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By A. C. Johnson

This circular is one of a series published by the Bureau of Mines describing mining and beneficiation methods and costs at various mining operations throughout the United States. Inclusion of the Abbott mine in this series is of particular interest, as the complex geology and the character of the deposits make their exploitation a unique operation. The mine operates on a high-cost, comparatively small-scale basis, and only the persistence of an aggressive management has enabled it to maintain its rank among the major mercury producers of California. Rising costs and decreasing metal prices, which continuously threaten the low profit margin, are reflected in increased efficiency of operation. This report summarizes past operations and describes, in detail, the geology and ore deposits; exploration and mining methods; and furnacing and condensing operations. It covers the entire operation from initial exploration to the actual production of mercury. Comparative production costs for 1944 and 1958 are of special interest.

Jan 1, 1962

By R. W. Stahl

Burning coal-mine refuse banks were surveyed in 15 States. The following characteristics were tabulated for 495 hanks: County; name, population, and distance of nearest town; size and status of bank; status and stage of fire; and topography. Ways of controlling fires were reviewed, the compacting and sealing method proving most satisfactory. Means for preventing refuse-bank fires by proper construction of banks are described.

Jan 1, 1964

By Frederick H. Raab

A power-line proximity-warning (PLPW) system must have a high probability of detection (alarm activation at a specific distance), low probability of false alarm, and minimal set-up and maintenance. Tests of electric-field sensors have not demonstrated a dependable alarm distance. Alternative sensing methods such as microwave radar, optical radar, and sonar can meet the requirements by direct measurement of the range from the boom to the power line. Suitable microwave techniques include RF pulse, chirp FM/CW, and baseband pulse. Baseband-pulse radar has adequate range capability and does not require expensive microwave components. The radar cross section of a power-transmission cable is adequate for its detection optical-radar systems based upon LEDs and photodiodes are inexpensive, but can achieve only marginal performance in this application because of their limited modulation bandwidth. Since laser diodes and cryogenically cooled photosensors must be used to achieve the desired range resolution, the cost of an optical-radar system is greater than that of a microwave radar system. Sonar systems are feasible, but are not as precise and cost at least as much as baseband-pulse-radar systems. The performance of both optical-radar and sonar systems is degraded by dirt, necessitating the inclusion of a "windshield wiper.' Baseband radar appears well suited to the PLPW application. The cost of a baseband-pulse radar PLPW system is expected to be comparable to that of an electric-field PLPW system. Development and testing of an experimental model are therefore recommended.

Jan 1, 1982

By Joseph Daniels

[Adequate supplies of suitable coal and coke are prime requisites in many industries, particularly those dealing with the utilization of mineral resources, recently interest has been focused on the possibilities of using electricity produced at Bonneville and Grand Coulee, Wash., in many electrochemical and electrometallurgical processes, in which core or some form of carbon is necessary in addition, discussion has been revived on the possibility of making iron and steel by the conventional methods employed in blast and open-hearth furnaces. The subject also is important at this time because of its relationship to industrial preparedness for national defense. A supply of coke from local sources on the Pacific coast is necessary in any program of production for strategic sufficiency of certain materials. An anal trio involving tae establishment of such industries should include detailed data on available supplies of coal, the quality and properties of the coke produced, and the technologic and economic factors involved in manufacture of echo and disposal of byproducts.]

Jan 1, 1941

By L. A. Stewart

This paper describes all occurrences of barite in Arizona that were known or reported to the authors. The history, ownership, production, and geologic setting are discussed for most of the deposits. The uses and specifications of product grades are briefly discussed. Seventy-five deposits were examined in 9 of the 14 counties of the State. The descriptions are given under county headings. No occurrences were reported in the four northeastern counties of Coconino, Navajo, Apache, and Greenlee, nor in Santa Cruz in the southern part of the State. From about half of the deposits examined, 55 samples were taken; of these, 45 were for chemical analysis, and 8 larger samples, ranging from 100 to 350 pounds, for beneficiation tests. A 30-ton bulk sample was taken for pilot-plant tests. Bench-scale flotation tests of the eight samples employing several different procedures and reagent combinations yielded marketable-grade barite products with barite recoveries ranging from 60 to 97 percent. Five of the samples contained enough fluorspar to warrant its recovery. Acid-grade concentrates, which accounted for fluorspar recoveries of 45 to 70 percent, were obtained from three of these ores. Batch laboratory tests of a representative portion of the 30-ton bulk sample revealed that acid-grade fluorspar and high-grade barite concentrates could be recovered. Results of the laboratory and continuous pilot-plant tests of this ore will be presented in a separate report.

