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By David E. Van Dillen

This volume is a task-by-task review of work performed in modernizing the BMINES finite element code. Much of the discussion is accomplished by cross reference to the user?s guide, which is Volume I of this two-volume report. The computer program described in this report provides for the static, three-dimensional, linear and nonlinear analysis of structural and geologic systems by the finite element method. The nonlinear material properties currently available in the code include isotropic, anisotropic, variable modulus, plastic, viscoelastic, and viscoplastic. Load application capabilities include gravity loading, surface tractions, and initial stresses. The element library includes rods, beams, plane and axisymmetric quadrilateral elements, three-dimensional brick elements, thick shell elements, and plane, axisymmetric, and three-dimensional joint elements. Special features include the ability to simulate excavation and construction sequences by means of element activity. An automatic mesh generator is included in order to simplify input preparation.

Jan 1, 1981

By John M. Devine

The oxygen bomb-is used extensively for determining sulphur in petroleum, although it has been suspected that the results obtained with this method are somewhat lower than the true varies. In this paper are compared the results given by the oxygen-bomb and Carius methods, the latter being generally accepted as the standard procedure for the determination of sulphur in organic compounds. The Carius determinations given hero were made in connection with a special study of this method.4 Only petroleum oils of the less-volatile type are covered in the present work. Summary and Conclusions. When used with oils containing 2.3 to 0.15 per cent of sulphur the oxygen-bomb method gives results that are consistenly if slightly lower than those obtained with the Carius method. This variation, for the oils used, amounts to 3.1 per cent (on tae basis of sulphur present) for the sample containing 2.47 per cent of sulphur, and gradually increases (as the percentage of sulphur in the oils decreases) to 7.3 per cent for the oil containing 0.15 per cent of sulphur. With the oils studied the presence of ammonium nitrate in the bomb does not influence the results materially.

Jan 1, 1928

By McHenry Mosier

The Anson Bette manganese mine, with two prominent manganese-bearing outcrops in schist, has attracted considerable attention for its variety of manganese minerals and its possibilities as a potential source of manganese. Little mining was done prior to 1925, when the present owner acquired the property, and operations since that date have been intermittent. Mine workings are open cuts with a maximum depth of 35 feet. The two outcropping ore deposits are irregular, pipelike bodies about 500 feet apart. As nothing was known of the grade or extent of mineralization in depth, four holes totaling 1,072.5 feet of bore Were diamond-drilled by the Bureau of Mines in the summer of 1943, with the results shown in figures 3 to 6. In.1945 a geophysical survey was run to map the magnetic anomalies in the manganese-bearing belt as a means of determining the locations of manganese deposits. Positive correlation of magnetite and manganese ore was not obtained.

Jan 1, 1949

By John J. Henn

An evaluation is presented for an ammonium sulfate leaching process designed to extract manganese from Cuyuna, Minn., and Aroostook, Maine, deposits. In this process the manganese and iron in the ore are reduced to MnO and Fe 3 0 4 in a shaft furnace; the reduced ore is then leached with ammonium sulfate solution forming soluble manganous sulfate while leaving most of the iron undissolved. After filtration, the manganese and some impurities are precipitated from solution as carbonates which are then pelletized and calcined to form a product composed mainly of Mn3O4. The plants are designed to produce 100 tons per day of manganese contained in a product that is suitable for the production of ferromanganese. A byproduct credit, together with the extra processing cost, is included for the Cuyuna ore processing plants because Fe2O3 may be recovered for use in blast furnaces. The estimated operating costs per ton of manganese, excluding income taxes and return on investment, are: [ ] The process with or without byproduct recovery, when treating Cuyuna or Aroostook ores, is not economically competitive with ores available at $71.43 per ton of contained manganese.

Jan 1, 1968

By J. N. Van Sant

Lignite mining in North Dakota was begun about 1884 to supply the domestic needs of settlers. Annual production has grown rather slowly but steadily, exceeding 3 million tons in 1950. The western part of the State has lignite reserves, amounting to 351 billion tons, underlying an area of 28,000 square miles. Contour strip mining has almost completely replaced underground mining as the method of production. Lignite is often found under rather shallow and easily removed overburden, and this is the primary reason for the change in mining practice. Current mining operations are conducted where the overburden is 30 to 70 feet thick. Contour strip mining results in high production rates, at present 27 to 56 tons per man-day. These high production rates result in relatively low production costs.

