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By Steven J. Page, William A. Heitbrink, Andrew B. Cecala, Edward D. Thimons, John A. Organiscak

Miners at noncoal surface mining operations are often exposed to high levels of respirable dust. In an effort to lower the respirable dust exposure of these surface miners, the National Institute for Occupational Safety and Health (NIOSH) has been conducting research to address this problem in a practical and economically viable manner. One successful effort deals with lowering the dust exposure of equipment operators in enclosed cabs. Many types of surface mining equipment utilize enclosed cabs to protect equipment operators from dust exposure. Normally when the equipment is new, the cabs are fairly airtight. These tightly sealed cabs, combined with good filtration systems, generally provide the operator with good dust protection. However, most mining equipment is older, and as aging occurs, many components of the enclosure deteriorate. The structural integrity of the cab diminishes and the effectiveness of the air filtration system fails. NIOSH has been successfully researching costs-effective methods to improve both filtration effectiveness and cab integrity of these older cabs in order to provide a healthier work environment for equipment operators. Dust sampling records indicate that drill operators and helpers have the highest dust exposure of all workers at surface mining operations. Since much of the overburden contains a high percentage of silica, the health hazard associated with this dust can be even more serious. NIOSH research is addressing techniques to lower respirable dust levels at surface drilling operations. INTRODUCTION NIOSH's mission is to assure a safe and healthy work environment for the working men and women of this nation. The primary emphasis of NIOSH's Pittsburgh Research Laboratory (PRL) is mining health and safety research. This report focuses on two areas of research

The Mine Safety and Health Administration (MSHA) defines an independent contractor as "any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine." Contractors that perform specific types of work are required to report the number of employees who perform work at coal mines and at noncoal mines.

Feb 1, 2005

By William R. Sharp

This Bureau of Mines report details a technique for aiding the engineer with the long-range design of an underground mine. The method is based upon the assumption that sufficient data are available to assign numeric values to some finite number of mineralized blocks; assignment of numerical values is problem dependent. By assigning appropriate weighting schemes, the algorithm developed in this report may be used to solve the optimal end-of-life underground mine layout, design least-cost electrical layout networks and efficient material handling networks, find least risk escape routes in the event of an accident, etc. The method is based upon the assumption that sufficient cost and geologic data is available to build a detailed mineral block inventory of the mineral deposit. It is further assumed that the cost assigned to any minable unit is independent of the neighboring blocks. The basic approach relies upon concepts and ideas from the theory of networks. To make the approach user oriented, a computer program is included and discussed. The computer code is written for an orthogonal, three-dimensional set of blocks. Computational costs and experience indicate that the program could be of great benefit in evaluating large complex mineral properties from the viewpoint of predesigning an underground mine layout.

Jan 1, 1974

By Nicholas P. Kripakov

The U.S. Bureau of Mines examined the applicability of existing material models to solve practical geotechnical mining-related problems by solving a yielding pillar stability problem considering confining effects on strength. Numerical difficulties normally encountered with modeling strain softening behavior were eased with a simplified computational procedure using a quasi-elastic approach to account for residual strength after initial failure. Although in agreement with a confined-core pillar design method using actual mine conditions that include mine layout geometry, overburden geology, and rock properties of the deposit and surrounding structure, the results cannot be verified because measured field data are not available at this writing.

Jan 1, 1981

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

Comprehensive ventilation surveys are made to review the adequacy of the mine system with regard to both statutory requirements and/or company policy, to evaluate improvements to the current ventilation system and to plan for £stun expansion. If computer simulation is to be used for these purposes, accurate quantity and pressure measurements become an absolute necessity since the validity of the computer generated output is heavily dependent on the accuracy of the input data. Consequently ventilation surveys that are run to generate input data for computer simu¬lation must use the best data collection procedures to guarantee as accurate results as are possible. These requirements have led to modifications in procedures that are used for routine ventilation surveying. McElroy and Kingery (1957) have recommended that pressures be measured independent of quantities since minor changes in mine conditions have a greater effect on absolute pressure measurements than on quantity measure¬ments. They estimate that, for large mines, a pressure survey may take only 1 to 3 days while the corresponding quantity survey would require 1 to 3 weeks. Although this procedure would undoubtedly lead to more ac¬curate pressure measurements, its use for the development of computer input data is not recommended for the following reasons. Atkinson's equation, H = RQ2, is used in computer oriented analysis to develop the airway resistance, R, based on quantity and pressure loss measure¬ments. It can easily be seen that since R a 1/Q2 and R a H, the effect of errors in quantity measurement is, in fact, more significant than those in pressure measurement. If the quantity and pressure measure¬ments are made at different times another problem results. Minor changes in quantity that may occur in the time between the pressure and quantity

