 200 feet or more. Prospecting and exploration must be guided by geophysical methods, drilling results, or projections of exposures found in operating mines because there are no outcrops near the productive parts of the range. Past drilling for the purpose of outlining iron ore generally was confined to the highly oxidized zones. Much of the manganese with which the Bureau of Mines is concerned occurs in thin-bedded unoxidized iron formations, too low in iron content to have been of interest to those seeking commercial iron ore. The primary objective of the core-drilling reported here was to obtain cores of different classes of manganiferous rocks and to determine whether or not the samples were amenable to beneficiation.

Jan 1, 1959

By Farrel W. Lytle

An X-ray emission spectrographic method of analysis is presented for determining rare-earth elements in fractions obtained from bastnaesite ore. The method includes determination of yttrium, thorium, lanthanum, and the rare-earth elements in various complex mixtures. The analysis technique is based upon comparing the samples with synthetic standards approximating the composition of the samples. Working curves are plotted on an absolute-intensity basis, with no correction for back-ground. Examples of working curves and the analyses of typical rare-earth concentrates are included. The selection of spectral lines for the various sample matrices is discussed. A special technique is used for samples in which rapid hydration and carbonation occurred. By analyzing synthetic samples of known composition, the accuracy of the method was determined. The average error of analysis was about 3 percent of the amount present in the range from 5 to 100 percent and about 7 percent in the 0.2-to 5-percent range. A maximum of about 40 samples per day may be analyzed for 7 elements each.

Jan 1, 1957

By Jingcheng Li

Currently many underground coal mines worldwide have installed or been planning to install a tracking system to trace miners mainly for their safety. Although many systems have been reported functional, a lack of sophisticated and systematic error correction methods apparently is still an issue for them; often it results in a low system resolution. To improve the system resolutions, this paper introduces two position adjustment methods for mine tracking systems. The first is an entry-matching method that optimally adjusts an off-course tracking device to the closest tunnel (entry). The second is a distance measurement adjustment method that accurately adjusts the position of a tracking device along an entry according to a measured distance from the device to a reference point. The coplanar node-path network mine model is used as the foundation for the development of these two methods.

Jan 1, 2009

By Clarence O. Babcock

This Bureau of Mines publication presents guidelines for mining near surface and underground bodies of water. The guidelines were based on information developed under contract in three phases of study, as follows: (1) Collection and documentation of data from worldwide sources; (2) application of existing guidelines, foreign, Federal, and State, to case histories of previous inundations; and (3) development of recommended guidelines for underground coal mining near bodies of water aimed at maximum efficient utilization of underground coal resources consistent with minimizing inundation hazards. While the contract guidelines were for the mining of coal seams, they may also be used for mining any tabular sedimentary mineral deposit. Tables are given for the determination of the size of coal pillars needed; for other bedded deposits, similar tables could be determined based on their strength properties.

Jan 1, 1977

By Gary E. Sherman

To aid the U.S. Army Corps of Engineers In their Resource Development Navigation Study, the U.S. Bureau of Mines (Bureau) examined the potential for mineral development near ten Alaska port sites. This report presents the results for the first three sites: Bethel, Kivalina (Red Dog), and Omalik Lagoon. The mineral deposits near Bethel are primarily gold and mercury; the nearest deposit being 55 mites away. Because of the expense of constructing and maintaining a road over the poorly drained lowlands, the potential of Bethel as a port site in the near-term is considered to be low. The Kivalina site currently serves the Red Dog mine and has the potential to handle material for similar deposits in the area. Results from a lead-zinc mine model indicate that potential for additional mine development exists in the area. Coal is the major deposit type found near the Omalik Lagoon site. Due to environmental constraints, development of a large-scale mine producing coal for export is considered unlikely. A small-scale coal mine model was used to examine the feasibility of producing coal for regional use. This alternative may be feasible but would require conversion of heating/generating equipment in the area.

