Search Documents

By Thomas R. Bur

This method of performing general transformations by use of Eulerian angles greatly reduces the time required for the determination of values for the elastic compliance constants (sij), elastic stiffness constants (cij ), Young's modulus, shear modulus, or Poisson's ratio for any orientation the cartesian coordinate system in an anisotropic material.

Jan 1, 1969

By John Soule

The Torpedo copper mine in the Organ Mining, District, Dona Ana County, N. Mex., was discovered in 1899, and production of copper from oxidized-ore deposits was begun in 1900. Production continued through 1907, but operations were only intermittent frown 1907 through 1921. The production of copper during these periods amounted to about 3,500,000 pounds. Reserves primary sulfide copper ore were believed to occur below the old workings, and after a detailed examination of accessible workings and a study of drilling records of several private companies by an engineer of the Bureau of Mines, a development program of diamond core drilling was initiated. This investigation was started October 3, 1949; and completed April 30, 1950. Four holes totaling 2,122.3 feet wore diamond-drilled, and 70 samples were analyzed. All drilling was done with a Government-owned hydraulic-feet drill having special rods and core barrels to increase the recovery of core in critical zones. This report describes the location, history, ore deposits, and factual data obtained by the Bureau of Mines from the drilling.

Jan 1, 1951

By L. R. Burdick

Sulfur compounds have long been recognized as damaging pollutants of the air. A number of investigations have been made to determine the amount of such compounds existing in the air of various cities; moreover, some study has been given to the conditions affecting the concentrations. This paper summarizes published investigation and includes a bibliography on the subject. The methods of obtaining data have differed to the type of sampling, analysis procedure, hour of sampling, number of locations, and number of determinations made. Sampling methods include both the continuous type, covering a day or a number of days, and what can considered the ?snap? type, covering very short periods. Continuous sampling has, given data representing the average concentration at the location chosen but no information regarding variations from hour to hour, are none that might be said to represent the average for a city. The snap-sampling method, while not giving a true average for any one location or area, has in some instances made available date regarding variations of concentration during different hours of the day and at various locations or zones within the area chosen. Although the sulfur compounds in the air nay include sulfur dioxide, sulfur trioxide, hydrogen sulfide, and organic compounds of sulfur, most investigators report on the basis of sulfur dioxide. This gas unites with moisture to form sulfurous acid.

Jan 1, 1939

By W. R. Crane

Subsidence and ground movement are phenomena common to and attendant upon practically all large-scale mining operations, and under certain conditions may occur in all workings, large and small. The interpretation of the cause of failure in rock masses involves a study of the nature of plants of weakness common to all rocks. The dominating planes of weakness can readily be determined by observation in any given locality, and in order of importance in the study of subsidence are (1) faulting planes, (2) bedding planes, (3) joint planes, and (4) other prominent planes of weakness such as thrust and shear planes and contacts. This report has mainly to do with the third item, joint planes, and is a preliminary statement which t to be followed by a more complete report in bulletin form.

Jan 1, 1931

By H. Robert Ensminger

The Belizean economy had an estimated annual growth of about 3.4% over that of 1986. Economic growth during the 2 previous years was slower and was characterized by a negative trade balance. The gross domestic product (GDP) was an estimated $200 millioni2 in current dollars. Limited natural resources and scarce finances continued to make the Government's task a difficult one. Belize and China signed an economic cooperation agreement in April under which the Chinese Government is to provide technical assistance, a cash grant of $60.000, and a long-term, interest-free loan of approximately $1.5 million. In May, it was reported that gold was discovered in a remote area of the Maya Mountains in western Belize. An estimated unassayed value of $400 million has been placed on the deposit by one of its discoverers. However, the government in Belmopan has played down the discovery. Two U.S. oil companies. Seahawk Oil International of California and Alston Oil Co. of Texas, were granted licenses to explore for oil. Seahawk Oil will explore a large area of the Orange and Corozal Districts, while Alston Oil will prospect a 90,000-acre area of the western Cayo District. Another U.S. oil company, Pecten Oil Co., recently completed seismic studies off-shore of Belize City. Pecten Oil has made plans to start drilling in 1988.

