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By R. J. Leary

The technologies of contemporary iron and steel production and of direct reduction processes have been studied to identify and estimate the potential effects of direct reduction on mineral consumption and the problems raised thereby for the Nation's mineral supply to the iron and steel industry. Contemporary patterns of mineral raw material and energy consumption were determined from a study of the 1964-70 period. Major changes were observed in requirements for 14 of 20 principal commodities. Average practice in 1970 was compared to best practice to estimate the potential effects of implementing existing technology without recourse to direct reduction. Potential effects of direct reduction were estimated by comparing the mineral requirements for 95 percent reduced pellets with 1970 best practice technology for two cases of use: (I) complete substitution for hematite pellets in blast furnace burdens, and (11) partial substitution (40 percent) for scrap in electric furnace steel charges. Effects upon mineral supplies are described; important collateral factors are analyzed, and the principal metallurgical, industrial, and environmental consequences of implementing direct reduction are discussed. Major effects of direct reduction on the domestic steel industry and its mineral supply system are foreseeable. Direct reduction will (1) create a large demand for low-gangue iron ore; (2) relieve the dependence of the steel industry on coking coal, and (3) permit great increases in furnace productivity, both in blast furnace ironmaking and electric arc furnace steelmaking.

Jan 1, 1973

By Xinquan Zhou, Rudolf E. Greuer

MFIRE, written in Fortran 77, is a computer program for ventilation state simulation in the steady state or transient state condition. It can be applied for the calculation of normal ventilation system planning or the analysis of the dynamic state variation in a ventilation system under thermal or mechanical disturbance. The state simulator MFIRE is a useful tool for mine fire fighting. In the case of a mine fire, mine ventilation engineers want to get some help to obtain more information, such as what is happening in the underground mine and how to control the mine fire, for correct decision making. By use of program MF'IRE, forecasts can be made on the variation of airflow, temperature, and contaminant distribution in a ventilation system during a mine fire. The paths which the contaminant takes at each time interval can be traced. The program MFIRE can be of assistance in the preplanning of escape routes. It can also be helpful during a mine fire emergency and mine recovery operation. Besides of offering the information of state simulation during a mine fire, MFIRE can be applied for state control by pretesting the suitability of the selected state control measures. It is to simulate the effects of the state control measures on the airflow distribution of a dynamic ventilation system. The testing result can be used for fire fighting in a similar real case of a mine fire. By employing empirical methods or a qualitative analysis like Budryk approach, ventilation engineers can choose different combinations of locations and sizes of control devices as samples of state control for an underground mine fire. Program MFIRE can simulate the different combination samples, that consist of a certain mine fue, the corresponding different control measures, and obtain the control effects. After the different control results are compared, the state control measure, which creates the best effect among the different state control measures, will be chosen for that fire case. When a mine fire, which is similar to one of the pretested cases, breaks out, the corresponding choice of the state control measure is applied to the ventilation system. It means that the simulator MFIRE has the function of indirect state control [10]. To achieve the above two functions, state simulation and state control, the mine ventilation system condition, sometimes, should be changed in a wide range to meet the requirement of the fire fighting. These wide system condition changes, such as adding operating fans, stopping or reversing fans, changing fan characteristics, adding regulators and making airflow shortcuts are represented in the time table of the input data set When the data files are changed in a wide range, however, an iteration divergence and some other computing errors in the distribution of airflow, temperature, and contaminant may occur. More serious logical programming and flexible selection on the algorithms are wanted to meet the request of the different data sets, to achieve correct state distribution simulation and improve the iteration convergence. To enhance the reliability and common suitability of program MFIRE, it is necessary to make investigation, analysis, and modification for the formal versions of MFIRE. The version 1.29, permitting dry .calculation, and versions 2.01/v2.0, permitting dry and humidity calculation, are widely applied

By G. Huang, S. Vytla

Computational fluid dynamics (CFD) is a continually developing numerical technique by which complex fluid flow problems can be solved on computers. To be able to transfer CFD expertise to analyze and design a face-ventilation system, a comprehensive validation study of current CFD tools against mining-related benchmark experiments is required. In the last four years, such studies, funded by National In¬stitute for Occupational Safety and Health (NIOSH) under Grant #R01 CCR415822, were conducted in the Department of Mining Engineering at the University of Kentucky. A wide array of ventilation schemes and mining configurations were considered. Recently, an additional study was performed in cooperation with the NIOSH Pittsburgh Research Laboratory. This study was dedicated to the methane behavior in the empty (containing no equipment) face area with a blowing curtain and a 10. 7-m (35-ft) setback. In this paper, the authors present and discuss the computer-simulation data and compare them with data collected during the laboratory studies at the NIOSH lab.

