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By W. W. Adams

The metal and nonmetallic mineral mines (excluding coal mines) of the United States had a more favorable safety record in 1935 than in any year except 1931 and 1932 since annual statistics of accidents first became available in 1911. The accident rate was even lower than that for 1911, when the recorded rate probably did not reflect all of the accidents that actually occurred because many companies had not yet begun to keep complete records of accidents, especially those causing only minor injuries, and when, therefore, the number of accidents revealed by the companies' reports to the Bureau of Mines was probably not as complete as that reported for later years. Compared. with 1911, the accident rate covering fatal and nonfatal injuries in. 1935 decreased 13 percent. Compared with 1925, when the rate was the highest ever reported, the rate for 1935 decreased 47 percent and compared with 1934, 7 percent. The progress in safety which the mines of the country made in 1935 was not confined to any section or mining region; it was shared by a majority of the mining States and applied to underground mining operations, to open-pit mining, and to work at surface shops and yards. The rate for underground mining declined 8 percent from 1934; the rate for open-pit mining declined 14 percent, and that for surface shops and yards 12 percent.

Jan 1, 1938

By F. S. Crawford

During the course of a study of the safety organizations of the various iron mining companies in the Lake Superior district considerable in¬ formation regarding the methods of safety inspection in use was obtained which may be of value to other companies beginning safety work or contemplat¬ ing changes in their methods. A short description of the safety-inspection methods of eleven of these companies is given in this paper, and in the appendix are illustrated a number of forms used for safety inspections by several of the companies. Most of the companies whose methods are described use few forms for formal inspection. The one long form (10) attached which is used for a general in¬ spection by the safety inspector appears to present a good method for enabling the inspector to check all branches of his inspection and to assure himself that everything has been covered. All names of companies have been deleted from this paper and from the forms because the object is to disseminate information of constructive value rather than to point out the methods of particular companies by name.

Aug 1, 1931

By Fredrick L. Johnson

In 1987, the U.S. Bureau of Mines began a study of the 4.0 million acre Toiyabe National Forest located in eastern California and western Nevada. This report is a compilation of published, company, and field data for part of the Paradise Range, Nevada. The information is intended to aid the U.S. Forest Service in their long range management of minerals and augment the USBM data base. The Paradise Range study area, located 60 air mi northwest of Tonopah, NV, encompasses about 100,000 acres of which approximately 71,000 are administered by the USFS. The area is in the Basin and Range Province and consists of an east tilted block of sedimentary, metamorphic, and volcanic rocks which have been intruded by granitic rocks. Three major mining districts, the Ellsworth, Gabbs, and Fairplay are in, or extend into the study area. The earliest recorded mining activity occurred in the Ellsworth district in the early 1860's. Commodities produced from the study area include gold, silver, copper, lead, zinc, mercury, tungsten, iron ore, magnesite, and brucite. The Phelps Stokes Iron mine has produced about 1.1 million tons of iron ore, the Baxter-Hancock mine has produced over 10,000 stu WO3, and the Gabbs Brucite-Magnesite mine has produced millions of tons of brucite and magnesite. Numerous other mines have produced, but quantities are relatively small. According to company information the Gabbs mine, currently producing, has brucite-magnesite reserves that will last at least 50 years at current mining rates. One hundred thirty one million tons of identified copper-molybdenum resources exist at the B.C. Springs prospect according to company information, but molybdic oxide (Mo03) prices would need to double or triple from the current $3.00-3.10 per lb before mining of the deposit would be economical. Most company exploration activity in the study area is now focussed on precious metals. Active, or recently active mining claims appear to cover more than one-half of the 100,000 acres studied.

