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By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the Purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of Procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By W. R. Hardwick

This paper describing the mining methods of the Inspiration Consolidated Copper Co. is one of a series being prepared by the Bureau of Mines on mining methods and costs in various mining districts of the United States. The story of mining at Inspiration is of particular interest because, after 127,812,000 tons of low-grade copper ore were successfully mined, the mining method was changed from block caving to open-pit. As the open pit became deeper, many features of the former block-caving operation that were exposed elucidated concepts of the mechanics of caving that previously had been assumed but not observed. The conversion to open-pit mining was accomplished by unique combinations of equipment and the introduction of ingenious engineering and operating practices that have extended the expected life of the mine for many years.

Jan 1, 1963

By V. H. Gottschalk, John Grodd, R. S. Dean

"Elemantary ConsiderationsAlthough magnetiem was first discovered in and derives its name from an oxide of iron found in magnesia and called lodestone its pracical uses date from the discoveries of Faraday concerning its relation to the electric current. We may therefore start our discussion of magnetic properties with Faraday's law for relation between induced electromotive force and the change in a magnetic where e is the electromotive force induced in an electric circuit by a unit rate of change of magnetic flux N, H is the intensity of the magnetic field, S is the area enclosed by the circuit, and i an angle between H and the normal to dS. In the simplest case we could use this law to measure the strength of a magnetic field by passing it at a measured rate through a coil of copper wire and determining the,electromotive force. As a matter of practical convenience, it will be simpler to nee the total quantity of electricity produced by a change of magnetic field. For this purpose we may let i denote the strength of the electric current induced by the change of magnetic field in time in a circuit of area a and resistance R. Then the total electric quantity. Q is given. by"

Mar 1, 1934

By Henry P. Chandler

COMBINED sales of abrasive materials in the United States during 1956 increased at about the same rate as the value of the Gross National Product in terms of 1954 dollars,3 which was nearly 3 percent. However, some segments of the industry did not follow the general pattern. Sales of abrasive grinding wheels increased 9 percent in value. Sales of surface-coated abrasives declined 5 percent in quantity hut increased 1 percent in value, Production of crude silicon carbide in the United States and Canada advanced both in tonnage and value, but that of abrasive-grade [ ]

Jan 1, 1958

By John P. Capp

Information is summarized on the major uses of fly ash and prospects for utilization in agriculture and in brick and mineral-wool manufacture. Technological aspects of utilization are discussed and references are given to the work of many of the leaders in the fields of fly ash production, processing, and utilization.

Jan 1, 1970

By W. J. Wenger

Colorado has been producing petroleum since 1863 but only recently has become a major oil State. The first well was drilled on Oil Creek near Florence, but out-put was relatively small until discovery and development of the Weber sandstone reservoir at Rangely. Oil was discovered in the Weber sandstone in 1933, and the reservoir was developed after 1940, bringing Colorado, in 1949, to 11th place among the 48 States as an oil producer. Colorado's output increased further because of the discovery and development of many fields in the Julesburg Basin since 1949 By 1954 Colorado was in ninth place and maintained that position through 1955.4/ Between 1946 and 1951, Colorado's oil production more than doubled, while the total United States production increased only 25 percent. It seems probable that production will continue to expand in Colorado for many years. This report presents analyses of 92 crude oils from 73 fields representing 90 percent of the production in 1955. Abridged analyses are listed for easy comparision, and complete analyses arc given in the appendix. Oil samples were collected for study from many different sources. Although many of the newer fields were not sampled, their oils probably are very similar to those from corresponding formations that were studied and tabulated.

Jan 1, 1957

By Eugene T. Sheridan

The United States has extensive reserves of peat. Peat and muck lands are estimated at approximately 79 million acres, with reserves of 13.8 billion net tons. Within the past decade domestic production of peat has increased 2-1/2 times, and apparent consumption has tripled. During the same period imports have increased greatly, and in 1955 they almost equaled domestic production. The substantial increase in the demand for peat in the United States was due chiefly to expanding markets in agriculture and horticulture, for the reason that in this country peat is used primarily as a source of organic matter to improve the physical condition of mineral soils and as a mulch for shrubbery. A valuable constituent of any soil is its organic matter, and its depletion will injure cultivated soils and subject them to greater erosion.

