Search Documents

By M. D. Marshall

This handbook is for the engineer or person responsible for the storage and removal of material from bins and silos in the minerals industry. The objective of the handbook is to prevent bin-related accidents by eliminating problems which require workers to enter bins. It provides basic information on handling materials so that knowledgeable decisions can be made on bin design and accessories to minimize flow stoppages. Materials are classified in terms of their flowability, and bin design and accessories suggested for each classification. A method for classifying a material is also given, and the various types of material flow aids reviewed. Safety around bins is the basic theme of the handbook. Federal regulations are reviewed and additional suggestions presented to prevent bin accidents. New equipment for releasing material hang-ups is reviewed.

Jan 1, 1984

By Frank E. Cash, John A. Johnson

"INTRODUCTION During the 6-year period, 1940-45, 481,485,000 gross tons of iron ore was shipped from the Minnesota, Michigan, and Wisconsin mines of the Lake Superior district. Approximately 367,000,000 tons, or 76 percent, of this ore was shipped from open-cut mines. The production of this large tonnage of iron ore from the open-cut mines of the Lake Superior district during the recent war was an outstanding achievement. It is questionable whether this record-breaking tonnage of iron ore, vitally needed for the successful prosecution of the war, could have been produced without the modern equipment and mining methods used in the district, The transportation of iron ore from the open-cut mines of the district is the most important phase of the mining cycle. Although some of the mines still use rail haulage advantageously, this method of haulage has been replaced at most nines with motor-truck haulage or a combination of motor-truck and belt-conveyor haulage.SCOPEThe transportation of iron ore in this report covers (1) power shovels, (2) rail haulage, (3) trucks, (4) belt conveyors, (5) shipping pockets, (6) accident statistics, and (7) safety rules pertaining to open-cut transporta¬tion. The purpose of the report is to discuss briefly and disseminate to the mining industry the modern methods, equipment, and safety practices used in transporting iron ore at the open-cut mines of the district.The 25 open-cut mines covered herein, located in the Marquette, Cuyuna, and Mesabi iron ranges of Michigan and Minnesota, shipped approximately 44,000,000 tons of iron in 1945, which amounted to 72 percent of the open-cut iron ore shipped from the Lake Superior district."

May 1, 1948

By Michael J. Friedel

As part of an investigation aimed at mitigating the hazards caused by abandoned mine openings, the Bureau of Mines conducted a series of electromagnetic surveys in the Galena, KS, area of the Tri-State mining district. The application of monostatic ground-penetrating radar (OPR) and inductive electromagnetic methods for detecting and delineating hazardous mine openings and attendant features was demonstrated to be feasible for shallow mine workings (i.e., less than 35 ft) occurring below flat-lying areas. Accurate determinations of depth to a mine roof appeared to be limited to roughly 20 ft using the GPR method. Features such as mine voids, fractures, and zones of subsidence were located beneath the Mainstreet (State Highway 26) site using the GPR system. Both the GPR and inductive electromagnetic techniques satisfactorily located mine openings and pillars at the Hell's Half Acre site. Geophysical interpretations were supported by exploratory drilling and mine maps.

Jan 1, 1990

By Tye J. Lasich

This project involved modeling rock masses with varying Rock Mass Rating (RMR) values to determine the degree of instability that develops around an underground opening as a function of RMR. The modeling was performed using Itasca?s UDEC distinct element software, which allows explicit modeling of blocks of rock and how they interact with each other. The analyses included three different orientations of the joint sets, four different joint spacings and three different values of joint strength, which combine for a total of 36 different combinations of model parameters. Two different modes of behavior were observed: local failure of area immediately surrounding the roof and sides of the opening, and deep-seated failure extending a large distance beyond the opening. Quantification of the size of the unstable area that developed provides numerical validation of empirical guidelines used in design of ground support and instrumented monitoring systems.

Jan 1, 2005

By Virgil J. Stachura

The Bureau of Mines conducted a series of delayed blasting experiments at a West Virginia contour coal mine that resulted in smoother highwalls. The 17; were smoother due to reduced overbreak and inherently safer A, to reduced likelihood of rockfall. Reduced overbreak was accomplished by an increase in the highwall hole delays, which changed the effective delay pattern geometry and the direction of burden movement. The blast delays in the highwall holes were 50 to 100 ms longer than the mine's nominal design pattern (flat V, 17- by 42-ms surface delays, 200-ms in-the-hole delay). The burden movement was effectively changed from a 45* angle to 90* with respect to the highwall. The results of the blast delay changes were evaluated using terrestrial photogrammetry to generate vertical profiles at regular intervals. This evaluation showed that delay changes produced generally smoother vertical profiles.

