Search Documents

By Fun-Den Wang

This report presents the results of two large scale field coal pillar strength tests (80 ft by 80 ft), the results of a series of laboratory small core sample tests, and the correlation between those field and laboratory tests. The concept of applying laboratory coal sample strength data to predict the in situ coal pillar strength appears to be feasible. The deformation property of large pillars can be obtained successfully by testing the coal sample in the laboratory within acceptable accuracy. There are prevailing directional strength and deformation properties in coal pillars along the butt and face cleat system.

Jan 1, 1976

By D. Harrington

Near the close of the nineteenth century electricity was introduced underground, and the mining industry automatically was confronted with another potential source of fatalities and injuries to mine workers. Electricity has become an increasingly vital factor in the production of goal, particularly in recent years, because of the greatly extended mechanization that has taken place underground. The enlarged use of electrical equipment for cutting, loading, and hauling coal unquestionably increased the potentiality of shock and explosion hazards underground. Electricity may be used in coal mines with minimum danger if electric equipment and power-carrying wires are chosen properly and installed and kept protected by proper safeguards; on the other hand, if vigilance is relaxed in the slightest degree accidents may result. Electrical accidents are caused chiefly by direct contact with electrical equipment or power-carrying wires, by ignition of explosive gas or dust, and by fires of electrical origin. Electricity now ranks fourth as a cause of coal-mine fatalities, not including deaths from explosions or fires of electrical origin.

Jan 1, 1936

By C. H. Riggs

This petroleum-engineering report of the Atlanta oil field in BO them Arkansas reviews reservoir conditions and pressure-production history of one of the important Smackover limestone fields in southern Arkansas. The study of the field was made and the report prepared to aid operators in this and similar fields to increase the efficiency of recovery through the application of better engineering practices. A similar study of the Magnolia field in Arkansas by Carpenter and Schroeder was the first of these reports prepared under a joint agreement between the Arkansas Oil and Can Commission and the Bureau of Mines. The increasing demands for petroleum and its products and the steadily increasing cost of discovering and developing oil field; emphasize the importance of conserving known reserves of oil and gas. In recent years vast improvements have been made in the technique of oil recovery, both by better utilization of the natural energy stored in the reservoir and by improved methods of applying external energy to the reservoir system. This report may aid in oil conservation by careful evaluation of the several factors that did or did not contribute the greater recovery in the Atlanta field and by suggesting improvements in production methods and applications.

Jan 1, 1949

By E. Morrice, R. D. Smith

Thermal expansion and electrical resistance measurements were made on cerium metal from 4° to 300° K. The apparatus developed , including a specimen holder and a cryostat system , are described along with the experimental techniques used in obtaining the measurements . The total linear thermal expansion Data at of 99.83 weight - percent cerium metal between 4 ° K and room temperature was 4.24 percent . The resistivity at 4° K was 7.0 x 10-6 ohm- centimeter . 4° K indicate a fundamental relationship between residual resistivity and purity of cerium metal . The effects of annealing and repeated thermal cycling on resistivity were determined .

Jan 1, 1964

By F. W. Horton

Investigation of an extensive deposit of chromite-bearing actinolite-talc schist situated on the summit of Casper Mountain, 10 miles south of Casper, Wyo., was one of the first projects Undertaken by the Bureau of Mines under the Strategic Materials Act (Public 117, 76th Cong., Ch. 190, 1st sess.), for which an appropriation became available August 9, 1939. During the previous summer; the Geological Survey? made? a magnetometrical survey of the area in which the schist occurred. It was exposed in several small lenses and two larger ones aggregating about 19?acres in area. Although the occurrence of chromite here had been known for many years, the only work done on the deposit was the digging of? a few shallow pits on some of the more promising outcrops. From August 23 to December 3, 1939, the Bureau of Mines investigated the larger of the two main schist bodies. Twenty-four trenches having a total length of 8,073 feet were dug across the deposit, and its subsurface extension was explored by 3,623 feet of diamond drilling. Over 32 tons of samples were shipped to the Metallurgical Division of the Bureau of Mines at Reno, Nev., for reduction, analysis, and ore testing. In all, there were 853 individual samples. Geological maps, based upon examination of outcrops, trenches, and drill cores, as well as a contour map of the area were made by the Geological Survey.

