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By D. W. Butner

This Information Circular , one of a series published by the Bureau of Mines , reports on the methods and costs of mining and concentrating zinclead ore at the Highland Surprise mine in the Pine Creek area of the Coeur d'Alene region of Idaho . The mine is owned and operated by the Highland Surprise Consolidated Mining Co. , which supervises operations of the Nevada Stewart group of claims , which is adjacent on the northwest . These properties are at the extreme eastern end of a zone of fracturing that strikes northwest across the Pine Creek area . In fractures along this zone are the principal Pine Creek mines ; these are the Highland Surprise , Nevada Stewart , Sidney , Denver , V and Idaho , Liberal King , and Northern Light . Country rock at the Highland Surprise is argillite of the Prichard formation (Belt series ) . Fracturing has permitted the movement of mineral- izing agents that have replaced adjacent walls and crushed country rock with sulfides . Ore minerals are sphalerite and galena with accessory pyrite , chalcopyrite , pyrrhotite , and siderite . Three principal ore shoots were found on the Highland Surprise property . The Highland ore shoot was mined from outcrop to the 400 level . The Surprise ore body has been developed to a depth of 1,400 feet on the dip of the vein . The outcrop of the Surprise ore shoot was 150 feet long and 2 to 4 feet thick ; on the 1,150 ( lowest ) level , the ore shoot is 320 feet long and 10 to 17 feet thick , with good zinc content . Surprise ore shoot No. 2 occurs 250 feet west of No. 1 and has been mined from the 500 to the 1,000 level . From 353,000 tons of ore mined between 1910 and 1948 , the property has a recorded production of 256,000 ounces of silver , 7,500 tons of lead , 24,000 tons of zinc , and 412 tons of copper . Both shrinkage and cut and fill stoping methods are used at the Highland Surprise , but shrinkage is unsuitable for mining below the 700 level , because faulting has weakened the walls . Development of the Surprise ore , as well as exploration laterally and along the strike , is prosecuted steadily . A prospect heading is being pushed westward toward Nevada Stewart ground from the 700 level . The mill has a rated capacity of 275 tons per day and operates near capacity . Selective flotation makes zinc concentrate that is shipped to the Anaconda smelter and lead concentrate that is trucked to the Bunker Hill smelter at Kellogg .

Mar 1, 1950

By J. F. Barkley

[There 1 s [\ general conce:!?t in the coal trade tha t the ;noi sture-and ash-free B. t.'I. of coal from t.he oome seam, and surely from the same mine, is substantially a cor.stant: that calculatio!: of the ::1oisture-and ash-free B. t. u. value f~~oJl t he proxima te ru:al~rsi sand. 3. t. u. determined in tl19 laboratory 111ill reveal v:?letller a coal came f~'om a. given : area or seam; and that, having this constant, the 3.t.u. value of a coal sample can be c lculatcd fairl...' closely 11:0on a? dry or as~received basis from the r.lois]

Jan 1, 1941

By R. E. Kennedy

The presence of combustible gases and vapors in air can constitute n extremely serious explosion hazard. This hazard is even greater when explosive mixtures are confined under high pressures, as the pressure can become tremendous immediately before the container is ruptured. Because of its interest in safety in mining and. allied industries, the U. S. Bureau of Mines has investigated the explosive properties of a number of gaseous and liquid compounds; the results of these investigations have been published in various government papers and journal articles. The increased use of liquefied, petroleum gases has intensified interest in the effect of high pressures on the explosibility of propane-air mixtures. The limits of flammability of natural gas-air mixtures have been determined at pressures ranging from 50 min. Hg to 3,000 p.s.i. As it is known that a combustible. gas or vapor cannot burn or explode when the oxygen content of the atmosphere is less than a certain value, critical values were determined for the oxygen content of atmospheres to which nitrogen had been added as a diluent. In this connection limits of flammability were determined for ethane in atmospheres containing added. nitrogen or carbon dioxide at pressures up to 900 p.s.i.g.

Jan 1, 1951

By J. F. Barkley

[There is a general concept in the, coal trade that the moisture- and ash-free B.t.u. of coal from the same seam, and. surely from the same mine, is substantially a constant; that calculation of the -moisture- and ash-free B.t.u. value from the proximate analysis and B.t.u. determined in the laboratory will reveal whether a coal came from a given area or sears; and that, having this constant, the B.t.u. value of a coal sample can be calculated fairly closely upon a dry or as-received basis from the moisture and ash values of its proximate analysis.]

