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By D. B. Taliaferro

An accurate knowledge of the water content of oil-bearing sands4/ now is recognized as an important factor in calculations of the flow of oil through the sands to producing wells and in the estimation of oil reserves, To this end the Bureau of Mines laboratories are using a method that is an adaptation of the A. S. T. M. method of determining the water content of petroleum products (1).5/ However, the apparatus and technique have been altered slightly, as described in this report, to increase the precision of the method without affecting the simplicity of procedure or speed with which determinations may be made. Until recently petroleum engineers, when estimating reserves assumed that the entire pore volume of the oil-saturated parts of producing sands was filled with oil, as it was generally thought that the oil, water, and gas in any formation had separated completely during geologic time into distinct layers because of their difference in density. In 1929 Lindthrop and Nickolaeff (12) reported experimental results from which they concluded that 22 to 30 percent of the pore volume of producing sands in the Grozay district, Russia, was filled with water when the fields were discovered. Since that time numerous investigators (5, 7, 8, 10) have found evidence of water in the sands of now oil-producing fields and old fields that never produced water with the oil.

Jan 1, 1940

By J. F. Barkley

The following questions and answers were prepared principally to supply information in answer to general inquiries received by the Bureau from those contemplating the use of propane and butane fuels . Primary or basic information only is covered; this usually gives enough guidance for most inquirers . To those who wish information of the treatise type , the handbook , Butane- Propane Gases , published by the Jenkins Publications , Inc. , 1709 West 8th Street , Los Angeles 14, Calif . , is suggested .

May 1, 1949

By Franklin P. Hall

U.S. supply and demand data for utility electricity by States and regions were tabulated for the years 1960 and 1965. Estimates are provided of State-by-State quantitative data for the utility electricity industry that can be integrated into State and regional energy balances by source, form, and major consuming sectors, and used to determine basic flow-patterns. The difficult problem of compiling interstate and interregional shipments of electricity was resolved by (a) assuming the negligibility of interregional shipments and (b) deriving a theoretical line loss percentage used for determining interstate shipments. The data developed were able to show an estimated total supply of utility electricity available for consumption. The tables also report the distribution of the supply among the major consuming sectors (household and commercial, industrial, and transportation). To compare the various energy sources of utility electricity, quantities were converted to their British thermal unit (Btu) equivalents. The Federal Power Commission, Edison Electric Institute, and Bureau of Mines are the sources of the data used in this study.

Jan 1, 1969

By C. Kwong, L. H. Rorden, T. C. Moore

This report describes the feasibility test of an electromagnetic method for locating, boreholes, with or without casing, that have been drilled in conjunction with mining operations but whose location with respect to the tunnel is not precisely known. The first tests were conducted with the cooperation of the Kerr-McGee Corporation, Church Rock Mining Operations, New Mexico, in September 1977. These tests demonstrated that accuracies of better than ±15% of range and ±1° of bearing can be achieved with a simple system and setups. Subsequent tests, in January 1978, on a horizontally drilled pipe line river crossing application, by Ti tan Contractors of Sacramento, California, demonstrated that accuracies of better than one-half percent of range and a few tenths of one degree of bearing can be achieved by using refined techniques. The demonstration tests were done at ranges on the order of 100 to 200 feet but the method is capable of working at much greater distances.

Jan 5, 1978

By Matthew J. DeMarco, Anthony T. Iannacchione

Coal bumps have presented serious mining problems in the U.S. throughout the 20th Century. Fatalities and injuries have resulted when these destructive events occur at the working face. Persistent bump problems can result in abandonment of large reserves or lead to premature mine closure. Through the years, alternative techniques such as artificial supports, extraction sequencing, destressing, pillar design changes and specific pillar retreat practices have been successfully implemented to mitigate coal mine bumps. Several techniques have evolved for room-and-pillar operations that control the way the roof rock breaks, regulating the manner in which stresses are redistributed in the mined section. Special mine layouts employed in longwall mines have also proved to be successful in safely redistributing or containing excessive loadings. However, with ever increasing production rates, greater overburdens and new mining systems, the need to evolve even more effective bump control designs will continue to challenge the U. S. coal mine industry.