Jan 1, 1991

By S. P. Sandoval

Previous research by the U.S. Bureau of Mines demonstrated that nonionic surfactants increased the leaching rate of copper in the flask leaching of chalcopyrite with ferric sulfate if sufficient ferric sulfate was present. This research was continued by the Bureau in Part 2 to further explore the application of nonionic surfactants to the dump leaching of chalcopyrite. A polyoxyethylene lauryl ether was selected as the superior nonionic surfactant tested at 25° and 50° C. The addition of the surfactant increased copper leaching by 116 pct at 25° C and 1.0 pct solids and by 61 pct at 50° C and 0.5 pct solids at Fe 3+ concentrations greater than 1 g/L. At 0.1.0 g/L Fe 3+ and below, the addition of the surfactant produced as much as a 35 pct decrease in leaching. Each of the nonionic surfactants studied was found to be heavily adsorbed by a typical chalcopyrite ore, which poses a serious barrier to the application of nonionic surfactants in an actual chalcopyrite dump.

Jan 1, 2010

By L. Yuan, A. C. Smith

To provide insights for the optimization of ventilation systems for U.S. underground coal mines facing both methane control and spontaneous combustion issues, a computational fluid dynamics (CFD) study was conducted to model the potential for spontaneous heating in longwall gob areas. A two longwall panel district using a bleeder ventilation system with a stationary longwall face was simulated. The permeability and porosity profiles for the longwall gob were generated from a geotechnical model and were used as inputs for the CFD modeling. In this study, the effect of methane emissions from the mined coal seam, including the longwall face and overlying rider seam reservoirs on the gob gas distribution was considered. The spontaneous heating is modeled as the low-temperature oxidation of coal in the gob using kinetic data obtained from previous laboratory-scale spontaneous-combustion studies. Unsteady state simulations were conducted, and the effects of the coal’s apparent activation energy and reaction surface area on the spontaneous heating process were also examined.1

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date and is being published as a similar series of seven miners' circulars (Nos. 51-57, revised) on accident prevention in metal and nonmetallic mines. These circulars are: Accident Statistics (Miners' Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the use of investigations and reports of all accidents.

Jan 1, 1957

By Ronald B. Stotelmeyer

This report summarizes studies of 55 Idaho national forest roadless areas completed by the U.S. Bureau of Mines (USBM) in the period 1966-1992. These roadless areas have been recommended for addition to the National Wilderness Preservation System, proposed as special management areas, or otherwise recommended for study by the U.S. Forest Service or the Idaho congressional delegation. The Bureau of Mines' studies indicate which parts of the roadless areas contain mineral resources. They also show where mining and prospecting are likely to occur in the future, where mineral production has occurred in the past, and where abandoned mine workings (possible hazards) would be encountered. The number of mine and prospect workings found are a measure not only of surface disturbance, but of areas not wilderness in character.

Jan 1, 1994

By Christopher C. Jobes, Alan G. Mayton, Timothy J. Matty, Joseph P. DuCarme

Mining injury statistics show that a significant number of back, neck, and head injuries are linked to exposure from vehicle vibration. Use of a suspension seat is a common way to isolate the vehicle operator from the adverse effects of vibration exposure. Thus, researchers at the National Institute for Occupational Safety and Health1 – Pittsburgh Research Laboratory (NIOSH – PRL) performed laboratory studies on four passive and two semi-active seat suspension designs. These are typical of seat suspensions commonly found on large off-road heavy surface mining, construction and agricultural vehicles as either replacement or original equipment manufacturer (OEM) systems. One included a pneumatic (air bladder) spring mechanism. The fifth and sixth suspensions were a NIOSH magnetorheological (MR) semi-active damper design based on the pneumatic (air bladder) and one of the coil spring suspensions above. These suspensions were modified with a commercially available MR damper substituted for the OEM damper. These six seat suspension systems were tested and analyzed, for vertical vibration only, using the ISO 5007 Standard [1]. This paper describes the laboratory vibration tests using a MTS® shaker table and discusses the results obtained for the different suspension designs and highlights the rheonetic technology studied. Implications of the seat suspension designs relative to their capabilities for isolating vehicle operators from vibration exposure are discussed. Results for suspensions 1 through 3 showed frequencies of isolation from 2.1 to 3.0 Hz using the 40-kg (88-lb) mass and from 1.65 Hz to 1.8 Hz using the 80-kg (176-lb) mass. Suspension #4, in tests with only the 80-kg (176-lb) mass, showed an isolation frequency of 3.7 Hz. With the MR damper added to seat suspension #4, the peak transmissibility was lowered from 1.3 to 0.95 and showed a corresponding downward shift in frequency from 2.25 Hz to 1.4 Hz. In fact, the results for suspension #5 (the MR damper added to seat suspension #4), using test #3 conditions of the programmed control algorithm, showed isolation (attenuation of transmitted vibration) throughout the test frequency range from 1.0 to 6.0 Hz.