Jan 1, 1957

By M. D. Marshall

A survey showed that there were 24 bin-related fatalities in the 5 year period of 1975 to 1979 in the minerals industry. Only 4 victims wore safety belts and only 1 of these had a second person attending his lifeline, as mandated by Federal safety regulations. Not one victim observed the three main Federal safety regulations governing work in and around bins. A study was conducted on the force necessary to pull victims partially buried in sand and limestone. Recommendations are made on procedures and safety equipment that can minimize bin-related accidents. A Handbook, directed to the plant engineer responsible for bin design and safety, was also issued detailing bin designs and flow-aid accessories as a function of the flowability of the stored material to better maintain material flow from bins. A comprehensive table of the flowability of many materials produced in the minerals industry is presented and simple procedures given for determining the flowability of materials if not available.

Jan 1, 1984

By K. K. Kelley

"INTRODUCTION The Bureau of Mines nitrogen peroxide process (2) 3/ for extracting manganese from low-grade ores is essentially a two-stage process involving the reversible reactionMnO2 + 2NO2 + 6H2O = Mn (NO3)2 . 6H2O (1).At lower temperatures this reaction proceeds to the rigth and affords a means of dissolving manganece and separating it from unreacted ore. At higher temperatures the reaction proceeds to the left and manganese dioxide is recovered and nitrogen peroxide regenerated for recycling. Evidently, therefore, the energy required for decomposition of manganous nitrate is a matter of practical importance. Similar information for certain other nitrates also is desirable beceuse the nitration step of the process produces appreciable amounts of nitrates of other metals, such as iron, aluminum, magnesium, calcium, and barium, some of which are not broken down in the evaporation and decomposition steps. Thus, a portion of the nitrogen peroxide is not directly available for recycling. Whether or not it is feasible to recover nitrogen peroxide locked in the more-stable nitrates depends partly on the energy required and the conditions necessary for their decomposition.To supply information bearing directly on these subjects, several researches were undertaken at the Pacific Experiment Station: (a) Heats of formation (24, 25, 26) of nitrates of manganese, magnesium, calcium, barium, and aluminum were measured at 298.2° K:; (b) low-temperature specific heats (23), in the range 51° to 298.2° K,, and entropies of nitrates of magnesium, calcium, barium, and aluminumm were determined; and (c) heat contents (21) above 298.2° K. of the nitrates of manganese, magnesium, calcium., and barium were measured. The results of these studies, when correlated by thermodymamic methods, permit evaluation, at any temperature of interest, of the energies required to decomposethe nitrates and furnish information concerning the equilibrium pressure temperature relationships."