By H. E. Powell

The mineral dressing research here reported is part of a continuing program by the Bureau of Mines to develop new or improved concentration processes for oxidized or partly oxidized lead and zinc ores. A sample of low-grade sulfide-oxide, lead-zinc ore from Jasper County, Mo., containing galena, cerussite, pyromorphite, hemimorphite, smithsonite, and sphalerite was concentrated by froth flotation and tabling to a grade of 66 percent lead. Because of the presence of a high content of slime-size values, the overall recovery of lead was limited to 64 percent at this grade. Tests to recover the zinc by froth flotation and by gravity concentration did not give satisfactory results. INTRODUCTION Since its establishment, the Rolla Metallurgy Research Center has con-ducted studies of base metals as a part of its overall program (1, 2, 3, 4, 5,6,7).3/ This research has been, and is, directed to beneficiating complex and submarginal ores, to retreating rejects from commercial installations, and to developing fundamental data.

Jan 1, 1960

By N. S. Dalal, X. Shi, V. Vallyathan

"Electron spin resonance (ESRJ spectrum of the hydroxyl (· OH) radical spin adduct with .the spin trap 5,5-dimethyl-1-pyrrolintt-N-oxide has been obtained in suspensions of freshly ground quartz particles. The concentration of the spin adduct (and hence of the • OH radicals) increases with the amount of grinding. The dust's potential for the generation of the· OH radicals is maximum when fresh (i.e., immediately after grinding) and decreases to 50% in about a day on storage in air. Studies involving metal chelates .indicate that the • OH radical formation involves mainly the silica surface and H20 rather than the Fenton reaction. The results suggest that hydroxyl radical reaction(s) could be important in the lipid peroxidation and fibrogenicity by quartz dust, particularly .in acute silicosis. INTRODUCTIONIn this paper we report on our electron spin resonance (ESR) detection of the formation of hydroxyl (·OH) radicals in aqueous suspensions of freshly crushed quartz particles. This work was undertaken with a view to find possible clues to the role of free radicals in the pathogenesis of quartz-induced fibrogenicity, commonly known as silicosis. We noted that while silicosis is one of the major health hazards in coal and mineral industries, the mechanism by which the quartz particles exert their toxic action on cells and the process(es) by which these actions progress to fibrogenesis are still poorly ·understood (Reiser and Last, 1979; Singh and .Rahman, 1987). It is generally thought, nevertheless, that the action of quartz particles on the biological membranes is the starting point of the silicotic process (Parazzi et - al., 1968). A possible clue to the mechanism of the membrane damage by quartz particles, in terms of the role of oxygenated free radicals, is suggested by the following observations. A suspension of quartz particles in contact with alveolar macrophages has been reported (Gabor et al., 1975; Koike et al., 1982) to initiate an enhancement of lipid peroxidation, defined broadly as the oxidative deterioration of polyunsaturated components of lipids. Hydroxyl (· OH) radicals are known to be capable of peroxidation by abstracting hydrogen atoms from cell-membrane lipids (Halliwell and Gutteridge, 1985) and of initiating lipid peroxidation in lysosomal membranes. (Fong et al., 1973). Arong other lines, it is known that exposure of cell membranes, fatty acids, and unsaturated food oils to ionizing radiation, which generates· OH radicals, causes rapid peroxidation (Halliwell and Gutteridge, 1985). Thus • OH radicals (and also other oxygenated species such as Oi, 10 2, and H20 2) might be expected to play a role in the toxicity of quartz. Earlier studies of the aqueous chemistry of quartz suspensions have reported detection of H2O 2 (Kalbanev et al., 1980), implicating the formation of ·OH radicals as transient species. However, we are not aware of any report of the detection of • OH radicals in quartz reactions, and thus the present study was undertaken. Since it-is known that, because of their high reactivity (hence short lifetime) in aqueous media, the • OH radicals cannot be detected via ESR directly (Finkelstein et al., 1980; Buettner, 1982) we have used .ESR combined with the spin-trap methodology (Finkelstein et al., 1980) for studying the· OH formation. The results show that· OH radicals are indeed formed in aqueous suspensions of freshly ground quartz; thus pointing to ·a possible new clue to the cytotoxicity of freshly formed quartz particles and thereby to silica fibrogenicity."