By E. P. Youngman

In the absence of any subsequent enactment of mining legislation, the Turkish mining law in effect in 1914, when Iraq became a British mandate, is still operative. The Constitution, or Organic Law, of Iraq, adopted by the Constituent Assembly on July 10, 1924, in articles 113 and 114, provides that:3 Ottoman en laws date and thao remained and lave pub- lished on or after that date and which have remained in force in Iraq u to the time of the publication of this law shall remain in force in Iraq' so far as circumstances permit, subject to any modi- fication or repeal in conformity with the proclamations, regula- tions, and laws referred to in the following article, and until they are altered or repealed by the legislative power or the High Court issues a decision rendering them null and void in accordance with the provisions of article 86. (Art. 113.) All proclamations, regulations, and laws by the Commander-in- Chief of His Britannic Majesty's Forces in Iraq, the Civil Commis- sioner, and the High Commissioner, and those issued by the Govern- ment of His Majesty King. Faisal, during the period between Novem- ber 5, 1914, and the date of the coming into force of this Consti- tution, shall be considered to be valid as from the date on which they came into force... (Art. 114.) 4 According to a German authority, it is the Turkish law of March 26, 1906, that, with a few modifications, is still in force. This law (similar to the French law of 1810) is discussed in a separate section of this paper.

Jan 1, 1933

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

These tentative inspection standards have been prepared as a guide for the Federal inspection of the anthracite mines of the United States. The Federal Coal Mine Inspection Division is not a mining-law-enforcement

Jan 1, 1943

By David White

This paper is the result of a comparative study of ultimate coal analyses made and published by the United States Geological Survey. This study, at first casually undertaken to devise an acceptable classification of coals based on chemical analyses, was continued in connection with a microscopic examination of a number of the coals. The initial comparisons, made from a relatively small number of analyses, not only confirmed a previous conviction that the elimina- tion of oxygen incident to the development of a coal is economically far more important than has been generally suspected, but also showed that oxygen is very nearly as harmful as ash in coal. The immediate purposes of the present study were: (a) To deter- mine more definitely, from a comparative examination of a large number of ultimate analyses, the relative importance of oxygen as an impurity in various coals; (b) to illustrate the transition between various grades of coal of similar origin-transition mainly due to progressive devolatilization, brought about more or less directly by dynamic influences; (c) to ascertain the relative proportions of oxygen, hydrogen, and carbon in coking coals, especially with refer- ence to a theory tentatively framed to explain the coking quality; and (d) to forecast the probabilities of successfully treating a large number of coals so as to render them amenable, in a softened condition, to satisfactory study under the microscope. Although the hypothesis as to coking quality finds but partial support in the chemical analyses, its consideration has led to a method of predicting from an analysis with a fair degree of certainty whether any given coal will coke by the ordinary process. The unbroken transition between coals originally similar but now classed in widely different groups, whether of the same age or of different ages, as a result of dynamochemical action, appears demonstrated by the analyses as well as by field observation. This subject will not be

Jan 1, 1911

By Donna L. Anderson

This information circular documents the status of a laser-based guidance system to track and control the tramming maneuvers of a continuous mining machine. The work is part of a multiple project effort at the U.S. Bureau of Mines to develop technology for computer-assisted mining systems. The system includes stationary offboard laser-scanning sensors that report the angular coordinates of retroreflective targets on the mining machine. A microcomputer system processes the angular coordinates, determines position and heading, handles requests for data, and controls tram maneuvers of a continuous mining machine. This report describes the hardware for the sensor and computer systems and the software algorithms for continuous miner position and heading determination, closed-loop tramming, and data request handling. Improvements made to the system since previous documentation include the rewriting of the software on a stand-alone real-time microcomputer system, the implementation of real-time programming techniques, the use of a new version of the laser sensor, and the design and development of explosion-proof enclosures for the lasers and corresponding power supply.