By Martin H. Rogoff

This publication combines a critical review of the literature on the microbiology of coal with an introduction to those areas of microbiology related to studies of coal as a biological material. The attack on coal by microorganisms as yet remains doubtful. Only the low-rank coals contain an indigenous microbial flora, and even these organisms are not peculiar to coal, but are common soil and water forms. No experimental data have as yet been presented, either in the literature or in the present work, which unequivocally demonstrate the oxidation of coal by microorganisms. Reasons for the resistance of coal to such attack, including insolubility, physicochemical structure, steric hindrance of enzyme action, and the presence of antibiotic materials in coal are discussed. Microorganisms do attack large aromatic molecules and the mode of oxidation of aromatic ring systems by bacteria is presented. Well-defined pathways are known for the oxidation of polycyclic compounds with one to three rings, and these paths with their key intermediates are described and related to the possible oxidation of coal.

Jan 1, 1962

By Douglas D. Reynolds

Intense vibration can be transmitted to the hands and arms of workers who use hand-held percussive or vibrating devices, tools, and work pieces. Continued habitual exposure to vibration directed to the hands can cause patterns of various symptoms associated with hand-arm vibration syndrome (HVAS). The International Organization for Standardization (ISO) first published ISO 5349 in 1986.3 This standard specified methods for measuring and evaluating vibration directed into the hands from hand-held vibrating devices, tools, and work pieces. The American National Standards Institute (ANSI) published ANSI S3.34 the same year.1 This standard was modeled after ISO 5349-1986 and specified methods for assessing exposure to hand-arm vibration. The Parliament of the European Union has issued the European Union Human Vibration Directive-2002/44/EC, which specifies vibration daily exposure action values (DEAV) of 2.5 m/s2 and daily exposure limit values (DELV) of 5.0 m/s2. These values have generally been accepted by medical experts, scientists, and engineers in governmental agencies, research institutions, and industry in the USA and other countries.2 When they are achieved, they will reduce the potential for the development of symptoms related to HAVS among workers exposed to hand-arm vibration. Significant improvements in measurement and analysis instrumentation, miniature and subminiature accelerometers, and medical diagnostic and assessment protocols have being introduced since 1986 when ANSI S3.34 was first published. In response to these improvements and the introduction of the EU Human Vibration Directive, ANSI Working Group S2.39 developed the revision to ANSI S3.34, which has now been published as ANSI S2.70-2006.2 Method ANSI S2.70 specifies the use of the hand-arm vibration measurement procedures outlined in ISO 5349, Parts 1 and 2.2,4,5 It requires the measurement of ISO frequency-weighted acceleration values in three mutually orthogonal axes of vibration. These values are then vectorially added to obtain the vibration total value, ahv: [ ] where ahwx, ahwy, and ahwz are the measured r.m.s. ISO frequency-weighted acceleration values in the x, y, and z directions, respectively. If multiple vibration exposure events are experienced during a work day, the overall vibration total value is obtained from: [ ] where ahvi is the vibration total value of the ith operation, Ti is time duration in hours of the ith operation, n is the total number of operations, and T is total time in hours associated with the n

Jan 6, 2006

By Sam S. Taylor

Subsurface disposal of oil-field brines was practiced in Oklahoma on a limited scale as early as 1925. The technique of subsurface injection has been improved immensely and has been applied with varying success in many oil-producing areas in Oklahoma, and elsewhere. This method of disposal, however, is only one of several methods available to operators of oil-producing properties, but, in contrast with usual methods of handling brines on the surface it eliminates the damaging effect of mineralized water on fresh-water supplies, vegetation, and aquatic and other animal life. Other methods of brine disposal approved by regulatory agencies in some States include (1) impounding in impervious ponds and solar evaporation, (2) controlled diversion into surface waters, and (3) recovery of the mineral salts of the brine. In most, States where oil is produced regulatory bodies authorize the use of one or more of these methods of brine disposal. In Oklahoma, for example, the Oklahoma Planning and Resources Board of the Conservation Commission has been authorized to adopt whatever methods or means may be necessary to prevent contamination by mineralization of all potable waters within the State.

