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By R. T. Sorensen

Bench-scale and continuous testing were performed to adapt the anionic process for flotation of calcium activated silica to the fine-grained hematitic-goethitic jaspers from the Marquette range, Michigan. These ores typically contain about 35 percent Fe and require grinding to about 80 to 100 percent minus 400 mesh to insure an adequate liberation of gangue from the iron oxides. A method for removal of troublesome slime fractions without excessive iron loss, by first dispersing the quartz and then selectively flocculating the iron oxides, was evolved in the laboratory and successfully accommodated to pilot plant practice. The efficiency of the flotation process was improved with respect to both reagent usage and concentrate grade and recovery by using the selective flocculation-desliming technique as a pretreatment. The benefits of the combined desliming-flotation procedure were most evident in pilot plant processing. The best tests on two ores yielded recoveries of about 84 percent in concentrates containing 65.1 percent Fe and 4.8 percent SiO2 and 66.2 percent Fe and 3.9 percent SiO2, respectively. These results are in comparison to recoveries about 10 percent lower than the above to concentrates containing 63.9 percent Fe and 6.6 percent SiO2 in the one instance, and 63.6 percent Fe and 7.2 percent SiO2 in the other, obtained by flotation without the prior desliming treatment.

Jan 1, 1967

By Alan Mayton, N. Kumar Kittusamy, Christopher Jobes, Farid Amirouche

Industrial equipment exposes individuals to whole-body vibration (WBV) and mechanical shock. This exposure can negatively impact their health, safety, comfort, and working efficiency and performance. Accordingly, proper seat design is an important consideration in reducing the adverse effects of WBV exposure to vehicle operators. Since the human body is sensitive to low frequency WBV, ride quality is a basic and important element of good seat design. When designing a suitable seat, it is essential to understand vibration exposure environment of workers and how well they can tolerate this environment [1]. This is particularly true in the mining industry. Mayton et al. [2] reported on a low-coal shuttle car seat design that underwent limited, yet successful underground mine trials. Building on this work, a follow-up study compared NIOSH and existing seat designs on low- and mid-coal seam shuttle cars. The NIOSH seat designs included viscoelastic foam, which has properties similar to those found in a mechanical spring/damper suspension system. The seats also included an adjustable lumbar support and a fore-aft seat adjustment. The NIOSH seat designs contrast with the existing seat design, which have little or no lumbar support and include inexpensive foam padding of the type commonly used in furniture. This paper will focus on the seat designs for the mid-coal seam shuttle car and compare subjective comfort data collected from five vehicle operators with ISO 2631 – based reduced comfort boundary (RCB) analysis of recorded vibration levels. Methods Experimental data were collected using three different tools: triaxial accelerometers, pre-amplifiers, and filters connected to a data recorder; a visual analog scale (VAS); and a short questionnaire. Researchers recorded quantitative or objective vehicle vibration data to determine the input and output acceleration at the operator cab floor and operator seat interface. Qualitative or subjective data, collected with the VAS, allowed researchers to obtain the operators’ immediate impressions of shock, vibration, and discomfort levels for the vehicle ride on each of the seat designs. Each shuttle car operator made six round trips with the vehicle each seat. The shuttle car operator marked the VAS on the first, third, and sixth round trip of the trials for each seat. A round trip consisted of traveling to the coal face with no load and returning to the load discharge location with a full load of coal. Results Total overall average ratings for the five vehicle operators of the mid-coal seam shuttle car, showed that operators sensed from 45 to 87% less discomfort with NIOSH seat designs compared to the existing seat design. Using a 95% CI, researchers computed a strong positive correlation for discomfort. Figure 1 illustrates the RCB analysis method for one of two NIOSH seat designs.