Sep 1, 1944

Kroemer(1-3) and Kroemer et al.(4) define the isoinertial technique of strength assessment as one in which mass properties of an object are held constant, as in lifting a given weight over a predetermined distance. Several strength assessment procedures possess this characteristic. Most commonly associated with the term is a specific test developed to provide a relatively quick assessment of a subject's maximal lifting capacity using a modified weight-lifting device.(1,5) The classic psychophysical methodology of assessing maximum acceptable weights of lift is also considered an isoinertial technique under this definition.(6) While the definition provided by Kroemer(1) and Kroemer et al.(4) has been most widely accepted in the literature, some have applied the term "isoinertial" to techniques that differ somewhat from the preceding definition, such as in a description of the Isotechnologies B-200 strength testing device.(7) Rather than lifting a constant mass the B-200 applies a constant force against which the subject performs an exertion. The isoinertial tests described here apply to situations in which the mass to be moved by a musculoskeletal effort is set to a constant. Is Isoinertial Testing Psychophysical or Is Psychophysical Testing Isoinertial? As various types of strength tests have evolved over the past few decades, some unfortunate developments in terminology have arisen to describe and classify different strength assessment procedures. This is particularly evident in sorting out various tests that have been labeled "isoinertial." One example was cited earlier. Another problem that has evolved is that the term "isoinertial strength" has two connotations. The first is the conceptual definition: isoinertial strength tests include any strength test in which a constant mass is handled. In practice, however, the term is often used to denote a specific strength test in which subjects' maximal lifting capacity is determined using a machine and a constant mass is lifted.(1,5) Partially as a result of this dual connotation, the literature contains references to both "isoinertial strength test" as a psychophysical variant(8) and the psychophysical method as an "isoinertial strength test" (4,9) To lay the framework for the next two chapters, the authors will briefly discuss some operational definitions of tests of isoinertial and psychophysical strength. In stating that the isoinertial strength test is a variant of the psychophysical method, Ayoub and Mital(8) refer to the specific strength test developed by Kroemer(1) and McDaniel et al.(5) Clearly, this isoinertial protocol has many similarities to the psychophysical method: both are dynamic; weight is adjusted in both; and both measure the load a subject is willing to endure under specified circumstances. However, while both deal with lifting and adjusting loads, there are significant differences between the psychophysical (isoinertial) technique and the Kroemer-McDaniel (isoinertial) protocol in their procedures and the use of the data collected in these tests. For our purposes, we designate the

Jan 1, 1998

By B. K. Cantrell, K. L. Rubow

"Two source apportionment techniques have been applied by the U.S. Bureau of Mines to aerosol measurements in diesel-equipped underground noncoal mines. The first technique is based on size-selective sampling and the premise that the diesel exhaust fraction of the aerosol is predominately submicrometer in size while the mineral dust fraction of the aerosol is mostly supermicrometer in size. The second technique, chemical mass balance (CMB) modeling, was used to referee the analysis of diesel and mineral dust aerosol concentrations with the size selective method.The size-distribution data were modeled using a lognormal regression to parameterize the submicrometer and supermicrometer fractions of the sampled aerosol and to estimate the mineral and diesel contributions to each. Using this analysis, 97 ± 2 pct of the submicrometer aerosol mass was attributable to diesel exhaust aerosol.The CMB analysis, applied to both fractions of the respirable mi11e aerosol, yielded the amount contributed to each by the diesel and dust aerosol sources. On the basis of this analysis, 94± 10 pct of the submicrometer fraction was diesel exhaust aerosol. As much as 20 pct of the diesel aerosol, however, was found in the supermicrometer fraction, requiring a correction of the submicrometer fraction results to account for the missing diesel mass. More accurate measurements will require a carbon-specific analysis of the aerosol.INTRODUCTION Measurement of the contribution of diesel exhaust to respirable aerosol in mine environments has become increasingly important because of current concerns over the occupational health effects resulting from exposure to diesel emissions. In response to this, the U.S. Bureau of Mines is developing and evaluating new sampling methods for measuring diesel aerosol in underground mines. Two such techniques are being studied by the Bureau, size selective sampling and CMB modeling. These techniques use measurable physical or chemical characteristics of a mine aerosol sample to infer the amount of diesel particulate material contained in the sample."

Mar 1, 1992

By Forrest T. Moyer

Injury experience at metal mines and mills (excluding officeworkers) in 1964 was 60 fatal and 3,672 nonfatal disabling work injuries during an exposure time of 149 million man-hours worked. These injuries occurred at a frequency rate of 24.57 per million man-hours and had a severity rate of 3,687 days lost or charged per million man-hours. Employment at 2,363 metal mines and 291 mills, excluding officeworkers, was 68,140 men in 1964. The average number of days worked was 274 The principal cause of fatal injuries at all mines and mills was haulage accidents and in underground mines, only, was falls of ground. The principal cause of nonfatal injuries was handling material accidents. The frequency rate at metal mines and mills in 1964 was slightly below that of 1963, whereas the severity rate was higher. Injury experience at 94 primary nonferrous smelters, refineries, and reduction plants (excluding officeworkers) was 8 fatal and 999 nonfatal disabling work injuries during a worktime of 98 million man-hours worked. The combined injury-frequency rate in 1964 was 10.29 and the injury-severity rate was 1,005. The 36,956 employees worked an average of 329 days during 1964. The principal cause of injuries at these plants was handling material accidents.