Jan 1, 1942

By Sidney Katell

This cost bibliography, covering the period from January through December 1960, is a continuation of the series which began with the publication of Information Circular 7516 in October 1949. It is also the second 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 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 petroleum and chemical plants and related facilities, came from the following sources: 1. Bureau of Mines Information Circulars. 2. Bureau of Mines Report of Investigations. 3. Chemical Engineering. 4. Chemical Engineering Progress. 5. Chemical Week. 6. Coal Age. 7. Coal. Utilization. 8. Cost Engineering. 9. Industrial and Engineering Chemistry. 10. Nucleonics. 11. Oil and Gas Journal. 12. Petroleum Engineering. 13. Petroleum Refiner. 14. World Oil.

Jan 1, 1961

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network, and 2)development of , set of digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the model; and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated for their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

By L. G. Marshall

This report describes dredging and processing of sand and gravel from a glacial-fluvial deposit in the Raccoon River valley near West Des Moines, Iowa. Preliminary cleaning and separation of the sand and gravel at the dredge site with subsequent transportation to separate plants and the production and disposal of the various grades of aggregate material are also described. The geology of the deposit is summarized. A tabulated summary of costs in units of labor, power, and supplies is included.

Jan 1, 1963

By Clarke E. Schuetze

This project had as its objective the experimental investigation of water capsule production utilizing the Southwest Research Institute's submerged nozzle encapsulation apparatus (U.S. Patent 3,389,194). Initial efforts on this project involved nozzle configuration and shell formulation optimization. The shell formulation developed on a prior program was modified during the course of the project to obtain the best balance of capsule breakage resistance and water retention. Subsequent effort centered on determining operating conditions which would produce the best quality capsules for each candidate shell formulation as determined by laboratory tests. Some preliminary work was done to increase the production capacity of the encapsulation equipment. The program was extended with major emphasis concerned with scale-up studies of capsule production capacity and the treatment of problems associated with grouting cartridge fabrication. During the course of the program, water-containing capsules were produced which have good long-term water retention, block resistance and adequate strength. Using a single-nozzle design, a production capacity of 15.9kg (35 pounds) per hour was demonstrated to give acceptable capsules based on initial results.

Jan 1, 1978

By L. C. IlsLey

"The use of trailing cables on cutting machines, loading machines, and similar electrically operated apparatus is recognized as a necessary adjunct to the economical operation of such units. On the other hand, such cables because of their liability to failure from being run over by cars, locomotives, and other track-operated equipment offer one of the greatest hazards - indeed, probably the worst hazard - met with in the operation and maintenance of permissible equipment. Therefore, the Bureau of Mines is seeking ways of making the use of trailing cables less hazardous.Recently the bureau conducted an extensive investigation of both concentric and duplex rubber-sheathed trailing cables at the Pittsburgh Experiment Station. The results of this investigation were published in two reports.3 4In a larger part of portable motor operations in mines a double-conductor cable can be used. The investigation already mentioned indicated that it is feasible to construct a 2-conductor cable that will stand considerable abuse, such as being run over by loaded cars or light-weight locomotives without producing dangerous arcing in the cable either from grounds or short circuits. There are conditions where more than two conductors are necessary, and in such instances it will probably be necessary to use a cable less resistant to this kind of abuse.Schedule 2C, covering the tests of electric motored equipment, was approved February, 1930. This schedule provides for performance tests on trailing cables as follows;Trailing Cable Performance: The following performance test, optional with the manufacturer, is established for determining the suitability of trailing cables for use on permissible equipment. Trailing cables that pass this test will be especially recommended for this service.The cable will be placed across the two rails of a track and a 4-wheeled 7-ton car will be run over it 50 times. The speed of the car shall be approximately 3-1/2 miles per hour and potential shall be applied to the cable during tests. The cable will be shifted in position after each passage of the car thus giving 100 places over which two wheels have passed. To warrant special recommendation of the Bureau, a cable must neither become short-circuited nor grounded either to the rails or wheels in more than 10 per cent of the 100 places.The Bureau of Mines is prepared to conduct tests as outlined in the foregoing paragraphs to determine the suitability of trailing cables for use on permissible equipment. Application for such tests should be made to the Director, Bureau of Mines, Washington, D. C. Each application should be accompanied by a check for $25.00, made payable to the Treasurer of the United States, to cover the expense of conducting the test on a given size and make of cable."