Jan 1, 1949

By Oliver C. Ralston

The growing popularity of perlite (sometimes spelled pearlite) as a raw material for thermal expansion into pumicelike products in the Western States has prompted a preliminary investigation of the properties of such material and the problems that want solution to put a perlite industry on a firm foundation. The Bureau of Mines is undertaking the gathering of data and the solution of these problems, and the following paper records some of the available information. and the promise of the material, with some comparisons of advantages of the various competing lightweight aggregates that can be made from siliceous volcanic glasses and rocks containing entrapped or dissolved water that causes their expansion on' quick heating to their softening points. This new industrial rock has caught the fancy of the mineral industry in the western States because it has Fume advantages over natural pumice. Chemically, it is typified as rhyolitic in composition, and one may find obsidian, rhyolite, pumice, pumicite, and perlite from the same vant and contemporaneous in origin. The material need not be rhyolite but should be a siliceous or acid lava and contain 2 to 5 percent water still in "solution" in the rock. On quick heating to the softening temperature the material puffs, due to conversion of the contained eater into bubbles of steam. Slow heating causes gradual release of the imprisoned water by decrepitation and. cracking and-results in, very little puffing. Perlite is often in the form of ovoid volcanic bombs formed by explosive eruption of large masses of lava into the air, where they, quickly cool, with escape of little of the contained water, exceptt perhaps for a hollow interior. Since they cool in layers they have an onion-type structure and a pearly luster from interference of light between the. layers, which is' the origin of the name "perlite." Perlite may occur in intruded flows that have been quickly cooled and partly expanded but retained most of their magmatic water content. Obsidian may be the same lava cooled quickly under conditions that prevented crystallization of feldspars and other minerals, leaving the volcanic glass that may or may not retain all of the original contained water.

Jan 1, 1946

By L. G. Marshall

Gypsum mining and processing has been one of the principal industries in Iowa for more than 75 years. For most of that period, Iowa has ranked among the five leading States in the production of crude gypsum and of calcined-gypsum products. The Fort Dodge area accounted for 11 percent of the gypsum products produced in the United States in 1956. Before 1927 the output by the major companies came from underground operations, using a room-and-pillar stoping method. At present, all production comes from quarries. The quarry methods at the various properties are similar. This paper describes the quarrying, methods employed in the district and the type of equipment used by each company. The sections on history and geology are, in part abstracts from State annual reports and an Iowa Geological Survey publication.3/

Jan 1, 1959

By C. D. Litton

This Bureau of Mines report presents a set of guidelines for determining the distribution of product-of-combustion fire sensors in underground mines. Sensor spacing is defined in terms of sensor alarm threshold, ventilation flow rate, and mine entry dimensions. Sensor spacing guidelines are presented for detection of fires from two primary combustibles, coal and wood, which are common to the majority of underground mines. The guidelines are based on data from full-scale and intermediate-scale fire tests conducted by the Bureau of Mines.

Jan 1, 1983

By V. E. Edlund

This report presents the results obtained in a study of the technical feasibility of recovering a usable pig iron by pyrometallurgical treatment of typical copper reverberatory slags . The iron in the slag was readily reduced with carbon , but the copper and sulfur content of the metal was best controlled by a three - stage procedure comprising ( 1 ) melting the slag with pyrite to remove copper as a low- grade matte , ( 2 ) smelting the partly decopperized slag with fluxes and carbon to reduce the iron , and ( 3 ) refining the impure iron alloy from step 2 with a flush slag to remove sulfur and residual copper . Laboratory - scale tests demonstrated that washing with 8 wt pct of pyrite lowered the copper content of a typical reverberatory slag from 0.58 to 0.12 Subsequent smelting of a mixture composed of 70 pct decopperized slag , 25 pct lime , and 5 pct coke reduced 84 pct of the iron to metal containing 2.27 pct sulfur . This metal then was successfully desulfurized by treatment with a basic flush slag to produce a finished metal that contained , in percent , 93.5 Fe , 0.02 S , 0.26 Cu , and 4.9 C. Overall recovery of iron under the conditions of trial was about 80 pct . This could be increased if higher tolerances for copper could be accepted . Commercial processing would be accomplished in three furnaces with molten materials passing from one to another . Currently produced smelter slag could be treated fairly inexpensively , because the molten product would require only a little additional heat to produce an iron byproduct that undoubtedly would be attractive to local foundries .

Jan 1, 1964

By John E. Lambert

Automatic control of drum head continuous mining machines was investigated as a means of reducing respirable dust generated and operator variabitity. Literature survey, manufacturer interviews and mine visits were the major information sources. Technically feasible automation concepts were Identified to control sump and shear rates, cutter head elevation limits and sumping distance. These are the elements of a programmed cutting cycle which maintains peak penetrating force on the cutter, to maximize depth of cut and therefore reduce dust generation. Based on the industry surveys, successful underground hardware demonstrations must be completed in order to stimulate the market demand for these advanced control features.

