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By J. Chilton

The fact that methane ignitions continue to occur at the mining face indicates that monitoring with machine-mounted methanometers does not always indicate the presence of high methane concentrations. Methane concentrations at the face change quickly due to changes in airflow. By measuring these changes in airflow, it may be possible to predict changes in face methane levels more quickly. Currently there are no techniques or instruments to accurately measure airflow in by the mouth of the ventilation curtain or tubing. Tests conducted in the NIOSH ventilation test gallery compare the data provided by one-, two-, and three-axis ultrasonic anemometers. The effects of changes in airflow direction and turbulence on instrument readings are discussed, and guidelines are given for selecting the type of instruments to be used for monitoring airflow near the mining face.

By John C. Machisak

THIS PUBLICATION presents injury experience and employment data for the nonmetal mining industry in the United States for 1960. Data for the mines and mills are presented separately, as shown in the list of tables. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry for their voluntary submission of injury and employment data. As the information submitted contributes largely to the promotion of safety in the industry, special effort has been made to ma e these questionnaires as complete as possible.

Jan 1, 1963

By Steven J. Page, Andrew B. Cecala, John A. Organiscak

In This Chapter [Drill dust control: wet and dry Enclosed cabs on drills and mobile equipment Haul road dust control] Overburden drilling generates most of the respirable dust that affects workers at surface mines. Both wet and dry methods are available to reduce this drill dust. Overburden removal by mobile excavation equipment such as bulldozers, front-end loaders, and haulage trucks can be dusty, particularly under dry and windy conditions. Tightly enclosed cabs with dust filtration systems can substantially lower the dust exposure of both drill and mobile equipment operators. Haul road dust control can be achieved by water application or chemical application. DRILL DUST CONTROL [Drill dust is controlled with wet or dry systems. Wet systems can be more efficient, but may freeze in the winter. Dry systems require careful maintenance of the drill deck shroud. An improved deck shroud is shown.] Wet Suppression. Wet drilling systems pump water into the bailing air from a water tank mounted on the drill. The water droplets in the bailing air trap dust particles as they travel up the annular space of the drilled hole, thus controlling dust as the air bails the cuttings from the hole [Page 1991]. In wet drilling systems, typical water flow rates are 0.1 to 2.0 gpm depending on the size and type of drill and the moisture level of the overburden. The drill operator controls the flow using a control valve located in the cab. Some drills are equipped with a flow meter to give the opera-tor a visual sign of the flow rate. Raising the water flow will improve dust capture, but too much water causes operational problems. Because of this, the drill operator must exercise care in find-ing the best water flow rate.

Jan 6, 2003

By Terry S. Cory

This report describes the results of a measurement and analysis program to characterize wireless radio transmission In metal/non-metal mines over a wide frequency range from 0.2 -1000 MHz and over a variety of mine environments. Six mines were chosen based on the relative economic significance of their product to the U.S. economy. Mine types Include 01 f shale, uranium, potash, lead/zinc, copper, and silver. Particular mines were chosen so that the group would embody the most Important mining techniques. The results show that transmission at medium frequencies are optimum tor wireless mine communications, In agreement with extensive testing previously performed by the authors in coal mines, and that mine-wide wireless systems are feasible with a minimum requirement for new dedicated wiring. At least one need for such a wireless system was identified in each mine visited.

Jan 1, 1981

By Victor R. Spironello

The Bureau of Mines has studied slags associated with ferrous melting, to evaluate substitutes for the auxiliary flux mineral, fluorspar. A waste material recovered from alumina reduction cells, "used potlining," was tested in an 18-in-ID basic-lined cupola and in a 1/4-ton, pilot-scale, basic oxygen furnace (BOF). One potlining fraction, No. 1 cut, is a carbonaceous (graphitic) material and represents the bulk of the entire cell lining. The other fraction, No. 2 cut, is a refractory backup. These materials contain significant quantities of fluorine and other elements fn various compounds. The potlining fractions were blended in ratios believed representative of available materials. Both lump and pelletized forms provided extremely fluid slag. No adverse effects were found on furnace performance, chemistry or strength of the metals produced, or the environment. Fluorine recovery in the slag and fluorine losses to the scrubber water and solids were about the same as when fluorspar was used. There was apparently no lining loss from the cupola, but there was lining attack in the BOF. Since the fluidizing ability of potlining is due in part to sodium and other elements such as aluminum and silicon, less fluorine is needed in the slags when potlining is used.