Jan 1, 1977

By R. V. Ramani, K. V. K. Prasad

"This paper was the subject of a cross-disciplinary presentation under the chairmanship of Dr A.M. EdwardsManagers need quality information for effective decision making. This demand, at the present time, is being fulfilled by the increased use of computers via information systems, decision support systems and management information systems. The idea of incorporating intelligence into computers to aid decision-makers has been evolving for over two decades. In recent years, significant progress is reported on applications to business and sciences. In engineering functions, the Artificial Intelligence approach that seems to have great potential is the application of Knowledge Based Systems.The primary objective of this paper is to identify domains in mining engineering where application of knowledge based systems could be beneficial. Incorporation of the expertise required during the analysis and interpretation stages of an engineering design problem through knowledge based systems is recognized as an area of significant benefit. To this end, the components of knowledge based systems for mine ventilation and strata control design are described. The potential applications and limitations of knowledge based systems are outlined. IntroductionCorrect decisions are the key to success in any enterprise. Scope of decisions varies with the echelons of management hierarchy. The decisions of top management are strategic, relating to the long-term future of the organization. In a mineral organization, these deal with such issues as the acquisition of a new mineral property or the diversification of the business to exploit additional markets. At the operational level, a manager is concerned with decisions pertaining to day-to- day eventualities related to production activities and other short-term needs. In either case, the prerequisite is the timely availability and use of information. The difficulty involved in decision-making depends on the situational aspect. In. many cases, the decisions to be made under given conditions are fairly straight-forward and standard. This may be due to experience gained from decision-making in similar situations in the past. In fact, many decisions in operations management are either repetitive or routine."

Jan 1, 1989

By J. Shawn Peterson, David S. Yantek, Adam K. Smith

Exposure to excessive noise over time can cause permanent hearing loss. Workers in the mining industry are frequently exposed to A-weighted sound levels in excess of 90 dB. The A-weighted sound level at the roof bolter operator’s location can exceed 100 dB while drilling. The National Institute for Occupational Safety and Health (NIOSH) measured the sound pressure at the roof bolter operator’s position and utilized a phased array of microphones with beamforming software to identify noise sources on a roof bolting machine while drilling. The test data indicates the sound level at the operator’s position is dominated by the 2000 Hz through 5000 Hz one-third­octave-band sound levels. The beamforming results indicate that the drilling noise is primarily from two areas: the portion of the drill steel just below the rock and the drill steel-chuck interface. This paper will discuss the methods used to identify the primary noise sources.

By S. H. Ash

California leads the Nation in the number of operating metal mines and the small number of persons employed at individual mines, which reached a minimum irk 1932 with an average of seven men. The mines are scattered over the entire State, which is the second largest in area (155,562 square miles) in the United States. The mines are situated at various altitudes, with portals ranging from approximately 300 feet below sea level to almost 12,000 feet above. Many of the mines can be reached only during the summer, while at others the heat of the regions adds so the difficulties during the summer months Supplied of explosives the use (or, probably more correctly, the misuse) of which constitutes one of California's gravest mining problems; are handled and stored under condition that contribute many hazards. The problem of providing medical care is serious and complicated, especially at small mines and more particularly in the almost inaccessible mountainous regions; instances in which a knowledge of first aid would have been beneficial but was lacking, or when first aid was instrumental in saving life or limb because it was available are too numerous to be mentioned.

Jan 1, 1936

By James E. Hill

The Bureau of Mines has been carrying on an extensive diamond- drilling program during the past 7 years on deposits of strategic and critical minerals . Often the project reports and the drill-hole logs describe the findings only in terms of the mineral being sought at the time . Then , too , results may not always be interpreted alike by several mining engineers , and the cores therefore provide a permanent tangible record to complement the project reports . The cores from projects in the eastern divisions are being stored at the Mount Weather Testing Adit . Core from a representative hole ( or skeletonized sections from several holes , if these are more representative ) is selected at each project and shipped to Mount Weather for permanent storage . At the Testing Adit an underground room was prepared and storage racks were installed . Wooden core trays designed to accommodate cores of various sizes were purchased .