Jan 1, 1960

By K. L. Whitehead

An examination of 60 mines, 11 illumination hardware manufacturers, and Q mobile face-equipment manufacturers was conducted to determine the state of the art of mine-illumination hardware, define lighting system installation and maintenance problems, and assess personnel acceptance of lighting. Longwall and mobile face-machine illumination were studied. Major problems on room and pillar installations include damage of exposed components, electrical failures, and reduced lamp life, with extreme variability in the degree of these problems. Most longwall systems had low or moderate maintenance requirements, cable damage being the most significant problem. Most mobile face-equipment operators liked their machines' lighting systems, but many complained of glare and other problems. Longwall lighting was unanimously accepted by face personnel, and most complaints were minor. Based on the survey, general installation and maintenance guidelines have been established, addressing hardware design aspects, approaches proved effective to minimize problems, and improper practices noted which are detrimental to effective lighting.

Jan 1, 1981

This work examined the feasibility of in-mine coal preparation in two phases. Phase I included a survey of previous investigations and a preliminary analysis of the economic and technical feasibility on a selection of representative sites and degrees of cleaning. The contract was terminated at the end of Phase I. The preliminary analysis determined that in-mine preparation systems can be applied using currently available technology. The most likely mines for application will have shaft or slope access and be deeper than 500 feet. The refuse disposal systems technically feasible are (1) pneumatic placement of coarse refuse in room and pillar panels or longwall faces, (2) mechanical placement of coarse and fine fractions in room and pillar panels, and (3) hydraulic placement of fine fractions in room and pillar panels. The economic feasibility is much more dependent on the refuse disposal-system than on the preparation system. It is estimated that the capital cost of an in-mine preparation and disposal system would be $6.00 per clean ton and the operating cost would be $1.24 per clean ton for a 1 million clean ton per year mine.

Jan 1, 1982

8186. Aquilina, C. Determinazioni relative di gravita eseguite nel 1939 (Relative Determinations of Gravity Made in 1939), Ric. Ingegn, Rome, vol. 10, 1942, pp, 6376. In 1939, the author made a survey of relative gravity in the Mediterranean-basin, 41° 35,5' to 41° 56.3' northern latitude and 0° 10,3' to 0° 28' longitude, referred to Mt. Mario. Ten stations were covered; 25 other stations had been occupied in the vicinity of Rome and in Albanian mountains during previous years. The new measurements revealed gravity anomalies ranging within the following limits: (1) With a free-air reduction, between + 29 and + 120 mgl., average + 60 mgl.; and (2) with a Bouguer reduction, between + 22 and + 87 mgl., average + 41.5 mgl. - V. S.

Jan 1, 1946

By B. K. Shibler

During a research program to develop improved methods for recovering elemental sulfur and useful sulfur compounds from secondary source materials, the technical literature was searched for pertinent articles on processing methods. This report summarizes results of the literature survey and describes the more important processes that have been used or suggested for recovering sulfur and sulfur compounds from all non-Frasch sources. The bibliography presented represents a survey of the available English language literature on the subject through 1958, with particular attention focused on the period 1950 through 1958. Engineering Index and Industrial Arts Index were the principal guides used in the survey of this period. Chemical Abstracts was used to a limited extent to identify a few key foreign articles and patents. The Sulfur Symposium (4)4 published in November 1950 by Industrial and Engineering Chemistry includes a broadly representative selection of the literature up to 1949. Therefore, this reference was used extensively to locate and list pertinent articles on processing methods reported in the period prior to 1950.

