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By Kenneth G. Skinner

Diatomite, also known as diatomaceous earth, diatomaceous silica, kieselguhr, and moler, has been used extensively for many years, but only during the past two decades has it become an important industrial mineral. United States sales for 1.936-38 totaled almost 280,010 tons,7 but relatively little (with the exception of that sold by an Oregon company affiliated with a larger California company) was sold by Pacific Northwest producers. In attempting to develop some of the many Pacific Northwest diatomite deposits, these producers have been handicapped by lack of published technical information regarding processing methods and the suitability of different deposits for specific uses. To determine some of the physical and chemical properties of known Pacific Northwest diatomites, the present investigation was started in 1938 by the Bureau of Mines in cooperation with the College of Mines, University of Washington. Figure 1 shows the location of deposits sampled. Because most relatively pure diatomites can be used as concrete admixtures or as inert fillers in rubber, paints, and plastics, this investigation concentrated upon determining some filter-aid characteristics and their relationship to other physical properties. A filter-aid is a powdered material that, when added to solutions to be filtered, improves flow rate, filtrate clarity, or both. Some chemical analyses also were made.

Jan 1, 1944

By R. J. Leary

This investigation was conducted to determine the effects of various rare-earth metal addition practices upon the macrostructure and the pattern of sulfur distribution in steel ingots. Heats of plain carbon steel were melted in a 1-ton, basic electric-arc furnace. Melts were treated with mixtures of rare-earth silicides, aluminum, and cryolite either in the furnace before tap or in the ladle after tap to determine the effects of this form of rare-earth treatment upon ingot macrostructure. Steels thus treated with rare earths in the furnace were characteristically free of the gross subsurface nonmetallics which typically result from conventional rare-earth treatments. Steel treated in the ladle showed only a few such nonmetallics, and practical techniques were developed for eliminating most of these. Results showed that furnace deoxidation was controlled by the concentration ratio of rare earths: aluminum. During casting, deoxidation was controlled by the concentration of rare earths. Oxygen contents equivalent to vacuum ladle degassing resulted from air-melt furnace treatments with the rare-earth mixtures described. Rare earths in steel inhibited the onset of equiaxed grain formation during ingot freezing, and also virtually prevented interdendritic segregation of sulfides.

Jan 1, 1968

By James M. Link

A program was initiated tinder sponsorship of the U. S. Bureau of Mines to investigate pipeline behavior of raw and spent oil shale slurries. Slurries were recirculated in pipeline loops with 150-mm and 200-mm diameter horizontal test sections and a 150 -mm diameter vertical test section. Slurry concentrations from 10 to 60 weight percent were investigated. Critical and deposition velocities were observed. Head losses were measured at various velocities. Rheology measurements were made on representative homogeneous samples from the pipeline. From these data, pipeline energy requirements were predicted by computer and compared to pipeline data. Computer programs were also used to analyze pipeline data for two flow models: 1. Heterogeneous flow regime for coarse, settling slurries 2. Homogeneous flow regime for nonsettling suspensions The economics of slurry transport of raw and spent shale were examined. Cost estimates encompassed a range of pipe diameters to transport a wide range of throughputs of both raw and spent shale. Similar estimates were made for conveyor belt systems to provide a valid cost comparison. Economic comparisons are valid in a general sense, but a specific study must be made to determine the cost advantages of hydraulic transport for a given mine.

Jan 1, 1977

By E. W. Parsons

Permanent support of the back is an important economic factor in maintaining a tunnel or other underground opening in condition to render the service for which it was driven. Timber has been most commonly used for support in tunneling and drifting because of its strength and ease of installation. Even when treated for decay, however, timber is subject to deterioration and, over a long period of time, should not be considered a permanent support. Concrete support or lining is permanent and has been used in tunnels of every size for many years but has been almost exclusively cast in place, a difficult, costly process. This report deals with the design and installation of precast concrete supports to combine the best features of both methods.

Jan 1, 1958

The overall objective of this study is to gather operational data from selected surface coal mining systems in the United States, and to assess the potential production and economic capacity of the systems. The study includes: four mines, each using a different mining technique and different equipment. One mine was selected from each of the major coal fields: Midwestern, eastern,, northwestern, and southwestern. The Midwestern Mine is located in the Central Plains and produced 1.45 million tons of raw coal during the study year The Midwestern Mine uses the area mining or box-cut technique. A large in-pit shovel and a bucket wheel excavator are used to remove the overburden. Coal is removed by a loading shovel and transported to the dumping point by large off--highway trucks.