Jan 1, 1983

By D. J. Dollhopf

The objective of this five year study was to investigate the means of establishing non-polluted ground-water and root zone systems in areas where surface mining intercepts physiochemically unsuitable overburden materials. Overburden may need to be sampled on a 60 m grid in order to delineate materials unsuitable for reclamation and to accurately implement selective handling operations. Unsuitable overburden materials were buried successfully in a dragline operation with a minimum of delays, but costs were increased 12 to 53%. After three years the buried material remains above the reestablished aquifer and below the root zone. Construction of a clay cap over the buried material may not be required in semiarid environments. It was shown that some unsuitable overburden materials do not have to be special handled. When inhibitory material constituted <5% of the total overburden volume, such material was essentially not detectable in the resultant spoil pile due to mixing/dilution processes. When inhibitory material exceeded 15% of the overburden volume it was always found in the resultant spoil pile, generally with a smaller extent, indicating partial dilution. At least a portion of the postmine aquifer had hydraulic conductivity rates lower than the premine system, indicating the reestablished aquifer may, in part, conduct ground water very slowly. Postmine ground-water chemical quality in spoil materials had poorer quality compared to premine ground water.

Jan 1, 1981

By Richard F. Hewlett

The purpose of this Bureau of Mines paper is to provide the mineral industry with current information on high-speed data processing and to illustrate how some of these techniques can be applied to the industry. The need for applying these techniques is generally recognized, but not much information is readily available on specific applications. This paper briefly describes high-speed data processing and reduction equipment in an effort to familiarize the reader with the functions of the equipment. A list and explanation of some of the possible applications of high-speed data processing for the mineral industry are included. A few of these applications are illustrated by the use of specific examples of existing computer programs or processing methods, including their calculation times and costs. Some of the programs cited herein were developed by the author at the University of Arizona for a Masters thesis in mining engineering. When a reference is made to a specific computer, the reference is given to make the information that is being presented as factual as possible; most of the manufacturer&apos;s equipment that is mentioned in the references was available at the University of Arizona, and no specific endorsement of that manufacturer is intended.

Jan 1, 1962

The purpose of this report is to describe the work accomplished by Mine Safety Appliances Company under Contract No. H0110845. This contract required the design, installation and testing of a permissible mine surveillance and communication system for the USBM Bruceton experimental mine facility. While much of the design and operational detail of this system can be drawn from the instruction manuals delivered with the equipment, some of it will be repeated here in Volume I for the sake of clarity, but the principal objective will be to report on overall system and subsystem performance and to suggest design alternatives for future consideration. Details of the overall system design will be found in Volume II of this report.

Jan 1, 1973

By John C. Machisak

THIS PUBLICATION presents injury experience and employment data for the nonmetal mining industry in the United States for 1960. Data for the mines and mills are presented separately, as shown in the list of tables. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry for their voluntary submission of injury and employment data. As the information submitted contributes largely to the promotion of safety in the industry, special effort has been made to make these questionnaires as complete as possible.

Jan 1, 1963

By R. H. Grau, S. B. Robertson, R. B. Krog

The National Institute for Occupational Safety and Health (NIOSH) has conducted research to improve the ventilation of large-opening mines. Large-opening mine ventilation is unique for the following reasons: (1) it is challenging to keep airflow velocities high enough to effectively remove or dilute airborne contaminants, (2) large air volumes can be moved through the mines with little static pressure drop, and (3) stoppings to direct ventilation airflows are costly to construct and maintain. The research results suggest that by incorporating ventilation planning into the mine planning process, using propeller fans, developing new stopping materials and construction methods, and using long pillars to eliminate crosscuts where possible, the ventilation of large-opening mines can be significantly improved. The ventilation improvements created by incorporating these various techniques into the ventilation plan will help reduce the exposure of mine workers to airborne contaminants in underground large-opening mines.