Jan 1, 1984

By Robert H. Peters

Are the safety rules in your work place effective? Do supervisors enforce them as they should? Do supervisors abide by these rules? Safety rules are an important aspect of many company safety programs, particularly if employees must work in an intrinsically hazardous environment such as a coal mine. However, for various reasons, supervisors sometimes fail to enforce safety rules (Arvey & Jones, 1985; Hartshorn, 1998). This paper presents some findings obtained from interviews with coal miners about why supervisors sometimes fail to enforce an important mine safety rule. It also contains a few suggestions addressing what could be done to help supervisors perform this job function more effectively.

By J. A. Organiscak

Enclosed cabs are a primary means of reducing the silica dust exposure of equipment operators at surface mines. The National Institute for Occupational Safety and Health (NIOSH) has investigated various factor effects on enclosed cab air filtration system performance. Factors experimen­tally investigated were intake filter efficiency, intake air leakage, intake filter loading (filter flow resistance), recirculation filter use and wind velocity effects on cab penetra­tion (inside to outside cab concentration ratio). Adding an intake pressurizer fan to the filtration system was also investigated. Results indicate that the intake filter efficiency and recirculation filter were the two most influential factors on cab penetration .Use of a recirculation filter significantly reduced cab penetration over the intake air filter by itself due to the multiplicable filtration of the cab interior air. Cab penetration was also affected to a lesser extent by intake filter loading and air leakage. Adding an intake pressurizer fan notably increased intake airflow and cab pressure while providing only minor changes to cab penetration.

Jan 1, 2008

By Herman W. Sheffer

This report describes and discusses present-day leaching technology employed to recover copper from low-grade mine and dump materials derived from the exploitation of copper ore deposits in the Western United States. Illustrations of the integral parts of the leaching, precipitation, and recovery operations at several copper-producing companies are presented. Schematic drawings are included to present typical flowsheets of leaching and precipitation operations. Operational problems common to most copper leaching and precipitation plants are discussed. Areas of present and future research to improve leaching techniques are cited.

Jan 1, 1968

By F. E. Cash

Much has been written concerning accidents in coal mines; the fact that accidents cost the employer and employee money is generally well known, but how much accidents actually cost is vague, even in the minds of many operators. Unquestionably there are hazards in coal mining, but many of them can be eliminated; and from the prevention of accidents there can be realized a material saving in dollars and cents as well as in human suffering. In presenting the frequency, severity, and cost of accidents in some Tennessee coal mines, it is hoped that other mines in Tennessee, as well as mines in other States, will by a comparison of the data with their own ex¬ perience be enabled eventually to reduce the number of' their accidents.

Dec 1, 1932

By Richard Stayner

Suspended seats perform two functions: Reduce effect of occasional large bumps; Reduce more continuous vibration at a lower level. The former needs high damping. The latter needs low damping. For most mobile work machines the inevitable compromise is generally better than a simple cushion seat, because that amplifies vibration at around 4 Hz which is a sensitive frequency for human vertical WBV. Why have standard tests for seat suspensions? • Seat suspensions are non-linear so any measure of performance depends on operating conditions. For comparison these need to be defined. • Seat manufacturers need benchmarks for product development; • Machine makers choose dynamic characteristics appropriate to their products; • Occupational health specialists wish to control operator exposure to Standard tests should be representative, repeatable and reproducible. These requirements are reviewed in relation to the history of seat test standards and the current position. Current position and history The current position is that we have standard tests for seats for agricultural tractors, earthmoving machinery, industrial (fork-lift) trucks. These tests comprise measurement of vibration transmission and of the rate of damping. Current standards developed as the technology developed, starting around 1960: 1. Test on machine driven over standard surface1. 2. Test on shaker reproducing standard surface. 3. Shaker input replaced by representative spectrum2. 4. Human subject replaced by dynamic dummy. (Not yet settled). Are standard tests representative? The development process has gradually moved seat tests further from reality. 4 hr samples of work exposure suggest that seats do not on average provide large reductions of vertical WBV3. For specific magnitudes of vibration they can work well. For low vibration, performance is reduced by friction and for severe vibration by length of travel. Recent work has led to a new test to quantify how a suspension controls over-travel 9.