Jan 1, 1962

By Sidney Katell

Covering the period from January 1961 through December 1961, this report is a continuation of the series that began with the publication of Information Circular 7516 in October 1949. It is also the third report in the series to be prepared as a cooperative effort by the Bureau of Mines and the American Association of Cost Engineers. The cooperative agreement between the two groups provides for the publication of an annual cost bibliography with the work load involved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related facilities, came from the following sources: 1. A.A.C.E. Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigation. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal Utilization. 9. Cost Engineering. 10. Industrial and Engineering Chemistry. 11. Nucleonics 12. Oil and Gas Journal. 13. Petroleum Engineer for Management. 14. Petroleum Refiner. 15. World Oil.

Jan 1, 1962

By Paul S. Goodman

Volume II The purpose of this study is to explain reasons for the productivity differences in mining crews. The literature on group productivity is examined. Then a new approach to estimating productivity differences is proposed and estimated across seven different mines. The results indicate a fairly robust model in terms of explanatory power. Recommendations on how the model can be used as a managerial tool are presented.

Jan 1, 1985

By L. R. Stark

Two wetland simulation experiments were carried out in order to determine the effects on manganese retention of several wetland design parameters, including flow rate, inlet pH, carbon supplementation, substrate type, and surface free water depth. The primary aim in each experiment was to determine if sustained manganese retention could be accomplished under the specific experimental treatments. If successful, these experiments could recommend design parameters for the construction of field wetland systems for manganese treatment. Crushed limestone clearly was superior to spent mushroom compost with respect to manganese retention. The presence of free surface water detracted from manganese treatment, while lower flow rates enhanced manganese treatment. Sustained manganese retention was achieved using crushed limestone as the substrate coupled with an absence of surface free water, under inlet water conditions of pH 7.0 and no appreciable iron. Sustained manganese retention was not achieved under reducing conditions using spent mushroom compost while varying flow rate, inlet pH, and carbon supplementation regimes. However, lowering the flow rate resulted in many significant beneficial effects on outlet water chemistry: lower outlet manganese concentrations (over the short term), higher outlet pH, lower outlet acidity, higher outlet alkalinity, higher outlet sulfide, lower outlet sulfate, and lower outlet redox potential. Supplementation of the wetlands with dairy whey resulted in lower outlet manganese concentrations (over the short term), marginally higher outlet sulfide levels, and acted to lower the redox potential under the high flow regime. Wetlands receiving a neutral pH had lower outlet acidity, higher outlet alkalinity, lower outlet sulfate, but equivalent outlet manganese concentrations than wetlands receiving an acidic pH. When manganese is the primary mine water contaminant and a passive water treatment system is to be used, it is recommended that crushed limestone with negligible surface water be used in place of composted materials. This recommendation assumes a source water with circumneutral pH and an absence of other metals.

Jan 1, 1993

By E. R. Maize

This report is the second of a series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company's Crucible mine, operating in the Pittsburgh bed in Greene County, Pa. This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

Rio Tinto has embarked on a journey to use automation to improve the performance of its surface mines. The driver for automation is to improve the accuracy and consistency of mining processes and less to do with cost savings through labour reduction. A key task in most surface mines is blasthole drilling. The degree to how well this is done cascades through the downstream mining process. It impacts scheduling, excavation, slope stability, material handling, beneficiation and final product blending. Improved blasthole drilling was identified as an objective that has a significant business case in most of Rio Tinto's surface mines. This paper describes Rio Tinto's drill enhancement project that has developed a robust system for automating most of the functions on a Terex SKSS16 drill rig. Automated drilling is currently being used in production at the West Angelas iron ore mine in the Pilbara region of Western Australia. A description of the essential elements of the drill automation system is given together with an overview of how automated drilling is performed remotely from the mine office. A review of some of the benefits of the enhanced drill system is given together with the future plans to extend the functionality of the automated drill and the expected benefits.