Jan 1, 1941

By F. E. Armstrong

This Bureau of Mines publication reviews 237 papery on radiometric prospecting, which is the measurement of naturally occurring radioactivity in the earth's surface and its application to petroleum and natural gas exploration. Many theories and documented surveys are listed in both support and refutation of this reported phenomenon, and the Bureau of Mines is conducting research to obtain direct field information in order to determine the statistical credibility of a radiometric method of predicting petroleum accumulation.

Jan 1, 1973

The workshop on "Cyanide Effluents from Mineral Processing' was held on February 2-3, 1982, at the U.S. Bureau of Mines, Salt Lake City Research Center, Salt Lake City, Utah. The workshop was sponsored by the minerals industry, supporting industries, the National Science Foundation, and the U.S. Bureau of Mines through the Utah Mining and Mineral Resources Research Institute, College of Mines, University of Utah Prior to the workshop, a Working Paper was prepared and delivered to the participants. This paper was used as a guide during panel discussions and forms the basis for this proceedings document. The workshop focused on use of cyanide as it relates to the gold and silver mining industry and the froth flotation processes employed by mineral mining companies. Its intent was to discuss "state of the art" technology and provide information pertinent to cyanide use in the minerals industry. No attempt was made to advocate regulatory limits or set policy governing the use of cyanide. The principal topics of discussion included- (1) the chemistry and use of cyanides; (2) control and treatment of cyanide mining wastes; (3) toxicity of mining wastes; (4) fate of cyanide in the environment; and (5) the analytical chemistry of cyanide.

Jan 1, 1983

By P. Kovalchik

The Bureau of Labor Statistics (BLS) classifies hearing loss as a separate illness category. Hearing loss accounted for 11% of all illnesses in 2005 (U.S. Department of Labor Bureau of Labor Statistics, 2006a). According to occupational data for coal mining provided by the Mine Safety and Health Administration (MSHA) from 2000 to 2005, operators that exceeded 100% noise dosage were from only seven types of machines: auger miners, bulldozers, continuous mining machines, front end loaders, roof bolters, shuttle cars (electric) and trucks (Title 30 CFR Part 62, 2000-2005). Roof bolting machine operators rank second among all underground machine operators that exceed 100% noise dose. There are approximately 600 underground coal mines with 3,930 roof bolting machine operators (U.S. Department of Labor, Mine Safety and Health Administration, 2005; U.S. Department of Labor Bureau of Labor Statistics,

Jan 1, 2008

By Jr. Jacobson

Thermal reactions of l-methylpyrrole, l-butylpyrrole, and l-isopropyl-pyrrole were investigated by a flow method in the temperature range of 4500 to 5750 C. Those of I-butylpyrrole and l-isopropylpyrrole were also investigated in the 3400 to 4000 C range in a static system. The I-substituted pyrroles isomerize by an irreversible reaction to 2-substituted pyrroles. A reversible isomerization reaction shifted the alkyl group from the 2-to the 3-position on the pyrrole ring. All of the isomerization reactions are homogeneous, unimolecular, nonchain, first-order reactions having similar mechanisms and transition states. There is decomposition and cleavage of the longer alkyl side chain when it is in either the 2-or 3-position giving, as products, pyrrole, 2-and 3-methylpyrrole, 2-and 3-ethylpyrrole, pyridines, and hydrocarbons. The decomposition reactions appear to be by free-radical mechanisms. Pyridine homologs are formed by the expansion of the alkylpyrrole: butylpyrrole produces pyridine, and isopropylpyrrole produces 3-methylpyridine. Approximate Arrhenius equations are given for the formation of the decomposition products.