Jan 6, 2006

This report, the second in an annual series, summarizes information on latest technological developments and advances, and identifies trends in mining and metallurgy based on a review of activities in the minerals industry in 1971. Exploration and mining data obtained from an annual canvass are presented for 1971 and are compared with similar data obtained over the past decade.

Jan 1, 1973

By E. D. Gardner

This paper is a progress report on the study of mining methods and costs in the western United States and summarizes that part of the work pertaining to the undercut block-caving method of mining. Ore is mined on a large scale exclusively by the undercut block-caving method at the following six mines in the western United States: The Morenci branch of the Phelps Dodge Corporation, Morenci, Ariz.; the Ray mines of the Nevada Consolidated Copper Co. at Ray, Ariz.; the Inspiration Consolidated Copper Co. at Inspiration, Ariz.; the Miamo Copper Co. at Miami, Ariz.; the Ruth mine of the Nevada Consolidated Copper Co. at Ruth, Nev.; and the Consolidated Coppermines Corporation at Kimberly, Nev. The undercut block-caving method is also used at the mine of the Andes Copper Mining Co. at Potrerillos, Chile.

Jan 1, 1930

By G. L. Oldwright, Virgil Miller

"The data presented in this paper were collected at the smelter of the Consolidated Mining & Smelting Co. of Canada Limited, Trail (Tadanac), Brithish Columbia. The authors are greatly indicated to S.G. Blayrock, vice president and general manager; James Buchman, smelter superintendent; and the staff members mentioned in Report of Investigation 3243. The authors are exceedingly grateful to George Murray, assistant smelter superintendent, for his keen interest, suggestions, and help in carrying out this investigation.INTRODUCTIONThe methods of charign the blast furnaces at Toole and Kelloggs were noted in Report of Investigations 2957 and 3094 respectively. Report of Investigations 2957 cited (4 to 9 inclusive) Hofman's Metallurgy of Lead (p. 226) and the work of A.S. Dwight, Thompson and Sicka, the staff of the Engineering and Mining Journal, and L.D. Anderson, N.F. Collins, in The Metallurgy of Lead (Chas. Griffin, London, 1910) also gives (pp. 247 254) the principles that he believes govern the successful charging of the blast furnace."

Dec 1, 1934

By L. F. Willmott

The Bureau of Nines at Morgantown, W. Va., has been investigating, on a pilot plant scale, various methods of gasifying bituminous coal with oxygen and superheated steam to produce synthesis gas, as part of the broader program of finding new uses for coal. Differences in the pressure gasification methods used have depended on differences in the manner in which the pulverized coal is fed to the gasifier. One of the methods of feeding the coal that was investigated was the continuous, integrated coal-water slurry system. Goal and water were first mixed to produce a slurry; then the slurry was pumped through a heated coil. to evaporate the water fraction; the resulting steam was superheated, and some of it was separated so as to adjust the ratio of the residual steam to the coal fraction and make the resulting mixture suitable for partial combustion with oxygen in a pressure gasifier. Both before and during this reported3 developmental work it was necessary to make an extensive literature search into the technology of aqueous slurries in order to establish design criteria for the pilot plant and to correlate results of various phases of the work with that of other investigators, The pilot work coincided with the commercial development of a long-distance pipe- line for the transportation of coal as a coal-water slurry, and this fact tended to broaden the scope of the pilot plant work and the extent of the literature search. This bibliography is the compilation of the material that was collected.

Jan 1, 1963

By J. L. Ambs

The U.S. Bureau of Mines (USBM) Diesel Research Program emphasizes the development and evaluation of emission control devices to reduce exposure of miners to diesel exhaust pollutants. Studies by the USBM have shown that diesel exhaust aerosol (DEA) contributes a substantial portion of the respirable aerosol in underground coal mines using diesel equipment not equipped with emission controls. The USBM and the Donaldson Co., Inc., Minneapolis, MN, have developed a low-temperature, disposable diesel exhaust filter (DDEF) for use on permissible diesel haulage vehicles equipped with waterbath exhaust conditioners. These were evaluated in three underground, mines, to determine their effectiveness in reducing DEA concentrations. The DDEF reduced DEA concentrations from 70 to 90 pct at these mines. The usable life of the filter ranged from 10 to 32 h, depending on factors that affect DEA output, such 'as mine altitude, engine type, and duty-cycle. Cost per filter is approximately $40.