Jan 1, 1989

By G. R. Peterson, K. E. Porter

The U.S. Bureau of Mines has estimated the potential availability of copper from 204 mines and deposits in market economy countries (MEC's). The evaluated properties have demonstrated resources totaling 436.4 million metric tons of contained copper and account for 90% of the Bureau of Mimes reserve base for copper in market economy countries. Total recoverable MEC copper resources are 340.8 million metric tons, 69% of which is from producing mines and 31% from nonproducing mines and deposits. Chile had the lowest estimated average total cost from producing mines of W.48 per pound of recoverable copper at a 0% discounted cash-flow rate of return (DCFROR), with estimated average total costs ranging from $0.40 to $0.81 per pound. The estimated average total cost of production, per pound of copper, for producing mines in the United States amounts to $0.57 in January 1988 dollars at a Wo DCFROR, with estimated total costs ranging from $0.36 to $0.85 per pound. In both real and nominal terms, the United States has, on average, significantly lowered its copper production costs since 1981. Rationalization of the industry and significant increases in productivity have made a strong improvement in the competitiveness of the U.S. copper industry to the extent that the United States should no longer be considered as a marginal producer of copper.

Jan 1, 1992

By R. G. Meara, O&apos

The land-pebble district of Florida, which in 1928 supplied 96.7 per cent of the phosphate production of that State and 82 per cent of the domestic requirements of the United States, is centered in Polk and Hillsboro Counties about 30 miles east of Tampa The deposits are unconsolidated sediments occurring as beds of phosphate matrix overlain by a mantle of barren sands and clays. The matrix consists of a mixture of Sand (quartz grains), clay, and phosphate rock in which the coarsest sand is much finer than the coarsest phosphate; that is, the sand is segregated in the fine material. Before the introduction of classifiers the concentration consisted of log washing, and screening at about 20-mesh, which was usually the finest size that could be taken to maintain commercial grade, 66 per cent B. P. L. (bone phosphate of limey or more. When classifiers were introduced some of the fines that had escaped at the head of the washery and some of the minus 20-mesh material isolated during the rushing and formerly lost supplied the feed.

Jan 1, 1931

By Kenneth L. Cashdollar

The Mine Safety and Health Administration (MSHA) and the West Virginia Office of Miners? Health, Safety, and Training (WVOMHS&T) investigated the explosion at the Sago Mine in West Virginia, which occurred on January 2, 2006, and resulted in 12 fatalities. As part of the investigation, the agencies requested that the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory evaluate the effects of explosions on specific mine ventilation seals and other structures and objects at its Lake Lynn Experimental Mine (LLEM). The results of the LLEM study would assist MSHA and WVOMHS&T in a more thorough understanding of the various questions that arose during their investigations of the explosion. Six large-scale explosion tests were conducted in the LLEM from April to October 2006. The protocols for these tests, and in particular the procedures for constructing various Omega block seals, were developed mainly by MSHA and WVOMHS&T. NIOSH developed the experimental procedures at the LLEM that would provide the required range of explosion pressures against the seals. Three 40-in-thick seal designs using Omega 384 low-density block were constructed in the LLEM and exposed to various explosion pressures. These seal designs are referred to in this report as the ?2001 design,? the ?hybrid design,? and the ?Sago design.? The 2001-design Omega block seal (80 in high) located in crosscut 2 of the LLEM survived all six explosions, with pressure loadings up to 51 psi. The 2001-design Omega block seal (88 in high) in C-drift was destroyed during Test 2, which subjected the seal to a head-on explosion that resulted in a pressure loading of 51 psi. The height difference between the two seals and the orientation of each seal to the explosion were contributing factors. The higher seal would be weaker for the same seal thickness. The hybrid Omega block seal in crosscut 3 survived an explosion at a pressure loading of 25 psi and failed during another explosion at a pressure loading of 39 psi at the seal. Based on these tests, it seems that the hybrid seal design is weaker than the 2001 seal design. The Sago Omega block seals were constructed in crosscut 3 and C-drift before Test 3. The crosscut 3 seal survived a pressure loading of 18 psi and was destroyed during an explosion at a pressure loading of 35 psi at the seal. The C-drift seal survived a head-on explosion that resulted in a pressure loading of 21 psi and was destroyed during an explosion with a pressure loading of 57 psi at the seal. Based on these LLEM tests, it seems that the Sago seal design is weaker than the 2001 seal design, yet it still complied with the requirements of 30 CFR 75.335(a)(2) that were in effect at the time of the mine disaster. During these LLEM explosion tests, the distance of seal debris travel was also measured. In Test 5, the C-drift seal was destroyed during a head-on explosion that resulted in a pressure loading of 57 psi, and the seal debris was thrown over 500 ft. In Test 6, the C-drift seal was destroyed during a head-on explosion that resulted in a pressure loading of 93 psi, and the Omega block debris was thrown over 900 ft. During these tests, the explosion pressure effects on other structures and objects were also documented. Unless otherwise specified, all of the pressure data listed in this report represent the highest recorded smoothed (averaged over 10 ms) explosion pressure loadings. The information in this report was used by MSHA and WVOMHS&T as supporting data in their analyses and investigative reports of the Sago Mine explosion.

