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By A. W. Fahrenwald

Many factors enter into the efficient operation of the reciprocating type of gravity concentrator. Earlier investigators who studied these factor invariably used natural (crushed ore) products for their experiments, but in the present study synthetic products were used. The variables considered were (1) specific gravity of the sand grains, (2) size of sand drains, and (3) shape of sand grains comprising the table feeds. It is recognized, also, that the percentage relationship of the different kinds of grains is a factor affecting results. This factor is variable in one group of experiments but is thereafter kept constant.

Jan 1, 1929

By D. Harrington

For several years, or from about 1932 to 1935, inclusive, the coal industry of the United States had an excellent record as to coal-mine explosions. In 1937 and in 1938 to date there has been a definite increase in the number of explosions attended by considerable loss of life and property damage. In most of these explosions one important underlying and contributing cause has been lack of sufficient (or at least efficient) ventilation to properly dilute and remove explosive gas from the mine. This increase in explosions indicates that. the lesson taught through bitter experience, many times in the not far-distant past, of the need for good ventilation is frequently being overlooked, partly because the relatively good experience of the industry in the past several years has made many mining people forgetful. Moreover mining practices are rapidly changing, and in some instances the changes are being made with little if any regard for safety. It appears, therefore, that a review of some ventilation principles and practices should be of value in preventing further disasters; this paper has been prepared with that object in mind. In coal mining the need for thorough ventilation of all underground working places is recognized by both mining practice and law; such ventilation is generally obtained by the use of fans that circulate a quantity of air much in excess of the quantity of coal produced, by weight as well as by volume. For example, in a relatively small mine producing 1,000 tons of coal per day and circulating 100,000 cubic feet of air, which is by no means abnormal, 2,000,000 pounds of coal and approximately 10,900,000 pounds of air would be moved out of the mine every 24 hours. Because of the need for adequate dilution and removal of methane issuing or likely to issue from mine strata and for removal of the carbon dioxide formed by coal and timber oxidation up-to-date coal mines usually provide an air volume which if adequately coursed not only removes these gases but also the gaseous products of the detonation of explosives (which may include carbon monoxide, hydrogen sulphide, nitrogen oxides, carbon dioxide, and nitrogen) and the carbon

Jan 1, 1938

By C. J. Walker

The ever-increasing use off natural underground formations for storing natural gas has focused attention on the behavior of such storage formations under varying operating conditions. The need for a means of evaluating in¬dividual wells and groups of wells has become manifest. It is essential that industry and others be able to determine the rates of flow that can be ex¬pected from a given well or group of wells under different conditions and to ascertain whether certain wells are deteriorating. Such questions need more exact answers now than ever before because of the vital role underground gas storage plays in the industrial and domestic consumption of natural gas. The Bureau of Mines--in cooperation with the American Gas Association--has main¬tained an active interest in gas-well testing because of the implications of such test procedures on the consumption and efficient production of natural gas. A basis for testing gas wells was provided by the back-pressure method of Rawlins and Schellhardt (12).4/ They showed that for normal gas wells there is a consistent relationship between rates of delivery of gas and corresponding pressures when the formation pressures are used as the basis of interpretation, The equation for this relationship is as follows: Q = C (Pf2 - Ps2)n where; Q = rate of flow, generally expressed in cubic feet per 24 hours. C = a coefficient.

Jan 1, 1960

By J. William Ganser

This paper is one of a series being prepared by the United States Bureau of Mines describing mining and milling methods and costs at cement-plant quarries throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs may in some instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1931

By O. H. Metzger

This is one of a series of capers being published by the Bureau of Mines on gold mining A the Western States. It describes the production of gold in the principal mining districts of New Mexico. The material was gathered red on a trip through tale State in the summer of 1936. ACKNOWLEDGMENTS The author acknowledges the aid and cooperation of mine operators in all parts of the State, who willingly contributed all information requested. Geological reports of the Geological Survey and the New. Mexico Bureau of Mince were drawn upon freely for information; credit to individual paper, is given in the text.