Jan 1, 1991

By G. E. McElory

"INTRODUCTION The subject of mine and tunnel ventilation has two broad aspects - (1) what atmospheric conditions to obtain in underground openings and (2) how to maintain the desired conditions efficiently. The first relates primarily to quantity requirements of ventilating systems, whereas the second relates more particularly to pressure requirements. Both, therefore, determine power requirements, which is the deciding factor in any system of mine or tunnel ventilation.Both divisions of the subject have received considerable attention from the Bureau of Mines since its inception in 1910 in the form of research, service, and correlation and dissemination of information. Numerous papers on various Phases of the subject have been published, of which a selected list, numbered and arranged in chronological order by type of publication, will be found at the end of this Paper. One of these, Technical Paper 705 (25) 2/ gives a complete bibliography of Bureau of Mines publications dealing with health and safety. As indicated by the selected list of publications accompanying this paper, the health and safety aspects have received most of the attention devoted to this work, chiefly because these have been dominant factors in Bureau policy, but partly because these aspects lend themselves to laboratory research and small-scale field studies. Although considerable attention has also been devoted to the engineering aspects of mine and tunnel ventilation, there has been, in the opinion of the author, who has been engaged on this phase almost continuously for the last 30 years, only sporadic recognition of the vital effect this phase of the work could have on improving health and safety conditions. As a matter of fact, ventilation activities have constituted but a very minor part of the total work of the Bureau of Mines, as, except for a few years in the nineteen twenties, there have been only a few short intervals when more than two or three men were engaged in field work and a similar number in laboratory research directly related to mine gases or mine air."

Mar 1, 1950

By H. F. Yancey

The investigations described in this bulletin are confined to a study of the washing characteristics of bituminous coals. The major part of the work was conducted by the Bureau of Mines in cooperation with the Engineering Experiment Station of the University of Illinois and the State of Illinois Geological Survey Division between 1918 and 1924, in accordance with the provisions of an agreement between these agencies. The washing characteristics of coals from many of the important coal-producing fields of the Eastern and Central States were examined. The coals of the Pacific Northwest States and Alaska have been studied separately by McMillan and Bird of the Northwest Experiment Station of the Bureau of Mines at Seattle in cooperation with the College of Mines of the University of Washington.2 OBJECT OF INVESTIGATION The object of the investigation of coal preparation by the Bureau of Mines has been to promote the production of better prepared coal and to facilitate the correct selection and design of coal-preparation plants by obtaining as complete information as possible regarding the washability of the various types of American coals and the treatment best suited to each. In addition, some attention has been given to the development of new methods of washing coal. The work naturally divides itself into three rather distinct steps: (1) Development of a systematic method of examining and testing a coal; (2) classification of the American coals on a basis of the occurrence of the impurities associated with the coal in the beds; (3) examination of one or more representative coals of each type.

Jan 1, 1929

By Daniel C. Boteler

Five lignites from the northern Great Plains province were carbonized at temperatures from 500° to 1,000° C in a bench-scale unit. A replicated Greco-Latin square experimental design was employed to allow testing of four independent variables at five levels. Independent variables investigated were temperature, source of lignite (mine), weight of charge, and moisture content of charge. Dependent variables were char yield, tar yield, light-oil yield, tar plus light-oil yield, carbonization gas yield, and carbonization gas heat yield. An analysis of variance indicated that, at the 99-percent confidence level, the independent variables of carbonization temperature, source of lignite, and weight of charge were significant for yields of char, tar plus light oil, and carbonization gas, whereas moisture content was only significant for carbonization gas yields. At the 95-percent confidence level, moisture content significantly influenced the carbonization gas heat yield per pound of lignite charge and the yields of dry tar plus light oil. All dependent variables were determined on a moisture- and ash-free basis. Multiple regression equations for predicting seven different factors of carbonization yields as functions of carbonization temperature and initial composition were developed using computer techniques. Equations for yields of char, tar plus light oil, and carbonization gas were compared with equations previously developed by others at the 500° C level.