Jan 6, 2006

"The mission of the Respirable Dust Center is to enhance the health, safety and productivity of the miners 'through advancing the fundamental .understanding of all aspects of respirable dust associated with mining and milling and the interaction of dus.t and lungs for reducing the incidence and severity of respirable dust disease. All Dust Center activities are focussed to be responsive to this mission which is shared by several federal agencies closely associated with the Generic Mineral Technology Center for Respirable Dust such as USBM, M,SHA, and NIOSH, and the mining industry. While significant progress has been achieved in making mine atmospheres cleaner and healthier, respirable dust disease remains the nations worst industrial hazard. GOALSThe goals of the Respirable Dust Center have been formulated to recognize the diverse scientific, engineering and medical aspects of respirable dust as well as the need to enhance the interaction, education and technology transfer in the respirable dust area.The Center goals are to:1. Enhance the understanding of the scientific, engineering and biological characteristics of fine and respirable mineral particles, fibers, organic aerosols, and complex particles found in the mining and milling atmospheres.2. Advance the understanding of the physical behavior of airborne respirable dust particles in flowing streams under different. stimuli during mining and milling.3. Advance fundamental understanding of the causative mechanisms for the occupationally related lung impairments and the airway diseases of mine and mill workers.4. Establish the relationship between natural and cultural factors (mine geology, mineralogy, mining and milling methods, equipment and control measures) in the generation, exposures, and pathogenic properties of fine particles.5. Contribute to the development of control mechanisms for reducing ambient respirable dust concentrations, worker exposure, the incidence and severity of dust related lung disorders and disease prevention in mining and milling atmospheres.6. Enhance functional integration among the various research personnel in the Center, as well as, with other groups, such as MSHA, NIOSH and USBM involved in respirable dust research and control.7. Develop technically trained personnel for employment in the mineral industry for respirable dust research and control.8. Enhance the availability of respirable dust-related information utilizing several technology transfer avenues."

Jan 1, 1990

By Katherine A. Margolis

Refuge Chamber Expectations Training was created by a multidisciplinary team at the National Institute for Occupational Safety and Health (NIOSH) to inform miners of what to expect psychologically and physically if it became necessary to use a refuge chamber in a mine emergency. The presentation can be used either for one large group or for individual miners. The training is a multimedia Adobe Flash presentation containing pictures, audio, video, and interviews with miners who have used a refuge chamber in an emergency. It must be run on a computer with Adobe Flash Player installed (refer to the computer system requirements section).

Oct 1, 2009

By W. A. Cole

This report covers the preliminary phase of an investigation of some clays and shales and other materials in North and South Dakota to determine the feasibility of lightweight -aggregate manufacture in the two States. The background of the light - weight -aggregate industry, on a national basis, and results of preliminary laboratory testing of samples of North and South Dakota clays and shales from various localities are presented herein. The countrywide search for lightweight aggregates was necessitated toward the end of the 19th century by the change in building design from thick, heavy, load- bearing walls to a framework of structural steel .beams and columns with thin walls, followed shortly by the use of reinforced concrete and structural concrete as materials for the load-supporting frame. Ordinary concrete, with sand and gravel aggregate, weighs about 150 pounds to the cubic foot. A lighter concrete was needed to relieve the dead load and make it possible to construct higher buildings or add stories to existing buildings.

Jan 1, 1954

By Pamela J. Watson

The U.S. Bureau of Mines has demonstrated in laboratory tests that drilling with surface-charge-neutralizing concentrations of polyethylene oxide (PEO) polymer solutions simultaneously improves penetration rates and extends bit life. The applicability of this additive to improve drilling performance in coal measure rocks was demonstrated under field conditions at an abandoned mine land site in Pennsylvania and a producing coal mine property in Ohio. Penetration rate improvements ranging from 15 to 50 pet were obtained when core drilling through a variety of coal measure lithologies. Drilling cost analysis indicates that the small added cost of using the polymer is more than offset by the savings that result from demonstrated increased drilling penetration rates, which translate into drilling cost savings of about 10 to 30 pct. This report also gives chemical analyses of a variety of coal measure rocks and some corresponding local drilling water samples, obtained from a wide geographical base, along with threshold concentrations of PEO required to effect the improved drilling performance in these rocks. From these data, the threshold PEO concentrations needed to ensure improved drilling performance can be estimated for any coal measure rock suite. Proper techniques for mixing PEO solutions are also presented.

Jan 1, 2010

By John M. Popovich

Disposing of coal mine waste at the surface has been and continues to be a problem which has yet to be resolved within the coal mining industry. A possible solution to this problem is to return the refuse back into the operating underground mine generating the waste material. It is believed that the approach described will provide an inexpensive and pratical solution to the problem. The designed system is installed and operable at the Millers Cove Energy Company, Inc. property in Lee County, Virginia. This system limits surfact facilities to a minimum size. It incorporates state-of-the-art hydraulic transport and backfilling technology and equipment to systematically backfill areas within the active mine. It maximized the benefits of reducing treatment of coal wasts while it minimizes environmental impacts on groundwater. The system approaches the problem in a manner to maximize benefits and minimize risks. The cost of returning coal waste back underground at the Millers Cove site is estimated at $0.67 per ton of marketable coal (1982 dollars), which is slightly higher than their surface disposal cost of $0.61 per ton of marketable mat (1982 dollars). The underground disposal costs do not include cost savings that should be realized within the preparation plant and treatment facilities at the surface. Preliminary tests of the system were conducted at the surface; funding restrictions prevented an in-mine trial. Efforts should continue to demonstrate the feasibility of solving the problem of refuse disposal. The installed system and plant at Millers Cove should provide the opportunity to test an underground disposal operation. This report contains guidelines to pursue this opportunity.

