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By D. R. Torgoson, Th. G. Sahama

"This paper contains some new thermodynamic data for silicates in the series Mg2SiO4-Fe2siO4 and MgSiO3-FeSiO3 and gives the results of a thermodynamic attack on the problems of stability end parageneses.. Although some data are lacking satisfactory agreement with mineralogical and petrological observations is indicated.The use of thermodynamic methods in mineralogy and petrology has been rather limited, because accurate thermal data, especially for the more complicated and more important rock-forming minerals, have been too scanty to permit any systematic application to problems in those fields. It is, nevertheless, a fascinating task to investigate to what extent the mode of occurrence and the stability relations of the minerals and mineral parageneses, as revealed by petrological and mineralogical observations, agree with predictions of thermodynamics. At the present stage of development calorimetric data are needed for most of the abundant silicate minerals.Measurement of the heats of solution in hydrofluoric acid of minerals in the series Mg2SiO4-Fe2SiO4 and MgSiO3-FeSiO3 affords a ready means of obtaining their heats of formation from the oxides. Combination of such data with entropy and heat-capacity values gives a means of obtaining free energies of formation from the oxides, which, in turn, are connected di¬rectly with stability and paragenoses.The two silicates of magnesium, Mg2SiO4 and MgSi03, occur as rock-forming constituents as forsterite and clinoenstatite or enstatite. The orthosilicate (forsterite) forms a series of isomorphic mixtures with ferrous-orthosilicate (fayalite). The continuity of this series, suggested by petrological observations, has boon proved experimentally by Bowon and Shairer.4/ The present work shows that those minerals constitute a series of perfect solid solutions - that is, a series of solid solutions for which heats of formation from the individual pure silicates, Mg2Si04 and Fe2SiO4, aro negligibly small.The metasilicates of magnesium and iron also form an isomorphic series. However, this series differs from the forstorito-fayalite series in the fact that the most iron-rich mixtures, between about En10Fs90 and pure Fs, appear to be unstable with respect to the paragenesis iron-rich olivine plus quartz. The supposed instability of pure FeSiO3 as a crystalline compound, at least at high and at moderate temperatures, is remarkable, as no crystal struc¬tural reason for such instability is apparent. The present work indicates, also, that these minerals form a perfect series of solid solutions and throws additional light on the instability question.In the following, the samples used in this investigation will be described. For each of the natural olivines and orthopyroxenes, with the exception of sample L, a chemical analysis was made of the purified and actually used fraction. All the analytical work was carried cut by Oleg v. Knorring, and the specific gravity determinations, by moans of a pycnomctcr, by Oiva Joensuu, both of the University of Helsinki, Finland. The determinations of the optical properties were made by Mrs. Toini Mikkola, of the Geological Survey of Finland."

Feb 1, 1949

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. A senior advisory staff, consisting of the Chief Staff Officer, Chief Scientist, and Chief Mining Engineer, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaisons with other government agencies, mineral industries, and professional societies. Bureau program activities are classified into two major functions: (1) Developing new and improved technology that will make the production and processing of minerals more efficient, safer and more healthful for mineral workers and the public, and more compatible with a quality environment.

Jan 1, 1979

By C. B. Manula

This report is volume 7 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design. Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation," and ventilation. This volume of the final report describes the Rail Haulage subsystem of the Master Design Simulator. This subsystem can be used as a free standing model or can be linked to the Production subsystem to provide rail haulage capability. Complex rail haulage systems can be realistically simulated with this model. This report includes complete instructions for operating the subsystem as well as a program listing. In addition, a case study is included which illustrates the application of the subsystem when linked to the production subsystem.

Jan 1, 1974

By Paul Hatmaker

Lime was a highly useful commodity thousands of years before the simple chemistry of its manufacturing process was known. The employment of lime for agriculture, building, and even certain essentially chemical purposes is so old that its origin is among the unrecorded details of man's first ventures into the manufacture and use of prepared substances. Lime is a most versatile material and consequently has come to be widely utilized in modern civilization. Immediately before the depression of the early 1930's the annual production of lime in the United States was more than 4 million tons, valued at 33 to 42 mil-million dollars. This output was sold to many industries, so many that mere enumeration becomes tedious.