Jan 1, 2011

By F. P. Haver

The purpose of this investigation was to determine the effect of common impurities, that is, oxygen, nitrogen, carbon, and iron, on the Brinell hardness of electrolytic titanium. On a weight basis, nitrogen had the greatest hardening effect, followed by oxygen, carbon, and iron in order. The hardening effects of oxygen and carbon were almost identical up to a concentration of approximately 0.1 percent by weight. Above this concentration, the relative hardening effect of carbon decreased rapidly, possibly because of its limited solid solubility in a-titanium. Hardness vs. composition curves for both oxygen and nitrogen were essentially straight lines over the range of Brinell hardness numbers (B.h.n.) covered in the investigation. The hardness of titanium was also determined as a function of the percentage of impurity atoms. On this basis, iron in concentrations up to 0.17 atomic percent had a greater hardening effect than either oxygen or carbon. INTRODUCTION Determination of the as-cast hardness of arc-melted titanium is a method of quality control widely used in industry. Numerous studies4/ have been made of the effect of impurities on the hardness obtained by this method. However, most of them have been based on the use of either iodide titanium or commercially pure Kroll sponge (B.h.n. >90), as a starting material.

Jan 1, 1959

By E. G. Noble

The effects of HBr concentration and temperature on the solubility and hydration state of AlBr3,' CoBr2, PbBr2, MnBr2, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the AI, Pb, K, and Na bromides were sparged with HBr gas at 20°, 40°, and 60° C, and saturated solutions of Co and Mn bromides were sparged at 20° C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr2. Aqueous solubilities at 20° C were, in percent, 51.7 for AlBr3, 53.2 for CoBr2, 1.1 for PbBr2, 59.6 for MnBr2' 39.5 for KBr, and 47.4 for NaBr. At 60° C, the solubilities were, in percent, 53.3 for AlBr3, 2.2 for PbBr2' 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20° C were, in percent, 0.5 for AlBr3, 42.0 for CoBr2, 32.2 for PbBr2, 21.0 for MnBr2, 0.6 for KBr, and 0.3 for NaBr. At 60° C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr3, 41.4 for PbBr2, 1.3 for KBr, and 0.4 for NaBr. CoBr2 precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr2 solubility because of the formation of bromide complexes. PbBr2 in-creased in solubility as HBr concentration increased.

Jan 1, 1988

By Lloyd Williams

1. The investigation shows that the Wilder (locally known as the Bon Air No. 2) is the only known bed of commercial importance in Putnam County, although at least 5 coal horizons are known. All of the coal production now reported comes from this bed, which is found In a basin with no known coal outcrops. Further drilling in the east end of the basin should disclose the location of the eastern end of the axial trough and the lateral extent of the basin in Putnam County and adjoining areas in Cumberland County. Continuity of this deposit with that in the area in Putnam County north of Monterey is not conclusively established but may exist. 2 Known (measured plus indicated) reserves of coal, based on a minimum bed thickness of 14 inches and on 1,800 tons per acre-foot in place, are estimated at 29 million tons, as of January 1, 1953. Of this total, 28 million tons are in beds 28 inches and more thick. All born coal reserves in Putnam County me under less than 400 feet of overburden.

Jan 1, 1954

By A. D. Garman

This paper presents one of a series of digests of foreign mining legisla- tion and court, decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Latin America has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it is being referred through the courtesy of the Department of State. Individual abstracts of the laws of each of the countries herein discussed have been prepared and published separately. This general summary is presented for the use of mining engineers and investors whose interests extend over the borders of a single country. It is also designed to bring out certain general principles of mining law and, so far as feasible, to indicate the trend of mining legislation in South and Central America. In order to gain perspective, the details of legislation are not com- pletely covered in this paper, but an effort has been made to bring out essential differences as well as points of similarity in the laws of the various countries. The course of legislation is first traced chronologically and the points discussed are then arranged in tables in somerhat greater detail. .Si. With a very few exceptions the existing mining legislation of Spanish America is a development, of the Spanish "Law Decree of Bases" (more briefly referr- ed to as the "Decree-Bases") of 1868. This in turn was influenced, particularly in its classification of minerals, by the French law of April 21, 1810.