Sep 1, 2009

By E. G. King

Difficulty has been encountered in making thermodynamic calculations of metallurgical reactions involving interoxidic compounds of the ferroalloy elements because of the serious lack of most thermodynamic data for these substances. This Bureau of Mines report (the first of a planned series dealing with entropies of vanadates, tungstates, and molybdates) presents low-temperature heat-capacity data and entropy values at 298.15° K. for three crystalline sodium vanadates--metavanadate (NaV03), orthovanadate (Na3VO4), and pyro-vanadate (Na4V2O7). The results are combined with data for the constituent oxides and elements to obtain entropies of formation of the vanadates. Previous to this report only one vanadate had been studied Similarly, ammonium metavanadate.4/

Jan 1, 1961

By Thomas A. Jones

An impure variety of barite, which lends itself well to the manufacture of heavy drilling mud for oil wells, is widely distributed throughout the Ouachita Mountains in Arkansas. The ore mined in the area and used for drilling muds usually contains an average of 67 percent barium sulfate, although ores as low as 50 percent BaSO4 are occasionally used. Due to the increased demand for barite for drilling caused by the intense search for hew oil occurrences during the years 1945 and 1946, the Federal Bureau of Mines began an investigation of barite deposits in the Ouachita? Mountains in October 1946. In all, 10 barite deposits were examined, trenched, sampled, and studied during the investigation, which was terminated in May 1947.

Jan 1, 1948

By K. O. Bennington

The thermodynamic properties of aegirine, of composition [(Na0.869Fe30+7362 Fe20+16Mn0.03Ca0.1121)(A10.141Sil 9738)(06)], were experimentally determined at the Bureau of Mines as part of its efforts to advance minerals technology. The standard enthalpy of formation determined by hydrofluoric acid solution calorimetry is AHf298 = -641.12±0.73 kcal/mol. The standard enthalpy of formation from the oxides is AH298 = -37.136±0.509 kcal/mol. Low-temperature heat capacities were determined by adiabatic calorimetry from 19.1 to 304.6 K. The derived standard entropy is S298 = 38.03±0.14 cal/mol?K. The heat capacity was measured over the range 348 to 1,198 K by differential scanning calorimetry. These experimentally determined data were combined with data from the litera¬ture to calculate the Gibbs energies of formation and equilibrium constants of form¬ation over the temperature range of the measurements. Standard enthalpies of forma¬tion are given as functions of temperature. The standard Gibbs energy of formation at 298.15 K is AGf298 = -600.36 kcal/mol.

Jan 1, 1984

By John A. Breslin

Size distributions and concentrations of particulates emitted from diesel engine exhausts were measured with cascade impactors. Samples were taken from the exhaust of two types of engines using three types of fuel and operating under five different engine speed and load conditions. The measured mass median diameters of the diesel particulates were typically about 0.3 um. There was no significant difference in mass median diameter between engines or fuels and only a slight dependence on operating mode. Concentration measurements ranged from 14.2 to 250.9 mg/cu m, and calculated mass outputs, from 52 to 3,443 mg/min. Significant differences in mass output were found between engines, fuels, and especially between different operating modes. The quantity of clean dilution air that would be required to reduce the particulate mass concentration below the 2.0 mg/cu m respirable dust standard for coal mines was greater than the dilution air required to meet the standards for noxious gases for both engines tested.

Jan 1, 1976

By N. A. Eilertsen

Among the numerous Low-grade manganese deposits in eastern Aroostook County, Maine, the Dudley deposit near Mapleton in the northern district is one of the few known to contain an appreciable tonnage averaging above 10 percent manganese. The ore body, consisting of stratified manganiferous hematitic shale, is over 5,000 feet long and ranges in width from 30 to 175 feet. The deposit was extensively explored during 1942-44 by the Manganese Ore Co., a subsidiary of M. A. Hanna Co. of Cleveland, Ohio. Data obtained from this work were made available to the State and Federal Geological Surveys for estimating ore reserves. An estimate by the Maine Geological Survey, using a 10-percent manganese cutoff and to a depth of 200 feet, shows 609,000 long tons of manganese metal in material averaging 12.6 percent manganese. By lowering the cutoff limit to 5 percent manganese, the estimate was increased to 919,000 long tons of metallic manga¬nese in material averaging, 10.4 percent manganese,

Jan 1, 1957

By Manuel Gomez

Carbon number distributions were obtained for tar acid fractions from five low-temperature tars by low-ionizing voltage mass spectrometry. Quantitative data for phenols representing seven structural compound types were examined by statistical analysis. It was shown that for the phenols discussed, the data could be represented by regression equations expressing phenolic concentration as a function of the reciprocal of the carbon number and the carbon-to-hydrogen ratio of the parent coal. The total concentration of each structural type present was found to depend on the molecular weight and boiling point of the initial member of the group. Carbon distribution data for the tar acid fractions studied support the view that low-temperature tars contain the same chemical compounds but in different proportions.

