Search Documents

"The mission of the Respirable Dust Center is to enhance the health, safety and productivity of the miners 'through advancing the fundamental .understanding of all aspects of respirable dust associated with mining and milling and the interaction of dus.t and lungs for reducing the incidence and severity of respirable dust disease. All Dust Center activities are focussed to be responsive to this mission which is shared by several federal agencies closely associated with the Generic Mineral Technology Center for Respirable Dust such as USBM, M,SHA, and NIOSH, and the mining industry. While significant progress has been achieved in making mine atmospheres cleaner and healthier, respirable dust disease remains the nations worst industrial hazard. GOALSThe goals of the Respirable Dust Center have been formulated to recognize the diverse scientific, engineering and medical aspects of respirable dust as well as the need to enhance the interaction, education and technology transfer in the respirable dust area.The Center goals are to:1. Enhance the understanding of the scientific, engineering and biological characteristics of fine and respirable mineral particles, fibers, organic aerosols, and complex particles found in the mining and milling atmospheres.2. Advance the understanding of the physical behavior of airborne respirable dust particles in flowing streams under different. stimuli during mining and milling.3. Advance fundamental understanding of the causative mechanisms for the occupationally related lung impairments and the airway diseases of mine and mill workers.4. Establish the relationship between natural and cultural factors (mine geology, mineralogy, mining and milling methods, equipment and control measures) in the generation, exposures, and pathogenic properties of fine particles.5. Contribute to the development of control mechanisms for reducing ambient respirable dust concentrations, worker exposure, the incidence and severity of dust related lung disorders and disease prevention in mining and milling atmospheres.6. Enhance functional integration among the various research personnel in the Center, as well as, with other groups, such as MSHA, NIOSH and USBM involved in respirable dust research and control.7. Develop technically trained personnel for employment in the mineral industry for respirable dust research and control.8. Enhance the availability of respirable dust-related information utilizing several technology transfer avenues."

Jan 1, 1990

By George T. Faust

The petrographer engaged in examining the products resulting from the beneficiation of ores and rock minerals is constantly required to develop new means and methods of assaying microscopically the results of such operations. From time to time investigators have published descriptions of apparatus that have aided in solving problems in processes f physical separation. Thus, in 191.9, Coghill and Bonardi 31 published a paper covering the application of the binocular microscope and camera lucida to the microscopic analysis of pulverized ores. Similar work has been published by Schneiderhohn 4/, Schwartz 5/, and Head and his associates6/, 7/, 8/. The present paper goes further and considers application of the polarizing comparison-microscope to problems directly concerned with mineral dressing where it is desirable to compare analogous products, and in addition it suggests new uses in various related fields. This work was conducted under the cooperative agreements of the Southern Experiment Station of the Federal Bureau of Mines and. the University of Alabama.

Jan 1, 1940

By J. P. Capp

The Bureau of Mines conducted field-scale experiments in underground gasification of coal with oxygen-enriched air. A path about 140 feet long was linked at the rate of LO feet per day through a coalbed hydraulically fractured with a mixture of starch gel and sand. During the best gasification period, which extended for 2-1/2 days, 785,000 std. c.f. per day of 124-B.t.u. gas was produced. In other periods the heating value at times was almost 300 B.t.u. per std, c.f,, but sustained production of such gas was not achieved. During gasification, a total of 50 tons of coal was gasified and 114 tons of coal was carbonized. Approximately 12 million B, t .u. per foot of nominal path was recovered at the surface.

Jan 1, 1962

By Terry J. Close

U.S. Bureau of Mines personnel studied the 33,900-acre Silver Peak Range North Wilderness Study Area (NV-060-338), in order to evaluate its identified mineral resources. The area studied lies between the towns of Silver Peak and Dyer, about 40 miles southwest of Tonopah, in Esmeralda County, Nevada. There are no producing mines in the area studied. However, development of Sunshine Mining Company?s Sixteen-to-One silver-gold mine, located in the Silver Peak mining district near the eastern edge of the study area in the early 19801s, has stimulated recent interest. The Sunshine Mining Company claimed two sites within the study area in 1985. Also, Intermountain Resources, Incorporated, located a group of claims at a prospect along the west side of the study area in the Dyer mining district, and in 1986, began drilling. Other claimants are holding two other claim groups by assessment. At the five currently (1987) held sites, precious metals occurrences are being investigated. There are no patented mining claims or mineral leases in the study area.