Jul 1, 1930

By Bertha R. Klahold

"In response to numerous inquiries regarding tests and analyses of minerals and related inorganic materials; Bureau of Mines Information Circular 6999, ""Laboratories That Make Fire Assays, Analyses, and Tests on Ores, Minerals, Metals and Other Inorganic Substances,"" by C. W. Davis and M. W. von Bernewitz, was published .in 1938 and revised in 1939 (I. C. 6999R). In this paper on analytical and testing laboratories, the original text has been rewritten and expanded, and a table has been added, in which are listed laboratories prepared to offer a number of special testing services in addition to ordinary assays and chemical analyses. The arrangement of laboratories on, a geographical basis has been maintained.This circular is compiled as a public service, and none of the laboratories listed herein is recommended over any other,These lists were compiled from questionnaires sent to organizations whose work is connected with mineral and metallurgical testing. The response in general was very satisfactory, and the author takes this opportunity to express her appreciation to the officers of the listed laboratories for their cooperation.Acknowledgment is also made of the valuable assistance of the members of the technical staff particularly Morris Slaving/ of the Eastern Experiment Station of the Bureau of Mines at College Park, Md., in the preparation of the questionnaire and technical descriptions.Many mineral samples are sent to government agencies in the National Capital with the request that they be assayed or chemically analyzed. It should be emphasized that there is no place in Washington D. C. where assays and quantitative analyses are made for the public b the Federal Government.Virtually all of the States maintain a bureau of mines, a geological survey, or some similar organization, frequently at the State University, where minerals found by residents of the State will be identified free of charge. Usually, a charge is made for assays. Specific tests, as on clays, are made by some of these offices.The Federal Bureau of Mines, although it attempts to avoid duplication of services rendered by State Bureaus, is always glad to give advice as to prospective markets. It does not compete with private assayers and chemists, but with respect to samples sent to its field laboratories, it does offer to identify them as far as this can be done by inspection and simple optical and chemical tests. This examination is usually sufficient to indicate whether the material has commercial value, or at least if the expense of an assay would be warranted. Except in connection with its own technical investigations, no assays or other special tests are made by the Bureau of Mines.The Federal Geological Survey and the National Museum also make simple tests of specimens as a public service. Neither of these bureaus nor the Bureau of Mines, however, can afford to render such services on long suites of specimens submitted by mineral dealers, well drillers, or others, when such work can be done regularly by commercial concerns."

Oct 1, 1949

By Frank E. Williams

This Bureau of Mines report deals with the urbanization of Tucson, Ariz., a southwestern city with an arid environment. Zoning regulations concerning known aggregate sources are described, and information relating to projected needs for the urban area is furnished. History of growth is outlined not only for the local aggregate industry, but also for the entire urban area. Past conditions are pointed out and background material for future conditions is provided.

Jan 1, 1967

By J. A. Markovits

Coal has been hydrogenated in Germany on a lather extensive scale for the past 20 years, but the process is new to the United States. Although pressures up to 15,000 pounds per square inch have been employed on commercial scale in the synthesis of anhydrous ammonia, and there is evidence that valves, tubing, and equipment have been developed recently up to 30,000 p.s.i. working pressure at moderately elevated temperatures for limited industrial production of plastics, such pressure ranges are unusual in American industry, and equipment designed for them is not commonly available. In the Coal Hydrogenation Demonstration Plant at Louisiana, Mo., 10,000 p.s.i. operating pressures are combined with temperatures up to 1,000° F., and the materials to be processed under these conditions range from gases to mixtures of viscous liquids containing high percentages of abrasive solid particles. These service conditions presented unusual engineering problems requiring thorough investigation, Limited financial resources arid rigid time schedules inherent in the synthetic liquid fuels act often forced decisions before the best answer to a problem could be developed. Sometimes the ideal technical solution proved to be beyond the financial limitations of the demonstration-plant program.

Jan 1, 1949

By Edmund S. Leaver

The Precious Metals Section is concerned primarily with ore-testing problems associated with precious metals and with the analysis and concentration of a large number of the strategic-mineral samples that have been included in the research program of the Bureau of Mines. During the fiscal year 1938-39, 30 projects were completed. The requests for this service are based upon the desire f the sponsor to obtain the best or most satisfactory method for maximum recovery of the minerals. In many instances it is a question of improving present milling practice, with due regard to utilization of present equipment. In others, the probable tonnage available maybe the deciding factor in the choice of a particular recovery method. Under all circumstances the results of tests axe prepared with the thought of aiding a competent metallurgist, familiar with local conditions, to formulate a practical flow sheet or to assist the mill operator to correct known losses. A microscopic examination for identification of the mineral constituents and their association in each ore is always a big help, in planning the tests and may indicate the reason for former troubles or assist with best procedure.