Jan 1, 1970

By Richard A. Watson

A frequency-shift keying (FSK) modulator-demodulator (modem) network has been devised for the Bureau of Mines mine-monitoring systems. This network permits an unlimited number of remote stations to communicate with one central station over the same pair of wires. The network operates at a speed of 4,800 Bd at distances up to 5 miles. This report describes the development and operation of the modems. The theory of operation, schematic diagrams, and printed circuit board layouts are provided. Although the modems were built for a specific application, a more general use is discussed whereby the network would operate with a typical serial channel format.

Jan 1, 1985

By R. T. DeWoody, J. W. Chester, W. C. Miller

The work was done to develop a relatively efficient muffler for quieting the exhaust of a rock drill . The exhaust of a pneumatic rock drill is the source of the major part of the noise generated by the drill . The exhaust noise can be reduced in a number of different ways , but this study involved only reactive mufflers . The reactive muffler can be simulated by an electrical circuit . Information obtained from analogous electrical circuits was used to design an efficient exhaust muffler for pneumatic rock drills . Electrical analogies proved to be a valuable tool in the design of mufflers .

Jan 1, 1964

By L. C. IlsLey

A list of permissible mine equipment, tested and approved p or to July 1, 1934, was published in Bureau of Mines Information Circular 6813/. The present list4/ includes virtually all the electric air compressors, coal drills, mining machines, loading machines, conveyors, mine pumps, room hoists, mine telephones, rock-dusting machines, switches, electric cap lamps, flame safety lanes, electric hand and trip lamps, electric flood lamps, methane detectors, blasting units, storage-battery locomotives, tandem locomotives, mower trucks, and concrete mixers tested and approved by the Bureau to January 1, 1937. The system under which these devices were tested permits the manufacturer, after his equipment has passed certain tests prescribed by the United States Bureau of Mines, to mark his equipment with a seal showing that it has been approved by the Bureau. These tests are designed to insure that equipments have the minimum requirements for safety in use. The only object of the bureau in making such tests and publishing lists of permissible equipment is to help decrease the hazards of mining.

Jan 1, 1937

By George H. Holmes

The water situation in Nevada mineral and related industries is described in this report. It contains information on the sources and adequacy of supply to current operators, requirements and uses, quality and costs, geography, hydrography, precipitation and evaporation characteristics, and Nevada water laws. Also, information is given on the water requirements of one public utility powerplant, and the source and consumption of water in four major cities. Water distribution at 24 operations is shown on schematic waterflow diagrams. The mineral industries of Nevada in 1962 used 8.6 billion gallons of new' water and reused 3.8 billion gallons for a total usage of 12.4 billion gallons. The copper industry was the major water user. The 1962 value of all mineral production in Nevada was $85.5 million. The large amount of water required to maintain thin high production is obtained principally from ground-water sources in alluvial valleys and the permeable rock formations of some mountain ranges. Some water is also obtained from perennial streams and springs. Sources of water utilized by existing industry ire near most mineral industry operations; however, seven companies are forced to pipe water distances ranging from 2 to 8 miles. Although water supplies of presently operating companies are adequate at most operations, several companies resort to large-scale reuse of water as a matter of conservation and economics. Acquisition of water by new operators is possible but takes considerable negotiation. Water rights, surface and underground, are controlled by the State. The quality of the water is satisfactory for most purposes. Analyses of 19 samples, listed in the appendix, show the range in water quality at various plants throughout the State. Costs of delivering new water to current operations range from 2 to 26 cents per 1,000 gallons with an average of 10 cents per 1,000 gallons for power and maintenance. No firm costs for recirculating water were available; estimated costs range from 1.5 to 2.5 cents per 1,000 gallons. The mineral-product value of the entire Nevada mineral industry in 1962 was equivalent to $10 per 1,000 gallons of new water and $26 per 1,000 gallons consumed. Projection of the 1962 water requirements of the Nevada mineral industry indicates that the demand For new water will increase from 8.6 billion gallons in 1962 to 11.9 billion gallons in 1980, a 43-percent increase. Water requirements in the year 2000 are estimated as 14.8 billion gallons, an increase over 1962 water demand of 78-percent.

Jan 1, 1966