Search Documents

By Robert E. Barieau

This report gives the principles of the method used by the Helium Research Center of the Bureau of Mines when solving nonlinear-regression problems and contains the mathematical equations necessary to accomplish the following objectives: the evaluation of the parameters in such a way that the sum of the weighted squares of the residuals of an experimental observable is a true minimum, regardless of the functional relationship between the variables and these parameters; and the evaluation of all variances and covariances of the parameters by means of the usual approximation of the law for the propagation of errors.

Jan 1, 1967

By P. L. Woolf

Seven evaluation tests with blast furnace iron bearing burden materials are described. The effects of pellet strength, fines in the burden, decreasing slag volume, pellet size, eliminating stone with superfluxed sinter, and eliminating stone by prefluxing the pellets were determined. Fluxed pellets and fluxed sinter made with the same ore fines were compared. The tests were conducted under cooperative agreements between the Bureau of Mines and North American steel companies. The objectives were to improve blast furnace practice, expand and develop understanding of the operation and theory, quantify the effects of changes, and explore the limitations of operability. This work was part of an extensive program of blast furnace research in experimental blast furnaces at Bruceton, PA conducted in the years 1958 to 1967.

Jan 1, 1984

By Franklin D. Cooper

Three model dwelling units were redesigned to achieve specific levels of noise reduction above that provided by conventional construction. Using 1968 prices, the added costs of materials and installation were found to range from $500 to $5,000 depending upon the size of the dwelling unit and the degree of insulation. The potential aggregate expenditures for sound insulation materials are projected to reach $617 million in 1975, including about $408 mil- lion for the mineral-based materials, in 1968 constant dollars. The report includes a brief review of the mechanics and effects of sound.

Jan 1, 1970

By P. M. Brown

The Bureau of Mines is investigating a dewatering technique for coal-clay waste that uses a flocculant, polyethylene oxide (PEO). This flocculant forms strong stable flocs that can be dewatered on a static screen. A field test unit (FTU) using this technique was operated at approximately 400 gal/min, using a waste stream from the flotation circuit of a coal preparation plant. Consolidated coal-clay material con-taining 55 to 60 pct solids was produced when the flotation circuit slurries of 2.7 to 8 pct solids were treated with 0.1 to 0.3 Ib PEO per ton of solids. The FTU was also operated at 64.5 and 87.5 gal/min using a portion of the underflow slurry from the preparation plant's thickener. Consolidated coal-clay material containing 55 to 60 pct solids was produced when the thickener underflow slurries of 19 to 24 pct solids were treated with 0.08 to 0.2 Ib PEO per ton of solids. PED-treated materials continued to dewater when placed in a pit.

Jan 1, 1983

By D. Harrington

Springing or chambering of deep drill holes is common practice in some quarries. It involves definite hazards from premature explosion during placing of the springing charges or the final charge due chiefly to heating of the bottom of the holes by the successive exploding of the springing charges or, in some instances, from burning of paper or other material following detonation of the explosives The danger is either unknown or disregarded in many instances by those who place the charges in the holes. Disregard of this hazard probably is, at least in part, responsible for the far too high fatality and injury rate due to charging explosives and premature slots in quarry work. Awareness of the danger' should result in elimination or at least of material decrease in injuries from this cause.

Jan 1, 1941

By Lee Blackman

The Malheur-Jordan Resource Areas (MJRA?s) is a tract of approximately 6.5 million acres of federal and non-federal land in the southeast corner of Oregon. This study evaluated the Resource Areas' economically recoverable mineral potential based on geological estimates provided in the USGS report (Smith, 1994). The mineral terranes are believed by geologists to contain undiscovered resources. The geological data is probabilistic; with estimates of the possible number of deposits and their grades and tonnages. Possible future development scenarios range from no development to numerous mines. Based on the analysis performed on these terranes, the most likely (in a statistical sense) future scenario for the resource areas would include the potential for two medium sized, predominately gold, mines. These would supply direct and indirect employment of up to about a thousand workers.

Jan 1, 1995

By Clark F. Grain

The monoclinic to tetragonal inversion of zirconium dioxide was studied by single-crystal X-ray methods, high-temperature X-ray diffractometry, and differential thermal analysis. The unusual features of the inversion, such as no definite transition Lperature, hysteresis, and athermal kinetics, were confirmed for powders who mean crystallite size was greater than 1,000 A. Samples of mean crystallite size below 1,000 A displayed classical kinetics, obeying a logarithmic rate law. A detailed mechanism based on Ubbelohde's theory of continuous phase transformations was proposed which is consistent with all the experimental facts.

