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By James W. Townsend

[The Harrington-Hickory mine in the Star raining district, Beaver County, Utah, has produced approximately 20,000 tons of lead-zinc-silver ores since 1910. Production previous to 1910 is not known. The mine is owned by the New Majestic Mining Co. The property was rehabilitated and operated by James D. Williams under a 10-year lease with option to purchase from April 1943 to May 1949, Loans from the Reconstruction Finance Corporation in the aggregate of $41,000 wore used in construction of an access road, rehabilitation of the mine, and purchase of equipment for full-scale operation. The improved, all-weather access road extends from loading ramps on the Union Pacific Railroad at Milord to the urine storage bins 5 miles west o f town. The mine is serviced electrically by a. 5,000-volt line owned by Telluride Power Co. Mine transformers step the voltage down to 440/220/110 for surface and underground service.]

Jan 1, 1953

By Herbert H. Einstein

Rock mass deformability is commonly predicted using correlations with RQD or other indices of rock mass quality, or by extrapolation from large in-situ tests. Based on the probabilistic description of rock masses empirically developed in Part I a new approach was attempted in modeling for predictions of deformability. This approach decomposes the rock mass into spatially variable joints described by probability distributions, and intact rock blocks. Stiffnesses and elastic parameters are associated with the joints and intact blocks respectively, and deformations built up by adding the contributions of each. This model allows relaxation of many of the simplistic geometric assumptions which constrain parallel attempts to model deformation in rock masses. The model has been applied to four standard cases in order to test its results against previously existing models, and to check whether it replicates empirical correlations. When joints are taken as parallel, common empirical correlations are closely approximated by the model output. However, the closeness to empirical correlation breaks down when variability of the jointing geometry is increased.

Jan 1, 1979

By C. Richard Groves

As the level of technology applied in the electrical measurement, control, and display portions of mine hoist systems continues to advance, the issues and concerns associated with the ramifications of the application of microprocessor technology on the safety-related aspects of these systems become paramount. This report, in part tutorial, addresses several aspects of these concerns. Beginning with discussions of microprocessor-based system architectures, the report addresses some existing and anticipated uses of this technology in mine hoist systems and discusses safety related considerations associated with the areas of data derivation; control and display panels; and system reliability issues. The report concludes with electrical maintenance and inspection considerations associated with the safety assurance of microprocessor based mine hoist systems.

Jan 1, 1986

By R. J. Hundhausen

The Takilma-Waldo copper district in Josephine County, Oreg., was studied by the Bureau of Mines from September 1950 to April 1.951 and from December 1953 to April 1954. Funds for the investigation were provided by the Bureau of Mines and the California-Oregon Power Co., Medford, Oreg., on a cooperative basis. The copper mines in the district are credited with a total production of ore worth $1,700,000. Since 1933 the mines have been unproductive and, except for minor exploration, largely inactive. The history of the district indicates that the copper deposits were mined principally during periods of high metal prices.

Jan 1, 1956

By Paul A. Pierce

In 1984, the Bureau of Mines evaluated an area previously identified as having "probable mineral resource potential" for copper, lead, zinc, gold, or silver within the Elkhorn Wilderness, about 5 miles west of Winston, MT. The purpose of this study was to determine whether the mineralized structures at nearby mines and prospects outside of the Wilderness extend into and contribute to the anomalous zone and, if so, to expand the domestic supply of strategic and critical mineral resources for future needs by identifying and quantifying resources on public lands. Fifty-eight soil samples, 23 rock samples, and 1 stream sediment sample were collected in the Staubach Creek area. Overall sample analyses suggest the anomalous zone in the Staubach Creek drainage is possibly associated with -.mall pyritiferous quartz veins. These veins or veinlets may be part of a system of northeasterly-trending structures prevalent in this art of the Wilderness. However, there is not sufficient evidence to prove that identified resources outside of the Wilderness extend into it in the Staubach Creek drainage, or that economic base- or precious-metal deposits are likely.

Jan 1, 1987

By R. P. Vinson

The Bureau of Mines conducted a series of tests to determine how well the Bendix BDX 60, the Gilian HFS 113U, the MSA Fixt-Flo, and the Spectrex PAS-3000 dust sampling pumps control the flow rate at 2 L/min. These tests were performed because users need to know the performance characteristics of sampling pumps to select the pump that best satisfies their sampling requirements. Long-term (6- to 8-h) flow stability at various backpressures was examined in relation to the flow control tolerance of ±5% of the flow, the level imposed by Federal regulations; four of the five Bendix pumps did not meet the criterion for this test, which was passed by all other pumps tested. Flow control recovery times were measured at transient backpressures; all pumps evaluated met the criterion for this test. The low-flow indicators of the sampling pumps were tested; only two Bendix pumps and one Gilian pump met the criterion of indicating a flow change greater than ±5%. In the pulsation flow measurement test all of the pumps passed, with pulsating flows greater than 20 Hz. The Bureau also evaluated the manuals accompanying the sampling pumps. All were judged adequate except the Spectrex manual, which was judged poor.