Jan 1, 1959

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 Loyal Clarke, H. H. Storch

"The discovery of large deposits of polyhalite (K2S04.MgS04.2CaSO4.2H2O) in Texas has led to an investigation of possible industrial proecsses for the extraction of potash from this material. This mineral was first discovored in small quantities in the European potash deposits in or about the year 1800. Chemists fire thought it to be a form of calcium sulphate, but a more accurate analysis by Strohmiyer indicated the composition as given by the above formula.The decomposition of polytalite by aster is very slow and results in the formation of a layer of gypsum at the surface of the polyhalite which retarts the solution of the potaseium and magnesium sulphates. To obtain a substantial yield of K2S04 in solution it is necessary to use large amounts of water at room temperature, for he concentration of K2S04 is limited by the low solubility of syngonite (K2S04.CaS04.H2O) whereas at 100º C. several days boiling are necessary to obtain more than a 6 per cent K2S04 solution even when finely powdered polyhalite is employed.In 1854 H. Rose discovered that calcination, followed by leaching with water, resulted in a larger extraction of the potassium and magnesium sulphates, as compared with leaching without precalcination. During the course of a series of investigations concerning formation of oceanic salt deposits, Van't Hoff and his pupils obtained sufficient data to construct the equilibrium diagram for the system K+Mg+SO4--Ca++.H2O for 25° C. and for 83° C. These data are very well summarized. in the International Critical Tables' and by Boeke and Eitel. From a consideration of the diagrams for 83º C. one would conclude that an extraction of polyhalite with moderate amounts of water at 33º C. would result in a solution whose maximum concentration of K2So4 would be about 3.6 grams per 100 grams of water and of M2SO; about 4.0 grams per 100 grams of water, corresponding to equilibriumwith the solid phases: Polyhalite potassiam-calcium pentasulphate and anhydrite.The fact that it has been found possible to obtain as high as 11.4 grams of K2S04 per 100 grams of water (see table 6) and an equivalent amount of MgSo4 (8.1 grams per 100 grams of water was obtained corresponding to a ratio K2/Mg of 0.98; indicates that the formation of these complex salts is very slow. To be sure, this results was obtained at 100° C. instead of 83º C. However, the work of Anderson and Nestall 9 on the double salts of calcium and potassium sulphates at 100º C. indicates that the diagram at 100º C. C. would not be greatly different from that at 83º C. This slow rate of approach to equilibrium when combined with precalcination of,of polyhzli-,a is the 17,asis of some of the more p:olisinE methods of extracting potash from polyhalite."

Jun 1, 1930

By E. S. Burnett

The temperature entropy (T, S) chart? of thermodynamic properties of nitrogen herewith presented is a complete (1949) revision and a considerable extension of similar charts prepared by the author for use of the helium section of the Bureau of Mines about 25 years previously on the basis of inadequate data then obtaining. During the interval since that early effort, much experimentally determined information on nitrogen properties and behavior has been published, which now permits a more nearly accurate layout and more extensive charting of these relations.

Jan 1, 1950

By John S. Berber

Tar produced as a byproduct from low-temperature carbonization of coal contains only small amounts of valuable lower boiling tar acids but relatively high percentages of high-boiling tar acids. These high-boiling tar acids are characterized by a high degree of alkylation and can be converted into the lower boiling homologs by catalytic treatment to remove the alkyl groups or decrease their chain lengths.

Jan 1, 1965

By Ernest R. Rodriguez, Allen D. Look

"INTRODUCTION The underground mine of the Miami Copper Co. has operated since 1927 without a fatality from blasting or the handling of explosives. To improve safety and efficiency, electrical blasting has been used exclusively since 1934. During the period January 1, 1934, to December 31, 1948, inclusive, over 4,000 tons of explosives were used to produce 60,925,071 tons of ore with 896,760 feet of development footage and 2,591,788 square feet of undercut area.The purpose of this paper is to recount the company's precautions to insure safe handling of explosives at this operation, where safety involves careful planning rather than ""trial and error.""GENERAL INFORMATIONThe Miami Copper Co. operates on underground mine in a large, low-grade, Porphyry copper deposit near Miami, Ariz. The deposit contains numerous fractures and planes of weakness, which contribute to ease of working the ore bodies by the block-caving method of mining.An individual stope-caving method is used with stoles 150 feet by 200 to 300 feet and 30- to 50-foot pillars between stapes. After the stope is undercut, the ore is drawn through the draw raises on the grizzly level, and thence through the transfer raises to the ore chutes on the haulage level.Access to the mine is by four active shafts, three of which are primarily for ventilation. No. 5 shaft is used for both hoisting and service. There are four operating levels in the mine. The elevations of the grizzly levels are governed by the contour of the bottom of the ore body and therefore vary in different locations in, the mine.Grizzly levels are on the 850, 900, and 975 levels. The 1,000 level is the haulage level. This mine operates in very low-grade ore and requires economical handling of large tonnages safely and efficiently."