Jan 1, 1940

By Edmund S. Leaver

The Precious Metals Section is concerned primarily with ore-testing problems associated with precious metals and with the analysis and concentration of a large number of the strategic-mineral samples that have been included in the research program of the Bureau of Mines. During the fiscal year 1938-39, 30 projects were completed. The requests for this service are based upon the desire of the sponsor to obtain the best or most satisfactory method for maximum recovery of the minerals. In many instances it is a question of improving present milling practice, with due regard to utilization of present equipment. In others, the probable tonnage available maybe the deciding factor in the choice of a particular recovery method. Under all circumstances the results of tests axe prepared with the thought of aiding a competent metallurgist, familiar with local conditions, to formulate a practical flow sheet or to assist the mill operator to correct known losses. A microscopic examination for identification of the mineral constituents and their association in each ore is always a big help, in planning the tests and may indicate the reason for former troubles or assist with best procedure.

Jan 1, 1940

By GLADYS G. HEFFNER, William H. Waggaman, Edwin A. Gee

Thallium is one of the rare and relatively neglected elements that has recently assumed conspicuous importance. This element is widely distributed in nature but occurs in such minute quantities in most rocks and minerals that its recovery at present is only commercially feasible as a byproduct of other industries. World War II, with its unprecedented demand for products having special or unusual properties, led to a study of a number of the rarer elements that previously had been given comparatively little attention for one or more of the following reasons: 1. 2. Limited knowledge of properties. Small quantitios present in available raw materials. 3. High cost of concentration and recovery. Some of those rare elements, either alone or in the form of compounds, have already proved of such value for certain military and industrial purposes that their extraction from ores and waste products, oven at high cost, is fully justified. On the othor hand, further investigation of their character- istics, discovery of more adequato sources, and improvement in methods of con- centration and recovery would greatly broaden their field of usefulness and establish new and expanded industries. The current market for some of these elements exceeds the available supply. One of the functions of the Bureau of Mines is to study the properties of such elements in greater detail, locate the most promising raw materials from which they can be derived, and work out methods of extraction that will render the recovery of such elements more economical. The purpose of a serios of information circulars on the raror elements is to present in condensed form the facts and data so far available. This information may serve as a basis in planning more complete investigations loading to a full utilization of such elements.

Mar 1, 1950

By E. O. Wagner, Manuel Gomez, W. S. Landers

The Bureau of Mines studied coking rates of a special Columbia - Geneva six - coal blend to establish the effect of the coking rate on coke properties . The tests were conducted in a 500 - lb , 14 - in experimental slot oven at essentially constant conditions of blend composition , size distribution , surface moisture content , and bulk density . The coking rate was varied as a function of oven flue temperature . Coking rates within the range of 0.56 to 1.35 in/hr were achieved . Increase in the coking rate decreased the size of the coke . The stability factor of the coke showed no significant change with coking rate until coking rates greater than 1.0 in/hr were reached , after which a decrease in the stability factor was observed . The apparent specific gravity increased to a maximum value at coking rates approaching 1.1 in/hr and decreased sharply with further increase in the coking rate . Coke parameters correlated well with the coking rate .

Jan 1, 1963

By J. N. Greaves

Investigations were conducted by the U.S. Bureau of Mines to develop flowsheets for the recovery of tungsten and gold from four Alaskan scheelite-bearing ores. Basic gravity concentration and cyanide leach tests were performed on all samples. About 46 pct of the tungsten and 30 pct of the gold from one sample were recovered in a gravity concentrate containing 24 pet W03 (tungstic oxide) and 119 troy ounces per short ton (tr oz/st) Au. Froth flotation of the gravity concentrate resulted in separate tungsten and gold products with grades of 38 pct W03 and 2,720 tr oz/st Au and recoveries of 60 and 97 pet, respectively. Additional gold was recovered from the gravity and flotation tailings by cyanidation. Overall recoveries of tungsten and gold from this sample were 28 and 94 pet, respeetively. A flowsheet with mill design parameters was developed that consisted of (1) free gold and scheelite recovery by gravity methods and froth flotation and (2) fme-grained gold recovery by cyanide leaching of reground gravity and flotation tailings, followed by a carbon-in-pulp (CIP) circuit. Data were developed from the Bond mill work index, gold and tungsten flotation, conventional and high-rate thickening, cyanide leaching, and CIP adsorption tests.

Jan 1, 1989