Apr 1, 1930

By S. J. Davenport

The increased consumption and importation of fluorspar and cryolite (1)3/ in recent years, and especially the addition of fluorine compounds to drinking water in the United States, have aroused renewed interest in the properties of such compounds and possible health hazards incident to their use. It has been suggested that the issuance of a revision and elaboration of Information Circular 7311, The Hazards of Hydrogen Fluoride Poisoning in the Mineral and Allied Industries, which hay been out of print for some time, would be opportune. Fluorine minerals have been known since the Middle Ages. Fluorine was isolated in 1886 by Moisson (2).

Jan 1, 1954

By D. A. Paice

Under the first phase of this contract as reported in the Phase I report it was determined that certain types of commercially available molded case breakers are capable of interrupting mine dc power supplies of nominally 300 volts or 600 volts rating. These circuit breakers incorporate conventional overcurrent trip units but also can be operated by means of low power signals fed to a shunt trip coil. Further development in the Phase I program produced a means whereby a discriminating circuit breaker detector unit could sense the presence of illegitimate loads on the dc electrical system and cause the circuit breaker to trip. The detector unit operated by detecting the presence of 3000 Hz currents which were generated in the illegitimate loads by means of a 12 volt, 3000 Hz signal applied to the dc system. Further development of the program has continued in Phase II with the aim of verifying the practicability of the complete discriminating circuit breaker concept and developing other types of equipments required to implement a system. These other equipments include electronic means for raising the apparent impedance of high power legitimate loads and static filters for smaller loads. The results of laboratory work and limited underground tests have been successful. This report describes the system and the tests that have been conducted on the various equipments that comprise the complete Discriminating Circuit Breaker Concept.

Jan 1, 2012

By Joseph D. Davis

Selection of a suitable coal or coals for the manufacture of coke of desired quality with due consideration of the purpose for which the coke is intended requires careful thought, and often it will pay to go to considerable expense in testing such coals as may be available. In general it will

Jan 1, 1942

By Motohisa Kanda

The time and amplitude statistics necessary to adequately describe electromagnetic (FM) noise in mines are illustrated through computer software techniques. They are 1) Allan Variance Analyses (AVA), 2) Interpulse Spacing Distributions (ISD), 3) Pulse Duration Distributions (PDD), 4) Average Crossing Rates (ACR), and S) Amplitude Probability Distributions (APD). These statistics are illustrated using data taken from a rather large store of raw analog data recorded in operational mines. The curves generated for the illustrations characterize the noise environment in the mines from which the corresponding data were taken, and should aid in the design of reliable communication systems for such mines.

Jan 1, 1974

By Stephen C. Tadolini, Raymond A. Mazzoni

The International Ground Control Conference in Mining has always provided an open forum for the publication, presentation, discussion, and often heated debate on roof bolting systems mostly with attention to how, when, and why they work. During the last 24 Conferences at least 170 papers have been presented by International Experts on these “simple” devices that range in length from 30-inches to 20 ft and from 5/8 to 2 inches in diameter. Roof bolts are primarily mechanically anchored, glued, cemented, or driven. Bolts are placed vertically, angled, or tied together with special fixtures (trusses and slings). They have been termed active, passive, stick-slip, and several other descriptive acronyms or mining slang expressions. This retrospective paper will present the changes in bolt types and usage, point out some of the biggest myths and hail the most significant advances (according to the authors’ opinions of course).