Jan 1, 1966

By A. C. Fieldner

In the course of its investigations on the properties of coal and in rendering fuel-inspection service to other agencies of the Government, the Bureau of Mines has accumulated a comprehensive file of coal analyses that includes data on virtually every coal field of commercial importance in the United States. As knowledge of the composition of coal is potentially valuable to every user of coal, the Bureau publishes its analytical records. Before 1921 such publications contained analyses of coal from all parts of the United States; individual analyses or average analyses of a series of shipments of coal were given with the name and location of the mine producing the coal. Beginning in 1921 the analyses were published by separate States because the quantity of data had become so great. The separate papers published to date, with Bureau of Mines Technical Paper numbers, are as follows: Alabama, 347; Arkansas, 416; Colorado, 574; Illinois, 634 and 641; Indiana, 417; Iowa, 269; Kansas, 455; Kentucky, 30S; Maryland, 465; Missouri, 366; Montana, 529; New Mexico, 569; Ohio, 344; Oklahoma, 411 ; Pennsylvania (bituminous), 590; Tennessee, 356; Utah, 345; Virginia, 365; Washington, 491 and 618 (618, published in 1941, supplements 491); West Virginia, 405 and 626; and Wyoming, 484. From time to time the various papers will be revised to include later analyses and other data. The Bureau of Mines annually receives many inquiries as to the composition of coals obtained from specific localities or, conversely, as to the localities from which a given kind of coal may be obtained. This paper presents a summary, in tabular form, of the composition of commercial coal resources of the country. Specimen analyses are given exemplifying the analysis of coal mined in each coal-producing county, or, where it was feasible, coal from each bed in each county; also, ranges of analyses, within which the composition of most of the coal represented will fall, are given where there were enough analyses to permit satisfactory determination of the ranges. In addition, the degree of metamorphism from lignite toward anthracite of much of the coal is indicated by the classification by rank. This classification reveals to more experienced users of coal some of the general properties of coal, that is, whether the flame will be long or short, whether the coal will cake in the fire, and how it is likely to behave on exposure and in storage.

Jan 1, 1942

By Sidney Speil

In the study of clays and related minerals, the analytical techniques commonly employed in mineral analysis are not always applicable. The X-ray examination of a clay sample usually will show the major constituents, but often minor· clay impurities will not be detected because of line broadening and the similarity of the main lines of clay· mineral diffraction patterns, The petrographic analysis of clay minerals with clay particles as small as a few microns is usually difficult. With still smaller particles, a gross effect often is noted in which a mixture of several constituents gives the appearance of a single constituent with the mean optical-characteristics of the mixture. 3/ The electron microscope has recently been used to study clay particle shapes of various aluminosilicates. 4/ However, this method has not yet been sufficiently explored. The Chemical method in which a mineralogical analysis is calculated from the oxide chemical analysis has been discussed by Wilson 5/ and others, and many of the shortcomings have been pointed out. It should also be recognized that the variable alkali and alkaline earth content of bentonites makes it inaccurate to assign these basic elements arbitrarily to feldspar or mica in any clay that contains appreciable bentonite.

Jul 1, 1944

By A. W. Fahrenwald

[In studying coarse sand flotation3/ the question of the relation between fineness of grinding and mill capacity logically arose. Everyone familiar with present fine-grinding practice knows that the capacity of a ball mill or similar mill is determined, among other things, by the fineness of the finished product. Undoubtedly a great many mining companies must have a good deal of data directly bearing on this point, yet no quantitative relationship between ball-will capacity and fineness of finished product has been established. The experimental study presented here is an effort to establish this relationship in a semiquantitative way. The subject is a tremendously large one and grows in complexity as the study becomes more searching. In this work the power consumed by the mill in the various experiments was not determined end neither vas the steel consumption measured; mill capacity only was considered.]

Jan 1, 1930

By Phillip N. Yasnowsky

This Bureau of Mines report summarizes State severance taxes imposed on minerals and mineral fuels, provides a hypothetical example of how a State severance tax affects selected components of a firm's income statement, and uses the Bureau's Minerals Availability System (MAS) to estimate the effect of assumed changes in State severance tax rates on copper recovery cost at given levels of potential copper availability. A reduction of the rates to zero or a doubling of them results in changes in costs that are of the same order of magnitude as the cost of transporting copper to the United States from major foreign producing countries.

Jan 1, 1982

By Rustu S. Kalyoncu

Nonoxide ceramics with improved high-temperature properties could substitute for high-temperature alloys and reduce toe Nation's dependence on imports of Cr, Co, Ni, and Mn. To meet this objective, the Bureau of Mines conducted research to synthesize u1trafine reactive boron nitride (BN) powders BN powders were prepared at temperatures ranging from -75? to 750? C. Low-temperature reactions (-75? to 200? C) between boron halides and N compounds led to formation of e1emento-organic compounds that were thermally decomposed to u1trafine (approximately 100-to 150-A particle size) reactive BN powders. BN powders were also prepared through the reaction of a 10w-me1tinginorganic B compound (boric acid, borax) with an organic N compound (carbimide and thiocarbimide) in N2 and/or ammonia (NH3) atmospheres at temperatures between 500? and 750? C.

