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By Foster Fraas

The Bureau of Mines investigated a method for calculating values of adsorption energy; the goal was to devise an equation consistent with experimental data accumulated in the investigation of adsorption as related to ore separation processes. Numerical identification of the constants of a previously formulated equation provided an equation by which values of adsorption energy could be calculated. Values thus calculated checked with those obtained by calorimetric measurement.

Jan 1, 1965

By R. R. Nothdurft

The internal friction of eight single crystals of magnesium with orienta-tion ranging from 10° to 84° was measured at 33.5 kc and 272° C, and the results were interpreted in terms of the pinned-dislocation model proposed by Granato and Lucke. Results show that the strain-amplitude-dependent decrement varies with orientation in a manner predictable by the G-L model. Different values of strain-amplitude-independent decrement were observed at different orientation angles, but correlation with the theory was not conclusive. Problems and steps for further study are discussed.

Jan 1, 1965

By H. E. Powell

Basic data were recorded on the decompositions that take place during thermal decomposition of siderite (FeC03). Both the naturally occurring and a synthetically prepared mineral were studied by differential thermal, thermo-gravimetric, X-ray-diffraction, and chemical (including gas) analyses. Thermal decomposition was studied in the media of dry air, moist air, dry carbon dioxide, dry helium, and dry carbon monoxide and at atmospheric and at reduced pressures. Results showed the thermal decomposition of FeC03 to be an extremely complex process, dependent on environmental factors and side reactions that cannot now be completely controlled. Therefore, full understanding of the reaction involved must depend on additional research with advanced evaluation techniques.

Jan 1, 1965

By Jr. Joyce

This report describes sulfatization of nickeliferous laterites from Puerto Rico and the Philippines for recovery of water-soluble nickel and cobalt sulfates. Temperatures ranging from 665 C to 710 C and a 10-percent sulfur dioxide-air reaction gas were employed during batch-roasting tests and during continuous countercurrent treatment in a 2-inch-diameter shaft furnace. A maximum of 69 percent of the nickel and 76 percent of the cobalt were recovered from one sample of Puerto Rican laterite, and a maximum of 96 percent of the nickel and 91 percent of the cobalt were recovered from the Philippine laterite.

Jan 1, 1965

By Juel H. Stears

Research was done to determine if a hydraulically operated penetrometer developed by the Bureau of Mines could be used to estimate the roof-bolt anchorage capacity of mine roof rock. Tests were conducted both in the laboratory using cement cylinders and underground in shale rock. Hardness readings were measured by the penetrometer around the periphery of the bolt holes at the anchorage horizon. Roof bolts Nere then installed and subjected to an anchorage test. The results showed that the penetrometer readings could be used to determine the optimum stratum for roof-bolt anchorage but could not be used to make an accurate estimate of the anchorage capacity.

Jan 1, 1965

By James D. Brown

The Bureau of Mines has written a computer program in FORTRAN to facilitate the calculation of concentrations from X-ray intensities in electron probe microanalysis. Philibert's absorption and Castaing's secondary fluorescence corrections are used; no atomic number correction is included. Background and dead time corrections are applied to the data before calculating the relative intensities. Data from any type of electron probe microanalyzer can be used with the program.

Jan 1, 1965

By Joseph A. Cavallaro

This report describes the timed release analysis technique that was developed to serve as a tool for assessing the froth flotation cleaning potentials of fine-size coals. Using this developed technique, 16 coals from 10 different coalbeds were tested. All of the coals included in this study were quite amenable to froth flotation with float coal yields ranging from 80.7 to 99.5 percentage points. Float-and-sink analyses of the coals tested are shown to be of limited value in predicting froth flotation cleaning potential. Generally the float-and-sink analyses indicated a better product could be obtained than froth flotation could provide; although, in four of the coals tested froth flotation results were superior to those expected from the gravimetric analysis. The fixed carbon content of the samples collected was found to correlate with the floatability of the coals. The higher rank coals were the most readily floatable coals while the lower rank coals did not respond quite as well to flotation.