Jan 1, 1986

By L. A. Eros

The U.S. Bureau of Mines and Western Fuels Utah, Inc. entered into an agreement to plan, install, and evaluate a micro-computer based monitoring and control system at Deserado Mine, an underground coal mine. The U.S. Bureau of Hines contracted the Colorado School of Mines (CSN) to independently evaluate the project. CSM evaluated and documented costs, benefits, problems, and management and labor perceptions in this report. Recommendations are provided for mine operators and monitoring system vendors considering future installations.

Jan 1, 1986

By David L. Veith

This report summarizes a Bureau of Mines review of selected literature on the effects of subsidence due to high-extraction underground coal mining on farmland areas. The data are presented for consideration in evaluating the subsidence effects due to similar mining techniques on the prime farmland areas of Illinois. In Illinois the ground water level in the glacial drift is only 2 to 15 ft below the nearly flat to gently rolling ground surface. The main subsidence concern is flooding, as caused by the lowering of the ground surface, and the subsequent effects on crop production. Positive drainage must be maintained in the farmlands, and the need exists for extensive regional planning by the mining and agricultural industries to maximize short- and long-term production from both efforts. The Bureau is cooperating with the State of Illinois to develop basic information necessary for such planning.

Jan 1, 1987

By C. A. Geffen-Fowler

This report, sponsored by the Bureau of Mines, presents the results of an examination of the safety of the Blind Shaft Borer (BSB) shaft sinking system and an alternative modified BSB design concept in comparison to conventional shaft sinking technology. Detailed study of the two systems was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the BSB systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the two BSB systems was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that both BSB systems are safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by over 30%, on the average, with the use of the original BSB system, and by an average of about 10% with the modified BSB. Design change recommendations to further improve the safety of these systems include better fire suppression systems, improved man haulage systems and more compact hydraulics. An operational safety manual was also developed for the modified BSB system.

Jan 1, 1981

By R. J. Leary

This investigation was conducted to determine the effects of various rare-earth metal addition practices upon the macrostructure and the pattern of sulfur distribution in steel ingots. Heats of plain carbon steel were melted in a 1-ton, basic electric-arc furnace. Melts were treated with mixtures of rare-earth silicides, aluminum, and cryolite either in the furnace before tap or in the ladle after tap to determine the effects of this form of rare-earth treatment upon ingot macrostructure. Steels thus treated with rare earths in the furnace were characteristically free of the gross subsurface nonmetallics which typically result from conventional rare-earth treatments. Steel treated in the ladle showed only a few such nonmetallics, and practical techniques were developed for eliminating most of these. Results showed that furnace deoxidation was controlled by the concentration ratio of rare earths: aluminum. During casting, deoxidation was controlled by the concentration of rare earths. Oxygen contents equivalent to vacuum ladle degassing resulted from air-melt furnace treatments with the rare-earth mixtures described. Rare earths in steel inhibited the onset of equiaxed grain formation during ingot freezing, and also virtually prevented interdendritic segregation of sulfides.

Jan 1, 1968

By H. N. Dunning

A comprehensive research program designed to aid development of new and improved methods for more complete production of petroleum from partly depleted reservoirs is being conducted at the Bureau of Mines Petroleum Experiment Station, Bartlesville, Okla. Water flooding has accounted for much of the petroleum produced by secondary-recovery methods; however, a considerable portion of the crude oil commonly remains in place after water flooding has been terminated. In recent years the possibility of increasing the efficiency of water flooding by using surface-active additives has received wide attention. In general, the results of laboratory research have shown that use of detergents as water-flooding additives will reduce the residual petroleum in porous media (1).3/ Some less extensive field tests have supported this conclusion but have not been entirely conclusive (2). Later studies (3, 4) have given conflicting evidence as to the relative worth of detergent additives for water floods in water-wet (hydrophilic) or oil-wet (hydrophobic or lipophilic) reservoir materials. The results of these studies emphasize the need for a more complete understanding of the fundamental principles involved in displacing petroleum from reservoir surfaces by injected fluids. Accordingly, a comprehensive research program was initiated to investigate the practical and fundamental aspects of detergency in petroleum production.