Provide the mining industry with a simple, accurate and readily available means of measuring the gas flow from pipe outlets such as gob holes Approach The Bureau of Mines conducted laboratory studies to establish correction or method factors for anemometers when used to measure gas flow from pipe outlets. Using the Anemometer Anemometers are used by the mining industry to make air velocity measurements in mine entries. Although the instrument has no appreciable influence on the airstream in mine entries, especially since the cross-sectional area of an entry is much larger than the cross-section of the anemometer, correction or method factors are used to correct the center line anemometer velocity to average velocity. This adjustment is made because the air velocity in a mine entry is highest in the center and lower at the sides. Anemometers can be used to measure gas flow from small diameter pipe outlets; however, since the instrument diameter is much larger than one-sixth of the pipe diameter, it will influence the air-stream from these small outlets. Resulting velocity measurements are erroneously high by as much as 30 percent. Method factors must be applied to such anemometer measurements taken at pipe outlets. Through a research investigation the Bureau of Mines established a set of method factors for center-line anemometer readings taken at the discharge end of 4-to 8-inch diameter pipes. These method factors were combined with method factors which were developed by the National Coal Board of Great Britain for 12-to 30-inch diameter pipes. The anemometer was mounted on the end of a short rod and held against the pipe for support except on the 4-inch pipe where the instrument was started and stopped remotely to prevent hand interference with the air-stream during measurements. Method factors were determined by comparing the anemometer measurements at the pipe outlet to the true average airflow which was simultaneously determined upstream by venturi measurements. Consequently, a method factor is nothing more than the ratio of the true velocity to an anemometer measurement.

Jan 1, 1987

By John C. Machisak

INJURY and employment figures for nonmetal mines and mills in 1959 are presented in this publication. Data for nonmetal mines are presented separately from those for nonmetal mills. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry each year requesting their voluntary submission of injury experience and employment data. The voluntary response to these requests has contributed greatly toward the promotion of safety in the industry, and every effort has been made to make the information as complete as possible.

Jan 1, 1963

By J. E. Chilton

The National Institute for Occupational Safety and Health (NIOSH) has conducted research to determine the influence of mining machine-mounted scrubbers on airflows and methane concentrations at the face when blowing ventilation systems are used. Tests were conducted in a full-scale ventilation gallery with a model mining machine that simulated airflow created by a dust scrubber. During the tests, ultrasonic anemometers were used to measure airflow speed and direction at several locations near the face. For the same test conditions, methane was released from the face and gas concentrations were measured at 21 locations above the machine using fixed point methanometers. Changes in airflow speed and direction are correlated with scrubber airflow and the measured methane distribution above the mining machine. The research results showed that operation of machine-mounted scrubbers improved face ventilation when blowing ventilation is used by increasing both the intake flow and the quantity of air reaching the face.

By Thomas Varley

During the past few years, since flotation has become the paramount treatment method for most all kinds of ores, the Bureau has gathered the data on consumption of reagents used in the flotation treatment. The first report was issued in 1916. A brief review of such reports snows the progress made in the art of flotation, and each year brings forth the development of new reagent a or combinations of reagents that seem sure to survive, but research and progress spell their defeat, if not by entire elimination, at least subjects them to considerable modification.

Jan 1, 1928

By James C. Patterson

Sintered fly ash was shown to have promise as a modifier for poorly drained soils. Turf grown in mixtures of sintered fly ash and soil benefited from increased water-infiltration rates, greater total pore space, and higher moisture availability, The result was an improved turf stand with increased grass yield and root density.

Jan 1, 1970

By John C. Machisak

INJURY and employment figures for nonmetal mines and mills in 1959 are presented in this publication. Data for nomnetal mines are presented separately from those for nonmetal mills. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry each year requesting their voluntary submission of injury experience and employment data. The voluntary response to these requests has contributed greatly toward the promotion of safety in the industry, and every effort has been made to make the information as complete as possible.