By Virginia E. Gleason

In this report, recommendations are made for programs to develop workable techniques to stop or prevent acid mine drainage formation in those underground coal mines where acid production could take place. These recommendations include development of mine closure technology, development of surface water infiltration control procedures, study of the effect of roof collapse on mine water characteristics, evaluation of the long-term effects of flooding underground mines above drainage, investigation of the effectiveness of section sealing in active mines, development of a simple model for predicting mine water quality and quantity, preparation of a manual on mine drainage abatement procedures, and development of a program to disseminate information on mine drainage abatement to the coal industry. These recommendations are based on an in-depth evaluation of information acquired over years of research on acid mine drainage formation, on numerous laboratory and field studies of methods of preventing or minimizing acid mine drainage formation, and on review of the geological, hydrological, and mineralogical factors involved. There are 772 references.

Jan 1, 1978

By J. S. Miller

The Bureau of Mines conducted surface tests to determine the feasibility of using liquid explosives for underground rock fracturing. The effects of configuration, confinement, length, critical layer thickness, and fracture-propping sand on detonation and explosive propagation velocity of desensitized nitroglycerin were studied, using polymethyl methacrylate and glass-plate reservoirs through lengths from 3 to 12 ft, with explosive-layer thicknesses from 0.1875 to 0.0312 in and in aluminum tubes 8 ft long with diameters from 2.000 to 0.125 in. Interval and continuous detonation velocity data were obtained. Under the test conditions detonation velocity was dependent upon explosive confinement and fracture-propping sand. The detonation velocity of a confined nitroglycerin explosion in aluminum tubes can be reduced by as much as 85 percent, when the tube contains fracture-propping sand. The shape of the reservoir, whether triangular or rectangular, has little effect on the detonation velocity or explosive propagation. The critical or minimum explosive-layer thickness between glass plates, capable of supporting propagation, was 0.0312 in. The presence of a fracture-propping sand in the sheetlike layers increased the critical explosive layer thickness to 0.0625 in. In nitroglycerin-filled and nitroglycerin-sand filled tubes, the minimum tube diameters successfully tested were 0.125 in and 0.375 in, respectively.

Jan 1, 1969

By E. R. Palowitch

Two samples of the Lower Hartshorne (Spadra) bed were collected: A sample of the raw coal with the machine cuttings excluded, and a sample of the machine cuttings exclusively. Analysis of the 5-inch by 200-mesh size fraction of the raw coal, excluding machine cuttings, showed that a product meeting minimum quality specifications could be produced by washing at 1.60 specific gravity, yielding a theoretical 93.7 percent of clean coal. A negligible amount of near-gravity material at the separation gravity indicated an easy washing problem. The sample of machine cuttings had a maximum size of 2 inches and contained about 50 percent ash. Washability tests of the 2-inch by 200-mesh size fraction indicated that a theoretical yield of 30.0 percent of specification-grade coal could be achieved by washing at 1.49 specific gravity. As the machine cuttings represent an estimated 10 percent of the total coal mined, their inclusion in the mine output would increase the theoretical net yield of salable coal by only 3.7 percent. Because the machine cuttings contained a high percentage of sink 1.80 specific-gravity material, they had neither an effect on the separating gravity required to clean the raw coal nor on the difficulty of separation. Gabbing underground versus transporting the cut-tings to the surface for disposal or washing either separately or combined with the raw coal involves a number of practical, economic; and intangible factors; hence, no specific recommendations could be made. A discussion of some of the factors involved in dealing with a similar problem is given by Gandrud and Riley.4

Jan 1, 1962

By F. D. DeVaney

Manganese-bearing deposits f the Leadville, Colo., district are of two distinct types. Manganosiderite, a combined or intimately mixed ferrous and manganous carbonate, occurs in unaltered zones as the predominant mineral. From 50 feet below the surface to as deep as 900 feet, psilomelane and wad, both black manganese oxide minerals, are found in intimate contact with hematite and limonite. A typical analysis of the black oxide ore shows 20.08 percent Fe, 18.64 percent Mn, 15.91 percent insoluble, 14.91 percent moisture, 0.94 percent Zn, and 2.13 percent Pb. A considerable tonnage of the oxide ore has been mined for production of spiegeleisen and for other purposes.

Jan 1, 1940