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By Louis C. Brichta

The rapid; depletion of' known high-grade ore deposits in the Tri -State lead-zinc district and the recognized need for the development of additional reserves led the Bureau of Mines to make preliminary examination of sites possibly adaptable to low-cost open-pit mining methods. Abandoned mines whose ore deposits were known to have occurred at shallow depths naturally presented favorable test points for the development of possible open-pit orebodies. The Lone Elm mine was in this category.

Jan 1, 1949

By L. C. IlsLey, M. W. Von Bernewitz

"Introduction.Several hundred thousand open lights are daily carried in coal mines of the United States, each lamp being a menace to life and property through fire or explosion. They have been responsible for many disasters in the past, and will be again. Flame safety lamps have been available for over a hundred years, but during the last ten years safe and practical electric lamps have been perfected. These have eliminated many of the flame safety lamps, and in a few mines have replaced open flame lamps. But there are still more than twice as many open lamps as electric lamps in our mines, and the open lamps should be discarded in favor of an approved type of electric lamp. There are several electric miners' lamps which have been approved by the Bureau of Mines for safety and efficiency, give good light, and are easily maintained and carried, some flame safety lamps will always be used, hut mostly for detecting gas; although they might be supplanted if some simple, reliable, and cheap gas detector were developed.Explosion Hazards from Open Lights.An open light and gas*** constitute a vicious hazard; while if there be coal dust present in the vicinity the consequences are multiplied many times. An open light and black blasting powder also constitute an explosion hazard, vividly attested by several serious disasters."

Jan 1, 1924

By E. L. Burwell

Preliminary results of an in situ oil shale retorting experiment conducted by the Bureau of Mines in a shallow bed of Green River oil shale at Rock Springs, Sweetwater County, Wyo., are described. Eleven wells were drilled into a 20-ft-thick section of the shale lying between 68 and 88 It deep, and attempts were made to connect the wells through the shale with a fracture system created by application of high-voltage electricity (electro-linking), hydraulic fracturing, and explosive fracturing. Ignition of the shale through the central well was easily achieved with a propane burner, and shale oil began to collect in three wells within 3 hours. Propane injection was discontinued after 7 days, and combustion continues, although attempts to control the direction of the combustion front have been unsuccessful. Production rates as high as 4 ½ barrels of nil per day have been recorded, but too little is known about underground conditions to permit an estimate of recovery efficiency at this time.

Jan 1, 1969

By W. K. Tolley

This report presents data collected during research by the Bureau of Mines on corrosion of grinding media. Corrosion rates of eight alloys commonly used in grinding media were tested in synthetic mill water using an ultrasonic grinding device especially designed for this work. Electro-chemical measurements showed variations in corrosion rates for these alloys between 9.8 mpy for medium-carbon steels and 0.14 mpy for high chromium white irons. Bureau data are discussed along with data from the literature to indicate that corrosion causes less than 10 pct of the wear of grinding media in commercial grinding mills. A comparison of corrosion rates for various types of grinding media shows that alloying elements and electrochemically active inclusions in steel affect the corrosion behavior of the media.

Jan 1, 1984

By T. Kessler

As part of a respirable mine-dust research program at the U.S. Bureau of Mines, spark-source mass spectrometry has been used for the semiquantitative determination of trace elements (200 ppm weight or less) in raw coals. In addition, several minor and major elements have been determined using this technique. Sixty-four elements ranging in concentration from 0.01 to 41,000 ppm weight were determined in one anthracite, two mvb, four lvb, and six hvab raw coal samples. The samples represented 10 coal seams located in Pennsylvania, West Virginia, Virginia, Utah, and Colorado.

Jan 1, 1973

By M. J. Sheridan

"INTRODUCTION In December 1942, the-Bureau of Mines reported favorably on a proposal to grant Government assistance-in constructing an access road (consisting principally of a timber-pile bridge across the Rio Grande at Hot Springs, N. Mex.) to the property under lease to the United States Fluorspar Co. At that time the property was being developed actively, and there appeared to be no immediate-need for exploratory or metallurgical assistance by the Bureau of Mines.Because milling facilities were inadequate; the access-read project was eventually disapproved, but prior to disapproval the company had discontinued operations. In June 1943, exploration was resumed by the Humphreys Gold Corporation of Denver, which had subleased the property. Difficulty of access continued to interfere with exploratory progress. In July 1945, at the request of the lessee, the Bureau of Mines directed sampling, using company employees.At the completion of this sampling program, the Bureau of Mines concluded that the property was potentially a important source of fluorite but that further development for production appeared to depend largely on the establishment, by exploration, of adequate reserves. Because of the relatively easy position-of metallurgical-grade concentrate and ores, it also was deemed advisable to investigate the possibility of producing acid-grade concentrate from the ore, for which a demand was becoming evident. Accordingly, a program of trenching, diamond drilling, and metallurgical testing was undertaken by the Bureau. The results of its investigation are reported herein."