Jan 1, 1963

This field guide is designed for use in planning pollution control and reclamation activities on small sand and gravel operations. Its purpose is to assist operators in selecting environmentally desirable pollution control and reclamation procedures based upon their particular mining situation. The guide includes information on interpreting physical and cultural factors that must be considered in planning and implementing a mining and reclamation program, achieving environmental protection objectives, and improving community/industry cooperation. Included as appendices are a summary of state laws and a list of additional readings on the subject.

Jan 1, 1981

This publication summarizes the in-house and contract research and development projects programed for fiscal year 1981 by the Bureau of Mines under its Minerals Environmental Technology activity. The document provides a mechanism for interested parties, including potential contractors, to gain insight into ongoing and projected work of the Bureau?s environmental research efforts. Research to identify and correct environmental problems associated with mining and metallurgical operations has long been an integral part of the Bureau&apos;s mission. The environmental research and demonstration activities of the Bureau were consolidate in 1979 with the formation of the Minerals Environmental Technology program, which is directed toward the elimination or reduction of environmental problems associated with the extraction and processing of minerals. Among the efforts underway are development of data and technology for assessing the potential environmental impact of minerals development, for monitoring minerals extraction operations, and for establishing viable reclamation requirements on abandoned mine lands; development and demonstration of technology &apos;or control of environmental disturbances during minerals extraction operations; development and demonstration of land reclamation and mine closure techniques to restore or enhance the productive use of mined lands; development of engineering techniques that incorporate state-of-the-art mining environmental technology in the design and planning of minerals extraction operations; development and demonstration of new mining systems that greatly reduce or eliminate the adverse environmental impacts of minerals extraction; and providing the technologic base for Federal, State, and local establishment of environmental standards for mining operations. Included in the minerals-processing-related work are projects to clean mineral-processing waters: demonstrate a Bureau process for scrubbing SO from powerplant stack :;as; recover dissolved minerals from process streams; stabilize discarded dusts, slags, and tailings: remove hazardous contaminates from byproduct wastes; reduce generation of waste solids; and improve metallurgical process engineering to eliminate pollution. Approximately $21 million was appropriated for this work in fiscal year 1981.

Jan 1, 1981

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 Lloyd G. Fitzgerald

"The dangerous nature of explosives makes them a potential hazard wherever they are used, but they are likely to exercise their greatest harmfulness under conditions inherent in coal mining. The ease with which explosives can be detonated and the suddenness and violence with which they detonate require great care in their handling and use, if acci-dents are to be avoided. Campaigns have been waged by the manufacturers, the Federal Bureau of Mines, coal-mining companies, and other agencies to educate users of explosives in their dangers and in their proper use and care.Probably 95 percent of the explosives accidents can be attributed to poor judgment, carelessness, negligence, or chance taking. In many explosives accidents it is difficult to determine the cause definitely, as the evidence of the origin is destroyed by the blast and frequently those involved have been killed. Survivors of the accident often are of little help in determining the cause, as the accident occurs so suddenly they cannot tell what happened or prefer not to divulge the information they have because it may point to their own carelessness.A survey has indicated that about 10 percent of all fatalities in coal mines were caused by explosives accidents (excluding gas and dust explosions initiated by explosives). A list of explosives accidents by States, from 1925 to 1932, classified according to the severity of the accidents, indicated that Kentucky and Wyoming had the greatest number of fatalities resulting from explosives accidents. Records of the Bureau of Mines show that 14 coal-mine explosions occurred from January 1 to June 1, 1943. Explosives were involved in four of these explosions. Black powder caused two of the accidents and permissible explosives used in a nonpermissible manner the other two. These statistics are mentioned to show that explosives are still causing severe accidents.Elimination of the hazards associated with explosives begins on the surface. Storage magazines should have no opening, except for entrance and ventilation; ventilators should be screened effectively to prevent the admittance of sparks as well as to prevent unauthorized entrance. The interior should be kept clean and dry, and the floor should be of nonsparking material with no metal exposed. The surrounding area should be kept free of combustible material for not less than 25 feet (and preferably 50 feet) in all directions. Storage magazines should be fire-resistant and reasonably bulletproof."

Aug 1, 1944