Jan 1, 1979

By D. R. Tesarik

Displacement and stress changes in cemented backfill and ore pillars at the Buick Mine, near Boss, MO, were monitored by engineers from the U.S. Bureau of Mines and The Doe Run Co., St Louis, MO. A test area in this room-and-pillar mine was backfilled to provide support when remnant ore pillars were mined. Objectives of this research were to evaluate the effect of backfill on mine stability, observe backfill conditions during pillar removal, and calibrate a numeric model to be used to design other areas of the mine. Relative vertical displacements in the backfill were measured with embedment strain gauges and vertical extensometers. Other types of instruments used were earth pressure cells (to identify loading trends in the backfill), borehole extensometers (to measure relative displacement changes in the mine roof and support pillars), and biaxial stressmeters (to measure stress changes in several support pillars and abutments). Two-and three-dimensional numeric codes were used to model the study area. With information from these codes and the installed instruments, two failed pillars were identified and rock mass properties were estimated.

Jan 1, 2010

By D. Harrington

Springing or chambering of deep drill holes is common practice in some quarries. It involves definite hazards from premature explosion during placing of the springing charges or the final charge due chiefly to heating of the bottom of the holes by the successive exploding of the springing charges or, in some instances, from burning of paper or other material following detonation of the explosives The danger is either unknown or disregarded in many instances by those who place the charges in the holes. Disregard of this hazard probably is, at least in part, responsible for the far too high fatality and injury rate due to charging explosives and premature slots in quarry work. Awareness of the danger' should result in elimination or at least of material decrease in injuries from this cause.

Jan 1, 1941

By Raymond B. Ladoo

The uses of talc are many but are not, in general well known or fully developed within the last decade several companies have realized the possibilities of greatly increased use and have intelligently proceeded to develop some of the fields which seemed most promising. This has had a tendency to lift talc from the obscurity in which it had existed for years, but the work is only started and much remains to be done. Considerably more attention has been paid to the technology and utilization of talc in Germany and Austria than in this country, despite the fact that the United States produces 65 of the world's talc and Germany and Austria combined but 5.4%. In the "Bericht,uber die tatigkeit des verbends der talcum-interessenten in Oesterreich-Ungarn" (Proceedings of the Austro-Hungarian Talc Association), for the years 1912 and 1913, many notes upon new uses appeared, together with suggestions as to further development of old uses. Aside from a few notes on the use of tar in paper, little has been published in the English language upon this subject. By recent action of the Talc and Soapstone Producers Association (U.S.A.) funds for research into the properties and uses of talc have been made Available and it is hoped that markets will be materially broadened a a result of this work.

May 1, 1920

By D. E. Shanks

As part of its goal to help maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines, U.S. Department of the Interior, is investigating a fused-salt electrolytic procedure for producing zinc metal. A previous report described preliminary, small-scale work on the fused-salt electrolysis of ZnC12. The present report covers a more detailed investigation of the properties of ZnC12-alkali metal chloride electrolyte systems in relation to the production of zinc metal and also discusses electrolysis in largescale, internally heated cells. The effect of composition on bath stability, current efficiency, cell voltage, and liquidus temperature was determined for the ZnCla-NaC1-KC1, ZnC12-NaC1-LiC1, and ZnC12-KC1-LiC1 electrolyte systems. An electrolyte com-posed of 38 mole-pct ZnC12, 31 mole-pct NaC1, and 31 mole-pct KC1 gave the best overall results. Sludge (ZnO) formation in the ZnC12-NaC1-KC1, ZnC12-KC1-LiC1, and ZnC12-KC1 systems was investigated during prolonged electrolysis. The ZnC12-KC1-NaC1 electrolyte showed the least sludge formation. A 1,500-amp cell was operated using the ZnC12-NaC1-KC1 electrolyte at 500° C. Zinc metal was produced at the rate of 4.0 lb/hr with a current efficiency of 95 pct.

Jan 1, 1979

By B. W. Jong

The Bureau of Mines studied reinforcement of sulfur concretes using glass, polyester, and aramid fibers. The objective of this research was to determine the feasibility of fiber-reinforcing the sulfur concrete to enhance the flexural properties. Optimum fiber sulfur concrete compositions were formulated with a cement-to-fiber ratio of 9.0:1 for glass-fiber and polyester-fiber sulfur concretes and 12.1:1 for aramid-fiber sulfur concretes. Test samples were prepared using techniques developed by the Bureau of Mines. Flexural strength values of up to 50 pct of compressive strength values were achieved with fiber additions. With non-fiber-reinforced sulfur concrete, the values ranged up to 20 pct. The impact strength and fracture toughness of sulfur concretes were increased sig-nificantly by reinforcement with glass or with aramid fiber and were adversely affected by use of polyester fiber. Strain tolerance was doubled and failure mode was shifted from catastrophic to noncatastrophic type by adding glass fiber. The glass-fiber and aramid-fiber sulfur concretes are resistant to acid corrosion and have proved durable in freeze-thaw cycles. This laboratory and field evaluation has shown that fiber reinforcement of sulfur concrete is feasible and that it enhances the flexural properties.