Feb 1, 1947

By L. M. Demers, R. E. Edelson, M. P. Rose, D. T. Superdock

The pulmonary alveolar macrophage is a major defensive cell which counteracts the invasive properties of bacteria and particles when these substances invade the pulmonary environment. Pulmonary exposure to coal dust particles is believed to activate these macrophages to release a host of d1emical mediators which can neutralize or contribute to the harmful effects of these dust particles. Our efforts have been concerned with assessing a specific family of mediator substances produced by the alveolar macrophage from arachidonic acid when these cells are in contact with activating substances such as coal dust. Metabolites of arachidonic acid produce a vast array of effects which can impact significantly on pulmonary function both with normal pulmonary events and with pathologic processes of the lung. Our studies demonstrate that isolated alveolar macrophages obtained from rats or guinea pigs cultured in vitro release appreciable amounts of the cyclooxygenase products prostaglandin E2 and thromboxane A2 and release significant amounts of the lipoxygenase products .5-HETE and LTB4. In the presence of l x 104 -1x10·7 g/ml of a coal dust suspension, alveolar macrophages from the rats and guinea pigs alters their pattern of arachidonic acid metabolite release. In the rat, exposure of alveolar macrophages in vitro to the higher concentrations of coal dust causes a significant reduction in PGE2, TXB2 and LTB4 in a 4 hour time course study. In contrast, macrophages from the guinea pig in response to coal dust had little change in TXB2 release, only a slight inhibition in PGE2 production and an initial stimulation in LTB.t release over the 4 hour time course. Cells from guinea pigs released considerably more TXB2 than the rat under these conditions while rat cells formed considerably more LTB4 than guinea pig alveolar macrophages. These findings support the following conclusions.

Mar 1, 1989

By Glenn Adkins

This report characterizes pivoting joints in the structures of mining machinery and how the wear on the various components, i.e., pins, lugs, yokes and bushings, may affect the safety of mine personnel where these components are allowed to wear excessively before repair or replacement.

Jan 1, 1979

By I. L. Feld

This report describes an attrition-grinding process and equipment for grinding coarse kaolins to the 2-micron particle-size range. The research was undertaken by the Bureau of Mines to devise an acceptable method for converting coarse kaolins, such as paper-filler-grade clays, to paper-coating-grade clays, thereby increasing the value and extending the life of the southeastern paper-clay deposits. The attrition-grinding process is basically the intense agitation of a slurry composed of the material to be ground, a granular grinding medium, and a suspending fluid. This process gave better particle-size reduction than that obtained by several other grinding methods. Results of batch tests in 5-and 10-inch-diameter attrition grinders demonstrated that a coarse kaolin containing about 13 percent minus 2-micron, equivalent spherical diameter (e.s.d.) particles was readily ground to give a product with 88 percent minus 2-micron e.s.d. material. Power consumption was reasonable in view of the increased value of the ground material. Comparison of particle-size reduction with power-consumption data for the two units indicated that better performance was obtained with the larger machine.

Jan 1, 1960

By O. Terichow

A pendulum sclerometer designed by the Bureau of Mines is described. Its method of operation is given, along with the results of tests made on representative mineral samples of Mohs' hardness scale to determine the applicability of the device for research on rock testing. The sclerometer hardness values obtained from the tests indicated that reproducibility and accuracy were good. A quantitative comparison of the pendulum hardness values with microhardness and surface energy values published by other investigators showed good agreement on minerals with Mohs' hardness numbers of 2 to 9.

Jan 1, 1967

By H. J. Heinen

To maximize productivity through improved minerals processing technology, the U.S. Department of the Interior, Bureau of Mines, is investigating particle agglomeration techniques as a means of increasing the percolation rates of leach solutions in heap leaching of clayey gold-silver ores. Simulated heap leach experiments were conducted on 50-pound charges of ore that were contained in 5.5-inch-diameter columns, 5 feet in height. Results indicated that the percolation rate of cyanide leach solution could be enhanced markedly by mixing the ore with controlled amounts of lime, flocculants, and water, and then aging the mixture prior to the column leach step. Experimental results obtained on 20-mesh silver tailings and gold ore crushed to 3/8 inch and to 1 inch showed that it was possible to increase percolation rates as much as 100-fold without sacrificing silver-gold extraction. Larger scale tests conducted in 24-inch-diameter, 16-foot-high columns closely paralleled bench-scale results. By improving percolation leaching, these techniques have the potential of helping to solve environmental problems associated with tailings disposal as well as making an important economic impact on gold-silver recovery operations. Investigations are continuing to develop binders superior to lime for particle agglomeration pretreatment.

