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By H. F. Feldmann

This Bureau of Mines report presents a method for the computer solution of the equilibrium compositions of any complex, multiphase, chemical system for which appropriate thermodynamic data are available. The method describes in detail the computation of systems in which solid or liquid species can form by heterogeneous chemical reactions where these species do not occur in any equilibrium equations. Also described are the calculation of phases formed by condensation (pure or solutions) and the inclusion of other system restrictions such as electroneutrality. The method is being used to compute the equilibrium composition of mixtures of an electrically conductive plasma and a liquid slag phase arising from the high-temperature combustion of coal for magnetohydrodynamic power generation. These mixtures can contain up to 65 species including gases, liquids, free electrons, and ions.

Jan 1, 1969

By Arnold M. Lansche

[Selenium and tellurium are rare elements in the earth's crust. Their scarcity and primary dependence of supply on copper and lead output are in consonance with the relatively small quantities consumed at 1964 level. Production depending on output of copper and lead creates a supply situation- which would appear to militate against development of large-scale usage of these elements. However, supplies have adequately met. demand in the past decade and can be increased substantially if warranted by new uses for either selenium or tellurium Ores of copper and lead re the principal sources of selenium and tellurium. Byproducts from the smelting and refining of copper and lead concentrates are incorporated in refinery anode slimes from which selenium and tellurium metal are recovered.]

Jan 1, 1967

By Patricia R. Devine

This report expands an earlier study by Jack Faucett Associates (OFR #40-88) of the same title. Both reports are based upon an interindustry analysis from 1963 through 1982, during which time U.S. metals consumption and production did not keep pace with economic growth. The report discusses three sources of change: technological change, economic growth, and composition of final demand, as well as the relative importance of the individual components of final demand for metals. The results show investment and personal consumption to be the most metal-intensive components of final demand, and technological change to be the major cause of decline in consumption growth during the study period. Technology change is defined as alterations in production processes resulting in more or less consumption of metal per unit of output, often because of material substitutions and design changes. A trade analysis shows the significance of import growth, particularly indirect imports (metal contained in imported goods) as a factor contributing to the reduced growth rate of domestic metal production. The effect of import growth is partially offset by indirect export growth, suggesting that continued increase of all U.S. exports can have a strong effect in reducing the negative trade balance in metals.

Jan 1, 1988

By Richard D. Smith

The Bureau of Mines evaluated the emission control methods, including the capital investments and operating cost, necessary for further reducing lead levels in ambient air at the Glover, Herculaneum, and Buick smelter-refineries in Missouri and the East Helena, MT, smelter. The U.S. Environmental Protection Agency (EPA) has proposed more stringent lead in ambient air standards than those currently in effect. This report presents theoretically achievable lead emission reductions and estimated capital and operating costs. Lead emission inventories theoretically can be reduced from 1985 levels by 2,421 lb/d at the three Missouri operations by containing and filtering fugitive emissions within structural enclosures and baghouses. The aggregated capital and operating costs in 1986 dollars using conventional environmental and workplace technologies are estimated to be $250,014,100 and $18,507,800, respectively. Estimated total incremental cost is $0.063/lb as refined lead. Additional regulatory costs attributable to Occupational Safety and Health Administration (OSKA), U.S. Department of Labor, workplace standards are included since proposed environmental controls may otherwise degrade workplace conditions. Continuous drossing is evaluated as an alternative to conventional OSHA controls. Substituting continuous drossing for conventional work- place technology results in an estimated aggregated capital and operating costs of $258,344,800 and $15,719,600, respectively. Estimated total incremental cost is $0.062/1b as refined lead. For comparison, the average open market price of refined lead during the first quarter of 1986 was $0.184/lb.

