Search Documents

By T. T. Campbell

Studies were conducted by the Bureau of Mines to develop a process for preparing thorium-magnesium master alloys or pure thorium metal by magnesium reduction of thorium tetrachloride in a semicontinuous reactor. Thorium tetrachloride was prepared in a fluidized-bed reactor by chlorination of thorium oxide or thorium oxalate. Conditions were established for producing a suitable thorium oxide feed for a fluidized-bed reactor. Thorium tetra-chloride was purified by vacuum sublimation and subsequently reduced by magnesium in a semicontinuous reactor to form thorium-magnesium alloys. Relatively pure thorium was produced by removing magnesium from the alloys by vacuum sublimation. Close to 100 percent of the thorium fed into the reactor was recovered either as metal (~93 percent) or as thorium oxide (~7 percent). The oxide can be recycled directly into the process.

Jan 1, 1971

By B. W. Gandrud, G. T. Bator

The recent introduction of small coal jigs in Alabama to meet the needs of truck - mine operators for cheap and economical cleaning equipment marks another step in Alabama's pioneering record in the mechanical cleaning and preparation of coal . During the past 4 or 5 years a number of these small jigs , with capacity of 5 to 10 tons per hour , have been installed at Alabama truck mines and at a few truck mines in Illinois , Tennessee , and Pennsylvania . Most of the installations have been at mines that specialize in the production of domestic , stoker coal . This report describes three models of small jigs and includes performance data obtained recently on one of the models by the Bureau of Mines, United States Department of the Interior , in cooperation with the University of Alabama, Tuscaloosa , Ala . , for the purpose of comparing it with fullsize jigs on a performance basis . With literally hundreds of truck mines now in operation throughout the country , it has been assumed in preparing this report that there is widespread interest in the availability of small - scale inexpensive preparation equipment for use at such mines in the production of steam and domestic coal and in some instances coal for manufacture of coke . Practically none of the coal from Alabama truck mines is scld to coke - oven plants ; but in some sections of the country truck mines supply a considerable amount of coking coal, and the use of small, inexpensive washers at some of them might be very advantageous during the present war emergency from the standpoint of increasing pig - iron production through improvements in coke quality .

Aug 1, 1943

By Wesley T. Holmes II, Lloyd H. Banning

Electric - smelting studies were made on titaniferous materials obtained from the Klukwan and Snettisham , Alaska ; Choteau , Mont .; and Iron Mountain , Wyo . , deposits with the objective of determining the feasibility of producing pig iron and an enriched titania slag in one test series and pig iron alone in another test series . In addition , related studies were conducted to determine the amenability of Choteau crude ore to wet -magnetic separation and to determine the quality of steel that could be produced from the titaniferous pig iron . The continuous smelting tests were made in a three - phase , submerged - arc , electric furnace , and the laboratory steelmaking tests were made in a singlephase electric - arc furnace . A continuous , belt - type , wet - magnetic separator was used in conjunction with a ball mill and a spiral classifier in recovering titaniferous magnetite from the crude Choteau ore . Pig irons containing less than 0.05 percent phosphorus or sulfur were readily produced from the titaniferous materials ; iron recoveries ranged from 92 to 98 percent . The Choteau ore was ground to minus 65 - mesh to produce a concentrate containing 60 percent or more iron . The steel produced from the titaniferous pig iron was a high - quality product .