Jan 1, 1988

By J. B. Gayle

The Bureau of Mines sole-heated oven has been used for studying coal expansion for some 20 years. During the period before 1940 emphasis was placed on studies of the mechanism of coal expansion and the effects of variations in operating conditions on the results. Since 1940 emphasis has shifted to a survey of the expansion properties of various coking coals. Because additional information concerning a number of unsolved problems in connection with the earlier studies appeared highly desirable, this investigation of the use of sole-heated ovens for studying coal expansion was undertaken. The principal findings, in order of their discussion in the text, may be summarized as follows. 1. Expansion results for binary blends of coking coals exhibit nonadditive behavior, both positive and negative deviations from additive behavior being noted, depending on the particular coals tested. Additive behavior can be achieved, however, either by charging the blend components in separate layers (which indicates that the observed phenomena are not characteristic of the particular expansion oven used) or by testing relatively coarse sizes of coal (which suggests that the effects of crushing on the expansion properties of coking coals may be even more complex than is generally recognized).

Jan 1, 1959

By John A. Organiscak

Laboratory and underground studies were conducted by the Bureau of Mines to evaluate the effectiveness of a water-powered scrubber and a brattice partition to create a clean split of air for longwall workers at the tailgate. In simulated laboratory tests, the system was very effective in creating a clean split of air. Observed system efficiencies were 74 and 84 pct with induced airflows of approximately 2,000 and 2,500 cfm, respectively. Underground evaluations indicated that the system was capable of reducing respirable dust at the tailgate. The first underground evaluation resulted in protection efficiencies of 30.7 and 42.5 pct at scrubber water pressures of 150 and 450 psig, respectively. A 33.7-pct protection efficiency was observed in the second underground evaluation with a modified partition and the scrubber operating at 250-psig water pressure. To be most effective, the system should have the scrubber operating at a flowrate of 10 gpm at 500 psig to deliver a maximum quantity of cleaned air behind a well-sealed partition.

Jan 1, 1983

By Sidney Katell

An estimated capital investment of $76,499,800 will be required for a plant designed and built to produce 90 million standard cubic feet per day (std.c.f.d.) of synthetic pipeline gas through Lurgi gasification of bituminous char. This investment figure does not include the pretreatment plant, the cost of which is assumed to be reflected in the cost of the char fed to the gasification system. Shift conversion, C02 removal, and methanation are required after gasification in the Lurgi unit to make a gas suitable for pipeline transmission. Capital investment data are based upon equipment costs, January 1959. Based on a 90-percent or 330-day operating year, the operating cost before profit and Federal taxes with the char price as a variable will amount to the following: [ ]

Jan 1, 1959

By R. Barany

This paper reports determinations of heats of formation (from the oxides and elements) of crystalline cadmium metasilicate and crystalline lead meta-silicate by hydrofluoric acid solution calorimetry. The results, in conjunction with known entropy values, yield free energies of formation. There are no earlier data of this type for cadmium metasilicate. The results of this investigation for lead metasilicate deviate from the literature values (which are less reliable) in the direction of increased thermodynamic stability. Both cadmium and lead metasilicate are much less thermodynamically stable with respect to their constituent oxides than are the corresponding compounds of the alkaline earth metals.

