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By L. C. IlsLey

"There are two general classes of accidents that prevail in and about mines, namely - (1) those that through the nature of mining work can only be lessened, and (2) those that by proper precaution can be eliminated altogether. Explosive accidents that ordinarily take place while explosives are being transported in and about mines belong to the second class, that is, by proper care all such accidents can in general be avoided.The following table gives a brief summary of several accidents and disasters that have occurred in the United States and indicates the need of universal preventive measures as a basic part of all State regulations.ACCIDENTS AND DISASTERS OCCURRING WHILE TRANSPORTING EXPLOSIVES.***"

Sep 1, 1923

To develop more accurate means of measuring low ventilating air velocities in underground mines to facilitate compliance with ventilation standards. The Approach: A commercially available vane anemometer which produces an electrical, rather than a mechanical, output was coupled to electronic circuitry to produce the Bureau's Digital Low Velocity Anemometer (see photo). [ ] How It Works: The experimental instrument has a vane anemometer head which produces an electrical output signal with a frequency directly proportional to the rotating speed of the vane anemometer shaft. The commercially available ABBIRKO FLOWMASTER anemometer head was used in this instrument. In the signal conditioning circuits the electrical signal from the anemometer is converted into pulses, which are counted during either 3-second or 1-minute intervals, depending on the position of the operator's control switch. (Readout is either "instantaneous" or averaged for a period of one minute.) The number of pulses counted is then translated (integrated and divided by a constant) in the logic circuits to get average speed. Average air velocity in feet per minute is displayed in illuminated digits. (See simplified diagram of circuitry.)

Jan 1, 1975

By G. A. Bole

"This paper presents a review of the literature and is an epitome of work acne and articles published by Schurecht, Robson and Andrews', in the investigation of the feasibility of making basic refractories from dolomite, was carried on successively by these men, at the Ceramic experiment Station of the Bureau of Mines, Columbus, Ohio.Scope of the work.The dolomite refractories investigation of the Ceramic Station includes a study of the many fluxes which could be used to aid in the dead-burning of dolomite and also a complete survey of the iron oxide-alumina-silica field as fluxes. The temperature of calcination and the resulting properties have been carefully investigated, and the most desirable calcines chosen for further investigation in the making of dolamite bricks. Many binders and the several methods in common use of fabricating bricks commercially were tried, and a thorough study was made of the properties of the most successful ware,Previous Investigators.Even before the World War, considerable work was done on dolomite this war greatly accelerated the efforts of the many Investigators."

Jul 1, 1924

Demonstrate the technical feasibility of using nontraditional, low-rank, coal-based fuels and new coal-based technologies for mineral and metallurgical applications. Approach A cooperative research effort was initiated between the Bureau of Mines, U.S. Department of Energy and the minerals industry to extend the application of the fixed-bed gasification process to low-rank Western coals. The research effort enabled cooperators to gain operating experience in the use of hot, raw producer gas for iron ore pellet induration and other high-temperature mineral processes. Researchers were able to gather data regarding the fundamental engineering aspects of the fixed-bed process and gas cleanup for a wide range of solid fuel properties. Applying Fixed-Bed Gasification As a prerequisite to gathering the data needed for the study, the Bureau of Mines designed and installed, at one of its laboratories, a 6.5-ft-diam. single stage, fixed-bed, air-blown atmospheric pressure gasifier. The gasifier was coupled with a hot, raw gas combustion system and iron ore pellet in. duration kiln. The gasifier is rated at 1.5 ton/h capacity of bituminous coal.

Jan 1, 1987

By Herbert H. Einstein

Appendices A through M contain information that is the basis for many developments reported in the main text (Parts I through V); this information is, however, not needed in applying the research results. Specifically the appendices contain: A: Geology of Sampled Sites B: Comparison of Distribution Forms with Observed Trace Length Frequencies C: Joint Attitude Pole Diagrams D: Resistance and Deformability of Rock Discontinuities E: Resistance and Deformability of Joints - Details of Data Recording Procedure F: Documentation and Details for Simplified 2-Joint Wedge Analysis G: Generalization of the Stiffness Approach H: Inadequacy Due to Simplifying Assumptions in Wedge Analysis I: Rock Slope Reliability Analysis: State of the Art J: Resistance Derivations for Mechanical Model K: Supporting Derivations for Analysis Method DAYLITE L: Supporting Derivations for Simplified 2-Plane Reliability Analysis M: Plots of SLOPESIM Runs

Jan 1, 1979

By Terry J. Close

In 1986 and 1987, at the request of the U.S. Bureau of Land Management, U.S. Bureau of Mines personnel studied 7,040 acres of the 7,240-acre Sheep Mountain Wilderness Study Area (OR-006-003) in order to evaluate its identified mineral resources. The area studied is along the divide between the Snake River and Pine Creek about 1.5 mi south of the village of Oxbow in Baker County, OR. No mineral resources or mineral-related activities were identified in the Sheep Mountain study area. The basalt covering most of the study area has no known mineralized sites. However, it contains common agate and opal that is of limited interest to mineral collectors. This basalt (stone) could be used locally as construction material (crushed stone or fill); however, suitable material is wide spread in the region and more accessible to possible markets.