Jan 1, 1979

By H. C. Brunaugh, James Westfield, R. W. Whittaker

"INTRODUCTION The purpose of this circular is to describe the sealing off of a mine fire and subsequent use of carbon dioxide gas to extinguish it.A fire of electrical origin occurred in the Valier mine of the Valier Coal Co., Valier, Franklin County, I11., on March 29, 1949, at about 1:35 p.m. It was discovered about 3:35 p.m. in 5 south west intake airway inby 1 and 2 west panels. The No. 5 southwest airway had caved, and the fire was in the top coal beneath a large fall of rock. All men, except officials, were ordered from the mine. The mine officials decided to seal the fire, and four temporary seals were erected, which isolated approximately 200 feet of 5 south west entry. The seals were completed on March 30 at 2:45 a.m., but on March 31, at 3;40 a.m,, two of them were blown out by an explosion of gas that was produced by the fire. The two seals were rebuilt, the work being completed on March 31 at 12:00 noon, but they were blown out by another gas explosion at 12:10 a.m. on April 1. It was then decided to extinguish the fire with water if possible.To accomplish this, concrete-block dams were constructed. On April 1, about 4:25 a.m., when the dams were about half completed, water was introduced into the fire area through a 2-inch pipe.On April 4, J. G, Crawford, general manager of the Valier Coal Co., notified James Westfield, chief of the Vincennes (Ind.) Branch, U. S. Bureau of Mines, by telephone of the fire in Valier mine and requested assistance to combat it. Westfield, accompanied by F. J. Smith and H. C. Brumbaugh, Federal coal-mine inspectors, went underground and inspected the seals and dams. Later, during a conference with company officials, it was decided that the concrete-block dams were not strong enough to withstand the hydrostatic pressure that would be produced by flooding the fire area. It was then decided to use carbon dioxide gas to extinguish the fire. Four seals were completed, and 5 tons of carbon dioxide gas was introduced into the fire area, which extinguished the fire."

Apr 1, 1950

By Louis C. Srichta

The rapid depletion of known high-grade ore deposits of the Tri-State district and the recognized need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores led to Bureau of Mines examination of several abandoned mining areas for possible deposits adapted to strip mining. Examination of the North Empire tract in Cherokee County, suggested that mineralized zones contiguous to previously mined 2e deposits presented probabilities of meeting the requirements for an open-pit mine - hence the tract was selected for further investigation by churn drilling. The zinc-lead deposit on the property is in a sink-hole structure that has been subjected to intense deformation and silicification. Numerous shafts, mine dumps, and surface caves are evidences of exploitation of an extensive area. The reported active mining period was 1895 to 1905. No production records are available, but it is generally stated locally that the value of the mill products exceeded $2,000,000 which represents considerable production, considering the low metal prices of that epoch.

Jan 1, 1950

By J. N. Geyer

In coal mining it is essential to maintain the roof over working places and roadways in the safest condition possible. To this end every effort should be made to win the coal with the least injury to the immediate roof strata, as broken strata certainly present a greater hazard than a sound roof. The chief causes of injury to the roof in mining are inherent in the method of development and recovery and the blasting practices followed. The first, which may produce severe stresses in the roof, weakening it over comparatively large areas has been discussed in previous papers3 and will not be treated here. The second cause is local in effect, but with the same general method of blasting being employed throughout a mine having uniform roof conditions, similar effects on the roof may be expected. In the Bureau's investigation of accidents caused by falls of roof and coal it has been necessary to make a careful study of blasting practices and their effect on the immediate roof. The purpose of this paper is to show the effect of the observed methods of blasting on different types of roof and to point out methods that have been proved to be least harmful to the roof strata. The data used in preparing this paper have been compiled from reports made by Bureau engineers engaged in the study of falls of roof and coal, and embrace mines opened in the Pittsburgh coal in Ohio and Pennsylvania and the Pittsburgh and Sewickley coals in West Virginia.

Jan 1, 1933

By F. Fraas, H. H. Storch

"In the second paper 4 of this series, data were presented concerning the decomposi¬tion of polyhalite by saturated salt solutions. It was found that uncalcined polyhalite upon leaching with boiling saturated sodium chloride solutions yielded a brine in which the (K2 Mg) /304 ratio was considerably higher than that obtained from the calcined material, and for this reason appeared more suitable for the production of potassium chloride. It was found, in fact, that the leach liquors from uncalcined polyhalite deposited a mixture of KC1 and NaC1 upon evaporation and subsequent cooling, whereas those from calcined polyhalite yielded mixtures which contained not only potassium and sodium chlorides but also large quantities of glaserite, K3Na (S04)2. Hence it was decided to study the evaporation of the uncalcined poly—halite leach liquor and postpone experiments on the calcined polyhalite liquors until such time as a process for further removal of sulphate was developed.A considerable body of equilibrium data is available in the literature on thesystem K+ Mg++ — Na+ Cl—S04 =,— H20 for temperatures up to 83º C. Owing, however, tothe lack of data other than that corresponding to the invariant points and the complete absence of data for temperatures of 100 to 115°C., and owing to the fact that supersaturation phenomena render unsafe the prediction of the behavior of such a system upon evaporation, it was considered essential to obtain the necessary data by actual evaporation and analysis of the brines thus obtained."