Jan 1, 1934

By J. H. East, D. Harrington

"INTRODUCTION Mining at its best is not a clean occupation for either surface or underground employees; and this applies alike to coal, metal, and non-metallic mines. The employees are handling minerals that have been blasted, or broken by some means and are subjected to mineral dust, whether it is coal, quartz, or talc. The employees usually wear clothes specifically adapted to the work in which they are engaged, and frequently these clothes are not suitable for use away from the mine. Many mines are wet, and employees must wear rubber boots to remain at least partly dry, and even on relatively dry mines, some parts of the mines usually have water falling from overhead, there are accumulations of water, or the floor or other surfaces are wet or muddy, Some mines are dusty, and the air-borne dust quickly settles on the clothes and body of the miner, especially, when he is working in confined areas, or in places that are hot, humid, or poorly ventilated. Most occupations around a coal tipple, anthracite breaker, or a mill at a metal or nonmetallic mine have their own problems of cleanliness as to skin or clothes or both. Mining in any of its phases is inherently dirty work, and the employees dress accordingly while at work.In the early stages of mining it was the custom or workers to wear their dirty clothes home and change there. This necessitated their going home after work in dirty clothes which were usually damp from perspiration or from contact with wet or muddy matelials or surfaces, and, in addition to being inconvenient this was a frequent cause of colds, pneumonia, other pulmonary diseases or, possible skin ailments. Men working in very wet mines found that it was more satisfactory to change into dry clothes in the boiler room at the mine after work and allow their wet clothes to dry overnight. The mining companies later provided the first of the so-called ""dry-houses"" which were heated but had, few, if any, conveniences, such as showers, lockers, or latrines. The miners changed into dry clothes after work, but would not bathe or ""clean up"" until they reached their homes. Later, progressive mining companies provided bathing facilities for the employees, and eventually the present modern wash and change houses were evolved. Unfortunately, many mines, still have no bathing accommodations, and many have only makeshift accommodations."

Dec 1, 1947

By W. D. Mcmillan

Important reserves of nickel ore occur in the Levies district in Oriente, Cuba. The area is mountainous and mostly covered by heavy vegetation. The ore bodies comprise surface tracts of nickeliferous laterite underlain with decomposed serpentine of ore grade. The Cuban Nickel Co., a wholly owned United States Government corporation, owns a plant for leaching the nickel from its ores at Nicaro, Oriente, Cuba, Between December 1943 and March 31, 1954, 5,902,225 short tons of ore was treated, with a recovery of 116,206,519 pounds of nickel (52,711 metric tons). In 1953, 1,330, 224 short tons of ore was mined and 27;"3,129 pounds of nickel produced. The Cuban Nickel Co. also owns a townsite, with the necessary facilities, mining equipment, and 11 miles of railroad. Ore for the plant has been produced from the Ocujal-San Juan claims on lends owned by the Nicaro Nickel Co., a sub¬sidiary of Freeport Sulphur Co. The Government enterprise is man-aged by the Nickel Processing Corp. The Cuban Nickel Co. has denounced mineral concessions and has purchased other claims from private owners.

Jan 1, 1955

By Stanley A. Feitler

This Bureau of Mines report deals principally with the resources and economic aspects of feldspar in the United States east of the Mississippi River. Although in a strict sense, all phases of the feldspar industry affect its economic structure, emphasis in this study is on supply, demand, and marketing. Although feldspar was originally mined for use in the manufacture of pottery and other ceramics, the glass industry, which began to use feldspar in the mid-1920's, now consumes more than half of the annual output. Most mining is open cut, and the methods used are similar to those used in mining crushed b stone. Excess plant capacity has been chronic, and production is usually about 30 percent of capacity fur the industry as a whole. Since 1947, feldspar consumption has grown more slowly than the average for all U.S. industry. This has fostered intense competition, especially for the glass market. Prices have not kept pace with inflation, and profits are small. The trend of consumption through 1970 for glass feldspar is expected to be upward; less rapid in consumption of ceramic feldspar is anticipated.

Jan 1, 1967

By Frank E. Williams

Nuclear detonation data were accumulated, studied, and evaluated by the Bureau of Mines to visualize how nuclear explosives might be used in a shale?-oil industry, The evaluation shows that the Green River Formation at the semi-isolated locale of Piceance Creek Basin, in northwestern Colorado; is thick and widespread enough to warrant consideration of nuclear mining in lieu of conventional methods, Because cost data for nuclear explosions are limited; cost comparisons are made largely by assumptions. Also described are the history of the shale-oil industry, the geology and size of oil-shale resources; and conventional mining methods and processing technology.