Jan 1, 1964

By R. V. Ramani, R. L. Frantz

"The U.S. Bureau of Mines (USBM) established on August 15, 1983, a Generic Mineral Technology Center (GTC) for Respirable Dust within the Mining and Mineral Resources Research Institutes (MRls) at The Pennsylvania State University (PSU) and West Virginia University (WVU) in association with participating MRis at Massachusetts Institute of Technology (MIT) and the University of Minnesota (UMN). The primary goal of the Center is to reduce the incidence and severity of respirable dust disease through researching and advancing the fundamental understanding of all aspects of respirable ~~9t associated with mining and milling and the interaction of dust and lungs. Other Center activities include the training of engineers and scientists, graduate students and undergraduate students through their respective institutions, and the technology transfer to the industry. The Center also serves as the reference center for publications in the respirable dust area. IntroductionExposure to respirable contaminants in mine atmospheres has long posed a serious hazard to miners. The control of these hazards, some of which can have sudden and catastrophic effects and some others, slow and long enduring consequences, has been a major concern for labor, management and government alike. This concern has manifested itself in four primary mechanisms of control -- (1) regulatory control through minimum standard setting by the passage of mine health and safety laws, (2) engineering control through design and operation of mines according to the best recommended practices, (3) interaction of dust and lung control through periodic physical examinations, wearing personal protection devices, etc., and (4) legal and social control through workmen's compensation laws for occupation related health deterioration.The stated objective of the Federal Mine Safety and Health laws is to"" permit each miner the opportunity to work underground during the period of his entire adult working life without incurring any disability from pneumoconiosis or any other occupation-related disease ."" Significant progress has been made in lowering the dust levels in mines since the inception of the Bureau's respirable dust research program. It is generally agreed that mines are less dusty today than they were a decade ago. However, the most serious hazard for workers in the mining and minerals processing industries is still the exposure to respirable dust, and solutions to the problem of respirable dust disease remain to be found."

Mar 1, 1989

By G. W. Jones

In the course of experiments on the stabilization of acetylene gas by addition of other gases, notably hydrocarbons such as methane, propane, and butane, it was observed that large quantities of carbon black are produced during the explosion of acetylene or mixtures of acetylene with the, above hydrocarbons, the added hydrocarbon being essentially decomposed into hydrogen and carbon. It is known that in the complete absence of air acetylene explodes upon application of an intense ignition source at pressure above 5.9 p.s.i. gage. The same is true of mixtures of hydrocarbons and acetylene. However, the pressures necessary for explosion are considerably higher in the case of these mixtures and depend on the amount of added hydrocarbon. The present report contains data on gaseous products and the physical characteristics of the carbon black formed by explosion at elevated pressures of various mixtures of acetylene and hydrocarbons as well as other gases, such as hydrogen, helium, nitrogen, and carbon dioxide.

Jan 1, 1950

By Farrel W. Lytle

Instrumental analysis has become an indispensable tool in research and production of the rare-earth elements. This development can be attributed mainly to a combination of two factors--the marked chemical similarity of the rare-earth elements, which excludes classical methods of analysis, and the speed and accuracy of instrumental-analysis techniques. With continued improvements in methods of producing high-purity rare-earth elements, keeping pace instrumentally is becoming much more difficult. Accordingly, greater emphasis is being placed on improving instrumental limits of detection and accuracy. The methods employed most frequently for determining impurities in rare-earth elements involve use of the optical-emission spectrograph (3, 4)4/ and the spectrophotometer (9). Although numerous X-ray-emission spectrographic methods (6-8) have been developed for analyzing rare earths, these techniques have not included detection of low-level impurities. This investigation was conducted to find the precision and accuracy of X-ray fluorescence in deter-mining impurities in rare-earth oxides in the 0.01-to 1.0-percent-concentration range.

Jan 1, 1959

By G. F. Friel

A series of experiments in the U.S. Bureau of Mines Safety Research Coal Mine at the Pittsburgh Research Center evaluated the effects of crosscuts on the travel time of carbon monoxide (CO) along an entry to improve the accuracy of a mine-fire locator program. Three entries, ten single crosscuts, and three double crosscuts were instrumented with CO sensors. One-percent CO in nitrogen was released and monitored as it traveled the entries. In addition to dispersion of CO at the front of the CO wave, CO was entrained from the entry into the crosscuts. It was determined for an entry and single-crosscut configuration that the measured travel time for a concentration change of 5 ppm was 27% greater than the predicted time based upon entry volume only, but 13% less than the predicted time based upon entry and crosscut volumes. For an entry and double-crosscut configuration, the measured travel time for the same concentration change was 25% greater than the predicted time based upon entry volume only, but 10% less than the predicted time based upon entry and crosscut volumes. An effective dispersion coefficient for CO dispersion along one of the entries was estimated to be 1.5 m2/ s.