Jan 1, 1965

By J. Gautam, T. Ong, W. E. Wallace, M. Keane, S. Xing, J. Harrison

"INTRODUCTIONOrganics extractable from respirable diesel exhaust soot particles by organic solvents have been known for some time to be direct acting frameshift mutagens in the Ames Salmonella typhimurium histidine reversion assay (Huisingh, et al). Upon deposition in a pulmonary alveolus or respiratory bronchiole, respirable diesel soot particles will contact first the hypophase which is coated by and laden with surfactants. To model interactions of soot and pulmonary surfactant, we dispersed soots in vitro in the primary phospholipid pulmonary surfactant dipalmitoyl glycerophosphorylcholine (lecithin) (DPL) in physiological saline. We have shown that diesel soots dispersed in lecithin surfactant can express mutagenic activity, in the Ames assay system using S. typhimurium TA98, comparable to that expressed by equal amounts of soot extracted by dichloromethane/ dimethylsulfoxide (DCM/DMSO)(Wallace, et al, 1987). Here we report additional data on the same system using additional exhaust soots and also using two other phospholipids, dipalmitoyl glycerophosphoryl ethanolamine (DPPE), and dipalmitoyl phosphatidic acid (DPPA), with different ionic character hydrophilic moieties. A preliminary study of the surfactant dispersed soot in an eucaryotic cell test system also is reported.MATERIALS AND METHODSSoots D4 and D6 were collected at two different times as scrapings from the exhaust pipe of a diesel tractor-trailer immediately after the engine was stopped. Surfactant dispersions were made by ultrasonic probe sonicating 25 mg of commercially obtained DPL, DPPE, or DPPA into 1O ml of O.85% physiological sterile saline (PSS) for 10 min at 40 watts power. For surfactant dispersions, 2.5 mg soot was mixed into 2.5 ml of the appropriate phospholipid dispersion. Mixtures were sonicated by 40 watts sonicator probe for one min, then incubated in the sonicator water bath for 30 min at room temperature; the mixture was then incubated for one hour at 37C while being rotated continuously. Dilution series were made with saline. For solvent extraction, 2.5 mg soot was mixed into 2.5 ml of DCM and incubated in a sonicator water bath for 30 min at room temperature. The sample was then mixed with 2.7 ml DMSO, placed in a dry bath at 45C, and the DCM evaporated under a stream of nitrogen gas until 2.5 ml of liquid remained. Ames salmonella/microsome assay utilizing TA98 for frameshift mutation was used for mutagenicity testing, with and without S9 activation, as described by Ames et al (1975). Unfiltered sample extractions or dispersions were preincubated with tester cells for 90 min at 37C : 0.1 ml of sample was mixed with 0.5 ml of PSS, or of S9 mixture, and 0.1 ml of an overnight TA98 culture incubated samples were then added to 2 ml of top agar supplemented with biotin and a trace amount of histidine, and overlayed onto Vogel-Bonner minimal media plates. After 48 hours incubation at 37C, revertant colonies were counted. Solvent controls were DMSO, DPL, DPPE, DPPA, and saline. Positive controls were trinitrofluorenone (1 ug/plate), for samples not treated with S9, and 2-aminoanthracene for S9 treated samples (2.5 ug/plate). All samples were assayed in duplicate. Sister chromatid exchange (SCE) assay was performed, following Lett, et al (1981), using V79 cells, of Chinese hamster pulmonary fibroblast origin. Stock diesel sample suspensions were made as 10 mg soot/ml DPL suspension, or 20 mg soot/ml in DMSO. Aliquots of these soot preparations were added to 15 ml of culture medium per sample flask to result in concentrations of 25, 50, and 75 ug soot/ml medium. After 12 hours incubation, 200 ul of 25 uM 5-bromodeoxyuridine (BrdU) was added to each flask. After another 35 hours incubation, 200 ul of 10 ug/ml colcemid were added; and the cells were harvested three hours later. Cells were swollen by hypotonic saline, and fixed twice with methanol/acetic acid, and burst on microscope slides. Cells on the slide were stained with Hoechst 33258, exp"