Jan 1, 1938

By Doyle A. Ellerbruch

An FM-CW microwave system was investigated for measuring coal layer thickness. Measurements were made in three different mines near Pittsburgh, Pennsylvania, near Fairview, West Virginia, and near Coffeen, Illinois. Microwave frequencies in the range 1-2 GHz were used to measure samples up to 55 cm thick. All samples were backed with a naturally occurring shale. Measurements were also made on coal and shale samples compounded in the laboratory at the Bureau of Mines Pittsburgh Mining and Safety Research Center near Bruceton, Pennsylvania. The results indicate that layer thickness can be determined in most cases, although large anomalies may, in some cases, produce misleading results. Many anomalies that were detected with the FM-CW system were verified visually by drilling into the coal layer. The dielectric constant of coal apparently varies significantly within a coal seam. The form of the output signals from the FM-CW system seem to simplify the data interpretation and analysis process as compared to the manually swept microwave system used previously. It appears that this technique has the potential of measuring changes in the dielectric constant of a coal seam and providing an output that can be used for real-time corrections in layer thickness; measurement.

Jan 1, 1976

By Frank E. Chase, John Rusnak, David Newman

During the past quarter century, coal mine geologists have evolved from providing a qualitative description of drill core and coal reserves into quantitative geotechnical specialists who bridge the gap between geology and engineering. In the late 1970’s and early 1980’s, hazard prediction mapping was in its infancy. At best, hazard maps identified rudimentary structures and conditions such as stream valley locations, sandstone/shale transition zones, and lineaments. A “technical disconnect” had existed between geologists and mining engineers as each profession operated largely independent of each other. Engineers did not readily integrate geology and geologic conditions, with the exception of coal thickness, into mine planning. Geologists were relied upon for reserve estimates and did not participate in mine planning or design. The employment and market slump of the 1980’s and 1990’s combined with mining more challenging reserves mandated that this gap be bridged and forced geologists to learn to speak more “numerically” to engineers so they could be understood. The purpose of this paper is to describe the procedures and thought processes used by coal mine geologists when determining various mineability and reserve extraction feasibility issues. The paper will also address underground geologic hazard mapping and prediction techniques. To achieve these objectives, the opinions and experiences of leading coal mine geologists, geotechnical and strata control specialists across the United States were solicited.

By Cecil Q. Cupps

Results are presented of a comprehensive study of the characteristics of the original oil in the Weber sandstone reservoir, Rangely oil field, Colorado. Through the medium of subsurface sampling, adequately representative samples of the original reservoir oil were obtained from many parts of the reservoir over a period of 5 years concurrent with active development of the reservoir. Data of differential gas liberation, pressure-viscosity, and. pressure-volume-temperature relationships are shown for 12 subsurface oil samples. Data also are given of reservoir pressure and. temperature, composition of liberated or solution Gas, composition of 22 produced-gas samples, and Hempel analyses of crude-oil samples from 18 wells. The characteristics or physical properties of the 12 subsurface oil samples, as determined by laboratory analyses, were correlated with elevation of the top of the Weber sandstone. These relationships of oil characteristics to elevation in the reservoir show that only the oil in contact with the initial gas cap was gas-saturated at the existing pressure and temperature. The characteristics of the original reservoir oil were marked by an appreciable decrease of saturation pressure and solution gas-oil ratio and increase of viscosity and density with depth below the gas-oil contact. The composition of solution gas and of' produced was also was found to vary with elevation of the oil in the reservoir.

Jan 1, 1951

By John G. Parker

Many of the so-called minor metals are derived as byproducts from the processing of lead and zinc concentrates in which they occur as minor constituents. Concentrates from some lead-zinc mineral deposits are more enriched in metals such as cadmium, arsenic, bismuth, silver, and selenium than are others, and these sources offer a continuing, assured supply of certain of these metals. Despite the age of the data collected, the Bureau of Mines feels it to be highly desirable to publish due to its relevance to the objective of the study which was to ascertain the flow of minor metals from certain smelter feeds Efforts to trace these metals through the complicated lead and zinc processing steps included trying to ascertain losses and mode of loss of these metals. Losses of some metals in processing may be surmised as occurring in gaseous and other emissions, or possibly in slags and residues.