Jan 1, 1987

By Steven J. Schatzel

Large-scale methane releases in dual salt mines have resulted in ignitions and mine fatalities as recently as 1979. Several past studies have implied that hazardous methane occurrences in U.S. salt domes are distributed neither uniformly nor randomly, but are geologically controlled and potentially predictable. A first step by the Bureau of Mines in addressing the problem of methane in deal salt mines required development of a new test to determine volumes of gases in solid salt samples. This report considers the results achieved when 80 deal salt samples were tested for gas content by dissolution in a controlled atmosphere chamber. Criteria were organized to delineate salt types based on geological occurrence. Outburst samples range from 0.014 to 7.4 cm3 CH4/100 g NaCl, anomalous salt samples from 0.0027 to 2.6 cm3 CH4/100 g NaCl, and normal salts from less than 0.0003 to 0.31 cm3 CH4/100 g NaCl. The presence of higher hydrocarbons was most common in samples containing larger quan¬tities of methane. The presence of higher hydrocarbons appears to be useful in detecting methane hazards where some methane may be lost before gas content testing. An exploratory rotary and/or core drilling program, dissolution testing for gas content, and up-to-date geologic mine napping could allow a mine operator to assess methane hazards in dual salt.

Jan 1, 1984

By Joan K. Kuenzi

This Information Circular brings together for consideration recommendations from U.S. Bureau of Mines research in the area of surface mine mobile equipment maintenance for the period 1982 through 1991. It updates the 1982 contract report by Baker and Alves that formed the basis for much of the work described in the present report. Recommendations for hazard abatement during work on mobile one equipment are presented and stem from the results and recommendations of the research in two areas: (1) equipment and workplace hazard reduction, and (2) management of maintenance information. Recommendations included in this report apply to both the operators and maintainers of mobile mining equipment as well as to the manufacturers of that equipment.

Jan 1, 1995

By Christopher C. Jobes

Computer-aided control of a mining machine requires a guidance system to aid remote positioning of the machine by determining its position and heading. The mechanical position and heading system (MPHS) developed by the U.S. Bureau of Mines provides such navigation information during face maneuvers. This report describes the required theory, which yielded a reliable algorithm for calculating machine position and heading, and implementation of this theory in hardware and software design, which made surface testing of the MPHS possible. Analysis of the errors and test results showed that the MPHS provides reliable results and can, therefore, provide useful guidance information for face navigation.

Jan 1, 2010

By James S. Wroth

The Act of Congress approved June 25, 1926 (Public Act 424, 69th Congress), authorized joint investigations by the U. S. Geological Survey and the U. S. Bureau of Mines to determine "the location, extent, and mode of occurrence of potash deposits in the United States." The particular deposits selected for exploration were the extensive rock-salt formations underlying large areas in western Texas and southeastern New Mexico, from which potash salts had been identified in the cuttings and sludges from oil wells drilled with cable tools. The evidence of these sludge samples was qualitative only and beyond definitely proving the presence of potash salts in the salt beds, gave little clue to the possible size, richness, or extent of the potash occurrences.

Jan 1, 1929

By Henry P. Cole

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/technical workplaces are described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training is explored. Research and development activities that may improve mine health and safety training are suggested. Most of these research and development activities were completed later in the project. This additional work is reported in the project technical report #2 and the final report. The research reported in the present document was completed in 1984 -85. Many of the initial findings reported in this document are updated in the later project final report.

Jan 1, 1988

By G. H. Gronhovd

This is the final report on a research program to develop a pilot plant gasifier for slagging gasification of lignite at high pressures and to obtain process data under various operating conditions. An operable pilot plant was developed, and the test results show that lignite is well suited for the process. Tests were run at pressures from 80 to 400 psig, and the results indicated that pressure had little effect on gas composition or the material requirements per unit gas produced. Gas production rates as high as 26,000 scfh/sq ft of reactor area were obtained at 300 psig, but limitations on auxiliary equipment prevented full-capacity operation at 400 prig. In several tests lignite having a 37-percent moisture content and 2,500° F ash-fusion temperature was successfully gasified. Refractory materials were found to have a short life in contact with high-temperature slag, and a water-cooled taphole was developed. Exploratory tests with coking coal were unsuccessful.