Jan 1, 2010

By O. E. Traubert, E. G. Meiter

"The daily sulphur dioxide content of the air at the Pittsburgh Experiment Station of the Bureau of Mines was determined by the bureau at the request of Committee D-14 on Screen Wire Cloth of the American Society for Testing Materials. The purpose of the investigation was to obtain data for use in interpreting screen-corrosion tests, which were conducted simultaneously and jointly by the committee4 and the Bureau of Mines.The plan of this investigation was to vale a single daily determination, except on Sundays and holidays, of the SO2 content of the atmosphere at the exposed test screens, for a period of one year. No attempt was made to determine the variation during the day, except on the morning of October 15, 1927, when the atmosphere was unusually foggy and smoky. Several successive determinations were made on that date to ascertain changes in the SO2 as the morning haze disappeared. The SO2 determinations were begun on August 11, 1927, and continued until August 11, 1923.The Pittsburgh Experiment Station of the Bureau of Mines is in a residential section about 3 miles east of the central or main business district of Pittsburgh. The air samples were taken on the roof above the auditorium, or the center rear of the building. This was also the place where the pieces of screen were placed for corrosion tests. The height was about 40 feet above ground level. Several sources of considerable smoke and SO2 are in the immediate vicinity. On the west side of the building is a double-track railroad. At this point the line runs through a cat below the level of the building. The horizontal distance between the air-sampling position and the railroad tracks is about 400 feet, and the vertical distance about 70 feet. The power plant for the Bureau of Mines building is about 250 feet south of the sampling position. About 1000 feet farther to the south are the engineering building and power plant of Carnegie Institute of Technology, and 1/4 mile to the southwest is the power and heating plant for the Carnegie Library and Museum. About 1 to 2 miles farther south and also southwest"

Jun 1, 1930

By R. T. Johansen, R. J. Heemstra

In water flooding the gradual accumulation of insoluble materials on the sand face causes the injection pressures to increase while decreasing the amount of water injected . This plugging material often is composed primarily of insoluble precipitates of calcium , iron , and magnesium . Treatment with sodium tripolyphosphate ( STP ) either eliminates or reduces the formation of precipitates . Field tests are discussed showing the almost immediate effects of using STP in the injection water . Methods of treatment , solubility of STP in fresh water and brines , and precautions to observe when starting to treat a waterflood with this chemical are given . Laboratory data show that the preferential wettability of a crude oil for reservoir rock can be reversed by adding a small amount of STP to the flooding water . This reversal in wetting tendency should not only decrease the injection pressures but also increase oil recovery by improving the sweep efficiency of a water flood .

Jan 1, 1964

By Herbert R. Babitzke

The purpose of this investigation was to optimize the high-temperature properties of columbium and tantalum. Columbium and tantalum were combined with selected alloying elements to achieve solid solution and dispersion strengthening. Fifty-six alloys were evaluated to determine their formability, hardness, strength at elevated temperatures, and oxidation resistance. The following six alloys showed high-temperature strength: [Cb-15Hf-5W-2Zr-4Al-4Ti-2N Cb-15Hf -5W-5Zr Cb-15.3Ti-4.1Zr-13.7Hf Ta-20Hf-4Al Ta-30Hf-4Al Ta-20Hf-5W-4Al] At 1,200° C, the columbium alloys had strength values of 40,000 psi or greater, and the tantalum alloys had strength values from 50,000 to 58,000 psi. For a 2-hour test period at 1,000° C, weight gains of only 9 and 8 mg/cm2, respectively, were observed on oxidation testing of two alloys, Cb-15Hf-5W-2Zr-4Al-4Ti-2N and Ta-20Hf-5W-4Al.