Jan 1, 2010

Hydraulic fluid power systems are advantageous whenever power output must be accurately and safely controlled. The load movers, cylinders, jacks, rotary actuators and hydraulic actuators in these systems can be made to smoothly and accurately start, stop, reverse, hold position or move steadily under heavy and variable loads or torques. Because hydraulic systems are simple, compact, reliable, and low cost compared to other power methods and because they can deliver controlled power anywhere on the machine to which a hose can be routed, they are a pan of almost every type of machine found on a coal mining section. Some of the functions they perform are positioning drill booms, driving drill pots on roof bolters, positioning curter booms, raising, lowering, and swinging conveyors, driving conveyors on continuous miners, raising, lowering, and applying sustained loads to longwall roof supports, and advancing the face conveyor and roof supports in longwall mining operations.

Jan 1, 1982

By E. E. Harton

Bureau of Mines Information Circular 16, Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants, was published in October 1949 as an aid in making estimates of investment and operating costs of processes for manufacturing synthetic liquid fuels. Development of such processes by the Bureau of Mines was authorized by Public Law 290, 78th Congress. This bibliography included refer¬ences to and abstracts of publications appearing from 1930 to September 1948 on all processes in general use in the petroleum refining and chemical industries. Publications in this field have been numerous since compilation of the above bibliography, and the present report was prepared to cover the field from September 1948 through June 1952.3/

Jan 1, 1955

By A. J. Kraemer

For a number of years the Bureau of Mines has been conducting an investi-gation of crude petroleum from producing fields in the United States and the Western Hemisphere and has published a series of reports on these fields. Analyses of crude-oil samples from some oil fields of Louisiana are given in Bulletin 291. Analyses Of 26 representative crude oils from various producing formations of southern Louisiana are given in this report. These samples are from 14 fields in 10 parishes in the southern part of the State, usually designated as the "Louisiana Gulf Coast area."

Jan 1, 1934

By Allen S. Smith

Analysis of the helium content of a natural gas presents more than the usual difficulties encountered in applying the thermal--conductivity method because of the relatively small amounts of this inert gas present and the wide variation in the other constituents. However, the numerous advantages of this method and its adaptability to continuously recording and control instruments make it worthy of consideration. A specific application of the method described yields quantitative results only when used with gas mixtures of known qualitative compositions which vary within predetermined limits. Periodic analyses for the helium content of a producing gas well may be conveniently made by an absorption method3/ and a continuous analytical method is not necessary for this purpose. Natural gas containing 1.75 to 1.90 percent of helium produced from Government-owned wells is processed in the Amarillo (Texas) Helium Plant of the Bureau of Mines. The helium extracted in the plant is supplied to the Army and Navy, and the processed natural gas is sold to a commercial gas company4/. As complete recovery of the helium in the raw material is not economically practicable, the processed gas contains 0.1 to 0.3 percent of helium, depending upon conditions of operation;- Production is checked against the helium removed from the gas, which before the installation of the thermal--conductivity apparatus was calculated from the analysis of a cumulative sample of the processed gas. As conditions of operation affect the residual helium content to a large extent, a composite sample was an uncertain index of the efficiency of the process.

Jan 1, 1934

ESTABLISHMENT of an effective inspection system has been held essen¬tial to any international agreement that may be designed primarily to curb the testing of nuclear weapons. A number of reports and papers already have described basic inspection concepts and appraised various pro¬cedures, techniques, and methods as to their probable effectiveness in detecting and identifying violations under such agreement. This report results from a study of only one part of the contemplated inspection system, specifically the final phases embracing onsite investigations and mine examination techniques. The results and reports of earlier work were reviewed in detail, and subjects that were found to have been exhaus¬tively evaluated are recognized by reference and not redescribed here. In other instances, previously described techniques, methods, and clues were revaluated to define more clearly their practical value to the final objective of an onsite inspection. Previous documentation does not refer to a number of subjects, techniques, tools, clues, and methods considered by the study; this report treats these in detail, even though when applied singly or collectively their practical value may be questionable.

Jan 1, 1962