Jan 1, 1975

By W. T. Benson

Peacetime production of mercury in the United States is controlled by world mercury prices, with significant lags to be expected between price increases or decreases and resultant increased or decreased production. Twenty-four mercury-bearing mines and prospects in widely separated districts in western and central Nevada and one property on the Nevada-Oregon border were examined and sampled. The purpose of the project was to determine if some of the properties warranted more extensive exploration work to obtain information on possible reserves of commercial-and sub-commercial-grade ores. The investigation of mercury deposits in Nevada was sufficiently widespread and indicated several areas of interest in the State that merit further exploration work.

Jan 1, 1956

By Worthen Bradley

This paper describing the metallurgical practice and costs at the reduction plant of the. Sulphur Bank Syndicate, Clearlake, Calif., is one of a series of papers on the treatment of ores being prepared by the Bureau f Mines. The reduction plant and mine of the Sulphur Bank Syndicate are on the eastern shore of Clear Lake, in Lake County, Calif., 4 miles from the town of Clearlake and 125 miles north of San Francisco.

Jan 1, 1931

"INTRODUCTION AND ACKNOWLEDGMENTSAt the request of the lessees, the Pearl tract was examined in February 1946, by Otto Ruhl, an engineer of the Bureau of Mines. From the evidence of old drill logs and from the few available records of mining operations on the Pearl and the adjoining Trussel (Big Tom) tract, it appeared that a relatively small churn-drilling program might develop enough lead-since ore to justify resumption of mining. In March 1946, funds were allotted for churn drilling, and the work was begun the following month. Ten holes totaling 1,933 feet were completed before the close of the project in August 1946. The work was under the general supervision of C. H. Johnson, chief, Rolla Division, Mining Branch, and under the direct supervision of the Bureau project engineers. 3/In its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to our national security and economy, It is the,of the Bureau to publish the facts development by each project as soon as possible after its conclusion. The Mining Branch, Lowell B. Moon, chief, makes preliminary examinations and conducts investigation of mineral deposits. The Metallurgical Branch, O. C. Ralston, chief, participates in this program by making beneficiation tests and analyses. In the present project, no metallurgical tests were made, and for the sake of speed the samples taken were analyzed by a local commercial assayer. 4/"

Jul 1, 1947

By Amitava Ghosh

A new analytical formula for predicting ground vibrations induced by blasting is proposed. One factor accounts for geometrical spreading. One factor corresponds to inelastic attenuation. The geometrical spreading function is based on likely source geometries, idealized as either square-root, cube-root or site-specific scaling, and on the propagation characteristics of predominant wave types. The inelastic attenuation is approximated by an exponential function. The empirical constants in these functions are backcalculated from field measurements. Regression analysis has been performed on twenty-three sets of measured data in order to determine the validity and the effectiveness of the proposed method. In many cases, the proposed method gives better correlation than the conventional method. In most of the remaining cases, there was no difference between the two methods. Best-fit lines given by the proposed method fit the data trend very well, especially at large scaled distances. At large distances the proposed method gives a prediction much closer to the actual values than the conventional methods. The statistical analysis shows not much difference between square-root, cube-root or site-specific scalings.

Jan 1, 1983

By H. C. Miller

Several agencies of the Federal Government are engaged in research and fact finding relative to petroleum and natural gas, and others are concerned with carrying out the provisions of specific laws that affect these natural resources in their broad aspects. The Bureau of Mines, however, is the only Federal agency designated by law to engage in research in oil and natures gas production, chemistry, refining, and

Jan 1, 1941

The Mine Safety and Health Administration (MSHA) defines an independent contractor as “any person, partnership, corporation, subsidiary of a cor-poration, firm, association or other organization that contracts to perform services or construction at a mine.” Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Sep 1, 2007

By A. E. Sands

This report deals with a portion of the research and development work in the field of synthesis gas purification, carried out by the Bureau of Mines at its Morgantown, W, Va., Station in cooperation with West Virginia University. The Bureau's work in connection with gas purification has been performed with the objective of finding effective, low-cost, processes for removing impurities from synthesis gas to protect the catalyst used in the Fischer-Tropsch process for production of liquid fuels. Synthesis gas used for the production of other chemicals, such as ammonia, alcohols, and methane, requires equally rigorous purification. Although present-day practice in the manufactured-gas industry does not require such a high degree of purification, there is increasing interest in the complete removal of sulfur compounds from city gas. Although the gas-purification work at Morgantown deals with several impurities, major effort has been devoted to organic sulfur compounds in gas; this paper represents a progress report on some of the more important studies in connection with those compounds. Because this is a progress report on the Bureau's experimental work, no attempt has been made to cover the work of others on the subject; references to the literature have been restricted to those bearing directly on the work described.