Jan 1, 1985

By L. M. Adams

Experiments in reclaiming acidic surface-mined coal lands with raw fly ash from bituminous-coal-fired powerplants were conducted by the Bureau of Mines at two sites in northern West Virginia. Plots at both sites were treated with varying tonnages of fly ash from three area powerplants and were planted with a variety of grasses, legumes, trees, and shrubs. Eight grasses and seven legumes were investigated. Greatest promise for growth under harsh soil conditions was shown by Kentucky 31 fescue, rye and red top grasses, and birdsfoot trefoil, a legume. Survival of trees and shrubs was negligible. Addition of fly ash to the spoil increased the pH to a range tolerable to some types of plant growth, improved the texture of the soil, and increased the available water of the resulting mixture.

Jan 1, 1971

By J. A. Cavallaro

The heats of formation of anhydrous barium carbonate (witherite), strontium carbonate (strontianite), and lead carbonate (cerussite) were determined by solution calorimetry. The solution mediums were hydrochloric acid for barium and strontium carbonates and perchloric acid for lead carbonate. The heats of formation at 298.15° K are as follows: BaCO3 -297.5 ± 0.8 kcal/mole; SrCO3 -294.6 ± 0.5 kcal/mole; and PbCO3 -168.0 ± 0.3 kcal/mole.

Jan 1, 1966

By H. D. Bemis

This paper describing the milling practice of the American Metal Co. at its Pecos con¬centrator is one of a series on milling methods and costs being prepared by the United States Bureau of Mines. ACKNOWLEDGMENT The author acknowledges the assistance rendered by Guy Martin, metallurgist, H. E. Brown and J. H. Hastings, chemists, and Thomas J. Fahey, accountant, in gathering and pre¬paring the data presented in this paper.

Jan 1, 1932

By H. G. Iverson

The purpose of this investigation was to beneficiate the Talladega gray iron ores by flotation. A component of the problem was the determination of the degree of beneficiation possible by flotation as well as the relative selectivity of certain reagents in promoting flotation of either the iron minerals or the siliceous gangue minerals. The scope of the present investigation involved only the use of small-scale laboratory equipment. Treatment by roasting and magnetic separation was not included in this study, inasmuch as a similar comprehensive investigation was completed and the results were published by the Bureau of Mines in 1927. The results of the work on Talladega iron ores are briefly summarized in this report. In the search for efficient and economic methods of beneficiating low-grade iron ores, the flotation process is among those that are receiving considerable attention. The Talladega ores are of particular interest for a flotation study, because they contain two iron minerals (magnetite and specular hematite) that are somewhat dissimilar in their flotative response.

Jan 1, 1949

By Stephen Krickovic, J. E. Carpetta, T. D. Moore

Air quantity-pressure and methane concentration surveys were conducted by the Bureau of Mines in accessible portions of an area being pillared in a Pittsburgh coalbed mine in West Virginia. These included two mined-out and three active butt headings and a bleeder system. The particular mine workings were started in virgin coal directly from a set of main headings; the main reason for the study was the difficulty usually encountered in adequately bleeding the gobs under such conditions. Although the two separate return airways in each active butt heading and the North and 1 Left bleeders contained acceptable methane concentrations (0.01 to 0.78 percent in the butts and 0.73 to 1.0 percent in the bleeders) with significant total methane removal (109 cfm in butts and 631 cfm in bleeders), there were relatively large areas in the gobs with possible minimal airflows. This condition appears to have developed from lack of systematic regulation of the airflow across the gobs and appears to indicate the existence of considerably more methane in the probably low flow areas in the gob.

Jan 1, 1973

By Richard F. Link

The objective of this report is to explain a statistical method for the summarization, organization, and classification of multivariate assay and other data from the mineral industry. Multivariate data are those characterized by several measurements at each data point, such as assay data from a mixed metal mine, or blast furnace data. A specific method of linear discriminant analysis, the Mahalanobis d2 procedure, is explained, starting from elementary principles; the d2 procedure enables many measurements at many data points to be studied by investigating the interrelationships among the data. The relation of linear discriminant analysis to other statistical methods for treating multivariate data, in particular the eigenvalue technique of factor analysis, is also explained. Example analyses are made on data from the Frisco mine, San Francisco del Oro, Chihuahua, Mexico. The data comprise assay values for silver, lead, copper, and zinc taken at some 19,000 sample points distributed into 91 groups.

Jan 1, 1967

By R. R. Allen

Gieseler plastometer tests were performed on eight western coking coals at retort - immersion depths ranging from 2 to 3-3 /4 inches (measured to the center of the coal charge ) . Increased maximum fluidities were associated with greater retort - immersion depths , the most pronounced increases being observed on highly swelling coals when tested at 3-3 /4 inches . The maximum fluidity of one of these coals when tested at 3-3 /4 inches was 146 percent greater than that observed at 24 inches . Retort - immersion depth had no significant effect on the temperatures of initial softening , fusion , maximum fluidity , end of fusion , and solidification .