Jan 1, 1959

This report summarizes the results of several field tests conducted by Collins for the Bureau of Mines under contract SO122076 and contract H0232056. The field projects represent a part of Collins continuing effort on a broad study of coal mine communications. These experiments analyze the propagation characteristics of radio signals in a working coal mine environment. The intent of the program is to provide basic propagation loss characteristics by which we may evaluate various approaches to an integrated mine communications system. The goal of such a system is to satisfy both operational and emergency communications needs in the mine. Field testing was conducted during the last week of November 1972, at a coal mine operated by Inland Steel Company, near Sesser, Ill, and in the Robena No. 1 Mine, Waynesburg, Pa, on 12 March 1974. The tests included uhf propagation losses and noise (200 MHz to 1 GHz) in the Sesser, I11 mine location and vlf propagation loss and noise (1 to 200 kHz) in both of the above locations. The basic experimental parameters were frequency, polarization, antenna type/orientation, and distance. The following reports treat the various aspects of the test programs in detail. Since different antenna configurations were used in the two mines, each report contains its own experimental predictions drawn from its corresponding test activities. A test equipment list and block diagrams of typical experimental setups for the tests of section 2 are contained in appendix A.

Jan 1, 1974

Three -dimensional boundary value problems are difficult to solve. Indeed, while the separation of the scalar wave equation can be effected in 11 different coordinate systems, an analytic solution requires that the boundaries, both external and internal, possess the same symmetry as the coordinate system. Numerical methods are thus of great importance for the solution of such problems; however, despite the availability of high-speed, large memory digital computers , the solution to a significant three -dimensional problem is by no means trivial. It is unfortunate that the results reported here by Jones are invalid. Jones discusses a model in which a three-dimensional island lies off a linear coastline where all the interfaces lie in the coordinate planes in a Cartesian system. A downward plane em wave polarized with the electric field parallel to the linear coastline, and two of the islands coast, is incident downward. This, of course, requires that the incident electric field is perpendicular to the other faces of the idealized Cartesian island. The significant equation used by Jones for his finite difference calculations is [ ] where n2 = sµ? . is the conductivity, µ=µo is the permeability of the appropriate medium, and w is the angular frequency of a Fourier component of the incident field. We see that the displacement current term is omitted, which is an excellent approximation for the parameters of interest in this model. In the similar equation for the y- component of the diffusion equation, the same considerations which we are about to discuss are equally valid. It can be seen from the equation that the field components are related and thus any errors introduced will be propagated into all three components. The difficulty arises when Ex or E is perpendicular Y to one or other of the surfaces of discontinuity in s. The continuity of current at the air-earth interface (upper surface), e. g., jy, requires

Jan 1, 1973

By R. Karl Zipf

MULSIM/NL (multiple scams, nonlinear) is a three-dimensional boundary-element method (BEM) program developed at the U.S. Bureau of Mines for stress and displacement analysis of coal mines and thin metalliferous veins. It can analyze one to four parallel seams that can have any orientation with respect to the Earth's surface. Three main new features distinguish MULSIM/NL from its predecessors: (1) nonlinear material models, (2) multiple mining steps, and (3) energy release and strain energy computations. MULSIM/NL has six material models for the in-seam material: (1) linear elastic for coal, (2) strain softening, (3) elastic plastic, (4) bilinear hardening, (5) strain hardening, and (6) linear elastic for gob. Detailed checks show that numerical stress and displacement calculations compare well to known analytic solutions for simple problems. The total energy release calculated by MULSIM/NL is comprised of three basic terms: (1) strain energy release from the mined-out material, (2) linear kinetic energy release due to change in gravitational potential over the mined-out area, and (3) nonlinear kinetic energy release due to nonlinear materials in the total backfill and gob area. The strain energy release term is modified to account for nonlinear stress-strain behavior in the unmined materials. Comparisons of these numerical energy release rate calculations with known analytic solutions show excellent agreement.

Jan 1, 1992

California's coal resources are estimated to be 100 million tons, of which 50 percent is lignite, 40 percent subbituminous, and 10 percent bituminous. The occurrence of coal in California is rather limited and is restricted generally to the foothill regions of the western slopes of the Sierra Nevada Mountains. Significant quantities of coal have been mined in five areas: Ione in Amador County, Alberhill in Riverside County, Stone Canyon in Monterey County, CorralHollow in Alarneda County, and Mount Diablo in Contra Costa County. Most of the coal was rnined in the early 1900s and was used locally for fuel. Current mining operations are located in Amador County near the city of Ione. The two producing mines supply fuel to a mine-mouth co-generation power plant. The fuel coal is processed prior to burning to extract montan wax. Because California does not have primacy, coal mining in the state is regulated by the Office of Surface Mining's Albuquerque, New Mexico, Field Office.