Jan 1, 1950

By E. C. Lane

For a number of years the Bureau of Mines has been studying crude petroleum from the producing fields of the United States, During the past year 10 crude-oil samples have been collected and analyzed from the producing fields of Pennsylvania and New York. This report gives the results of these analyses and for the purpose of comparison also analyses of samples of crude oils taken previously from some of these fields. This survey includes samples from normal producing properties as well as from properties using stimulative production methods such as water flooding and rapressuring. The outstanding feature of the survey is that the crude oils from tike various fields throughout this general area are similar in character and uniform in quality although they were produced from different sands and by various methods. Samples from fields in Venango County, Pa., however, appear to have a lower gasoline content than the others. This report includes two analyses reprinted from Bureau of Mines Bulletin 291.4/

Jan 1, 1938

By H. B. Hill

The Salt Flat field, formerly called the Toe -Bruner field, is located northeast of the town of Luling in Caldwell County, Tex. This field, which is a fault structure, approximately parallels and is about 5 miles east of the Old Luling field. The proved area is approximately 1,280 acres, on which 332 producing wells (September, 1930) have been drilled. The majority of the wells are producing from the Edwards limestone at an average total depth of 2,700 feet. A few wells are producing from the Austin chalk or from other formations above the Edwards limestone. The Wilcox formation is exposed, and the fault trace in places is scarcely evident. The strike of the structure is approximately 111. 20 to 45° E. The displacement of the fault is probably 200 to 500 feet. The discovery well was completed in the Austin chalk by the Lutex Oil Co. during April, 1928. In October, 1928, the Sun Oil Co. completed the discovery well in the Edwards pay. This well was an important discovery, as it indicated the potential oil possibilities of the Edwards limestone in echelon fault structures. The discovery led to the development of the third fault field in the Edwards limestone and opened up a large area for future prospecting. The total oil production for the Salt Flat field to and including September, 1930, was 19,833,215 barrels. The most reliable figures available of water production were compiled for a number of leases and wells in the south half of the field. These data show that the water percentage for the average well in this part of the field increased steadily from 30 per cent for January, 1929, to 81 per cent for December, 1929. The estimated daily water production of the entire field for December, 1929, was about 82,000 barrels as compared with a daily oil production of 29,725 barrels; or approximately 2.7 barrels of water were produced with each barrel of oil 14 months after the discovery well was completed in the Edwards pay. Estimates of water production in the (Old) Luling field, which is near the Salt Flat field, place the daily water production at about 150,000 barrels (July, 1929) as compared with a daily oil production of 11,000 barrels. These figures indicate that in the Luling field approximately 14 barrels of water must be lifted for each barrel of oil produced. The Luling field was discovered in August, 1922, and a peak annual production of 10,210,000 barrels was reached during 1924. The production during 1928 was 5,057,000 barrels of oil from an average of 567 producing wells for the year. Although water appeared early in the life of the Luling field, the oil production has been well sustained. Another feature of outstanding interest is the comparatively few producing wells that have been abandoned on account of water during the soven years of operation of this field. Comparison of data between the Luling and Salt Flat fields is of importance because of the nearness of the two fields. The Luling field is a narrow strip or "shoestring" approximately 8 miles long, with a maximum width of 3,400 feet. Production is obtained in the Edwards limestone at an average depth of 2,200 feet on the upthrow side of a fault. Similar conditions of accumulation are found in the Salt Flat field at greater depth to Salt Flat field as outlined (April, 1930) is about 7 miles long? with a maximum width of 2,000 feet. At the time the field work was begun (July, 1929) in the Salt Flat field, drilling operations had been almost completed in the south half of the field, while the north half was still under development. Cross sections and a structure contour map interpret the subsurface conditions in the south half of the field, where the water conditions first became serious.

Jan 1, 1931

By F. E. Block

The reaction between calcined dolomite and ferrosilicon has been studies with the aim of developing a continuous process for magnesium production. Small-scale tests were made in vacuum retorts similar to those used in the vacuum retort process as developed by Pidgeon (1)2/ and operated during the period of World War II in several Government-owned plants. Factors investigated with respect to the silicon efficiency were the reaction temperature, reaction time, amount of excess dolomite in the charge, and effect of adding sodium silicate to the charge to serve as a binder. Additional laboratory tests were made to study the reaction at elevated temperature but at atmospheric pressure. Silicon efficiencies exceeding 80 percent were found to result when operating in the temperature range from 1,750° to 1,800° C. for periods of 20 to 30 minutes.