Jan 1, 1965

By Michael J. Friedel

As part of an investigation aimed at improving the health and safety and competitiveness of the mining industry, the U.S. Bureau of Mines evaluated the application of common offset radar profiling, using a 250-MHz ground-penetrating radar (GPR) system, for the detection of fractures in igneous rock. A series of radar reflection surveys were conducted to detect and delineate the extent of fracturing at various granodiorite and gabbro quarries and outcrops located in Minnesota. The application of radar profiling for detecting joints, sheeting fractures, shear zones, and depth to water table was demonstrated to be feasible with minimal processing. Radar reflection interpretations were verified by visual inspection of the rock mass and field mapping of local structure. The radar reflection section provides a simple, rapid, and cost-effective means for mapping of shallow (less than 10 m) small-scale fractures (greater than 0.25 cm) in igneous rock masses (characteristic of velocities between 0.061 m/ns for gabbro and 0.125 m/ns for granodiorite). Depth or distance estimates to fractures are within 10 pct of the actual, and time-shift compensation is necessary only when topographic irregularities exceed 30 cm.

Jan 1, 2010

As part of its regular program to provide timely information on domestic mineral commodities, the Bureau of Mines conducted an engineering appraisal of more than 1,300 lode and placer gold deposits in the United States to deter-mine their gold production potential. While these deposits were estimated to contain over 400 million ounces of gold, only 9 million ounces, or slightly more than 2 percent, was found to be producible at $35 per ounce under prevailing mining and metallurgical technologies. The study revealed that any significant increase in available gold in the United States is most likely to come from the discovery of new sources, intensive exploration and development of the more promising known mineralized areas, and development of new or improved mining and metallurgical techniques.

Jan 1, 1967

By Henry M. Harris, Hal J. Kelly

Electrical dewatering tests are described in which the laboratory cells were designed for continuous operation using an endless metal belt as the anode . The test slurries were dilute , containing from 2.5 to 14.4 percent solids (specific gravity of 1.02 to 1.10 ) that were all minus 8 microns in size . Recovery of the solids of low water content was the practical objective of the investigation . Process variables evaluated and reported are : The effect of feed rate , amount of electrolyte , samples from different sources , and the use of two cells in series . These variables are evaluated on the basis of yield of clay per kilowatt - hour , recovery , and the amount of solids in the deposited clay . Recovery , yield , and solid content of the belt anode product are interdependent , and changes that will improve one of these characteristics often are accomplished at the expense of the others . Tests in which recoveries range from 50 to 60 percent usually result in yields of 8 to 9 kilograms (kg ) of dry clay per kilowatt- hour (kwhr ) . Under these conditions , the solid content of the deposited clay approximates 50 percent . One test sample , composed of kaolinite , showed very high yield , 13 to 16 kg per kwhr ; high recovery , 53 to 58 percent ; and 52 to 54 percent solids in the cake .

Jan 1, 1964

By John E. Miller

Absolute viscosity values for gases usually are determined with a capillary tube viscosimeter, One of the correction factors applied to the experimental data is that for nonuniformity of the capillary bore. This report contains useful analytic expressions of the nonuniformity correction for the following cases: ellipse, cone, sine wave, sawtooth wave, square wave, and the general case. The methods herein described are applied to estimate the nonuniformity of a section of stainless steel capillary tubing to be used at the Bureau of Mines Helium Research Center. Several other examples are given to illustrate the usefulness of the present results.

Jan 1, 1967

By Kenneth J. Miller

Laboratory batch flotation tests were conducted to determine the viability of the Bureau of Mines coal-pyrite flotation process in desulfurizing various coals from the midwestern coalfields. Nine coals obtained from western Kentucky and Illinois were used in the study. In addition to the Bureau's coal-pyrite flotation process, some of the coals were subjected to two-stage rougher-cleaner coal flotation for comparison. The results of this work showed that up to a 70-percent pyritic sulfur reduction could be obtained by flotation and that the Bureau's coal-pyrite flotation was superior to rougher-cleaner coal flotation. Because many of the coals retained far too much sulfur even after second-stage flotation treatment, it was concluded that these midwestern coals are more difficult to desulfurize by flotation than are the Appalachian coals tested in earlier Bureau experiments.