Jan 1, 1965

By C. O. Hawk

Distillable oils derived from coal were desulfurized and hydrogenated at 2,500 psig in a two-step vapor-phase catalytic operation to give a product rich in saturated cyclic hydrocarbons. The first step was mainly a desulfurization at 400 C, the second a saturation at 300 C. One of the oils used as feed stock was from low-temperature carbonization of a bituminous coal, the other was from the liquid-phase hydrogenation of coal in the Bureau's pilot plant. The product from the saturation step was distilled to remove the light ends and high-boiling residue and to recover a fraction having acceptable properties with respect to heating value, density, freezing point, viscosity, and boiling range according to specifications suggested by the Air Force for ultra-high-speed aircraft fuel. Quantities of the fuel fraction available were too small for the thermal stability test approved by the Air Force. The experiments, performed on laboratory scale, comprised mostly a study of the effect of varying the oil feed rate (at constant oil-to-hydrogen ratio) on the yield of the desired fuel fraction. The yield of the fuel fraction made from low-temperature carbonization oil was a little more than 1 percent of the weight of coal carbonized; that from coal-hydrogenation oil was about 12 percent of the weight of coal hydrogenated. A few attempts to do both desulfurization and saturation in one operation with sulfur resistant catalysts, developed for vapor-phase hydrogenation or hydroforming, were unsuccessful. By leaving the low-boiling ends in both feed stocks to desulfurization, another product was obtained: a low-sulfur aromatic cut boiling below 200 C. This material would be suitable as a solvent or a chemical raw material.

Jan 1, 1965

By K. C. Dean

This report is the first of a series concerned with processes for producing magnesium. These reports will evaluate metallothermic, carbothermic , and electrolytic production methods, and will furnish a cost basis for comparing the processes. Areas deemed most promising for future research will be delineated for each procedure. This report presents briefly the history of the metallothermic process, and describes the operations of the Defense Plant Corp. (DPC) plants that employed the process. A hypothetical plant designed to produce 12,000 tons of magnesium per year, using ferrosilicon as a reductant, is described, and raw materials, energy, and major equipment requirements are estimated. Several process modifications are suggested for future research.

Jan 1, 1965

By Jerry W. Ramsey

The Bureau of Mines examined a low-, a medium-, and a high-volatile Pennsylvania anthracite by densimetric methods using four mesh si.s of each anthracite. Using high-pressure mercury the macropore volumes and distributions of these pore volumes determined, densities in mercury were calculated, and specific pore vo1.r. ware obtained from these mercury densities in conjunction with helium densities. The helium densities were also used with the ultimate analyses of these anthracites in calculating structural parameters by statistical densimetric methods. The effect of 106 or 108 rads of gamma irradiation in the presence of air and in vacuum upon the properties studied with two mesh sizes of each anthracite. Results of the statistical densimetric method seem to show some breakdown of condensed ring structural units at the lower irradiation level, with subsequent polymerization at the longer period of gamma irradiation. The structural parameters obtained also indicated that in going from high- to low-volatile anthracite, either the number of condensed rings per structural unit increased, or the degree of polymerization increased.

Jan 1, 1965

By G. L. Gates

The Bureau of Mines studied the scales formed in producing wells in the Wilmington field, California. The scales were primarily barium sulfate and resulted from the mixing of injected sea water and formation waters; there was excess sulfate in the injection water and the formation waters contained appreciable barium. After breakthrough, the produced brines were supersaturated with barium sulfate. Laboratory tests indicated that barium sulfate precipitated quickly When the supersaturated brines were agitated with crystals of barium sulfate and fairly rapidly when more sulfate solution was added. Precipitation occurred slowly on standing or under nonturbulent conditions. Both the apparent and equilibrium solubilities of barium sulfate in these brines were determined and compared with equilibrium solubilities in distilled water and sodium chloride solutions.

Jan 1, 1965

By J. L. Eakin

The Bureau of Mines determined agents that are effective in foaming heavy brines and oil from gas wells in severe concentrations of sodium chloride, in severe concentrations of calcium chloride, or in moderate oil-brine mixtures. Dynamic foam tests were designed to select the more effective foaming agents. Numerous foaming agents were tested in concentrated simulated brines, in oilfield brines having varied concentrations of ions, in heavy natural brines, and in a commercial brine generally used as a reservoir pressure-balancing fluid. Several agents were detected that could perform efficiently in the field under the most severe saline conditions. Agents that promote foaming in oil-brine mixtures were also determined.

Jan 1, 1965

By Alla D. Mah

The heat of combustion of TaC0.996 was determined by oxygen bomb calorimetry to be -302.8 ±0.4 kcal/mole. The corresponding heat of formation of TaC0.996 is -35.4 ±0.5 kcal/mole, and the calculated heat of formation of TaC1.00 is -35.5 ±0.5 kcal/mole.