Jan 1, 1968

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network. and 2)development at a set pit digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the models and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated fur their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

"SUMMARYThe K.M.A. reservoir was discovered to be oil bearing at a depth of 3,719 feet on March 11, 1931. Extensive development, however, was not begun immediately, because the discovery well had a low initial daily oil production, and market conditions for oil were unfavorable. Development of the field progressed slowly for the next 6 1/2 years. In the latter part of 1937, a wildcat well approximately 2 miles southwest of the discovery well was drilled on a magnetometer high and completed with an initial flowing production of 2,016 barrels of 43° A.P.I.-gravity oil in 12 hours. Rapid development of the southwestern part of the K.M.A. field was begun immediately and continued until over 700 wells were drilled and approximately 12,500 acres proved oil productive.Because of the large size of the entire K.M.A. field, this report is limited in scope to the southwestern part only, and the discussion that follows pertains to this area only. The closing date for production statistics is August 1, 1949.The K.M.A. structure is a complex anticline having a maximum closure of 250 feet, and the K.M.A. formation is composed of sediments that grade from limestone through sandy lime and limy sand to sandstone with thin streaks of shale. Two distinct members of the K.M.A. formation, zone I and zone II, are oil productive. Core analyses indicate the average porosity to be 16.5 percent for zone I and 16.1 percent for zone II. A relationship was established from core data, which showed the correlative permeabilities to be 42.1 millidarcys for zone I and 39.5 millidarcys for zone II, whereas the arithmetical averages of the permeabilities were 84 millidarcys for zone I and 216 millidarcys for zone II. Connate water saturations were 17.5 percent for zone I and 20.0 percent for zone II. The porosity-saturation method, using a thickness-correction factor, was employed to calculate the volume c 168.1 million barrels of stock-tank oil initially in place in the reservoir. Analyses of the reservoir oilIn that, although the initial reservoir pressure was 1,750 p.s.i., the original reservoir oil was saturated to only 1,300 at which pressure 1 barrel of stock,tank oil contained 525 cubic feet of gas in solution.A serious decline in reservoir pressure during the 2 years of rapid development alarmed the operators and caused them to consider a cooperative pressure-maintenance program. In the latter part of 1939, the K.M.A. Pressure Maintenance Association was organized, and the gasoline plants in the field agreed to process the wet gas and return the dry gas to leases having gas-injection wells. Approximately 27 percent of the cumulative volume of produced gas had been returned to the reservoir by August 1, 1949."

Jun 1, 1952

By J. R. Thoenen

In June 1929 the Bureau of Mines issued a 13-page Information Circular entitled "Mineral wool." This was one of the first publications to present to the public some technical aspects of the mineral-wool industry. Since that time several articles have appeared on the subject in the technical press as well as publications by State organizations. Inquiries for information on mineral wool have continued to be received by the Bureau of Mines in large numbers, and in 1935 it was decided, with the cooperation of the is industry, to make a field survey of the plants then producing and to collect therefrom technical data to be compiled in a paper for public distribution. As a first step, a brief questionnaire was mailed to the known producers asking if they would cooperate for publication. Favorable replies were received from of percent of the manufacturers, and the field work was started. As the study progressed and tie number of plants visited grew, it became more and more apparent that the industry had made rapid strides in technical operation and control of their product, as well as in increasing production during the mast decade.

Jan 1, 1938

By Michael E. Henderson

Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. This particle degradation report is a summary of the particle distribution data obtained at the HTRF for the period 26 November 1982 to 1 October 1983. The testing covered herein is for coarse Pittsburgh Seam coal in the 6-in (150 mm) and 12-in (300 mm) pipelines, at velocities ranging from 5 to 18 ft/s (1.5 to 5.5 m/s), and at concentrations by weight ranging from 15 to 55 pet. Particle size distribution samples were taken systematically throughout the testing.