Jan 1, 1992

By G. S. Rice, H. P. Greenwald

"Experience and experiment have goth shown that a cloud of coal-dust in air can be inflamed and an explosion developed only when a certain minimum concentration of the dust in air has been equaled or exceeded. Those who have had experience in the handling of coal know that dust is frequently present in the air and may be of sufficient density to obscure an ordinary electric light at a distance of 40 or 50 feet; yet flames may be, and times without number have been, introduced into such clouds, when no additional coal-dust has been stirred up, with no effect other than the burning of the dust particles which actually enter flame. Evidently the density of the dust cloud is insufficient to give self-supporting combustion.The minimum amount of dust in air required to give a spreading flame will vary with a number of factors such as the composition of the dust and its size. This amount in a unit space may be considered analogous to the lower limit of inflammability of fire damp (methane) in air, although the variation in limit of explosibility of gas is small even when conditions of the experiment are altered. In large-scale determinations of the lower limit of inflammability of coal-dust there is no certain method by which a sample of the dust cloud can be snatched and its density determined. It is necessary to produce the best possible dust cloud from a known weight of dust, in a known volume and assume - probably with considerable error - that the dust cloud is reasonably uniform. The dust cloud must be formed and the source of ignition applied to it simultaneously; this is generally accomplished by the use of blow-out shots of black blasting powder, dynamite, or similar explosive so prepared as to blow out like a cannon shot, or by a gas explosion. The more violence attending the source of ignition, the greater is the probability that all the dust is raised in a uniform cloud; and the greater the length or intensity of the flame, the greater are the chances of ignition. As a result one may obtain a variation in apparent minimum density with different sources of ignition. This difference is more apparent than real and must remain until devices for instantaneous sampling of dust clouds during explosions are perfected."

Aug 1, 1931

By Charles D. Litton

Experiments were conducted to determine the optical scattering properties of diesel particulate matter (DPM) and various combustion aerosols from both flaming and smoldering combustion sources at discrete angles of 151 and 301 in the forward direction and at a light source wave length of 635 nm using a simple light scattering module. In addition to the scattering data, simultaneous measurements were made of the total aerosol mass concentration; light extinction at an average wave length of 546nm; and the response of a common bipolar ion chamber typical of residential smoke detectors modified to allow the aerosols to flow through the chamber. The results of these experiments indicate, for DPM and combustion aerosols, the intensities per unit mass concentration depend not only upon whether the aerosolis DPM or combustion aerosol but also upon the type of combustion aerosol. The results also indicate that the ion chamber responses are greatest for DPM, followed by the response to flaming combustion aerosols (FCA)and lowest for smoldering combustion aerosols (SCA). For light scattering, the greatest intensities are found for SCA, followed by the intensities from FCA, and lowest for DPM. This report describes the experiments, their results, and the use of these results to developed sign criteria for early warning fire sensor capable of the rapid and reliable detection of fires in atmospheres that may or may not be contaminated by the products produced from diesel engines. © 2002 Elsevier Science Ltd. All rights reserved.

By Michael A. Trevits

The National Institute for Occupational Safety and Health (NIOSH) in partnership with Strata Products tested the sealing capability of Ventstop®? as part of an ongoing mine fire control and suppression research program. Ventstop®? is a multi-purpose, inflatable device that is produced by Minvent Solutions and is available world wide for use in the metal and nonmetal mining industry. Ventstop®? is also used in the Australian coal industry as a temporary ventilation control device. The device can be quickly deployed, is reusable and can be placed in horizontal and vertical mine voids to control dust, fumes and smoke. Deployment, multi-day inflation and air leakage tests were conducted at the NIOSH Lake Lynn Laboratory to determine the capability and limitations of Ventstop®? in a simulated coal mine setting. During the tests, Ventstop®? was also subjected to low level forces of a nearby methane gas ignition. It is thought that Ventstop®? could be used by the US coal mining industry to temporarily close an underground mine area in response to a fire or spontaneous combustion heating event, to temporarily redirect mine ventilation during longwall equipment moves or during stopping construction. This paper describes this inflatable temporary mine sealing technology and presents the results of the NIOSH tests. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of NIOSH.