May 1, 1950

By R. V. Ramani, K. Bode

"IntroductionIn part 1 of this paper, the results of the experimental work in a wind tunnel under controlled conditions were presented. To understand the spatial and temporal behaviour of airborne dust under mine conditions, experiments were performed in the Lake Lynn Experimental Mine of the US Bureau of Mines. The mine airway experiments were designed to study the variations of ambient concentrations along the length of an airway, and the deposition rates and deposition velocities in an airway cross section. Other objectives of the study were to investigate the spatial and temporal behaviour of airborne dust with regard to air velocity and particle density, the size distribution of the airborne dust cloud as it travels in the airway, and the size distribution of the dust particles deposited along the airway. Other objectives of the study were to compare wind tunnel results with In-Mine results, whenever appropriate.Experimental ProcedureLocationA complete description of the Lake Lynn Laboratory Mine of the US Bureau of Mines (USBM) can be found in the US Bureau of Mines Information Circular 8911 (Mattes et al., 1983). This mine provides excellent facilities for dust experiments. The airway dimensions are similar to those of a coal mine airway. The mine has a drift (D Drift, see Figure 1) that extends almost 500 meters without interconnecting airways, stoppings, or bends. The D drift measures approximately 6m in width and 2,25m in height.The Lake Lynn Laboratory Mine· is ventilated by a variable speed, 75 kW (100 hp), 28,3 m3/s (60 000 cfm) blower fan installed on the top of the ventilation shaft. Air velocities of 1, 1,3 and 1,8 m/s, respectively, could be obtained in the D Drift. However, the temperature changes at the surface can cause small variations in air quantities and velocities underground. The low background dust level in the mine reduces the problem of sample contamination from other sources of dust. Extended periods of uninterrupted data collection can also be scheduled. Mine airway parameters which are important for the analysis include the dimensions of the airway and the ventilation data such as the air velocity, and the pressure loss in the drift. All these data were acquired during altimeter surveys which were conducted prior to each of the experiments."

Dec 1, 1995

By R. Hogg

"Some basic features of the science and technology of particle systems are reviewed in the context of agglomeration processes. Emphasis is placed on the force of interaction among particles and with their environment and on their dependence on particle characteristics and interfacial phenomena. The complex role these forces play in the various stages of agglomerate formation, growth, consolidation and structure development, and their influence on final product properties is discussed.INTRODUCTION Agglomeration is an example of a process where the technology has generally preceded the science. Process development• has very often been by trial-and-error albeit with an eye on some basic principles. Nevertheless there is' a scientific basis to the process and a better understanding of the fundamentals can surely lead to improvements in process design and control.Successful processes for the agglomeration of fine particles depend on proper control of the adhesional forces between particles, to encourage agglomerate formation and growth and to provide adequate mechanical strength in the product. At the same time the rheology of the particulate system can be critical to the rearrangement of particles necessary to permit densification of the agglomerate and the development of an agglomerate structure appropriate to the end-use requirements.AGGLOMERATION SYSTEMSUltimately, the performance, of any agglomeration process depends on the• characteristics of the particles and their environment. The specific effects, however, are often complex and may be very difficult to pinpoint by simple observation of the process. A typical agglomeration process involves a number of concurrent or consecutive steps - adhesion, growth, compaction, etc., - each of which is affected by the characteristics of the system, but not necessarily in the same way. The effect of particle size, say on agglomerate growth may be quite different from its effect on compaction and its optimum value may differ widely from one stage to the other. Obviously there.is a general need for compromise in the design and operation, of agglomeration systems. Furtnermore, an understanding of the details of the process and their complexities can be critical to process optimization and improved product quality control."