May 1, 2010

By P. R. Tisot

Structural response and/or deformation was determined for each of four different grade Green River oil shales (27.0-, 34.5-, 45.5-, and 63.5-gal/ton) as they were heated in an inert atmosphere, under constant compressive stress, from ambient to subretorting temperatures; that is, below those required for rapid pyrolysis of the organic matter. Small cores and small columns of confined fragments comprised the test specimens, which were heated, in a specially designed microunit, at a uniform rate either to 725° or to 825° F under three different stress levels, 80, 200, and 325 psi. Structural response of some cores was observed as they were heated in a stress-free environment. The obtained stress-strain-time-temperature relationships provide information regarding the oil shale's yield temperature, yield stress, rate of compressive strain, loss of mechanical strength, and nature of structural deformation. Effects of structural deformation on induced permeability in small columns of fragments are presented. Results indicate that underground retorting of Green River oil shale may be seriously impaired through loss of induced permeability brought about by structural deformation of rich oil shale under the influence of heat and compressive stress.

Jan 1, 1971

By O. C. Blade

Total sales of diesel fuel in the United States continue to Increase. This growth is due primarily to two causes: More conversion to diesel units by the rail-roads In recent years, and the greater use of diesel engines in trucks, busses, and tractors. Following are some figures on the distribution of the fuel computed from data issued by the Bureau of Mines.2/ [ ] Deliveries of diesel type fuel from refineries totaled 91,522,000 barrels during the first six months of 1955,3/ corresponding figure for 1954 was 91,170,000 barrels. Information on the properties of this engine fuel is very important to the petroleum industry, engine manufacturers, and consumers. To supply such information the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, under cooperative agreement, are conducting annual surveys of diesel fuel oil produced in refineries in this country.

Jan 1, 1955

By J. B. Czirr

MESA Corporation has completed a four-year program for the Bureau of Mines to develop a technique for measuring roof competence in underground coal mines. The preferred technique employs a tracer gas that is injected into a roof borehole drilled near the working face. The tracer gas performs the dual purpose of determining the pressure loss rate from the borehole and of marking the diffusion pattern of the the escaping gas. The primary detection technique relies upon observation of the rate of pressure drop in a hole drilled in the roof strata under test. If this measurement indicates a significant probability of roof collapse, the gas diffusion pattern is outlined with the Leak-gun tracer-gas detector. These two techniques provide a comprehensive method for predicting the relative probability of roof collapse in operating coal mines.

Jan 1, 1985

By E. R. Maize

This report is t e second of s series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company?s Crucible mine, operating in the Pittsburgh bed in Greene County, Pa, This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

By T. L. Johnston

The Dobbins property, about 4-1/2 miles northeast of Cartersville, Ga., was fist operated in 1866, it is the oldest manganese mine in Georgia and one of the oldest minus in the United States still producing manganese ore. Changes in ownership, lessees, and operators and lack of records prevent the compiling of statistics regarding total production of ore from the property.

Jan 1, 1942

By M. P. Hardy

Copper-Nickel ores in northeastern Minnesota could establish a new industry in a region where underground mining has not been active. This study reviews geotechnical data relevant to the selection and design of underground mines in this region and by numerical structural analysis evaluates the importance of some geotechnical parameters to mine method selection. Because of the rapid development of computer modeling many new techniques have become available for modeling rock mass behavior in recent years. An overview of these methods is presented and their applicability to mine design reviewed. Methods included in this summary were the differential continuum models, such as finite Pint and finite difference, integral continuum models, such as boundary element, displacement discontinuity and boundary integral equation methods, and discontinuum methods such as the distinct block model. The displacement discontinuity method was used to evaluate the influence of geotechnical parameters on some aspects of mine design. Three problems; room stability, pillar stability on a weak inclined contact and sill pillar thickness influence on sill pillar stability, were analyzed to evaluate the relative importance of insitu stress field and joint properties on design. It was concluded that for stability analysis the initial horizontal stress is of most importance in all aspects of design. The position, orientation, persistence and strength of joints is also of primary concern. In a more general sense, however, it was concluded that detailed geotechnical parameters have much less influence on mine method selection than more general factors such as rock quality, initial stress state, orebody shape and economics.

Jan 1, 1978