Jan 1, 1987

YOUR mom was right …count to 10. Most workers today report that they find their jobs stressful. Miners, in particular, are faced with hazardous and changing environments. Every shift provides different conditions and challenges. Coping with stress is an important tool to maintain your physical and mental health. Now, back to mom. Studies on stress tell us that shifting your focus away from what is causing your stress increases your ability to cope. Counting to 10 is one method. Science proves mom right. The stress response We are born with the stress response, which is a survival instinct, sometimes called the "fight or flight" response. When approached by a tiger in the jungle, our ancestors would perceive danger and prepare to fight or run. The body prepares for the fight or flight response in a number of ways. The bloodstream brings extra glucose and oxygen (fuel) to the heart, the sense of pain is dulled, and memory and thinking improve. The pupils dilate for better vision and the lungs take in more oxygen, while heart rate and blood pressure increase. Body hairs become erect, as puffed-out hair makes an animal look bigger and more dangerous. Once the perceived danger is gone - we have run fast enough to get away from the tiger or won the fight - the body returns to normal functions. Unfortunately, civilization gives us too many opportunities to experience this response. If activated too often, it can create wear and tear on the body, which may lead to injury and illness. Chronic and traumatic stress There are two key types of stress: chronic stress and traumatic stress. Both types can cause both physical and psychological symptoms. Chronic stress builds up from the day-to-day hassles. Traumatic stress results from a traumatic event such as a natural disaster, a mine disaster, or the sudden death of a loved one. Chronic stress is associated with an increased risk of a number of health problems including heart disease, depression, back pain, and carpal tunnel syndrome. Traumatic stress may lead to post- traumatic stress disorder (PTSD), Miners may experience both chronic and traumatic stress in their work.

By T. H. Jeffers

The Bureau of Mines conducted a laboratory investigation of copper electrowinning from electrolytes produced by solvent extraction. The purpose of the research was to gain a better understanding of the fundamental relationship between copper electrowinning conditions, anode corrosion, and cathode purity. Processing variables were evaluated in a cyclic semicontinuous system in which the depleted electrolyte was used to strip copper from loaded organic extractant. For the production of high quality copper cathodes, the electrolyte was dosed with cobalt and stripped of organic solvent extraction reagent. An optimum cobalt addition of 60 ppm, and removal of the entrained extractant with activated carbon provided the best conditions for electrowinning copper containing the least amount of lead and controlling anode corrosion. As little as 13 ppm of the entrained organic extractant, LIX 64-N, significantly accelerated anode corro-sion. However, the addition of 1,000 ppm of organic diluent kerosine did not affect anode corrosion. After cobalt dosing and removing the entrained extractant, cathodes containing less than 2 ppm lead were consistently electrowon at widely varied current densities, electrolyte copper and acid concentrations, and temperatures. Dosing of the electrolyte with selected impurities including magnesium, aluminum, manganese, and iron did not affect the cathode purity. However, 0.05 giL of chloride ions markedly increased anode corrosion and the sub-sequent transfer of lead to the cathode copper.

Jan 1, 1985

[This Report represents the culmination of work perfomed under Contract No. .,JG1551A8 for the U.S. Bureau of Mine.The &apos;.:o-< embeded a site evaluation, engineering E:-y- ,, esign, and preparation of specifications for construction of a Transport Research 7 :4 (HTRF)The HTRF is designed as a research facility J evaluate the hydraulic transport of large lump coal at a prototype ;e scale. The HTRF is to be constructed and operated by the Pittsburgh and Safety Research Center of ;. re U.-AN a*, their Bruceton, Pennsylvania test center. In terms of technical capability, the HTRF will have transport pipeline:: of -, twelve-, and eighteen-inch diameter _&apos; with supporting coal handling n , water forage a.^ &apos;d conveyance, mixing, pumping, and dewatering equipment, plus instrumentation and controls. Maximum design velocity 13 20 ft/sec.; solids concentration, by, volume, will; 1 be a maximum-- of sixty, percent. Each test loop is designed to accommodate solids of up to one-third the diameter e - of the pine. The Final Report Pr.-&apos;I-rents information of t HTHF,. including the site evaluation, design criteria, a description of the a description of the procedure to be used for operation of the facility, an estimate of the cost to construct the f^Cilit:r, 1 p el_~lli.&apos;iU construe`, icn Schedule, and a construction suicJ_iicaT.l_ccn&apos;. T e c011SLr?Jc&apos;.ion soecl_ i.on _ccnta_i:s technic.&apos;..i re7,uir: (-n`,s for !&apos;urr1S~ &apos;~latcr..al. and ec-uipr,ent for :":C1 C_`:_C ti on of ti,_ H ice&apos; u:&apos;.:i ._II u s(-.6 for ~.Iir: .3!7 soliciting bids. `.l_o included n cc&apos;;,art_- c?r~.air sV:et..: :s ^nd rr^.?]