Jan 1, 1968

By Robert M. Becker

The evaluation of existing rock stresses from measurements of the change in diameter of a borehole that is stress relieved by overcoring has become a common practice, The stress evaluation has been generally based ,on isotropic relations whereas rock in varying degrees is anisotropic. A plane elasticity solution for a circular hole along one axis of an orthotropic medium is adapted for evaluation of in situ stress from borehole deformation measurements. A consistent triaxial testing approach for determining elastic properties of the overcore is also outlined. Comparison of isotropic with anisotropic interpretations of the state of stress show that large errors in evaluation may occur if the anisotropic character of the rock is neglected.

Jan 1, 1967

By M. G. Zabetakis

This publication presents a simplified graphic method for determining the explosibility of mine atmospheres under mine-fire conditions from mine- atmosphere composition data. Sometimes it is necessary to seal part of a mine during a fire to exclude air and thus extinguish the fire. Unfortunately, liberation of methane and formation of hydrogen and carbon monoxide in the sealed area may create an ex- plosive or flammable atmosphere if enough oxygen is present to support combustion. On the other hand, the oxygen concentration may be reduced through combustion processes and the concentration of inert gases (nitrogen and carbon dioxide) increased enough to render the atmosphere within the sealed area non-explosive. Before an area is unsealed, it is extremely important to know if the sealed atmosphere contains Flammable gases in proportions that might form explosive mixtures when air is introduced. If an explosive mixture forms and the fire is rekindled, a gas explosion will result. Various experimental methods may be used to determine the explosibility of a particular mine atmosphere; however, these methods usually are impracticable in the field.

Jan 1, 1959

By C. M. Frost

The hydrodesulfurization characteristics of a residual fuel prepared from Wilmington, Calif., crude oil were determined at temperatures from 600° to 900° F, pressures of 200 to 800 pSig, and space velocities from 0.2 to 2.0 Vo/Vc/hr, using cobalt molybdate type catalysts. A prediction equation, developed from the experimental data, satisfactorily predicts the fraction of total sulfur that can be removed under any combination of operating conditions within the ranges investigated. Yields and properties of the low sulfur product are correlated with the fraction of total sulfur removed. Kinetic calculations show that the apparent reaction order and activation energy change with space velocity and temperature.

Jan 1, 1970

By Charles A. Steen

Publication of this information circular results from an invitation extended to the Bureau of Mines by the Utex Exploration Co. to visit the company mine, on the Mi Vida claim about 39 miles southeast of Moab, in the Big Indian mining district, San Juan County, Utah. The Bureau is pleased to present this record of the Utex mine -- a property that in the relatively short period of 4 months has become one of the major uranium-ore producers on the Colorado Plateau. The ore deposit was discovered in July 1952 by Charles A. Steen, a geologist-prospector, now chief geologist of the Utex Exploration Co., in tae course of drilling the first diamond-core borehole in the Big Indian district. High-grade ore, 14 feet thick, was penetrated by the borehole. Sinking of a shaft, from which to develop the ore body, was begun in October, and the first shipment of ore left the property December 6, 1952. Ore production, as recorded on ore-settlement sheets received by the company up to July 15, 1953, totaled 16,000 tons averaging, 0.51 percent U305 and 1.25 percent V205. Discovery of the ore body and the large production of ore were achieved without any financial assistance from the Government.

Jan 1, 1953

By Nicholas Kyriazi

A joint effort by the U.S. Bureau of Mines and the U.S. Mine Safety and Health Administration (MSHA) was undertaken to determine how well self-contained self-rescuers (SCSR's), deployed in accordance with Federal regulations (30 CFR 75.1714), survived the underground environment with regard to both impact damage and aging. This report presents findings regarding laboratory-tested SCSR's from 1982 through 1990. The SCSR's were tested on human subjects and on a breathing and metabolic simulator (BMS). These results indicate that most of the apparatus, if they pass their inspection criteria, perform as expected except for units with manufacturing defects or design deficiencies. However, when the apparatus are carried in and out of the mine daily and stored at the working section, they may suffer abuse. Physical signs of abuse, unless extremely obvious, are frequently not detected by the miners or mine operators. This poses a potential danger to a user in an emergency. Recommendations include improved training in inspection procedures.