Jan 1, 1989

By Ernest L. Corp

The natural marine environment can be divided into four basic categories: the air-sea interface, the water zone, the seafloor, and the subbottom. Efforts are being made to accumulate data to delineate the conditions in each of these areas and to conduct engineering studies which will determine how these environmental parameters affect the mining process. Laboratory facilities have been constructed and equipment and techniques for scientific data collection and laboratory research have been developed. Major emphasis is being placed on studying the subbottom material. The objective of this emphasis is to study the engineering properties of marine placer deposits in order to assess their influence on the design and performance of the various mining subsystems involving penetration, excavation, transportation, and disposal. Presented are the results of engineering properties tests on a placer simulant which is currently being used for model and prototype testing of coring tools. The effect of these engineering properties on penetrability, core recovery, and sample recovery is discussed.

Jan 1, 1970

By Alfred E. Schwaneke

A versatile torsion creep tester was instrumented with electromechanical and servomechanical components to operate automatically and unattended, producing digital printed outputs. The apparatus uses an electrical system for applying torsional stresses, and a unique angular transducer as a null detector operating a servocontrolled strain measuring system with the digital readout. The tester is designed to measure the creep in single-crystal or polycrystalline zinc, zinc alloys, magnesium, magnesium alloys, or other metals and alloys. Applied stresses may be varied from zero up to 2,000 psi in the outermost fibers of a 1/8-inch-diameter, 4-inch-long specimen. Strain readings to 0.001 degree, equivalent to a strain of 2.73 X 10-7, may be made automatically from one every 5 seconds to one per month. The apparatus has provisions for programed temperature control and special atmospheres or vacuum operation. A discussion of applications of the system to other mechanical testing apparatus is included.

Jan 1, 1970

By Charles H. Shapiro

[In July, 1924, the Bureau of Mines, through its Petroleum Experiment Station, undertook a field study of methods used in oil-field shops for dressing and tempering fishtail bits. The purpose of this work was to suggest chances that would be helpful to the bit-dresser in turning out better treated, harder, and tougher bits, and thus cut down the excessive loss of time caused by too frequent changing of bits. It was the intention to eliminate as much as possible the guess work connected with dressing and tempering bits under the method of judging temperature by eye, by developing; practical methods of controlling temperature. If there were some possible means of accurate temperature control, then it would be an easy matter to bring all bits to the proper temperature for maximum hardness rued toughness, thus doing away with the source of most of the trouble experienced in the present method of bit tempering. Shortly after the Bureau of Mines began its study, a chop In the Stroud, Oklahoma, oil field announced method for tempering fishtail bits that Would increase the drilling footage of each bit treated. The method accurately regulates, by the use of a bath of molten salt, the temperature to which a bit is heated before being quenched to produce hardness. There is nothing new in using silt baths for the, heat treatment of steel, but this was the first attempt to introduce it into the oil fields for use in hardening bits, and for this purpose it proved to be admirably adapted. In tempering, by the old system it is not possible to measure the temperature of the heated bit by means of an electrical instrument for that purpose, whereas this is an easy matter with the now method. If heating steel to slightly above the critical point rind quenching suddenly will bring out its best properties, their here is a method of accurately bringing the steel to that point.]

Jan 1, 1925

By Frank D. Lamb

Pyrophyllite, a hydrous aluminum silicate (Al2 Si4O10 (OH)2 ) has been mined in North Carolina and marketed without beneficiation for the past 100 years, but recent demands for higher-grade material indicate that an economical concentration method is needed for at least a part of the pyrophyllite production. Past production has depended upon selective mining and hand sorting, which is often unsatisfactory because of the finely disseminated character of the ores. The major impurity in North Carolina pyrophyllite ores is quartz, which accounts for the abrasiveness of the commercial product. Since pyrophyllite is only slightly heavier than quartz, those ores cannot be beneficiated by simple gravity-concentration methods. Some separation can be attained by differential grinding and air classification because of the difference in hardness of the two minerals) but the separation is not sharp. Froth flotation of pyrophyllite from Quartz has never been attempted commercially, but if the demand for high-grade material is sufficient, it would seem that this process offers the most premise of being economically feasible.