Jan 1, 2009

By C. M. Bouton

Although much valuable work has been done in the study of dust explosions, the laboratory technique has not been developed to the point where the many factors involved can be properly controlled, and thus where really fundamental information can be obtained. This paper presents a brief discussion of the difficulties encountered in fundamental work on dust explosions, a description of apparatus intended, to overcome some of them, and an account of some results obtained. FACTORS INVOLVED IN DUST EXPLOSIONS The more important factors pertaining to the dust cloud itself which are known to determine the phenomena of explosions are (1) the kind of dust; (2) its fineness; (3) its concentration in the exploding cloud; and (4) the nature of the interior motions, or turbulence, of the cloud before and during the explosion. These factors are arranged in what seems to be an ascending order of complexity. The kind of dust is the factor most easily subject to control. The fineness of the dust at first sight seems to be a controllable factor, but when it is recalled [that] most explosible dusts are mixtures of particles of continuously varying sizes so small as to pass through the finest woven sieves, and therefore difficult to separate either for purposes of analysis or experiment, the fineness is seen to be a factor difficult to control accurately.

Jan 1, 1929

By Charles A. Kumke, GROVER J. DUFF

This paper describes mining and milling practices at the San Xavier mine of the Eagle- Picher Mining & Smelting Co. in Pima County , Ariz . It is one of a series being prepared by the Bureau of Mines on mining methods in various mining districts of the United States . The mine and the mine surface buildings are situated in sec . 11 , T. 17 S. , R. 12 E. , in the Sierrita Mountains in Pima County , 20 miles south by southwest from Tucson via the San Xavier Mission and Twin Buttes road ( fig . 1). A well-maintained dirt road continues southward toward Twin Buttes for 4 miles and then branches off northeasterly for 5-1/2 miles to Sahuarita , where the concentrator of the Eagle - Picher Mining & Smelting Co. is situated on the west slope of the Santa Cruz River Valley . Tho mill is connected by a railroad branch to the main line of the Southorn Pacific Railroad between Tucson and Nogales . It is generally assumed that the San Xavier silver - lead deposits became known to the Jesuits and Spaniards in the early part of the eighteenth century . However , no extensive mining operations were conducted by the Jesuits in what is now Arizona before the middle of the eighteenth century . The completion of the Southern Pacific Railroad from Los Angeles to El Paso in 1881 marked the beginning of intense activity in mining throughout the southern part of the State . The San Xavier mine produced 6,000,000 pounds of lead , considerable zinc ( exact figures not available ) and $200,000 in silver from 1897 to 1918 . The Eagle- Picher Mining & Smolting Co. re- opened the San Xavier mine in 1943 and built a 175-ton concentrator at Sahuarita . The capacity of the plant was increased in 1944 to 500 tons in order to take in custom ore . The surface rocks at the San Xavier mine are , in great part , of sedimentary origin . Limestones of various ages comprise most of the exposed sedimentaries , some quartzites and shales also being present . The sedimentaries rest upon coarse - textured , intrusive , igneous rocks comprised mainly of granite and granodiorite . The San Xavier deposit is composed of galena , sphalerite , chalcopyrite , and pyrite . Generally the individual ore bodies are small , discontinuous , and occur as irregularly spaced shoots or lenses . The present mine workings extend horizontally a distance of 2,700 feet and vertically 900 feet . Owing to ground weight, all mine openings are timbered on the levels and all stopes are square- setted and waste -filled .

Sep 1, 1950