Jan 1, 1978

By D. W. Butner

As a part of the Bureau of Mines program for the discovery and development of critical and essential mineral deposits, the Darwin district, Inyo County, Calif., was chosen for investigation as a possible source of, tungsten ore. Two properties were active in the district at the time. One was producing tungsten concentrate and the other was preparing to produce tungsten concentrate as a byproduct in the milling of lead-zinc ore. The objective of the project set up by the Bureau was to investigate promising areas and to sample, thoroughly those which preliminary inspection indicated contained tungsten ore. Work was begun November 17) 1941, and completed January 19, 1942. In the course of the project, 18 localities were inspected and 9 were sampled. The following pages brief the history, note the location, and outline the physical features and geology of the district. The work performed by the Bureau of Mines is described and supplemented with assay maps.

Jan 1, 1949

By D. J. Bauer

This report covers a phase of an extraction project carried out as part of a research program on rare-earth technology. The current project--the production of pure cerium compounds--is an intermediate step between ore processing and metal reduction. In this connection, a study on a separatory-funne1 scale was made on nonreducing extractants for recovering cerium (IV) from tri-n-butyl phosphate (TBP) and of methods for recovering the cerium nitrate from the strip solution. Dilute sulfuric acid was found to be 100 percent effective in stripping cerium (IV). Several precipitants were effective in recovering the cerium from the strip solution, and ethanol was especially promising. A scaled-up investigation was made into the use of spray-tower type equipment to perform the function of extracting, washing, and stripping. This equipment, referred to as the pressure-bubbler, utilized the system developed on the separatory-funnel scale. Feed solutions were prepared from a bastnasite concentrate by two techniques. Of these, the sulfated bastnasite solution was most successful, resulting in 86-percent recovery of the cerium at 99.7+-percent purity.

Jan 1, 1959

By Charles K. Rose

This paper presents some research studies of the rotary drilling of oil shale at the Bureau of Mines Oil-Shale Mine, Rifle, Colo. The experimental procedures and the rotary drill test equipment are described. Theories of rock drillability, rotary bit cutting action, and bit design are presented and discussed. The actions of various bit designs are analyzed and compared with the observed results of actual drilling tests. A cost estimate is made for drilling Colorado oil shale.

Jan 1, 1955

By N. S. Dalal, X. Shi

"The oxidation of NADPH by vanadate(V) in the presence of glutathione reductase showed typical enzymatic kinetics. The oxidation was inhibited by N-ethylmaleimide, a glutathione reductase inhibitor. Superoxide dismutase had no significant effect on the oxidation, indicating non-involvment of the superoxide radical. The vanadate(V) reduction was found to be a one-electron transfer process. These results suggest a new pathway for vanadate(V) metabolism and a new function of glutathione reductase. Compounds of vanadium(V), such as NaV03 , exert potent toxic effects on a wide variety of biological systems (1-3). Despite intense current activity, however, the biochemical mechanism of vanadate(V) toxicity is still not well understood (1- 14). It is believed that one of the important pathways involves the oxidation (by vanadate(V)) of NAD(P)H (15, 16), but, to our knowledge, there has been no report of the identification of any vanadate(V) reductase. With a view to finding if there exists any vanadate(V) reductase, we have investigated the oxidation of NADPH by vanadate(V) in the presence of glutathione reductase. Glutathione reductase (GSSG-R)2 was selected because our previous studies have shown (17) that GSSG-R can act as a reductase for chromate(VI), which is isoelectronic with vanadate(V). We find that GSSG-R does indeed function as a NADPH-dependent vanadate(V) reductase, thus pointing to a new pathway for the metabolism of vanadate(V), as well as to this property for GSSG-R. MATERIALS AND METHODSSodium metavanadate (NaV03 ), henceforth vanadate, was purchased from Aldrich and its solution was always freshly prepared. The GSSG·R used was from bovine intestinal mucosa and was purchased from Sigma. The oxidation of NADPH was followed photometrically as the decrease in absorbance at 340 nm. The spin trap, 5,5-dimethyl- pyrroline-N-oxide (DMPO), was purchased from Aldrich and used without further purification, since very weak or no spin adduct signal was obtained from the purchased sample when used alone.ESR spectra were obtained at X-band (9.7 GHz) using a Bruker ER200 ESR spectrometer. The magnetic field was calibrated with a self-tracking NMR gaussmeter (Bruker, Model ER035A) and the microwave frequency was measured with a digital frequency counter (Hewlett-Packard, Model 5340A). An ASPECT 2000 computer was used for data storage and analysis. The concentrations given in the figure legends are the final concentrations. All experiments were carried out in the phosphate buffer solution (pH 7.2) and at room temperature."