Jan 1, 1950

By V. R. Spironello

One of the primary objectives of the Bureau of Mines solid waste utilization program is the recycling of the magnetic fraction of municipal solid waste called raw refuse scrap. In this investigation, several types of scrap of differing quality, including refuse and turnings, were melted in a 1-ton electric-arc furnace in various combinations to produce steel in noncritical (construction) grades. In-formation on furnace operation and on the behavior of tramp and alloying elements was obtained. The research showed that it is possible to produce acceptable steel from a variety of steel scrap. Although some scrap is routinely used in steelmaking, it was found that up to 50 to 55 pct of the scrap charge can be ref-use, provided it is combined with higher quality scrap. The chemistry of the steels was generally acceptable, and all of them were rolled without difficulty. The specification (ASTM 615) for the steels produced was grade 40 or grade 60, containing 0.30 or 0.40 pct C, with mini-mum yield strengths of 40,000 or 60,000-psi, respectively. Most of the steels met the specification requirements. In-formation on typical microstructures of some of the steels is included. The composition of some furnace dusts showed high levels of Sn, Pb, and Zn.

Jan 1, 1981

By E. D. Calvert

As part of its goal to minimize the requirements for critical and strategic minerals, the Bureau of Mines is conducting research to foster the use of domestically abundant materials such as molybdenum. This report describes the development of an investment shell molding technique that can be used to make castings of molybdenum and its alloys. The mold material is cubic Zr02 with a monoclinic Zr02 binder. The shell, formed by standard investment molding techniques described in the text, is prepared for molybdenum casting by firing for 6 hours at 1,550° C (2,822° F) or for 4 hours at 1,650° C (3,002° F). The resulting castings have predictable and reproducible dimensions with good detail. As-cast strength is poorer than the strength of wrought materials below 1,600° F. At and above this temperature, tensile strengths of cast and wrought materials are nearly equal. Aqueous corrosion of the castings in most media is insignificant.

Jan 1, 1982

By John Millhiser, Margaret Bonarek, Dennis McLaughlin

This report contains a description of the contract activities performed by ENSCO, Inc. under contract No. H0178069. The purpose of this project was to enhance the Bureau of Mine's Cableless Electronic Survey System use to aid in the drilling of long (approx. 2000 feet) boreholes in coal. This drilling is performed as part of the methane drainage program. The system that was ultimately developed was field tested and demonstrated in actual in-mine drilling activities. The significance of this system as compared to previous drill survey systems is the fact that it surveys without having to be inserted and removed for each survey point. It is so designed that it can withstand the shock and vibration experience by the drill string during drilling. This means an increased productivity is now possible in that drill operators can determine drill bit positioning in a near real-time environment.

By H. Kim, R. W. Plummer, T. J. Stobbe

"The probability of developing coal workers' pneumoconiosis (CWP) varies among miners in different geographic areas, coal seams, and jobs. Many studies have revealed the correlation between mineral content and the frequency and severity of CWP development still remains controversial. Furthermore, the mineral content and its variability in different areas is unknown.Since mineral content is expected to vary from location to location within a mine, between mines, between coal seams, and over time, this information will be valuable in understanding the variations in CWP incidence, as well as in establishing the appropriate kinds of dust to use in toxicological research programs studying CWP.Size-selective airborne dust samples were collected using 4-stage cassette impactors at 9 different locations in each of five coal seams. These coal seams were the Upper Freeport, Pittsburgh, Kittaning, Coal Burg, and Pocahontas. Mineralogical analyses were done by a x-ray powder diffraction photographic technique.Common minerals found in coal mine dust were illite, calcite, kaolinite, quartz, siderite, dolomite, gypsum, anhydrite, and pyrite. The distribution of minerals in interand intra location samples will be reported. Early results on the mineral content show wide variations between locations.in a mine and between coal seams, and small, but significant, variations between particle sizes.INTRODUCTIONIn spite of its long history of incidence, and the large amount of research conducted on it, coal workers' pneumoconiosis (CWP) is still prevalent among coal miners and needs further research to develop effective preventive and remedial measures. Although the dose-response relationship between simple CWP and coal mine dust has been established (1), the causal agent(s) and the mechanism(s) involved in the progression of simple to complicated CWP are not yet defined. Many plausible hypotheses have been made to explain the mechanisms involved in the disease progression however none of them is satisfactory. In addition, the source of variation in occurrence of CWP among miners in different geographic areas (2), rank of coal seam (3,4), and job (5) remain unsolved."

Jan 1, 1988