Jan 1, 1969

By D. Oyler

The National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Research Laboratory (PRL), RAG Pennsylvania and Strata Control Technologies of Australia collaborated in an intensive study of ground behavior, reinforcement performance, and stress redistribution at the Emerald Mine in Southwestern Pennsylvania. The study site was a longwall tailgate subjected to a severe horizontal stress concentration. Field measurements indicated that the stresses applied to the study site nearly doubled during longwall mining, resulting in roof deformations extending to a height of 4.8m (16 ft) above the entry. A computer simulation of the field site was conducted using FLAC-2D, incorporating a broad range of rock behaviors and failure mechanisms. Comparison between the measurements and the simulation showed that the model was able to capture the most significant aspects of the roof and support system behavior, particularly, the extensive slip along bedding that created a partially destressed "softened" zone in the immediate roof. The model also showed that supplementing the normal roof bolt support pattern with cable bolts would allow the entry to survive a further 20-25% increase in the applied horizontal stress. Such information could have very practical application to the design of roof support systems for coal mines.

By S. H. Ash

THE MAGNITUDE of the anthracite industry's drainage problem in the Lackawanna River drainage area is realized when it is known that in 1948 the 27 pumping plants in this region pumped over 48 billion gallons of water to the surface from the mines in the Lackawanna Basin of the Northern field. This is almost 92,000 gallons per minute pumped against an average hydrostatic head of over 300 feet for that year. By comparison, Lake Wallenpaupack, the largest artificial body of water lying wholly in Pennsylvania, contains 71 billion gallons of water in its 24-square-mile area: the volume of water pumped from the mines in the Lackawanna Basin during 1948 was approximately 68 percent of that impounded in Lake Wallenpaupack. The Lackawanna. River and its tributaries drain a troughlike area of 345 square miles. The synclinal axis of this trough lies within the coal measures. All surface drainage into the valley must traverse some part of the coal measures. On the basis of 45.03 inches of rainfall recorded by the Scranton station of the United States Weather Bureau for 1948, the runoff from the Lackawanna River drainage area during that period was 135 billion gallons, approximately three times the volume of water pumped by all mine pumping plants in the Lackawanna. Basin of the Northern field during 1948. In other, words because of the pervious condition of the strata overlying the mine workings, approximately one-third of the total runoff in the Lackawanna River drainage area becomes mine water. This report, reveals that less than 7 percent of the 72 miles of pervious stream beds examined between Archbald and Pittston have been unproved.

Jan 1, 1952

By Joseph B. Cummings

"INTRODUCTION The property was first examined by an engineer 3/ of the Bureau of lanes in December 1942 and was later investigated by the sane engineer in January and February 1943. Prominent outcrops and underground exposures of high-grade iron ore, together with mention of sizable intersections of hematite in logs of four widely scattered churn—drill holes, indicated the possible occurrence of a substantial tonnage of iron ore at this old copper producer.From March to May 1943, detailed topographic and geologic mapping of the property was done by the Federal Bureau of Mines, the Federal Geological Survey, and the Arizona Bureau of Mines.Funds were allotted for exploration of the property by churn and diamond drilling. This work was started in December 1943 and completed in June 1944.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Nines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts, developed by each exploratory project as soon as practicable after its conclusion. The Mining Drench, Lowell B. Moon, Chief, conducts preliminary exmination, performs the actual exploratory work, and prepares the final report, The Metallurgical Branch, P. G. Knickerbocker, Chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision Dr. R. S. Dean, Assistant Director."

Dec 1, 1946

By Stanley A. Feitler

This Bureau of Mines report deals principally with the resources and economic aspects of feldspar in the United States east of the Mississippi River. Although in a strict sense, all phases of the feldspar industry affect its economic structure, emphasis in this study is on supply, demand, and marketing. Although feldspar was originally mined for use in the manufacture of pottery and other ceramics, the glass industry, which began to use feldspar in the mid-1920's, now consumes more than half of the annual output. Most mining is open cut, and the methods used are similar to those used in mining crushed stone. Excess plant capacity has been chronic, and production is usually about 50 percent of capacity fur the industry as a whole. Since 1947, feldspar consumption has grown more slowly than the average for all U.S. industry. This has fostered intense competition, especially for the glass market. Prices have not kept pace with inflation, and profits are small. The trend of consumption through 1.970 for glass feldspar is expected to be upward; less rapid growth in consumption of ceramic feldspar is anticipated.