Jan 1, 1987

By J. L. Holman

The Bureau of Mines, at its Rolla Metallurgy Research Center, has devised methods for separating and reusing the major portion of waste plastics discarded in urban and industrial refuse. Waste plastic concentrates from a local collection drive, recycling center collections, urban refuse pilot plants, and the secondary metals industry were separated into three major thermoplastic families--polyolefins, styrenes, and vinyls--based on differences in density using a Bureau-designed sink-float-elutriation hydraulic separator. Other separation methods and systems such as air classification, jigging, liquid media, screening, and electrostatics were studied. Vinyl plastics contain up to 50 percent HC1. It was found that over 90 percent of the HC1 in vinyls can be recovered as usable hydrochloric acid by pyrolysis at 350° C. The remaining pyrolysis products which had heats of combustion in excess of 12,000 Btu/lb, could become valuable as a future source of energy. A characterization study conducted on eight chopped wire insulation wastes from secondary copper and aluminum processors showed that most wastes contained 2 to 7 percent residual metal and large percentages of vinyl. The residual metal content of some of these wastes was lowered to 0.1 percent and the vinyl portion segregated using various separation techniques. The research also suggests ways in which reclaimed thermoplastics may be fabricated into useful products.

Jan 1, 1974

This study was conducted to determine the feasibility of using large tractor dozers in land reclamation of strip-mined areas. The procedures used are patterned after engineering models developed for evaluation of military ground vehicles in cross-country operations. Tractor dozer manufacturers furnished information on capabilities of existing equipment and ideas on the practicability of using dozers larger than those currently available Generally, they believe that current dozers in the 500? to 700-horsepower range are about as large as can be built and remain economically feasible. However, one manufacturer has a wheeled dozer rated at 1200 horsepower, and another is testing a tracked dozer of about the same horse-power.

Jan 1, 1975

By Peter Grandone

"INTRODUCTION The Bureau of Mines, recognizing the importance of knowing the evapor¬ation losses of aviation gasoline as larger quantities of this material must be stored, has made studies at a large refinery in the Texas Panhandle area during the past 13 months to determine the magnitude of the losses, by evaporation, under different storage conditions. Proper storage of aviation gasoline is very important, not only because large supplies are being stored for military use but because the specifications to which his fuel must conform are very rigid. Aviation gasolines that conform present-day specifications are blended from base-gasoline stocks (in some instances relatively pure hydrocarbons), each of which has different physical and chemical characteristics. Consequently, partial loss of any one of the more volatile components from the blended fuel results not only in material loss of the blended fuel but also may affect the characteristics or performance of the gasoline. One characteristic that has considerable influence or the vaporization tendency of gasoline is vapor pressure; and although the vapor pressure of aviation gasoline usually is lower than that of average commercial motor fuel, the quantity of certain components having relatively higher vapor pressure is greater in aviation gasoline, so that under prolonged storage the evaporation loss of these components may be appreciable."

May 1, 1943

By F. A. Penning

This report describes the development of skip and guide desings for vertical shafts in deep vein mines. Skip and guide systems for bottom dump skips are identified as being used in current practice. Mine visits were made to obtain current information on the needs and problems of operating mines. Methods of structural and mechanical analysis of skip bodies and bails are outlined. A dynamic computer model was written to find the dynamic interaction between skips and guides for guides with geometric misalinements. A materials evaluation section identifies currentavailable and applicable materials that can be used effectively for new skip construction. Guide materials are also presented. Analysis includes the economies resulting from streamlined buntons and from low skip payload ratios. Selection of materials is based on strength, abra¬sion and corrosion resistance. Design requirements related to the shaft environment are presented. Consideration for the selection of guides and buntons is also given. Conceptual design includes the concept of cylindrical skips, center-seeking guide rollers, and asymmetric bail design to decrease dynamic interaction. An outline for field tests is presented. Future research areas are: testing, guide geometry measure¬ment, advanced suspension, dynamics, and structural configurations.