Jan 1, 1990

By J. S. Gomer

The U.S. Bureau of Mines conducted Cu exchange tests for six common clays under simulated in situ leaching conditions. Regression equations were obtained from the data expressing the Cu exchange capacity as a function of Cu concentration, pH, and temperature. Using these equations, an analysis was made of the impact each clay could have on overall Cu recovery. The results suggest that Ca and Na montmorillonite clays could have a major impact on Cu recovery and that attapulgite and illite clays could have a smaller, but still significant, impact. Kaolinite and ripidolite clays pose little threat to loss of Cu from in situ leaching solutions.

Jan 1, 2010

By L. B. Pankratz, R. Barany, W. W. Weller

Experimental determinations were made of the heats of formation at 298.15 ° K of cuprous ferrite and cupric ferrite ; the heat capacity of cuprous ferrite was measured over the temperature range from 50 ° to 298 ° K and the entropy at 298.15 ° K was evaluated ; the heat contents of cuprous ferrite and cupric ferrite above 298.15 ° K were measured to 1,500 ° K and 1,100 ° K , respectively . These thermodynamic values were combined with other pertinent data to obtain heat and free energy of formation values at high temperatures . The stability of the two ferrites with respect to their constituent oxides is discussed . Thermodynamic values are included for the decomposition of cupric ferrite to form cuprous ferrite , magnetite , and oxygen .

Jan 1, 1964

By C. R. Bopp, N. A. C. Smith

"For a period of several years, beginning with 1915, there has been a continuous change in the quality of motor gasoline. The average volatility has decreased, this to the fact that higher boiling fractions of the crude oil have been included in the gasoline. This change in quality was made necessary by the tremendous increase in the demand for motor fuel, caused by the development of the motor car, and during the war was an absolute necessity to avoid gasoline shortages. The Bureau of Mines has kept in close touch with this situation by making surveys from time to time of the gasolines sold throughout the country, as this information is of value to manufacturers and users of motor cars and also indicates when any changes are required in the Government specifications. The Bureau has just completed a gasoline survey and is in a position to make public the fact that there has been very little change in the quality of motor gasoline in recent months.During the period from January 17 to February 3, 1920, 81 samples of actor gasoline were collected by representatives of the Bureau of Mines in seven districts of the United States. The cities selected for this survey were New York, N. Y., including Brooklyn; Washington, D. C.; Pittsburgh, Pa.; Chicago, Ill.; New Orleans, La.; Salt Lake City, Utah; and San Francisco, Cal., including Berkeley. In every case the samples collected were taken in such a manner as to represent material actually being sold as motor fuel, and to include samples from each refinery marketing in the district."

Jan 1, 1920

By W. W. Weller

Heat capacities of ferrous molybdate (FeMoO4) and ferrous tungstate (FeWO4) were measured over the temperature range 51° to 298.15° K. Ferrous tungstate has a lambda type heat capacity anomaly at 74° K. The 298.15° K entropies are FeMoO4) 30.9 cal/deg mole and FeW04) 31.5 cal/deg mole.

Jan 1, 1966

By C. B. Barmore, B. W. Gandrud, B. M. Bird

"The Bradford mine of the Alabama By-Products Corporation is located in the Warrior coal field of Alabama, in the northern part of Jefferson County, about 25 miles north of Birmingham. The coal mined from the Black Creek bed at this point is not considered to be ideal for coke making by itself but because of its exceptionally low ash content is mixed with the higher-ash coking coals from other beds of the district to control the ash content of coking mixtures. Further reasons for using this coal only as a diluent of the higher-ash opals are that the thinness of the bed renders the production costs relatively high and the reserves are somewhat limited.This paper, which is the fourth of a series on the washability of Alabama coals, Like its predecessors dealing with the Mary Lee beds and the Clark bed,6 contains screen-sizing and float-and-sink tests of a representative sample of the raw coal, and flakiness tests showing the proportions of flaky particles in certain selected sizes. However, inasmuch as the float-and-sink tests of the coarse sizes showed excellent liberation of coal from impurities, crushing tests have not been considered necessary.The data on which this report is based have been obtained in connection with an exhaustive study of coal preparation in Alabama now being conducted by the U. S. Bureau of Mines and the University of Alabama with the cooperation of the different coal operators. As the work progresses other papers will follow containing further data on Alabama coals and giving results obtained in preparing these coals by various methods."

Apr 1, 1931