Jan 1, 1979

By B. K. Shibler

A highly flexible laboratory-scale fluidized-bed reactor was designed, constructed, and successfully operated continuously at temperatures up to 1,300° C during an investigation of thermal methods for decomposing gypsum. This report discusses briefly the many problems encountered in developing the 10-inch-diameter reactor and describes its design and construction in sufficient detail to enable other research organizations to build a comparable unit. The reactor consists of a 10-inch-inside-diameter vertical tube which can be varied from 6 to 10 feet high; it is formed from 2-and 3-foot sections of silicon carbide pipe. The tube is surrounded by a 3-inch heating space formed by an outer 4.5-inch-thick circular wall of insulating firebrick. A cone-shaped fluidizing chamber is bolted to the bottom of the reactor. Fluidizing gas enters through the bottom of the cone, and ore is introduced by means of a screw feeder connected to an inlet located just above the gas port. A silicon carbide overflow tube of 1.25-inch inside diameter extends upward into the reactor. The depth of the bed is controlled by substituting different lengths of overflow tube. Twin dust-recovery systems, each composed of a cyclone and Fiberglas filter, are attached to two gas outlets at the top of the reactor tube. The reactor is designed for research on both exothermic and highly endothermic reactions. It can be fired externally by means of four natural gas burners that jet tangentially into the annular space at the base of the reactor. Alternatively, it can be fired internally, using a mixture of air or oxygen and natural gas as the fluidizing medium. A separate instrument panel contains flowmeters, manometers, an automatic program controller, and a multiple-point recorder for printing a record of the temperatures measured by thermocouples located at critical points in the reactor.

Jan 1, 1963

By D. Bienstock, J. H. Field, M. J. Lempel

A computer program is presented to perform the detailed and numerous calculations required for determining the interface temperatures and steady - state heat flow through a furnace wall composed of several refractories in layers . A method is developed that will allow the designer to determine the various thicknesses for each refractory layer to minimize either the total wall thickness or the cost of the wall per unit of area . A sample problem is presented and analyzed to illustrate the techniques involved .

Jan 1, 1964

By Gary A. Kingston

This examination of Pacific Northwest (Idaho, Montana, Ore on, and Washington) ferrous scrap-industry opera ions, principally those in Oregon and Washington, points out factors influencing the supply and consumption of scrap materials, such as the complete dependence of steel ingot producers in these States on scrap as a metal raw material and the sizable quantity of scrap exported from Seattle and Portland to Japan. The pattern of the industry is presented as a movement of materials from their diverse sources to the consuming market. The geographic locations of the consuming industries in relation to the area generating scrap materials and the movement pattern of the supply from source to destination strongly influences the cost of the commodity. The best measure of the scrap supply available in an area is experience in terms of how much scrap was withdrawn at a given price. Scrap availability is not finite, because the return of materials as scrap is secular and influenced by constantly varying market conditions. Steel ingot producers use 75 percent of the approximate 500,000 tons of scrap consumed in Oregon and Washington; steel foundries take 15 percent of the total; and iron foundries, ferroalloy plants, and other miscellaneous consumers utilize the remainder. Also, from 1955 to 1960 an average of about 200,000 tons has been exported annually from Oregon and Washington. The foreign exports are supplemented by lesser .shipments to other steel producing States, principally in the western United States. From 1955 to 1960 the preferred and higher value heavy melting scrap grades accounted for about 60 percent of total withdrawals which varied between 600,000 and 950,000 tons annually. Total scrap withdrawals from Oregon and Washington are projected to 1.8 million tons by 1985, 60 percent (1.1 million tons) of which will be heavy melting grades. No. 1 heavy melting scrap is most attractive to scrap consumers at $35 per ton or less. Price-supply relationships compared with projected scrap requirements indicate future prices possibly over $35 per ton. High prices over a long period could motivate the Pacific Northwest scrap consumers to produce steel from iron ore. However, technologic changes taking place at integrated steel plants could reduce scrap withdrawals from the Pacific Northwest, which might keep the scrap price sufficiently attractive to obviate production of competitive iron products by the Pacific Northwest scrap consumers.