Jan 1, 1977

By Harry R. Nicholls

The objectives of this investigation were to determine the strain propagation laws for a strain pulse in salt and to compare the seismic effects from the detonation of different explosives in salt. The investigation showed that a strain propagation law of the type, e = K(R/W 1/3 ) n, and a strain energy propagation law of the type, Ea/W 1/3 = K(R/WI/3)b , are valid in salt. A change in the regression law coefficient, n , was noted with strain level. A similar change in b was inferred because strain energy is proportional to the square of strain amplitude. Particle velocity data may be used interchangeably with strain data under the test conditions.

Jan 1, 1962

By R. H. Hiltz

The Coal Mine Health and Safety Act of 1969 legislated maximum dust levels for the working place. As the law was implemented, extensive efforts were undertaken to provide the technology necessary to control dust generation. One approach to dust control was the use of high expansion foam in place of the usual water sprays on coal cutting equipment. At the time of the act, high expansion foam had already seen considerable testing for the suppression of dust in underground coal mines. Work by MSA, several coal companies and the Bureau of Mines itself had provided data which showed foam to have some merit as a dust control mechanism. It suffered in a few areas, however, which limited its practical application. Its principal difficulty was persistence which hampered operations due to foam buildup, but problems were also encountered due to equipment size and form.

Jan 1, 1975

By A. E. Ketler

A second generation lighting system was installed in the Greenwich Collieries longwall. This report describes the hardware, installation, maintenance, and final results of the program.

Jan 1, 1978

By G. F. Kuncir

The time-cost-risk analysis described herein was performed as part of an evaluation of the Advancing Oil Shale Mining Technology Program performed by The Aerospace Corporation. The objectives of this analysis are to assess the feasibility of the program relative' to time and cost constraints, and to determine the probabilities of achieving various technological goals. A combination of standard program planning and analysis techniques were used to achieve these objectives. These included a critical path analysis, a resource allocation analysis, and a risk analysis.

Jan 1, 1977

By Bing W. Jong

A bench-scale evaluation of coal and coal waste materials as aggregate materials for use in longwall mine supports was undertaken as part of the Bureau of Mines Health and Safety program on ground control. Performance data were obtained on portland cement concretes (PCC) prepared with coal and coal wastes as aggregate materials. The effects of high-early-strength accelerators on strength and creep and of superplasticizers on strength properties of PCC formulated with coal and coal waste were investigated. Concrete formulated with a high-early-strength accelerator and coal and coal waste has 20 and 40 pet greater compressive strength, respectively, than the control samples without admixture. A concrete formulated with coal waste and the high-early-strength accelerator, using four bags of cement per cubic yard and a water-cement ratio of 1.0, had the lowest creep value of all the coal- and coal-waste-formulated PCC's tested.

Jan 1, 1983

By Earl Redman

The Juneau Gold Belt portion of the Juneau Mining District has historically had the greatest mining and exploration activity within the district. Between 1880 and 1983, the mines within the Juneau Gold Belt produced 6.7 MM oz gold, 3.1 MM oz silver, and 45 MM lbs lead, which had a total value of about $157,000,000 at the time of production. This report summarizes Bureau of Mines work completed in 1986, the second year of the Juneau Mining District study. Fifty mines, prospects, and occurrences were examined and 638 samples were collected for analysis during 1986. Metallurgical samples were collected from seven deposits and preliminary tests of cyanide amenability have been completed for five of these. The simultaneous discovery by private industry and the Bureau of gold-bearing quartz veins cutting diorite gneiss recently exposed by the retreat of the Herbert Glacier is the most notable result of work during 1986. This location yielded gold values up to 7 oz/st.