Jan 1, 2010

By A. J. Forney

This report summarizes the findings of methods of treating caking coals in a fluid bed to destroy their caking properties. In batch tests it was found that several coals, including those with a free-swelling index greater than 8, could be decaed at temperatures from 400° to 425° C with a fluidizing gas composed of inert gas or steam containing 0.2 percent oxygen and a minimum residence LS,-;,' of 5 minutes. When treatment decreased the free-swelling index from about 8 to 1-1/2 or lower, the resulting treated coal was noncaking. In a continuous unit with continuous feed and discharge of coal, slightly more severe conditions were required to decake the coal. For 18- to 100-mesh coal a temperature of 430° to 440° C and an oxygen-to coal ratio of 0.4 cubic foot of oxygen per pound of coal feed was necessary. Finer mesh sizes required lower oxygen-to-coal ratios. In tests using air only as the fluidizing medium and treatment temperatures well below the softening range, the caking properties of 150- to 200-mesh coal were destroyed in 30 to 40 minutes of residence time at 200° C. Coarser sizes of 18 to 48, 48 to 100, and 100 to 150 mesh required longer residence time.

Jan 1, 1966

By A. J. Kraemer, O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States is a continuation of a series of reports made in accordance with a cooperative agreement between the Coordinating Fuel Research (C. F. R. ) Committee of the Coordinating Research Council (C. R. C.) and the Bureau of Mines of the United States Department of the Interior . The first of these reports contained data on motor gasolines sold during the winter of 1935-36 and further reports on motor gasolines sold during the succeeding summers and winters to the summer of 1941

Dec 1, 1943

By R. D. Leitch, C. A. Taylor

Trinitrotoluene is made by the direct nitration of toluene by a mixture of nitric and sulphuric acids . The exact procedure varies , but the product , where Grade I of TNT is desired , is similar , and consists largely of material that has a melting and setting point of 80.6 °c . The purification consists of draining off the liquid portions , including the acid and liquid nitro compounds . The mass is crushed and washed until the TNT is acid - free . It may still have a low-melting point due to the presence of material of lower nitration. Other isomers also have the same effect . The crystal mass may be washed with a solution of sodium sulphite , thiosulphate , sulphuric acid , or with an organic solvent such as alcohol , benzene , or carbon tetrachloride , Where a very pure product is desired , the TNT is separated by fractional crystallization from solution in organic solvents . The TNT is If it forms In some cases the material is melted during purification . agitated as it cools to prevent solidification in a solid mass . in a solid mass , this is broken up and screened . There has been some question as to the effect of the different methods of purification on the strength and sensitiveness of TNT , although all methods left a product that would give satisfactory tests .

Sep 1, 1923

By Foster Fraas

A comparison has been made between cubes and spheres in the matrix of the high-intensity wet magnetic separator. For two inclined plane surfaces, such as may occur with cubes, the maximum force value, H [dH-dx] is at the point of nearest approach and is much higher than the force resulting from adjacent spheres. Although the maximum force value for cubes is higher, it decreases more rapidly at increasing distances. The maximum force for spheres is at an appreciable distance from the point of nearest approach. At field intensities for magnetic saturation of the iron spheres, the force extends to further distances with greater uniformity approximating that of the constant force or isodynamic field. The force is also independent of the sphere diameter, which permits the scaling of the sphere diameter to provide changes in particle migration distances without changes in force gradient.

Jan 1, 1972

By J. L. Shultz

Mass spectrometric analyses were obtained for naphthalene and anthracene oils, heavy creosote, and three fractions of a pitch. The average molecular weight, aromaticity, and mean structural unit were determined for each fraction. The investigation of these fractions of coal tar has resulted in semiquantitative data for 38 structural types and carbon number distribution data for their alkyl derivatives. The molecular weights of 10 of these structural types indicate ring systems not previously reported in products from high-temperature carbonization of coal. Two of these structures are poly-nuclear aromatic hydrocarbons, two are oxygen-containing compounds, one contains sulfur, and five are nitrogen-containing compounds.

Jan 1, 1967