Jan 1, 1953

By P. R. Bradley

This paper is one of a series , dealing with mining methods and costs , sponsored and published by the U. S. Bureau of Mines . Papers of this series are written by engineers and executives of mining companies , at the solicitation of the Bureau , and in accordance with an outline prepared by Bureau engineers , for the purpose of securing uniform presentation and conformable data . The property of the Alaska Juneau Gold Mining Co. is situated near the city of Juneau , Alaska , in what is known as the Harris mining district . Wholesale mining operations have been adopted on a large scale and 10,000 to 11,000 tons per day of gold- bearing ore are mined and sent to concentrators near Juneau . In addition to gold , the ore yields 0.6 ounce of silver and 13.0 pounds of lead to each ounce of gold recovered .

Oct 1, 1929

By N. B. Aughenbaugh

This report summarizes the results of an investigation into the causes of coal mine roof instability caused by the environmental characteristics of the air ventilated through a mine. The field studies, which were mostly in the Illinois Coal Basin, concentrated on collecting data of surface weather conditions, mine air characteristics (relative humidity and temperature), roof material types, roof movements, and characteristics of roof deterioration. The field studies revealed seasonal changes in weather are reflected in the mine air. The intake air undergoes rapid tempering along its course as it interacts with the ambient mine conditions. There are seasonal moisture interchanges between the mine rock and air, and a mine will lose more water than it gains on a yearly basis. The field studies also established that when the roof rock is shaley, seasonal changes in the humidity will cause roof deterioration because of the detrimental action of moisture on the shale. Roof falls were inventoried and classified by geometry. In the laboratory investigations, physical tests proved unreliable for evaluating shales for roof stability. The Franklin slake test lacks the sensitivity needed to differentiate shale durability for roof stability. A relative humidity test that reveals the sensitivity of a shaley rock to moisture change was devised. Environemntal chamber studies showed that neither temperature nor barometric pressure have a direct influence on shale durability. Photoelastic studies showed that the rate and depth of moisture absorption into a shale is controlled by bedding planes, fractures, and holes interrupting the exposed surface.

Jan 1, 1976

By O. C. Blade, Elizabeth Hughes

Conservation in the utilization of any product is always subject to improvement if the composition and properties of the product are known. Petroleum is no exception, and knowledge of the characteristics of crude oils, even when given on the broad basis of routine type analyses has proved useful to chemists, engineers, and geologists in improving pro- duction and utilization of petroleum. For a quarter of a century the Bureau of Mines has sought to provide such information regarding crude oils and has analyzed many samples of petroleum by its standardized rou- tine method. Most of these analyses have been published, sometimes in special compilations, other times in connection with reports of research on petroleum. This report is a finding index for all analyses published up to January 1, 1948. The routine method used for all these analyses is basically the same as that described by Dean, et al.. Briefly, the procedure consists of testing by standard methods, small samples of a crude oil for gravity, sulfur, color, and viscosity, and of distilling a sample of the crude oil by a standardized procedure and determining certain properties in the sep- arated fractions and residuum. Careful records are made during the proce- dure, and the distillation data obtained are used to calculate the approx- imate amounts of products present in the sample such as percents of gas- oline, kerosine, gas oil, and lubricants. The data obtained are recorded on a standard analytical report form. An analysis of a sample of typical midcontinent crude oil is shown in table 1. Compilation of these analyses, sometimes in tabular form and usually for specific geographic areas, are published from time to time. Analyses are often shown in connection with other studies, such as engineering field reports. This bibliography is a compilation of references to 115 publications, which contain analyses of crude oils by the Bureau of Mines. References may be found to analyses of crude oils from the United States, Canada,

Jun 1, 1948

By Paul M. Tyler

The colony of French Guiana ( or Cayenne ) is administered by a governor , assisted by a privy council of five members . A council - general of 16 members is elected by French citizens resident in Guiana, and the colony is represented 3 in the French parliament by one deputy . The area is about 34,740 square miles . French Guiana is the largest gold producer of the French colonies , producing nearly $ 1,000,000 worth annually . Considerable prospecting has been done on the bauxite deposits , which are extensive . Copper , iron , lead , and 4 mercury deposits are also reported . In 1931 , 10,000 prospectors for gold were reported as working . The French Government is taking an active interest and has sent a committee of mining experts to explore the region ; no permits are to be issued to individual prospectors while the committee is in the colony . Plans for development of mining industry include consideration of 4,500 convicts and 2,500 natives already in the colony and available for labor .