Jan 1, 1976

By K. J. Liles

The Bureau of Mines conducted laboratory semicontinuous and continuous heavy liquid tests to determine the feasibility of producing commercial-grade products from the high-clay sylvinite ores of the Permian Basin in New Mexico. Continuous test operations demonstrated that concentrates containing 59.9 percent K2O and recoveries of over 75 percent of the contained potash can be obtained. The organic heavy liquid was effectively recovered by vaporization, condensation, and absorption methods. Less than 5 parts per million of heavy liquid vapors were released to the atmosphere. This loss represents only 0.02 pound of heavy liquid per ton of ore treated.

Jan 1, 1973

By S. Malhotra

Processes for the recovery of manganese contained in low-grade domestic sources are evaluated. Conclusions are based on analysis of literature, technical evaluation and cost analysis. The Nossen Nitric Acid Process, the Sulfuric Dioxide Process rind the Ammonia Leach Process should be developed further as they offer the hunt opportunity for commercialization.

Jan 1, 1984

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 L. J. Froisland

The U.S. Bureau of Reclamation requested U.S. Bureau of Mines (USBM) assistance in developing design data for moving lead-zinc-gold tailings from their current location without disrupting the existing chemically stable conditions. This report presents results of USBM work in determining (1) the minimum required time to air dry the tailings to approximately 20 pet moisture under various drying conditions both in the laboratory and in the field, (2) the degree of oxidation or reduction that occurs during drying, (3) the effect of lime or cement addition before drying, and (4) the likely equilibrium conditions of the dried tailings after deposition at the new location. The limited number of tests performed by the USBM in the available time frame established trends in oxidation levels but did not provide absolute statistical validity of data values. All data from drying and oxidation testing are included in appendices to this report.

Jan 1, 2010

By Laurance L. Oden

The Bureau of Mines is developing melting data for binary combinations of the alkaline earth fluorides and yttria to facilitate the formulation of slag compositions. The present report deals with the CaF2-Y203 system for which solidus and liquidus temperatures and solid solubilities were determined. The information is presented as the phase diagram. All specimen compositions were blended from high-purity materials and encapsulated in Mo or Pt20Rh prior toheat treatment. Liquidus temperatures were determined by ceramographic examination of heat-treated and quenched specimens. Solidus temperatures were determined by differential thermal analysis and by electron microprobe analysis of quenched specimens. Terminal solid solubilities were derived by parametric methods. The peritectic system was found to be pseudobinary due to the formation of yttrium oxyfluoride at temperatures near the liquidus. The peritectic point occurs at 7 mole pct Y203 and 1,438° ± 5°C. The terminal solid solubility of Y203 in CaF2 decreases from 7 mole pct at 1,438° C to 1 mole pct at 1,100° C, and the solubility of CaF2 in Y203 decreases from 9.5 to 7 mole pct over the same temperature interval.

Jan 1, 1970

By John D. Sullivan, Alfred P. Towne

"In copper percolation-leaching plants the ore is usually crushed to a maximum size of about three-eighths inch. Ordinarily an ore is crushed as finely as feasible since the rate of extraction of copper is increased with decreasing size of particles owing to the greater surface exposed and. the shorter path required for solutions to come into contact with the minerals to be dissolved. However, greater degree of crushing also increases the amount of fines. When ores are charged into leaching vats the coarse and fine material tend to segregate, resulting in channeling of solutions and leaving the areas where fines predominate only partly leached. An improvement in the method of charging the ore into vats that would minimize the deleterious effects of the segregations of fines would increase the percentage extraction of copper.The Inspiration Consolidated Copper Co.4 recently installed classifiers to remove the primary slimes from the ore, before charging it into the leaching vats. This necessitates a separate agitation treatment for the slimes.Recent publications5 of the bureau have shown the advantages of agglomeration followed by trickle leaching to extract copper from concentrator tailings. It was shown that when equal parts of ore crushed to about 1/4-inch size and concentrator tailings were agglomerated with approximately 10 per cent of moisture, either in the form of water or leaching solution, and the mass was charred into a leaching vat the ore could be treated successfully by open-drainage trickle leaching. Even with 30 or 35 per cent of minus 200-mesh material present the ore could be leached, if it was not flooded with solution.The results obtained in agglomerating ores and slimes suggested the possible advantages to be gained by wetting the crushed ore for standard percolation-leaching plants before charging it into the vats. Wetting the ore whould make the fine material and slime cohere to the larger pieces of ore thus tend to prevent segregation when the ore is charged into the vats. The bureau, at its southwest Experiment Station and in cooperation with the Department of Mining and University of Arizona, Tucson Ariz., therefore made a study to work: out A way in which slimes could be handled in percolation leaching. The study showed that the method of charging ore into the leaching vats governed the distribution the fines and consequently the rate extraction of copper. The results of the study reported in this paper."