Jan 1, 1956

General economic conditions continued to improve in the second quarter of 1984 as real gross national product advanced at an annual rate of 7.5 percent (table 1). This followed an even larger first quarter annual rate increase of 10.1 percent. The slower second quarter growth was greeted as a sign that the economy is not over-heating. The signs of slowed growth in some sectors suggest that the recovery may continue well into 1985 without the inflation symptomatic of a rapid recovery. Most of the slowdown in growth was absorbed by business inventories, personal consumption of durable goods, and residential fixed investment. Business inventories grew by only 68 percent as much as in the first quarter, personal consumption for durable goods grew by 58 percent of the first quarter rate, and residential fixed investment slowed to only 44 percent of the first quarter growth. Sectors with accelerated growth in the second quarter included personal consumption of nondurable goods and of services, which increased at annual rates of 9.6 percent and 3.8 percent, respectively, and Federal purchases of goods and services, which increased at an annual rate of 47.9 percent.

Jan 1, 1984

The coal-bearing strata of Oklahoma occur in the eastern part of the state over an area of 14,500 square miles, 20.7 percent of the state's total area. Commercially valuable deposits of bituminous coal cover about 8,000 square miles in seams ranging from ten inches to five feet thick. Estimated reserves in Oklahoma are 1.6 billion tons, representing 0.3 percent of U.S. coal reserves. The vast majority of coal mined in Oklahoma used in a single power plant within the state. Oklahoma gained primacy when its regulatory program was conditionally approved January 19, 1981. Authority for the state to administer the Abandoned Mine Land program was granted January21,1982. On April 30,1984, the Office of Surface Mining substituted direct federal enforcement of the inspection and enforcement portions of the Oklahoma program. This substituted enforcement was based upon a finding by OSM that Oklahoma had not operated the inspection and enforcement portions of its program effectively. As of January 1, 1986, Oklahoma inspection and enforcement authority was reinstated. Full program authority was granted to Oklahoma on January 14, 1986.

Jan 1, 1992

By R. S. Dean

This report, the third of a series of annual reports of the Metallurgical Division to be released in this form, covers the fiscal year July 1, 1936, to June 30, 1937. The technological work of the division is performed by sections. Thus, an efficient organization is provided to prosecute the various problems under investigation, and a logical system is set up for presenting the material contained in this report.

Jan 1, 1937

By M. M. Ayoub

With a return to coal as a major energy source for many companies, more emphasis is being placed on recovery of coal from areas that were formally considered uneconomical to mine. Increasing emphasis is being placed on production from low coal (seam height 48 inches or less) as high coal seams are depleated. Mining in restrictive spaces requires unusual work postures that can turn easy jobs into demanding ones. The objectives of this research were: (1) to evaluate the job demands associated with low coal mining, (2) to survey the anthropometry, strength, and aerobic capacity of low coal miners to determine if they differ from the U. S. population, and (3) to recommend, on the basis of available information, optimal job and work station design for low coal mining. This research effort was supported by the U. S. Bureau of Mines. The male and female anthropometry with the exception of weight and circumferential dimension, was quite similar to the comparison population. Back strength for male and female miners was significantly lower than the industrial worker population. This can be one of the contributing factors of low back problems in mining. Shoveling, timbering, and helpers tasks were physiologically demanding activities. However, due to the frequent stoppage of work, adequate rest was usually available. If work stoppage is corrected, then better work/rest schedules are essential.

Jan 1, 1981

By C. M. Harrer

Reconnaissance investigations were made of 129 iron occurrences in Arizona to determine their extent, attitude, and potential; character samples were analyzed to determine their quality and impurities; and pioneer metallurgical investigations were made on character samples to present their metallurgical problems. Some factors influencing past and potential western iron markets are discussed. The location, features, qualities, extent, and potential of iron occurrences and some associative resources--limestone and dolomite, coal, petroleum and natural gas, power, and water are discussed. The most abundant iron minerals are magnetite and hematite. The higher grade deposits are extensive contact-metamorphic or pyrometasomatic replacements of calcareous Paleozoic to Proterozoic rocks associated with intrusives. Large low-grade deposits of great potential are present as Precambrian taconite, semitaconite-, and jaspilite-like iron formations of magnetite-hematite. Iron occurs also as low-grade concentrations of magnetite in extensive alluvial deposits. Nonferrous metallurgical slags, nearly 100 million tons, are considered a potential source of iron. Various accessory elements are associated with the iron minerals and these pose metallurgical and economic problems.

Jan 1, 1964