Apr 1, 1947

By Donald O. Capstick

In 1981, U.S. Bureau of Mines personnel conducted a survey of claims and prospects in the Wheeler Ridge RARE II area to determine if mineral resources or potential for resources exists at deposits in the area. Results of Bureau of Mines investigations indicate the area contains no identified mineral deposits. However, the geologic setting at the Round Valley Peak Prospect near the center of the study area is considered to be favorable for the discovery of tungsten resources with associated molybdenum and copper. Tungsten deposits, should they be present, would be expected to occur at depth in tactite at or near the calcareous rock-granite intrusive contact. Sand, gravel, and stone deposits in the area are not considered to be resources because equal or better quality material is available closer to major markets. INTRODUCTION The 16,200-acre (6,560 ha) Wheeler Ridge study area is 11 mi (18 km) northwest of Bishop, California, on the eastern flank of the Sierra Nevada range. The John Muir Wilderness adjoins the study area's western boundary (fig. 1).

Jan 1, 1983

"The Generic Mineral Technology Center on Respirable Dust was established in August 1983, at the request of the Bureau of Mines, to conduct research that affords ""...each miner the opportunity to work underground during the period of (his/her) adult working life without incurring any disability from pneumoconiosis or any other occupational disease"". The Center consists of the Mining and Mineral Resources Research Institutes (MRI) of The Pennsylvania State University (PSU) and West Virginia University (WVU) in association with the MRIs of the Massachusetts Institute of Technology (MIT) and the University of Minnesota (UMN). (FIGURE 34) Michigan Technological University (MTU) is also affiliated with the Center in the area of diesel particulates.The Center brings together experts concerned with particles causing potentially disabling or fatal diseases including pneumoconiosis (""black-lung""), silicosis, and asbestosis. The latter is of deep concern not just to workers in the mineral sector of the economy but also to the general populace. The primary goal of the Center is to reduce the incidence and severity of respirable dust disease through advancing fundamental understanding of all aspects of respirable dust associated with mining and milling, and the interaction of dust and lungs. The research program of the Generic Mineral Technology Center explores these scientific, engineering or medical concerns with the objective of refining existing strategies and developing new respirable dust control techniquesand technology that are consistent with the fundamental dust-lung interaction processes that lead to mine worker disability. The work concentrates on five areas (FIGURE 35):"

Nov 1, 1988

By Oliver Bowles, J. E. Crawshow

A line of cordeau detonating fuse was placed in hole No. 2, no electric detonators being used in the hole. After 12 or 13 cases of 40 per cent nitro starch powder had been poured into the hole in loose form, it was found that a space of only 17 ft. remained for stemming. It was decided that space for an additional case of powder might be obtained by tamping the charge. The tamping was done with a heavy plunger, about 3 or 3 inches in diameter and 10 inches long, made of lead with an iron core with an iron eye in the top to which a 3/4 inch rope was attached, and weighing between 30 and 40 pounds. This weight was intended for use in sinking explosive in wet holes, and not for tamping. It is estimated that the tamping had continued at least 10 The quarry superintendent had gone a considerable distance for a box of powder, returned, and reached a point about 10 feet from the hole, minutes.

May 1, 1920

By Erle C. Donaldson

The pendant drop interfacial tensiometer is being used to study interfacial phenomena that influence the production of crude oil. A description of the instrument showing the modification of the cell and cell holder is presented. The modified cell and cell holder allow formation of a precise and reproducible drop size, and the image of the drop is easily alined and focused. Interfacial tension measurements and observations of film formation can be conducted at various temperatures with the jacketed cell.

Jan 1, 1967

By W. R. Reed

A computer model named the "Dynamic Component Program" (DCP) was specifically designed for predicting the dispersion off dust from haul trucks at surface mines. Validation of the DCP was completed by comparing its results with the results of the 1SC3 model and with actual dust measurements taken front two operating mine sires. Comparisons of the field measurements, predictions of the ISC3 model and the predictions of the DCP demonstrate that the results from the DCP represent, on average, an 85% improvement truer the ISC3 dust dispersion model results.