Jan 1, 1964

By R. D. Leitch, J. G. Calverley

"INTRODUCTION Although many investigators have provided information on the strength and other properties of concrete the published literature cites few data on the effect of mixing cement with acid mine waters or on acid resistance of concrete in contact with mine waters. Most of the reported work on the effect of impure waters has dealt with the resistance of cement specimens to ""sulfate waters,"" that is, waters or soils with a relatively high sodium sulfate content. The ""Merriman test"" is used commonly to determine the corrosion resistance of cements for 28 days, but it does not seem certain that a cement having a high sulfate resistance in the Merriman or similar tests necessarily will show correspondingly great resistance to the sulfates of iron and, particularly, to sulfuric acid, which usually are present in acid mine waters. Extensive use of cement mortar for laying up masonry stoppings in coal and other mines and for constructing concrete mine haulageways and shaft linings, coal-storage and other retaining walls, highway bridges, culverts, and many other types of construction where it is difficult to obtain fresh water for mixing or where the structures are later exposed to contact with acid waters makes it important to know the effect of these conditions on cement and whether there is a cement better suited for such work than ordinary portland cement.CONDUCT OF THE INVESTIGATIONFor a short time early in 1935 the opportunity to obtain at least some additional information on the effect of acid mine water on cements was presented by the Relief Works Division, which provided money for irregular and indefinite employment for several months. Purchase of apparatus or material was not permitted under this arrangement, and indefinite duration of the work, intermittent employment, and finally complete cessation of the work prevented planning for extensive investigation of this particular problem."

Jan 1, 1940

By T. H. Dubaniewicz

Many mines rely on toxic gas sensors to help maintain a safe and healthy work environment. This report describes a prototype monitoring system developed by the U.S. Bureau of Mines (USBM) that uses light to power and communicate with several remote toxic gas sensors. The design is based on state-of-the-art optical-to-electrical power converters, solid-state diode lasers, and fiber optics. This design overcomes several problems associated with conventional wire-based systems by providing complete electrical isolation between the remote sensors and the central monitor. The prototype performed well during a 2-week field trial in the USBM Pittsburgh Research Center Safety Research Coal Mine.

Jan 1, 1995

By P. E. Churchward

The Bureau of Mines developed a process using amines for recovering tungsten as ammonium paratungstate from alkaline leach liquors without producing synthetic scheelite as an intermediate product. Over 90 pct of the tungsten in low-grade scheelite or ferberite concen-trate was recovered as ammonium paratungstate by (l) autoclave leaching the concentrate with Na2CO3, (2) solvent extraction of the acidified leach liquor with kerosine solutions of either a quaternary amine (Aliquat 336) or a primary amine (Primene JM-T), (3) stripping the tungsten values from the quaternary amine with ammoniacal NH4C1 or from the primary amine with NH4OH, and (4) crystallization of ammonium paratungstate from the strip liquor. Reagent consumption in pounds per pound of W03 recovered was, for the quater¬nary amine, 3 Na2CO3, 3.5 H2SO4 , 2.2 NH4Cl, 1 NH3, and 0.4 glacial acetic acid; for the primary amine, it was 3 Na2CO3, 3.5 H2SO4, .06 NH4Cl, and 0.9 NH3. Both reagents extract molybdenum along with tungsten. Silicate and phosphate are partly extracted and contaminate the product; leach liquors containing these impurities require preliminary purification.