Jan 1, 1986

By E. D. Gardner

This paper on the square-set system of mining embodies the results of a special study of the subject made as a part of the Bureau of Mines general investigation of mining methods and costs. Data for the paper were gathered by the authors during visits to mines using square-set mining, from Information Circulars prepared by consulting engineers to the Bureau on mining methods at individual mines, and from articles in the technical press and the Transactions of the American Institute of Mining and Metallurgical Engineers. The square-set system of mining is very widely applied and is one of the oldest methods in use in the United States. It is mainly employed for extracting relatively high-grade ore in heavy ground. It is also useful in taking out pillars left in mining by other methods. It is used to some extent as an auxiliary method with many underground systems and as an alternate with cut-and-fill, shrinkage, and open-stope methods when heavy ground is encountered. In some cases as much as 50 per cent of the ore may be extracted by square-setting at mines listed as using some other method of mining. A large tonnage is mined yearly by square-setting, principally in the Western States.

Jan 1, 1933

By J. B. Gayle

Oven widths for experimental and commercial slot-type ovens differ appreably in most instances; the experimental ovens usually ranging from 10 to 14 inches and the commercial units from 14 to 21 inches. Application of results obtained with experimental ovens to commercial practice thus requires major extrapolations. A critical survey of the literature indicated that sufficient information about the effects of variations in oven width on the carbonizing process is not available to permit such extrapolations to be made with any considerable degree of confidence.

Jan 1, 1960

By W. A. Selvig

EQUIREMENTS of montan wax for industrial use in the United States before World War II were met by imports, nearly all of which came from Germany. An important industry for extraction and refinement of this wax from certain brown coals had developed in Germany. At the beginning of the war, montan-wax imports were shut oft, and American industry was forced to rely largely on substitutes. Since the war, relatively small amounts have been imported from Czechoslovakia. Because of the shortage of montan wax at the close of the war and the fact that industry in the United States had to rely on foreign sources in the past, this investigation was started in 1945 to determine probable yields of wax from domestic lignite. Results of the investigation and the properties of extracted waxes are described in this report. Also included in the report are discussions of the occurrence and geology of lignite deposits of the United States from which samples were obtained for wax extraction and the petrographic composition of lignites, particularly in respect to those components that contribute to wax yields.

Jan 1, 1950

By J. L. Wiley

[NOTE. - P before the number indicates that the ab tract appears in patent section. Abstract numbers without. P appear in literature section. A Abietic acid, hydrogenolysis - 404 Acetone, recovery - P-4024 Acetylacetonate catalyst - P-3352, P-3664, P-6067 Acetylene, production - P-2556, P-3169, P-4064, P-4221, P-4222, P-5002 Acid catalyst - P-4584 Salts - P-4555 See also Specific acid. Acid treatment. See Procedure. Adsorption. See Hydrogen, adsorption. Agitation. See Equipment, agitators; Procedure. Alcohols: Decomposition -1128 Hydrogenation - P-3288, P-4743 In motor fuel - 1486]

Jan 1, 1952

By R. A. Cortese

The U.S. Bureau of Mines has developed a flame-radiation-powered trigger device to explosively activate suppression barriers to quench gas and coal dust explosions. The major component of the device is a silicon solar panel, which converts radiation from the developing explosion into electrical energy to initiate an electric detonator, which releases an extinguishing agent into the advancing flame front. Solar panels that are rated to produce 20 W of electrical power when exposed to the sunlight are producing about 200 W when exposed to a full-scale dust explosion. The solar panel is electrically isolated from the detonator by a pressure-sensitive switch until the arrival of the precursor pressure pulse, which always precedes a deflagration. This combination of pressure arming and flame-powered photogenerator prevents false barrier activation and requires no external power supply.

Jan 1, 2010

A significant amount of information regarding the crushed stone and sand and gravel industries in each State is available from State agencies and State trade associations. These organizations continuously monitor the State mineral industries and are therefore an important source of detailed information at the local level. This third edition of the directory was prepared to provide a listing of government agencies and trade associations that can assist the users interested in obtaining detailed listings of crushed stone and sand and gravel producers, in addition to the information published by the U.S. Bureau of Mines.

Jan 1, 1994

By Merle Randall

Application of a new chemical spray in a mercury mine in which ore rich in native metal was causing salivation among the miners has given such favorable results that it is believed the process will be useful in other mines and perhaps in some plants where similar conditions exist. The process was originated by Merle Randall, professor of chemistry at the University of California. GENERAL PROBLEM The presence of native quicksilver in mines from which the metal is produced has long been a source of trouble and danger to the workers. Men have been sickened and some of them have been disabled by exposure to the vapors present (even in workings that were well-ventilated by ordinary standards) and to contact with dust, dirt, and moisture with which the finely divided quicksilver was mixed. Where the ore was rich and this exposure was considerable men were able to work only a few days or weeks; where the exposure was less they were weakened and subject to ailments often attributed to other causes.

Jan 1, 1942