Jan 1, 2011

By Michael S. Miller

During U.S. Bureau of mines mineral investigations, in 1981 and 1983, no mines, prospects, or mineral resources were identified in the Little Sand Spring Wilderness Study Area (WSA). Placer gold values in near-surface samples from alluvial fans within or near the WSA contained no more than 66 cents gold per cu yd, at $400 per troy ounce gold price. Sand and gravel and carbonate rocks occur in large quantities, but transportation costs to distant markets preclude their classification as resources. Nitrogen, lithium, clay, pumice, perlite, aragonite, and agate occurrences in the WSA are small or low-grade. The Silvia Mine, adjacent to the WSA contains gold-, silver-, copper-, and lead-bearing shear zones which strike toward the WSA. INTRODUCTION The Little Sand Spring WSA, encompassing 33,500 acres, is approximately 56 mi east of Big Pine, California, by paved and graded dirt roads (fl;. 1). Elevations range from 2,600 ft in Death Valley Wash to 5,600 ft along the California-Nevada boundary. The nearest permanent facilities are at Grapevine Ranger station and Scotty's Castle (Death Valley Ranch), about 9 and 11 mi, respectively, south in Death Valley National Monument.

Jan 1, 1983

By Wilbur L. Webb

An electrically powered methane sampling system for application on mining machines was designed, fabricated and laboratory tested. The system will sequentially draw sample air at a controlled rate from up to three machine positions across the mine face and deliver the air to either an approved methane monitor, methanometer or flame safety lamp. The prime considerations in the design were to provide an intrinsically safe, water and dust resistant control box and an explosion-proof power box capable of being operated from the various mining power sources. The power box contains an internal battery that provides operating power prior to mining machine start-up and alter machine shut-down. The internal battery is recharged automatically when mining machine power is available.

Jan 1, 1977

By K. T. Menzies

Over 1500 literature citations related to diesel exhaust sampling and analysis were obtained as a result of both computer and manual searches of nine data bases. Abstracts and hard copies of relevant citations were reviewed and those considered appropriate for evaluation were included in a bibliography. Based on the literature collected, available sampling and analysis methods for the following diesel exhaust contaminants were evaluated: CO, CO2, NO, NO2, Hydrocarbons, Particulates, PNA, S04, Oxygenates Emphasis was given to both laboratory and field methods for these species. Methods were evaluated on the basis of sensitivity, selectivity, accuracy and reliability and a selected list of preferred methods was developed for each compound/ class. The selected methods were additionally evaluated through communication with current investigators. Sampling and analysis methods for all compounds except CO and CO2 were observed to have some unreliability. Recommendations were made for future research to develop, improve, and validate methods.

Jan 1, 1979

By William N. Patterson

This report describes the design and testing of an improved quiet hard rock percussion drill. The improved drill incorporates a tappetless design with independent rotation in a hand held drill weighing 50 lbm. Laboratory and field testing in three mines were conducted. The testing showed improved drilling performance with no increase in measured noise levels over the fist design.

Jan 1, 1985

By Dayton C. Bolin

This paper is one of a series being prepared by the United States Bureau of Mines describing quarrying methods and costs at stone quarries throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total production costs. It is recognized that publication of total production costs might in many 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 the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scrope of the cost tabulations shall ensue. ACKNOWLEDGMENT The author wishes to acknowledge the assistance of J. R. Thoenen, mining engineer, United States Bureau of Mines, in the preparation of this paper. Acknowledgment is also made to E. R. Lederer, vice president in charge of the company's operations, through whose kindness the preparation of this paper was made possible. E. T. Eubank, superintendent of the quarry, and J. A. Hodges, quarry foremen, gave much of their time to this work. The cost data were compiled by the company's chief clerk, J. von Carlowitz.

Jan 1, 1931

By Terry R. Neumann

In 1989, the Bureau of Mines conducted a mineral resource investigation of the 52,350-acre Jersey Jack study area, located in the Clearwater Mountains of north-central Idaho. Twenty-eight mines and prospects were examined, and 483 rock, placer, and petrographic samples were collected during the field study. Two properties contain gold resources; mining company data show the Robinson Dike mine contains an estimated 940,000 tons of "drill proven and probable reserves" averaging 0.041 oz/ton gold, and the Bureau of Mines investigation showed the Blacksand placer mine contains an estimated 64,000 cubic yards of identified placer resources averaging $8.13 in gold per cubic yard. Sample analyses from other properties indicate that gold resources are likely to exist; however the low tonnage, narrow, fissure-vein type deposits would require mining by relatively high-cost underground methods and would be subeconomic at a gold price of $400/oz.

Jan 1, 1991