Feb 1, 1931

By Louis R. Iverson

Analysis of seed numbers present in topsoils (a grazed area, an ungrazed area, and two stockpiles) indicated that seeds of the most prevalent colonizers (e.g., Kochia scoparla, Setaria virdis, and Salsolo collins) were not present in the topsoil upon respreading but rather appeared by immigration from the surrounding areas. The grazed site had a seed density of over 7,700 seeds m-2 (of which 43% were from weedy species) and the ungrazed site had 3,900 seeds m-2 (of which 7% were weeds); the stockpiled topsoils had very low seed densities (255 and 520 seeds m-2). Seed densities and diversity decreased with depth on both the grazed and ungrazed sites; this was especially true on the grazed site where 94% of the seeds were found in the surface 7.5 cm. Several species were present in the seed bank (e.g., Hedeoma hispida, Artemesia ludoviciana, A. frigida, and A, abslnthlum) which were also found on the three and four year old mined sites in the aboveground vegetation survey. Seeds from these species may germinate after several years of dormancy, thereby starting populations on mined sites and enhancing plant diversity. Seed bank analysis was also undertaken on mined sites ranging in age of 2 to 6 years (plus an unmined site). Mined site seed densities ranged from 1630 to 3980 seeds m-2, with the four year old site having the greatest density (largely because of high Melilotus spp. populations); unmined site and stockpiled topsoil sample had lower seed densities. A significant positive correlation between total viable seed content and soil-water saturation percentage indicated that soil texture may influence seed viability/ dormancy (the. finer the material, the higher the seed population). As with the previous part of this study (and other studies), there was a poor correlation between the aboveground flora and the belowground seed composition.

Jan 1, 1982

By E. J. Gleim

The importance of "good voltage,? especially for direct-current systems in coal mines, is not always fully appreciated. From the practical 4 aspect there are three viewpoints from which low voltage may be considered, namely: (a) its effect upon operation of electrical equipment, (b) its effect upon cost of maintenance and power, and (c) its effect upon safety in the mine. The design of electrical motor-driven equipment usually is based upon a given or assumed constant value for the voltage of the system; consequently, when there is an appreciable drop below this value, unsatisfactory operation is likely to follow. In the case of shaker conveyors, for example, one manufacturer has pointed out that these conveyors must be operated at a certain definite speed if maximum output is to be secured. As shunt motors are used in the conveyor drives, either a rise or fall in voltage will produce corresponding changes in speed and thus seriously affect the efficiency of the conveyor. The introduction of automatic control for mine equipment has been greatly retarded because the relays, contactors, and other special devices required have failed to function properly when attempt was made to operate them on systems subject to variable and low-voltage conditions.

Jan 1, 1937

By O. C. Blade

In its general study of crude petroleum, the Bureau of Mines has published several reports that include analyses of samples of crude petroleum from Oklahoma fields3/. This report discusses briefly the properties of crude oil samples collects in come of the major producing Yields in the State. ACKNOWLEDGMENTS This investigation was conducted by the Bureau of Mines in cooperation with the State of Oklahoma. The study was via e under the general supervision of R. A Cattell, chief engineer, petroleum and Natural-Gas Division, Bureau of Mines, Whishington, D. C., and N. A. C. Pith, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and. Under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.

Jan 1, 1939

By O. C. Blade

[In its general study of crude petroleum, tic Bureau of Mines has published several reports that include analyses of samples of crude petroleum from Oklahoma fields3/. This report discusses briefly the properties of crude oil samples collects in come of the producing fields in the State ACKNOWLEDGMENTS This investigation was conducted by the Bureau of Mines in cooperation with the State of Oklahoma. No study was made under the general supervision of R. A Cattell, chief engineer, petroleum and Natural-Gas Division, Bureau of Mines Washington, D. C., and N. A. C. Smith, supervising engineer, Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt senior petroleum engineer Bureau of Mines, Bartlesville, Okla.]

Jan 1, 1939

These proceedings consist of an introduction and four descriptive papers. The first paper is an update on fire protection for large haulage vehicles, the second paper is concerned with improved visibility systems for large haul- age vehicles, the third paper is on improved ladders for large haulage vehicles, and the fourth paper is concerned with large haul-age vehicle operator training systems.

Jan 1, 1980