Jan 1, 1970

By Glen C. Ware

The Bureau of Mines determined the factors involved in the corrosion of starting sheets used in the production of electrolytic zinc with the ultimate purpose of adapting zinc starting sheets to commercial practice . Under present practice , zinc is electrodeposited on aluminum cathodes and subsequently stripped for melting . The use of zinc instead of aluminum would eliminate the need to strip the deposit , thereby reducing the cost of handling and melting it , but zinc has not been suitable because it was too vulnerable to the corrosive attack of the electrolyte . Serious attack was found to be limited to the areas of the cathodes situated immediately above the surface of the electrolyte and to re - entrant corners . It was possible to avoid solution - level corrosion by immersing the starting sheets completely , exposing only a relatively heavy suspension member to solution - level attack . Zinc starting sheets could be made as reliable as aluminum and could be continued in residence for periods up to 39 days . Periods as long as a week were feasible under conditions similar to those found in commercial practice . A test of zirconium as a starting - sheet material showed that it promoted corrosion of the deposit to a lesser extent than aluminum and that the deposit adhered less tenaciously . These two properties lend themselves to the development of ways to strip deposits mechanically from zirconium starting sheets . Titanium was unsuitable for use as a starting - sheet material .

Jan 1, 1963

By SUMNER S. SMITH

Mine inspection in Alaska by the Federal mine inspector was somewhat handicapped during 1915,the inspector having to spend a large part of the summer and fall in examining the Matanuska coal field in connection with the designation of the Government reservations and the leasing units in that field. However, in addition to>this work, the mines in southeastern and southwestern Alaska were inspected by both Federal and Territorial inspectors, a considerable number of men near the Federal inspector's officeat Juneau were trained in first aid to the injured and in the use of mine rescue apparatus, the mines of the interior and of Seward Peninsula were inspected by the Territorial inspector, and a suit was brought in the name of the Territorial inspector for the nonreporting of serious accidents under the Territorial inspection law. The work of the Federal inspector was handicapped also by a lack of field assistants. This condition is likely to be serious, as preparations have been made for opening the Matanuska, Bering River, and Nenana coal fields, and a number of permits granting the free use of 10-acre tracts in other fields throughout the Territory have been issued. The need of a comprehensive inspection law and experienced engineers to safeguard the opening of coal mines by operators who are not familiar with coal mining and are using inexperienced help is obvious.

Jan 1, 1917

By S. C. Termes

To help develop the basis for new fine-particle separation methods, the Bureau of Mines has investigated the use of cross-linked starches containing four chelating groups--carboxylate, iminodiacetate, dietha-nolamine, and xanthate--as flocculants for selected metal oxide and hydroxide mineral fines. It was found that those starches capable of interacting with the mineral surface by a chemisorpti,on mechanism (as indicated by zeta potential measurements) produced the highest recover-ies and'grades of the metal oxide or hydroxide when flocculated from a binary mixture with quartz. The effects of pH, dispersing agent, stirring rate, stirring time, and starch dosage on selective flocculation were studied for binary mixtures of hematite and chromite with quartz. Floc strength becomes important in achieving maximum recoveries by mechanical postflocculation separations.

Jan 1, 1985

By W. H. Coghill, F. D. DeVaney

"Introduction Numerous investigators have studied grinding. Each has contributed his bit to a literature that is difficult to correlate. Too many of the results have been transformed into curves with no many ""inflection points"" and ""counterflexures"" that they obscure the issue.Some of the investigators have neglected the very essence of the problem, namely, the power and the amount of material to which a known amount of work was applied. The purpose of this paper is to show the ease with which results can be interpreted when these quantities are duly recognized. Some grinding tests will be given for illustration.Grinding studies are of two kinds: (1) Study of the character of the ore and (2) study of the performance of the machines. Several ores may be crushed by a given machine, or several machines may be used on a given ore. The illustrations given in this report cover both objectives.Grindability Characteristics When the ores are being studied the information sought is grindability characteristics (grain-size distribution) and the grindability (work required to produce new surface) of a group of ores.When the study is of the machines, several machines are used for a given ore or given types of ores, and the grinding performances of the machines are compared by a grain-size study.Table 1 gives the grindability characteristics and grindability of six substances, one of which is coal. The substances are arranged from left to right in progressing order of tons per horsepower-hour. Curves and graphs are not needed for elucidation. The secret of the ease of interpretation is the order mentioned and the similarity of the sizing analyses. Power records must be complete in grinding studies.The grinding device was a ball, plunger, and mortar called the drop weight.' It may be used to advantage when the amount of material to be tested is too small for the orthodox machines.The upper part of table 1 shows the grindability characteristics by the cumulative-sizing analyses. Note how closely the percentage weights agree for a given sieve size. The lower part shows the grindability in terms defined elsewhere. The present paper should be read in conjunction with that paper."