Jan 1, 1965

By Robert C. Johnson

Single crystal whiskers of ZrO2 and TiO2 were grown by solution and crystallization of these oxides in molten baths. Mixtures of Na2B407 and LiC1 were the most suitable growth media for zirconia. Sodium borate alone and Na2CO3 plus SiO2 were best suited for titania. The solubilities of zirconia and titania in molten sodium borate were determined, Whether zirconia whiskers were dendritic or nondendritic depended on the temperature used. The best single crystal whiskers were grown below 1,100° C. Titania whiskers always grew as single crystals. The tensile strengths of zirconia and titania whiskers were about 15,000 psi and 50,000 psi, respectively. Modulus of rupture was about 49,000 psi for zirconia whiskers and 75,000 psi for titania whiskers. Chemical analyses showed the zirconia and titania whiskers to be pure. The zirconia and titania whiskers were shown by X-ray analysis to be, respectively, baddeleyite and rutile.

Jan 1, 1965

By James S. Browning

The Bureau of Mines conducted laboratory batch and pilot plant flotation tests to determine the technical feasibility of recovering commercial-grade mica from a California micaceous schist. Best results in the laboratory batch tests were obtained using sodium carbonate and sodium silicate for pH control and quartz depression, and a combination of fatty acid and cationic reagents as the mica collector. In continuous pilot plant flotation tests, an alkaline fatty acid-cationic method recovered about 70 percent of the mica in a concentrate analyzing 95.6 percent mica.

Jan 1, 1965

By G. E. Rennick

A siphon-type laboratory airlift well was designed and operated by the Bureau of Mines to study the concurrent flow of air and oil in small-diameter pipes. Glass flowstrings ranging from to 1 inch in diameter and from L4 to 64 feet in length were equipped with various-sized air-entry jets. Liquid holdup volumes were used to correlate vertical-flow data, and empirical equations for computing gas requirements were derived. The effect of flowstring length on flow efficiency, oil- and gas-production rates, and gas-oil ratios was relatively minor at all flowing pressures. Air-jet sizes and flowstring diameters, however, had a marked effect on flow efficiency and oil- and gas-production rates. The small air-jet sizes increased maximum flow efficiency and its associated flowing pressures but decreased oil- and gas-production rates. An increase in flowstring diameter increased maximum flow efficiency with its associated flowing pressure and also increased the production rates of oil and gas.

Jan 1, 1965

By Thomas A. Morgan

The distribution of stress adjacent to each of 25 mine openings was determined by the borehole stress-relief method in the FMC Corp. Westvaco trona mine at Westvaco, Wyo. The purpose of the stress determinations was twofold: First, to study the effect on these distributions of various factors such as opening shape, stress level, and loading history; and second, to estimate the distribution of stresses adjacent to extensive high-extraction (85 to 100 percent) areas. Stress distributions in areas of low average stress correspond closely to the theoretical distributions based on elastic theory. However, in areas of high average stress, the stress distributions are of a type associated with plastic failure. The stresses adjacent to a mined-out area supported by remnant pillars were significantly higher than the stresses adjacent to another area in which the remnant pillars were removed.

Jan 1, 1965

By C. E. Arthur

The Bureau of Mines has investigated the problem of radioactive contamination using nuclear explosives to fracture petroleum reservoirs in an attempt to stimulate production. It was concluded that some contamination of petroleum products will almost certainly occur. However) the degree of contamination cannot be predicted except by a full-scale experiment) since simulating the problem in the laboratory is economically impossible because of the extremely high temperatures and pressures that must be reached in extremely short time intervals if a reasonable analog is to result.

Jan 1, 1965

By George C. Price

The Bureau of Mines conducted this study in the Roslyn No.5 coalbed in the State of Washington to determine the feasibility of mining hydraulically the portion of the coalbed that was steeply pitching. All of the experimental mining was done while advancing raises and rooms. A Bureau-developed hydraulic mining machine was used successfully in the pitching coalbed. It consisted of a remotely controlled monitor mounted on a self-advancing roof support unit of the type commonly used for roof support in longwall mining systems. The coal cutting rates averaged 0.73 and 0.54 ton per minute in raise and room mining, respectively, while using water volumes up to 230 gpm at a pressure of 4,000 psig. Productivity averaged 4.7 and 5.2 tons per man-shift for raise and room mining, respectively, compared with 7.5 and 8.5 tons per man-shift, respectively, by conventional hand mining methods.

Jan 1, 1965

By F. X. Tartaron

This report describes work done by the Bureau of Mines to simplify the design and operation of the vortex cone, a new device for prerefining blast furnace iron. Three new apparatus arrangements were tested. Results with one of these arrangements average 74.2 pct silicon removal and 61 pet oxygen efficiency (disregarding removal of carbon and manganese).

Jan 1, 1965