Jan 1, 2008

By E. H. Denny

A most interesting safety record has been made by the Colorado Fuel and Iron Co. s. Robinson ho. 1 mine located at Walsen, Cola. Mr. J. L. McBrayer has been superintendent of the Robinson No. 1 and 2 mines for the past 2 1/2 years, and Mr. David Muir has been foreman of the Robinson No. 1 mine since June, 1913. The last fatal accident at Robinson No. 1 mine occurred on July 27, 1915, and the tonnage produced at this mine since July 28, 1915, has been as follows:.

Jan 1, 1929

By Constantine C. Popoff

During 1946 several high-grade limestone deposits in western Washington were examined by the Federal Bureau of Mines. The purpose of the examinations was to disclose new sources of industrial limestone and to indicate the commercial potentialities of little-known and undeveloped deposits. These examinations were part of a long-range program of investigation of mineral resources of the Pacific Northwest. The following report on the Whitechuck travortine deposit is one of a series prepared in the course of the investigations.

Jan 1, 1949

By D. S. DeLong, A. Giza, D. G. Fraser, V. A. Robinson, T. B. Whitmoyer, J. E. Sneckenberger

"A cotton dust animal exposure system has been modified to incorporate a microcomputer feedback loop to monitor particle concentrations. The loop's major components are a minature real-time aerosol monitor (miniram) to estimate concentrations and a microcomputer to read the miniram's data and to control a stepper motor that adjusts the amount of dilutant air mixing with respirable cotton dust. Ninety minute trials of this system indicate that the standard deviation of particle concentrations is within 0.68 Mg/m3 of the average concentration, insuring a near constant concentration of respirable dust throughout the exposure.INTRODUCTION Previous workWeyel et al. (1984) have determined that respirable cotton dust can be shaken from bulk cotton samples using acoustical energy. The particle generator designed to utilize this fact operates like a commercially available sonic sifter, but on a much larger scale.While this generator successfully resuspended trapped respirable cotton dust, the generator output concentration decreased exponentially with time. This disadvantage was solved by Frazer et al. (1986) by operating the generator with a sinusoidal voltage near the minimum resonance frequency of the generator. This adjustment enabled the generator to produce respirable cotton dust for six hours or longer.Frazer et al. (1987) utilized the modified acoustical generator to produce a cotton dust animal exposure system. The cotton dust concentrations were estimated by a miniram, a light scattering aerosol Monitor. The system operator used the miniram values to adjust the system's parameters to maintain the desired concentration level.PurposeThe objective of this study was to introduce a computerized feedback loop to the operator controlled cotton dust animal exposure system. The miniram's estimates were analyzed by a microcomputer to determine what adjustments in the flow of dilutant air were necessary to maintain the desired cotton dust concentration. These modifications were intended to improve system performance and ease the system operator's work burden."

Jan 1, 1988

By N. F. LeJeune

For a number of years the Bureau of mines has conducted semi-annual surveys to determine the changes in the characteristics of the motor gasoline being sold in the United States. The Bureau of Mines surveys, from April, 1917, to January, 1943, indicated a progressive decrease in the end point range. The survey for July, 1923 showed an interruption in this progressive decrease. This interruption, as shown in Table 1, in the line marked "Difference," was apparently a definite one, for the data obtained in the surveys of July, 19233, January, 19244, and the present one, apparently substantiate it. The figures in Table 1 were obtained by averaging the end points of the least volatile and most volatile samples of gasoline. For example, of 850 samples analyzed in 1919, the 10 per cent (85 samples) having the highest end points and the 10 per cent having the lowest end points were grouped, and the end points of each group averaged. These averages are represented in the table as the "Maximum 10 per cent" and the ?Maximum 10 per cent," respectively. The same scheme was used on the succeeding surveys.

Jan 1, 1924

By S. H. Katz, J. J. Bloomfield

Fires in zinc dust have sometimes given particular trouble owing to their resistance to extinguishers and the liability of explosions . Similar problems , notably with aluminum dust* , have previously been subjects of investigation by the Bureau of Mines .

Mar 1, 1922

By A. Z. Dimitroff

An improvised rock-dust disseminator, consisting of a 10-gallon galvanized metal milk can that dispenses rock dust in return air currents by the injection of compressed air has reduced the float dust explosion hazards at the Koehler coal mine, Koehler, N. Mex.

Jan 1, 1965