Jun 1, 1934

By R. S. Lang, C. C. Merrill

The recovery of zinc from oxidized zinc minerals by the caustic soda leach and electrolytic or chemical precipitation was investigated . With the exception of willemite ( 2 ZnO • Si0₂ ) oxidized zinc minerals were readily soluble in 180 to 240 g / 1 NaOH solutions . A high- grade zinc flake was recovered electrolytically from solutions which had been treated with zinc powder to precipitate copper and lead . Solutions were recycled to the leach stage with a recovery of about 85 percent of the zinc from an ore containing 21.2 percent zinc . Electrolysis was conducted at a current density of 120 amp / ft2 with a power consumption of about 1.5 kwhr /lb zinc . Zinc was also recovered from leach solutions by dilution of the solutions , carbonation of the solution , or the addition of sulfur to boiling solutions . A dilution ratio of 5 : 1 precipitated 59 percent of the zinc in 9 days . Carbonation of the solutions precipitated the zinc as zinc oxide ( ZnO ) and solutions could be recausticized for recycling . Zinc precipitated as the sulfide with sulfur was easily filtered and washed . Approximately half of the sulfur added to solutions was lost in the form of sodium thiosulfate ( Na S₂03 ) .

Jan 1, 1965

By Alexander May

The U.S. Bureau of Mines investigated the application of oxidation-reduction potential (ORP) and pH measurements to environmental studies of mining and mineral processing wastes, and developed a computer program to estimate the concentrations of species of lead present in samples from a lead processing waste site. The methods and techniques for the ORP-pH measurements were investigated using known standard solutions made in the laboratory, samples from a ferric oxide waste disposal pond at a rutile production plant, and samples of well water and stream water from the lead processing waste site. ORP values were measured from 5 to 80 °C, from pH 1 to pH 12, and at various ratios of oxidant to reductant. The ORP-pH values can help identify valence values and species of ions present, including those of major, minor, and trace concentrations, and also indicate possible reactions at various pH values. The ORP measurements versus temperature yield data from which thermodynamic values can be calculated. The application and limitations of these measurements are discussed, and a brief discussion of the computational program to identify species of lead is presented.

Jan 1, 2010

By J. W. Thompson, M. N. RICH

That there is wide interest in the preparation and properties of metallic zirconium and its salts is indicated by the many articles recently published in scientific and technical journals and the many patents issued. The compounds of zirconium have numerous important uses and more uses will doubtless be found. In the course of the special work on rare metals that were of military importance during the war, the authors of this bulletin were detailed to the Golden mining experiment station of the Bureau of Mines to prepare metallic zirconium and to investigate its properties. A number of investigations in recent years have indicated that sintered or coherent zirconium metal is very resistive to acids; that it can be used for electrodes, and it probably will find metallurgical uses. A steel containing zirconium has been proposed for use in armor plate and automobile parts, and nickel-zirconium alloys have been suggested for high-speed cutting tools and for cutlery. Numerous articles in scientific journals have recommended the use of zirconium oxide as a refractory, an abrasive, a pigment in paints, and as an opaquing agent in enamel ware. The salts have been used in the textile industry' as a mordant and also for weighting silk. When the authors began their investigation, they found it necessary to collect all of the available literature on the general subject of zirconium and its compounds. Pure salts could not be obtained on the market, and in order to get these, as a preliminary step to the preparation of the metal, the literature had to be classified and the methods of preparing the salts investigated. Also, there was much difficulty at first in making satisfactory analyses, and this phase of the work received careful attention. As it was necessary to begin with a historical review of the literature, such a review is given as Part I of this report, and a bibliography is included as Part IV. References to the numbered items in this bibliography are made throughout the text, the usual footnote references being omitted. Analyses of the products and conclusions as to their purity are given under the descriptions of methods of preparation. A table showing the properties of the amorphous metal, and another showing the properties of the coherent metal, will be found under appropriate headings in Part II. No attempt has been made in the historical review to discuss fully all the published information about zirconium and its compounds, but only such material has been assembled as has a direct bearing upon the present work. Considerable difficulty was experienced in collecting this material because of the confusion of terms by various authors who perhaps did not thoroughly understand the chemistry of zirconium.