Jan 1, 1966

By J. W. Thompson

RIGHT OF LIFE TENAN1' TO OPEN MINES. The common-law rule that a life tenant was not permitted to open or share in mines does not prevail in Michigan; but a life tenant by dower right is permitted to share in the royalties, as the strict common- law rule is not in harmony with the spirit of our institutions and the policy of our law and would often result in defeating the purposes of dower statutes. Poole v. Union Trust Co. (Michigan), 157 Northwestern 430, p. 432, March, 1916. SALE AND CONVEYANCE. PURCHASE OF ENTIRE ESTATE--FRAUD. A purchase of land where no exceptions or reservations of minerals were made and the land was bought as property, when nothing is excepted and no qualifications or reservations are embodied in the agreement, was presumptively and by common understanding a purchase of the property in its entirety; and the insertion in the deed of a reservation of mineral rights in violation of the contract of purchase and without the grantee's knowledge or consent was fraudulent. Mtynarczyk v Zyskowski (Michigan), 157 Northwestern 566, p. 569, March, 1916. RESERVATION OF MINERALS--EXTENT AND EFFECL A reservation in a conveyance of land excepting and reserving to the grantor all coals and mines beneath the surface with the sole right and privilege to remove the same, is not as broad as the grant itself. A contract for the purchase of a mine recited that a deed had been executed by the owner and placed in escrow to so remain until the sum of $30,000 should be paid. The contract provided that $1,200 of the purchase price was to be paid in cash, $800 in 60 days, and the remainder out of 20 per cent of the gross output of the mine, such per cent to be paid in five years unless the vein and value of ore should not continue in depth, in which event the purchaser was to have two years longer to complete the payment of the purchase price. The contract contained other covenants to the effect that the purchasing corporation would fit up a certain specified mill and would continue development work at such rate as to keep the mill in operation if ores sufficiently valuable should be found and in the absence of unavoidable accident. The contract also provided 1/ that abandonment of work for a period of six months at anyone time, except as above, on said property," should operate as a forfeiture of the purchaser's right. In an action by the vendor to quiet the title to the land and to have the contract declared void, the court found that the purchaser failed to perform the work on the property and failed to place thereon the improvements as required by the contract and permitted debts to accumulate against the property, taxes to be levied thereon, and that for more than a year the purchaser had not done any work or labor of any sort upon the mine or premises, and that the contract contemplated development work from the time the purchaser took possession of the property, or at least promptly thereafter, and the fact that no machinery was in place for a year or more after the execution of the contract was a breach of the covenant of continued development, and that the clause in the contract" except as above" does not contemplate a delay in the development resulting from a failure to install machinery, but it means that unless prevented by unavoidable accidents the purchaser shouLdhave no valid excuses for neglecting the work for a period of six months or more.

Jan 1, 1917

By Lulie H. Crump

Salient historical data on consumption of fuels and energy have been summarized by State and census district for the years 1960 through 1972. This Information Circular covers States east of the Mississippi, and Information Circular 8705 covers States west of the Mississippi. These data replace previously published compilations of energy consumption statistics by States and districts. Future annual studies are planned using the same Btu conversion factors applied in these two. Information Circulars.

Jan 1, 1976

By Joseph J. Wallace

1. The Pittsburgh is the most important bed in Washington County from the standpoint of present production and recoverable reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 4,181 million short tons as of January 1, 1954. Of this total, 4,132 million short tons is in beds 28 inches and more thick. Areas in some beds were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1955

By W. E. Cooper

The International Intercalibration and Intercomparison Program (HIP), consisting of several selected laboratories from four countries, held a radon progeny intercomparison measurement at the U.S. Bureau of Mines experimental Twilight Mine on September 12-14, 1988. Grab samples were taken at four different conditions of low and high radon progeny and condensation nuclei concentrations, respectively. The results showed good agreement among all seven participants. The coefficient of variation of all measurements was 4.7%; after minor corrections for flows and some systematic biases, it was reduced to 3.2%.

Jan 1, 1990

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Nicaragua has been prepared from the best available information in Washington , but is released subject to correction and amplification , if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Jul 1, 1930