Jan 1, 1964

By L. A. Morley

This report summarizes the work performed on Bureau of Mines Contract J0199106, "Portable Trailing Cables, Splices, and Couplers - Design and Installation Considerations," from May 1, 1979 until December 31, 1981. Splice installations and considerations for the possible use of conductive-rubber shielding in low-voltage trailing cables as well as coupler installations in high-voltage cables were the principal tasks. Flammability measurements on cable components and general testing facilities for mine electrical equipment were secondary tasks. Theoretical and empirical data indicate that conductive rubber with high resistivity values is an unsatisfactory shield design for current-sensing fault detection. Elimination of partial discharge in coupler installations requires meticulous care.

Jan 1, 1982

By W. H. Kerns

The Critchfield manganese deposit, Huntingdon County, Pa., was investigated by the Bureau of Mines in October 1942. Iron ore was mined from an open cut just southeast of the manganese deposit about 80 years ago. The Critchfield Sand & Feldspar Co. was operating (1942) a clay-mining and beneficiation plant northeast of the manganese deposit. The Bureau completed six rotary bucket-drill holes and three hand-auger holes, aggregating 370 feet on the deposit. This report describes the work performed and presents the results obtained.

Jan 1, 1948

By Glenn E. Johnson

The Bureau of Mines investigated the production of hydrogen cyanide by reacting powdered coal (minus 300 mesh) with ammonia at 1,250° C in a bench-scale study. Both metallic and ceramic reactors were used. Yields up to 0.7 cu ft of hydrogen cyanide per cubic foot of ammonia consumed r- obtained. The resulting ammonia conversion of about 75 volume-percent approximates conversion obtained commercially in processes utilizing natural gas and platinum catalysts. The coals that had higher volatile-matter contents gave the best yields of hydrogen cyanide. Allowing the coal to adsorb ammonia before reaction resulted in increased yields of hydrogen cyanide. Cost studies for a plant with a 40-million-pound-per-year capacity indi-cate that hydrogen cyanide can be profitably coproduced with carbon black, from coal and ammonia, at the current market price of hydrogen cyanide (11.5 cents/lb). These figures are based on heating the reactor electrically. If a cheaper heating method were devised the economics of the process would be more favorable.

Jan 1, 1967

By Robert B. Fulton

Summary of data and estimates for 52 fluorspar properties in the following 13 foreign countries: Mexico Thailand China (PRC) Morocco Tunisia Italy Spain South Africa France United Kingdom Kenya Namibia Federal Republic of Germany Data includes deposit type, resource tonnage and grades, mining and beneficiation methods, annual production, fluorspar products and by-products, manpower requirements, capital and operating cost estimates. For operating properties, engineering and cost data have been developed for present and anticipated levels of production. Hypothetical operations have been assumed for undeveloped deposits.

Jan 1, 1984

By K. J. Liles

The Federal Bureau of Mines conducts a comprehensive test program on clay and shale at the Tuscaloosa Metallurgy Research Center. All samples are subjected to standard preliminary ceramic tests, which include firing formed briquets at temperatures ranging from 1,000° to 1,250° C to identify firing range and colors, and quick-firing to determine bloating characteristics. Materials that shop potential as structural products are further tested after either extrusion or dry-pressing. If the quick-fire test is positive, bulk samples can be fired in a rotary kiln to evaluate their potential as light- weight aggregate A number of miscellaneous tests also can be conducted if requested. These tests determine properties such as refractoriness (pyrometric cone equivalency), oil-bleaching characteristics, oil absorbency, viscosity for drilling-mud applications, sand-bonding properties for foundry usage, and pelletizing characteristics.

Jan 1, 1977

By A. W. Fahrenwald

Coarse sand flotation, both alone and in conjunction with gravity concentration, is a subject of research at the U. S. Bureau of Mines Field Office, Moscow, Idaho. One of the most important results of this work which is being carried out in cooperation with the University of Idaho, has been the development of a concentration process embodying flotation, classification, and tabling, in the order named. The flow sheet of the process is given in Figure 1. The type of feed desired for this process is coarser than is common in present "all flotation" practice, and is about the size of table feed.

Jan 1, 1929

By E. C. Perkins

Preliminary experiments are reported utilizing bacteria to leach manganese from a variety of domestic low grade manganiferous materials. In two large leaches manganese extraction ranged from 71.7 to 92.5 percent, and the products analyzed over 48 percent manganese. Nutrient requirements and leaching time experiments were made. The mechanism of leaching is not understood, but is different than the mechanism encountered in the microorganism accelerated leaching of copper in the presence of sulfide minerals.

Jan 1, 1962