Jan 1, 1921

By A. L. Podia

The purpose of this research was to develop a system capable of detecting changes in the structure of rocks, leading to failure of mine roofs, and/or excavations. A prototype system was developed, field tested and delivered to the United States Bureau of Mines for further evaluation and research. This system is based on the analysis of acoustic signals generated on the surface of the roof by an impact device and which are reflected or backscattered by flaws and discontinuities in the rock. The specially designed impact source is capable of generating high frequency acoustic signals with excellent repeatability. The system can also be used in conjunction with conventional acoustic pulse transducers. The received signal is digitized and the data transferred to a minicomputer for processing and display. This capability allows the immediate determination of wave velocity and/or distance to a reflecting interface. Various data processing techniques such as averaging, differentiating, and comparing of different signals can be selected by entering the appropriate commands on the keyboard. Being a programmable system it is possible to implement more advanced signal processing techniques. All results as well as the signal are displayed on a CRT. Furthermore, a permanent record of the data can be generated on paper tape, which can be reentered and processed at a later date. A communications interface allows transmission of the sampled signal to a large scale re-mote computer. The system was tested extensively in the laboratory, and field tested at the York Canyon Coal Mine. These tests proved the feasibility of operation in the mining environment. Results indicate that further investigation and development will have to be undertaken to fully develop the potential of this system in satisfying the goals of this research.

Jan 1, 1973

By Carlon S. Land

The Bureau of Mines investigated the influence of a free gas saturation on oil recovery by water drive. A digital computer was used to calculate the combined oil recovery from solution-gas drive to various states of depletion. Results of these calculations are compared and optimum conditions for the maximum oil recovery are found for various fluid-rock systems. For most of the fluid-rock systems, the calculations show an optimum gas saturation other than zero. Using fluid and rock properties as parameters, graphs are plotted showing the optimum gas saturation and increase in oil recovery brought about by the gas saturation. The effects of fluid properties and relative permeability on the optimum gas saturation are seen in these graphs. The graphs can be used as guides in connection with other considerations in determining the optimum time to start a waterflood. They should also be helpful in determining the MER of a water-drive reservoir. The effects of compressibility and solubility of the trapped gas saturation are investigated for select cases using a backward difference scheme to solve the partial differential equation of three-phase flow. From these calculations, it is observed that some benefit of a gas saturation remains for injection pressures up to 1.5 times the original bubble-point pressure.

Jan 1, 1974

By J. K. Whyatt

During the past 2 years, U.S. Bureau of Mines (USBM) researchers reviewed an in situ stress investigation conducted in 1977 at a test site on the 4250 level of the Lucky Friday Mine, Mullan, ID. Although the field measurements of over core strain were found to be useful, significant deficiencies were found in the stress field estimation procedure. The stress field estimate was then updated to incorporate recent progress in statistical capabilities and new understanding of stress concentration factors for doorstopper cells, as well as to correct an error in the original stress solution procedure. Simple models were used to examine the possibility that systematic variations in material properties and stress fields existed at the site. These models succeeded in reducing the sum of squared error somewhat, but fell short of completely describing stress variations throughout the test site. This overcore measurement will be supplemented by two other measurements described in the second and third reports of this series. Other observations of stress field characteristics are discussed in the fourth report The final report will also characterize the natural in situ stress field in the vicinity of the Lucky Friday Mine. This work was undertaken to support USBM research on mining method design and rock-burst control for deep mines.

Jan 1, 2010