Jan 1, 1967

By J. Koster

In the western United States occurs deposits of low-grade chromite which, when concentrated, may be reduced to ferrochromiun in electric furnaces that derive energy from dams and hydro plants now in course of construction. Montana ore was chosen for the experiments. A 1-ton sample contained 26 percent Cr203, 17 percent Fed, and 17 percent SiO2, plus other constituents, and the concentrates therefrom assayed 44 -percent Cr203, 23 percent FeO, and 0,79 per cent SiO2, Gravity concentration was found to be the best method. Ferrochromiums are of two grades - high-carbon with 66 to 70 percent chromium and 4-112 to 6 percent carbon and low-carbor with 67 to 72 percent chromium and 0.6 to 2 percent carbon. Both are made in electric furnaces that use anthracite as a reducer and suit-able fluxes. The concentrates mentioned mere smelted under different conditions, and it was concluded that domestic ore could be reduced with anthracite to produce a ferrochromium of S to 10 percent carbon content at yields of 90 percent without re-treating the slag. This carbon may be lowered to required proportion with calcium and silicon, but the former requires a great excess and the latter leaves an alloy high in silicon. INTRODUCTION Chromite occurs in several regions of the United States, but the known deposits of this mineral have not been large enough or high grade enough to permit them to compete under normal conditions with imported ores. There are numerous deposits of chrome ore along the West coast. These are generally conceded to be relatively small, although some were worked during the World War. There are some indications of a revival of interest in California chromites. Montana contains large chromite deposits in Stillwater and Sweetgrass Counties. The utilization of chromite for ferrochromium and. the manufacture of stainless steels is distinctly an electrometallurgical problem; consequently, a study of methods for treatment of chromite might pave the way for the establishment of new electrometallurgical industries in the Western States. This thought is supported by the cheap power that is soon to become available from the western dams, Farther, submarginal domestic chrome deposits might thus be turned into profitable producers.

Jan 1, 1936

By J. Koster

In the western United States occurs deposits of low-grade chromite which, when concentrated, may be reduced to ferrochromiun in electric furnaces that derive energy from dams and hydro plants now in course of construction. Montana ore was chosen for the experiments. A 1-ton sample contained 26 percent Cr203, 17 percent Fed, and 17 percent SiO2, plus other constituents, and the concentrates therefrom assayed 44 -percent Cr203, 23 percent FeO, and 0.79 per cent SiO2, Gravity concentration was found to be the best method. Ferrochromiums are of two grades - high-carbon with 66 to 70 percent chromium and 4-112 to 6 percent carbon and low-carbor with 67 to 72 percent chromium and 0.6 to 2 percent carbon. Both are made in electric furnaces that use anthracite as a reducer and suit-able fluxes. The concentrates mentioned mere smelted under different conditions, and it was concluded that domestic ore could be reduced with anthracite to produce a ferrochromium of S to 10 percent carbon content at yields of 90 percent without retreating the slag. This carbon may be lowered to required proportion with calcium and silicon, but the former requires a great excess and the latter leaves an alloy high in silicon. INTRODUCTION Chromite occurs in several regions of the United States, but the known deposits of this mineral have not been large enough or high grade enough to permit them to compete under normal conditions with imported ores. There are numerous deposits of chrome ore along the West coast. These are generally conceded to be relatively small, although some -were worked during the World War. There are some indications of a revival of interest in California chromites. Montana contains large chromite deposits in Stillwater and Sweetgrass Counties. The utilization of chromite for ferrochromium and. the manufacture of stainless steels is distinctly an electrometallurgical problem; consequently, a study of methods for treatment of chromite might pave the way for the establishment of new electrometallurgical industries in the Western States. This thought is supported by the cheap power that is soon to become available from the western dams. Farther, submarginal domestic chrome deposits might thus be turned into profitable producers.

Jan 1, 1936

By R. Craig Smith

This report presents the software documentation for PREY AL, a prefeasibility mineral property evaluation program developed by the U.S. Bureau of Mines on a Lotus 1-2-3 spreadsheet. It is presented in a step-by-step "user?s manual" format. Appendixes contain the technical assumptions, program default values, and a summary printout detailing capital and operating costs and cash-flow analysis.

Jan 1, 1992

By James R. Dunn

Samples were taken of industrial mineral waste materials which are potentially capable of being used for filling underground coal mines for subsidence control in the Pittsburgh and the Scranton-Wilkes Barre areas of Pennsylvania. The samples were subjected to potentially relevant standard tests which are commonly used 1n the evaluation of soil materials and mineral "aggregate materials. Measurements of plasticity, liquid limit, and gradations, particularly in the -200 mesh size range, indicated a comparative lack of clay minerals. Cementitious reactions between sources of alkali, such as calcium hydroxide or portland cement stack dust, and of silica, such as clay or fly ash, were found to occur in various mixes of high-bulk materials. Strengths of up to about 400 psi at 84 days were observed. The possibility of emplacement of high-bulk material by both turbid flow (or density currents) below water and by mud flows above water were considered and both appear to be reasonable and possibly simpler than the current mechanisms of emplacement.