Apr 1, 1933

By Charles L. Kusik

A study was conducted for the Bureau of Mines, U.S. Department of the Interior, to provide information which will lead to an increase in the recycling of mineral materials, in order to help conserve the Nation's mineral resources. Data were collected on energy requirements to recycle prompt industrial and obsolete scrap for nine metal commodities: Iron and steel, aluminum, copper, zinc, lead, stainless steel, titanium, tin, and nickel and nickel alloys. Major process routes for recycling were considered, starting from the first collection point through scrap preparation, transportation, smelting and/or refining to the molten metal, ingot, or other semi- finished form approximately equivalent to a primary metal of a similar composition. Available data for 1976 were collected on the amounts of each metal commodity recycled by major scrap categories. In addition, energy requirements were estimated for separating municipal solid wastes into four major categories: Refuse-derived fuel, and magnetic, aluminum, and glass cullet fractions. Finally, areas of research were identified to enhance recycling and/or increase the efficiency of energy use.

Jan 1, 1978

By E. P. Youngman

The mining law of British North Borneo is entitled " The Mining Ordinance , 1927. 113 The only mining regulation or rule available is " Rules 313 , 114 passed in accordance with article 26 of the ordinance of 1927. Before the passage of this legislation , the country had no specific law governing the granting of mineral rights , although the land law contained provisions relating to mining lands . The land ordinance of 19135 still controls in a few details . All references in this paper , unless otherwise specifically designated , are to the mining ordinance .

Mar 1, 1933

By Michael Rieber

Among the principal gathering/distribution systems for coal is over-the-road trucking. Where alternative trunk line modes such as barge or rail links are weak or nonexistent, trucks may, particularly for relatively short line hauls, act as substitutes. Their major application, however, appears to be in connection with smaller mines or coal users particularly where terrain problems are significant. Truck use has increased as rail lines have been abandoned or suffered neglect. For example, in 1956 about 38 percent of the coal transported in eastern Kentucky and about 8 percent of the coal moved in western Kentucky went by truck. By 1975, the percentages were almost 77 percent and 26 percent, respectively [4,U-11]. While rail route .limitations and deterioration played a part in the change, increased emphasis on road building, particularly during the 1950's and 1960's, and improved truck load capacity and efficiency were also important.

Jan 1, 1977

By H. Netuka, J. V. Horak, A. W. Khair

"A general review of major problems concerning mathematical modelling of roof bolting problem is given. A mathematical model (MM) of interactive set Bolt - Resin - Rock and its discretization based on the Finite Element Method (FEM) is developed to calculate numerically course of displacement, stress and strain fields in this set. This new MM enables to get also course of the normal and tangential components of contact stress vector, normal displacement and then mutual tangential slip at the bolt - resin and resin - rock interfaces, respectively.Behavior of system on all interfaces is modelled in the MM as a ""unilateral contact"" governed by so called non-classical boundary condition of Signorini's type including Coulomb's law of friction between resin and rock, and ""a given friction"" law between bolt and resin (see Duvaut, Lions (1972) for mathematical formulation).Numerical example and some values of resulting stresses are shown and remarks on necessary and sufficient conditions for solvability of the problem are also given.IntroductionAs is well known roof bolting has become the primary support system in almost all underground coal mines. But the ""theoretical"" design criteria for roof bolt patterns are rather problematic because: "" ... real mechanisms by which the roof bolts reinforce the immediate roof of underground coal mine entry are still relatively unknown"", see Peng (1986).The aim of this contribution is to present brief description of fundamentals of mathematical theory (see Hlavacek et al., 1988) which could be, according to our opinion and knowledge, very helpful for numerical modelling of a such type of problems. For the sake of brevity we restrict ourselves here to just one of the simplest possible problem: analysis of the behavior of interactive set composed by only single full - length - grouted bolt, resin (or cement) and suitable part of domain of a ""immediate"" neighborhood of bolt which should represent physical action of real rock material."

Dec 1, 1995