Feb 1, 1931

By H. H. Schrenk

There are several well-recognized procedures for controlling exposure to hazardous atmospheres in industry. They include (a) substitution of less toxic material, (b) enclosure of processes, (c) wet methods, (d) local exhaust, (e) general ventilation, and (f) use of respiratory protective devices. In addition to their employment as a control measure in occupational exposures, respiratory protective devices also are essential in emergencies that may arise from failure or improper use of other control equipment. Respiratory protective devices usually are employed to supplement other methods of control, as temporary expedients, or when other methods are not readily applicable or practicable. It seems reasonable to assume, however, that where respirators are used consideration has been given to the factors involved and that the devices can provide satisfactory protection if used properly. Their use should not be arrived at simply by a process of elimination of other methods that are more difficult to apply.

Jan 1, 1943

By H. L. Gibbs

A portable radon monitoring instrument capable of making on-the-spot measurements of the radon gas content of uranium mine atmospheres was designed and constructed. The monitor was tested in the laboratory and in operating uranium mines. Good correlation was obtained between the monitor readings and radon measurements made on mine atmosphere samples taken in radon bottles.

Jan 1, 1973

By Timothy J. Rohrbacher

This report presents results from an ongoing U.S. Bureau of Mines study defining domestic coal reserves. Examinations of five 7 ½ -minute central Appalachian quadrangles have been completed to date. Only 26.4%, 5.0%, 6.5%, 8.2%, and 4.2% at the coal resources remaining in the Matewan, Boltsfork, and Hoskinston, KY; Vansant, VA; and Beckley, WV quadrangles, respectively, constitute economically recoverable reserves. An evaluation of the coal mining industry's impact on the economy of Pike County, KY, wherein the Matewan quadrangle is located, was also completed in order to provide a basic understanding of the influence of coal mining on the local economy. Results show that coal mining is the only major income producing industry in Pike County, accounting for about 46% of the county's income, and 21% of the total available employment, in the base year 1990. If similar results are found in subsequent investigations, a strong argument can be made that traditional coal producing regions may soon be experiencing resource depletion problems far greater and much sooner than previously thought. This will affect not only the coal industry but, given the obvious dependence of Pike County's economy on its coal mining industry, the entire social and economic infrastructure of large areas.

Jan 1, 1994

By W. R. K. Wu

Studies are reported on the structure of coal and coke with the graphical , statistical densimetric method based on the relation between the molecular volume per carbon atom ( M / C ) and the atomic hydrogen - carbon ratio ( H / C ) . Previous work , mostly from chemical and physical investigations , is critically reviewed . Difficulties in evaluating the ring increment are demonstrated for coal and coke for the statistical densimetric method based on the additivity of atomic volumes of constituent elements . A new diagram is presented for the graphical method . Methods are introduced for correcting M /C and H/C for the presence of minor constituents in coal and coke . With the graphical method , the fractions of aromatic carbon atoms in the total carbon atoms are estimated for a coal , a resin , and 5 petrographic components ; the types of condensed structure in the fundamental units of molecules are discussed for these substances , 28 coals , and 6 " average " cokes at 500 ° to 1,000 ° C. It is also shown that the number of rings in the fundamental units of coal generally increases with increasing rank and that of coke , with increasing carbonization temperature .

Jul 1, 1960

By L. C. Brichta

The Melrose zinc-lead. deposit is in an area of structural disturbance of sedimentary rocks in the Melrose mining district in Cherokee County, Kans., 25 miles west of Joplin, Mo., adjacent to the northwest limits of the Tri-State district. Mining and milling in the Melrose district has been sporadic and. very limited, largely due to the high cost of exploration through great thicknesses of barren rock, 350 to 440 feet overlying the ore deposits. No mining has ever been done on the Melrose zinc-lead tract, but it has been drilled extensively. The drill-hole logy indicate extensive structural deformation, silicification, and zinc-lead deposits in the Boone limestone-chert formations of the Mississippian series, which is overlain by thick-bedded Pennsylvanian shale and sandstone. Analyses of samples from Bureau of Mines drilling indicate the ore minerals are sphalerite and galena with no evident oxidation. During the period from November 2, 1949, to March 13, 1950, the Bureau of Mines investigated the deposit by churn drilling and sampling 23 holes aggregating 10,405 feet of bore. Factual data on the investigation and logs of holes drilled by private parties and the Bureau of Mines are presented in this report.

Jan 1, 1951