Jan 1, 1990

"Minimizing Particle Contamination During Generation of Fresh Dust for Inhalation Studies J. Abraham, MS, Mechanical and Aerospace Engineering, West Virginia University, 1995Correlating Lung Crackle Using Holographic Interferometry Ali Afshari, MS, West Virginia University, 1989Effect of Bit Wear on Dust Generation Mudassar Ahmad, MS, West Virginia University, 1992 The Effect of Surfactants on Suppression of Non-Wettable Particles Ali Alaboyun, MS, Mineral Engineering, The Pennsylvania State University, 1989 Geochemical Characterization of Kerogens, Shales, and Coal Refuse Associated with Allegheny Formation of Cases of Northern West Virginia Dick Andre, MS, West Virginia University, 1987Size and Mass Characterization of Airborne Particulate Matter in Underground Coal Mines Using Diesel-Powered Equipment Indranil R. Bardhan, MEM Report, The Pennsylvania State University, 1992Size and Mass Characterization of Airborne Particulate Matter in Underground Coal Mines Using Diesel-Powered Equipment I. Bardhan, R. V. Ramani, and J.M. Mutmansky, Mining Engineering, The Pennsylvania State University, University Park, PA, Final Report to the U.S. Bureau of Mines, April, 1994Particle Concentrations in a Hazelton Inhalation Chamber Shahram Bavani, MS, West Virginia University, 1985Use and Potential of Lazer Holographic Interferometry and Subsidence Model- Study of an Underground Room and Pillar Mine Richard Begley, MS, West Virginia University, 1984Development of a Mechanistic Model for Prediction of Subsidence in a Longwall Mine Richard Begley, PhD, West Virginia University, 1990Redesign of Micro-Orifice Uniform Deposit Impactor Steve Behm, MS, University of Minnesota, 1991Evaluation of a Two-Phase Spray System for Dust Suppression B. Belle, MS, The Pennsylvania State University, 1996Evaluation of a Two-Phase Spray System for Dust Suppression B. Belle and R.-V. Ramani, The Pennsylvania State University, University Park, PA, Final Report, September 9, 1996A Fracture Mechanics Study of Crack Propagation Mechanism in Coal: The Mechanics of Fine Fragment Formation Z.T. Bieniawski and R. Karl Zipf, Jr., Mining Engineering Department, The Pennsylvania State University, University Park, PA. Final Report, October l, 1988A Mathematical Model for the Prediction of Ambient Dust Concentrations in Mine Atmospheres R. Bhaskar, MS, Mining Engineering and Operations Research, The Pennsylvania State University, 1984Spatial and Temporal Behavior of Dust in Mines-Theoretical and Experimental Studies –R. Bhaskar, PhD, Mining Engineering, The Pennsylvania State University, 1987"

Jan 1, 1998

By H. E. Powell

This Bureau of Mines study describes two processes for recovering zinc, copper, silver, and iron from the magnetic fraction of a waste generated by the primary smelting of zinc in horizontal retort distillation furnaces. The laboratory-scale procedures include reduction melting to produce a high-copper iron and matte smelting to produce a copper-silver-iron matte and metallic iron. Zinc is fumed in each process and recovered as the oxide. Direct reduction melting yields a metallic iron high in copper and a small rich matte from the sulfur contained in the waste. The products of the second process are a matte containing essentially all of the silver, about 80 pct of the copper and 37 pet of the iron, and an iron-copper alloy containing all of the remaining copper. Extraction with metallic lead or sodium sulfate recovers essentially all of the copper from the molten high-copper iron and yields an acceptable foundry iron.

Jan 1, 1973

The performance of two large-capacity ventilation systems was compared through tests conducted in a large dead-end heading at a pilot oil shale mine in Colorado. Sulfur hexafluoride (SF6) tracer gas was used to measure the performance of the two systems: a free-standing jet fan and a reversible fan with rigid duct. The tracer gas was used to simulate the production of mine air pollut-ants, including blasting pollutants, hot diesel emissions, free methane from surrounding strata, and methane desorbing from muck piles. The test room was 55 ft wide, 30 ft high, and 320 ft long. The performance of the two fans was similar, but the jet fan used less power. The tests showed that either system could provide effective ventilation during oil shale mining.

Jan 1, 1986

By R. R. Allen

Gieseler plastometer tests were performed on eight western coking coals at retort - immersion depths ranging from 2 to 3-3 /4 inches (measured to the center of the coal charge ) . Increased maximum fluidities were associated with greater retort - immersion depths , the most pronounced increases being observed on highly swelling coals when tested at 3-3 /4 inches . The maximum fluidity of one of these coals when tested at 3-3 /4 inches was 146 percent greater than that observed at 24 inches . Retort - immersion depth had no significant effect on the temperatures of initial softening , fusion , maximum fluidity , end of fusion , and solidification .

Jan 1, 1964