Jan 1, 1985

By R. E. Heithecker

[The principle of determining volumes of liquid by alternately drawing in and discharging given quantities of the fluid from a confined space or compartment of known volume and mechanically counting the number of displacements is well established. This is true particularly in water measurement. For several years, oil meters employing the same basic principle have beer, used for gaging oil production from individual wells, groups of wells, and in some areas for metering the entire production from a property. Especially in areas where there is town-lot drilling and space for tankage in at a premium, oil meter have been used successfully to gage the oil. This facility has obviated the necessity of installing gage tanks. Oil meters also have been used in pip-line and refinery operations and in loading tankers. Present knowledge of the subject shows that positive-displacement oil meters can be used for measuring crude oil in the field and elsewhere, provided the meter-counter mechanism is in proper adjustment and the oil has been studied sufficiently to determine the proper factor to be applied to the volume as registered by the meter, making possible the adjustment for the shrinkage of the oil caused by liberation of gas from solution.]

Jan 1, 1938

By John R. Dudo

The Bureau of Mines Morgantown Petroleum Research Laboratory, with the cooperation of the Penn York Oil Company, cored the Dewdrop, Bradford Third, Lewis Run, and Sartwell sands in the Sartwell oilfield, McKean County, Pa. This report contains a review of the geology and depositional history of the field and an evaluation of the feasibility of secondary recovery of oil from the Bradford Third and Sartwell sands by waterflood or gas drive. Core analysis, geologic data, and electrical and radioactivity logs were used to evaluate the reservoir characteristics. Reservoir geometry, rock properties, fluid characteristics and saturations, and relative permeability-saturation relationships were used to assess the floodability of these two sands. The results of this study indicate that between 53,000 and 61,000 barrels of oil can be recovered by water or gas injection. The success of a waterflood or gas drive will depend on the field injection rates of the reservoirs comprising this oilfield. Following an economic evaluation, additional field work is recommended to further test the floodability of the reservoir.

Jan 1, 1967

By G. G. Campbell

The Bureau of Mines in cooperation with Quaker State Refining Corp. conducted two underground-combustion oil-recovery experiments in the Venango Second sandstone in the Reno pool, Foster-Rena-Oil City field, Sugar Creek Township) Venango County, Pa.) to determine the applicability of the process for reservoirs producing Pennsylvania-grade paraffin-base crude oil. Tests were terminated when analyses of produced gas showed that a self-sustaining combustion front did not exist. It was thought that insufficient fuel had been deposited in the formation. Laboratory retort tests made after the second field test was concluded showed that crude oil from the Reno area would deposit enough fuel to support combustion if air flux, temperature, and time were maintained within defined limits.

Jan 1, 1967

By Ernest E. Fairbanks

[Microscopic methods have proved to be valuable assets in the study of low-grade ores. While the chemical assay u a ally discloses tine total content of valuable metals in such an ore, a thorough knowledge of the nature of the ore should form the from which to prepare an efficient means of recovery. In the treatment of low-grade ores, inefficient recovery, as indicated bay the amount of valuable mineral permitted to go to waste in the tailings, is too frequently the rule rather than the exception, As methods of recovery become more efficient, many low-grade 10 mineral A posits suddenly assume o commercial significance, In much of this material the minerals are so finely disseminated and intermixed that identification even by microscopic methods is a difficult matter. The application of microchemical qualitative analysis with the aid of new device described in this paper, will solve many of the problems of identification encountered in the study of low-grade potential ores. In these ores, especially, the limitations of ordinary microscopic methods are liable to become very great. The microchemical tests obtained by applying a standard set of reagents to a polished knoting whether or not a tarnishing action develops, have considerable value but arc far from being infallible. It is well-known that electrolytic effects are apt to affect seriously the diagnostic value of the tests, end this effect is encountered much more frequently in dealing with finely desseminated minerals. resort to microchemical qualitative analysis, therefore, becomes indispensable.]

Jan 1, 1924

By E. P. Youngman

This paper presents one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative, to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the mining laws of British Guiana has been prepared from the best available sources in Washington and is, released subject to amplification and correction, if necessary, by United States foreign-service officials. INTRODUCTION The sources of information available in the preparation of this paper are the following: 1. The Crown lands ordinance, No. 32 of 1903, September 26, 1903.

Jan 1, 1934