Jan 1, 1977

By Lorraine B. Burgin

This study by the Bureau of Mines documents the leadtime required for preliminary and detailed exploration, development of the mine, and construction of beneficiation and support facilities for selected copper deposits in Arizona. The time for major exploration ranged from 1 to 15 years, time for open pit development (or construction) was 1 to 4 years, and time for under- ground development was 4 to 8 years; one underground mine presently being developed may require 12 years to achieve production. Construction of the beneficiation plants required 8 months to just over 2 years. The data are supported by historical facts for each deposit during the leadtime stages from location of claims through exploration, construction, expansion, and leaching. The sequence of development and factors contributing to differences in the time spans are discussed. Histories are detailed for the Miami, Castle Dome, Copper Cities, San Manuel-Kalamazoo, and Twin Buttes properties; briefly summarized are the Pinto Valley, Miami East, Esperanza-Sierrita, Pima, and Mineral Park Properties. Each mining operation had its own pattern of development, and together they present a source of planning information for the development of other properties.

Jan 1, 1976

By G. R. Fitterer

In the manufacture of steel by any process the refining period involves the partial elimination of the metalloids carbon, manganese, phosphorus, and silicon, by virtue of their reactions with ferrous oxide. At the end of this refining stage the metal consists chiefly of iron in which small amounts of these materials are dissolved. Unless some deoxidizer is added to the steel at this time, the reaction between carbon and ferrous oxide will continue with such force that it is impossible to form sound steal in the ingot molds. Instead, the product will exhibit a marked porosity due to the formation and trapping of carbon monoxide-the product of the reaction mentioned. However, if deoxidizers are added, steel may be obtained which is dense and free from gas bubbles. At the same time the deoxidation products will remain in the steal as impurities. For example, silicon additions form Si02 or combinations of Si02 and FeO. Additions of manganese form deoxidation products consisting of various proportions of MnO and FeO. It is also quite obvious that simultaneous additions of manganese and silicon will form oxide combinations either in the binary system MnO-SiO2 or in the ternary system FeO-MnO-SiO2. Work at the Pittsburgh Experiment Station of the United States Bureau of Mines, in cooperation with the Carnegie Institute of Technology and the Metallurgical Advisory Board, involved the study of such deoxidizing reactions and their products. In this connection considerable information is necessary concerning FeO, MeO, Si02, and Al 203, and their various combinations. Some of the most needed data are the melting points of all of these materials. At the outset of this work ordinary methods of melting point determinations were found to be inadequate for various reasons, and the procedure finally selected involved the use of the micropyrometer with occasional corroboration by quenching methods, The reasons for this selection, together with a description of the apparatus, are given in the following pages.

Jan 1, 1932

By Paul M. Ambrose

Overall the domestic abrasives industry had one of its best years in 1965. Production and value of all commodities increased over that of 1964 which also was a good year. Production of tripoli that was down in the previous year rebounded and production from two new mines was reported. Plant capacities for production of silicon carbide and fused crude aluminum oxide and production from plants in the United States and Canada increased, but demand was high and yearend stocks were less than at the end of 1964. Foreign Trade.-Increases in value of most imports of abrasive materials in 1965 were offset by a decrease in the value of imported industrial diamond. Production of fused aluminum oxide and silicon car-bide in the United States and Canada and imports of these commodities into the United States increased, but combined exports of finished grain of these materials was virtually unchanged from the previous year.

Jan 1, 1966

By C. B. Manula

Simulation continues to hold the spotlight among the Operations Research applications in the operational side of mining. One reason for this is the need to solve the many waiting line and storage problems common to the industry. A second reason for using simulation is the central requirement of retrospect testing. Acceptance of a model by management is more likely to depend on its tested performance rather than on the underlying validity aspects of the model itself. Mathematics have not been and may not be developed that will allow all desired system elements to be considered simultaneously. It is in this realm that simulation bridges the gap between theory and useful design procedures. One of the earliest published accounts of simulation at work in the coal industry is demonstrated by the application cf Monte Carlo methods to explore changes in future operating policies for an existing track system (Manula, 1963). By modifying certain control parameters, revision in design changes were evaluated in the computer rather than in the actual production section. A second application which has found wide use in practice is the VFI-OCR Face Simulator (Prelaz et al., 1968). The model developed here has the purpose of allowing the comparison of methods for room-and-pillar face operations end observing their effect on mining prior to actual installation. Proposed changes are tried in the model and the best of these are selected as a guide for better mire management: IBM's own simulation package, the System 360 General Purpose Simulator, has experienced heavy use in solving similar problems and other steady-state situations.

Jan 1, 1974