Jan 1, 1985

By Avis W. Effinger

In conjunction with pilot steamflood tests in the Venango sands of Warren and Venango Counties, Pa., the Marx and Langenheim (4)3 calculations were adapted and programed for digital computer solution to predict test performance. The Monte Carlo technique was incorporated in the calculations to provide values of several variables which could not be adequately defined from available information. The computation methods are explained and the FORTRAN IV program listing is presented. Data and results of the prediction calculations for Venango oil sands are also shown.

Jan 1, 1969

By R. A. Egen

The purpose of this book is to provide an indication of what good hoisting practice is and how it might be achieved. To this end the book contains discussions of equipment and inspection and maintenance procedures developed and used by mining people in striving for safe, reliable hoisting equipment. Most of this information comes from domestic practice; the rest is foreign, notably from Canada. Most things discussed have long proved their general worth, and others promise to; a few are beginnings. However, nothing is conjectural or theoretical; the practices described herein are in use somewhere in the mining world. The stress is on equipment in use; it is not a design-guidelines manual. Nevertheless, there are some sections dealing with design material since it may be of value in a maintenance/ replacement sense. Mine hoisting installations encompass such a wide variety of equipment and conditions that it is impractical to specifically cover them all. This book mainly treats conventional systems using conventional components with some discussion of the more common unconventional (special) systems in use. There is no recognized definition for a "conventional" mine-hoisting system. Herein the term means those systems most commonly used in daily operations for transporting men, materials, and product-electrically driven drum and friction hoists, with guided conveyances running in vertical or inclined shafts. Beyond this, what "conventional" means is probably best illustrated by the topics discussed.

Jan 1, 1975

By N. S. Dalal, J. F. Mega, X. Shi, V. Vallyathan

Several studies have suggested that pulmonary toxicity to asbestos and silica may be mediated through oxidant-induced cell injury. We have reported recently that surface radicals associated with freshly fractured silica may be an imponant factor in cell injury and induction of pulmonary disease. Although the generation of oxygenated radicals in dust-cell interactions has been demonstrated, there are no data correlating the toxicity of a dust with the level of oxygen radical generation by the dust during its interaction with phagocytic cells. In the present study, we have investigated the in vitro generation of oxygen free radicals from human neutrophils and rat alveolar macrophages stimulated with freshly fractured silica, aged silica, amosite, crocidolite, chrysotilc, and a nontoxic dust, barite. Electron spin resonance (ESR) with the aid of a spin trap phenyl-N-ten-butyl nitronc (PBN) was used to measure the oxygen radicals generated during phagocytosis of the dusts. The relative toxicity index and ESR peak heights, on an equal surface area basis and normalized to barite as one, showed a direct relationship. The normalized toxicity indices and peak heights were: silica, 3.5 versus 2; chrysotile, 4 versus 2; crocidolite, 11 versus 8; and amosite, 26 versus 13. Addition of hydroxyl radical scavengers such as catalase, dimethyl sulfoxide, 1,3 dimethyl-2-thiourea (DMTU), sodium benzoate, and mannitol prevented the radical generation. Carmustine, a glutathione reductase- glutathione peroxidase inhibitor, caused a 5-fold increase in the radical generation. These results indicate that a nontoxic dust such as barite generates toxic oxygen radicals at a minimal level that can be quenched by the normal cellular defense system. For toxic dusts such as silica, amositc, chrysotile, and crocidolite, the potential for oxygen radical generation is enhanced by their surface propenies, physical dimensions, and the surface-based radical-generating redox sites. The enhanced radical generation may impair the cellular defense system, resulting in cell injury. Use of scavengers, chelators, and potentiating agents suggests the membrane-based oxidase system as the probable primary source of the radical-generating system. The data presented herein suggest the generation of oxygen free radicals as an important primary event in silica- as well as asbestos-induced cell injury.

Mar 1, 1992