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By J. B. Gayle

Oven widths for experimental and commercial slot-type ovens differ appreably in most instances; the experimental ovens usually ranging from 10 to 14 inches and the commercial units from 14 to 21 inches. Application of results obtained with experimental ovens to commercial practice thus requires major extrapolations. A critical survey of the literature indicated that sufficient information about the effects of variations in oven width on the carbonizing process is not available to permit such extrapolations to be made with any considerable degree of confidence.

Jan 1, 1960

By N. J. Olson, G. W. Toop

A regular solution is characterized by a finite molar heat of mixing and entropy due only to ideal or random mixing. The thermodynamic properties of binary regular solutions which exhibit constant atomic coordination number and constant atom-atom intefac-

Jan 1, 1967

By V. F. Parry

The object of this report is to present certain pertinent data on the physical and chemical properties of South Arcot lignite and to present the results of several special tests to show how the raw lignite can be upgraded to superior fuels for certain special uses. The Bureau of Mines Branch of Coal Technology laboratories at Denver have advocated the drying and carbonization of all low-rank fuels for special uses and have introduced and developed new techniques for upgrading and refining noncoking coals. Application of these techniques to the South Arcot lignites was the object of the investigation, and this report presents significant data necessary for planning a fuel program based on utilization of dried and carbonized dusts. In general, the South Arcot lignite is similar in chemical properties to the high-moisture lignites found in the United States and has some physical properties similar to Australian brown coals. The samples submitted for test had lost moisture before delivery to the laboratory, and it has been necessary to estimate the analysis of the lignite in place in the mine. Various observations made in India by qualified technicians indicate that the bed moisture content of the entire seam is in the range of 54 to 56 percent. For estimating purposes in this report, the bed moisture content has been taken as 56 percent and the ash content of the fresh coal as 2.5 percent. The average analysis estimated for the as-mined lignite is: [Moisture percent 56.0 Volatile matter do.22.0 Fixed carbon do.19.5 Ash do.2.5 Heating value B.t.u. per lb. 4,890]

Jan 1, 1957

By R. R. Lowery

An analysis of three 1-1/4-diam manufactured wire ropes of 6x19 classification was done to identify and describe reference conditions of new rope. Reference condition is of value when examining tested or retired ropes. Measurements of strand and rope pitch and of wire and rope diameter confirmed adherence of all ropes to those construction specifications. Mechanical properties of strength and ductility were determined by accepted methods for the ropes and wires from the ropes. Individual wires from one rope failed to meet minimum wire ductility values. Wire chemical composition varied in average carbon levels, from 0.70 to 0.78 wt pct, and in manganese content, from 0.45 to 0.80 wt pct. One manufacturer's product contained 1 to 3 wt pct Ni and Cr. Heavily wrought pearlitic steel microstructures were porous and contained inclusions. Cold work variations were evidenced by wrought grain width. Recorded anomalies reflected the condition of the manu-factured products. The report provides data that compare the three wire ropes studied, but cannot verify the effects that these conditions or anomalies have on rope service life.

Jan 1, 1983

By Robert M. Becker

Part 5, the last of this series, deals with the theoretical confirmation and application of results developed in parts 1 and 2. The bulk-sampling variances of Hassialis and Kassel and Guy are compared with those in part 2, both as to formulation and as applied to ores and coal. The results provide confirmation for much of the development in part 2. Examples are presented for determining the reliability of bulk samples with respect to various measurable characteristics. These characteristics include, for example, assays for elements or compounds and particle surface area. The bulk samples considered consist either of a given weight, a given volume, or a given number of particles. In addition to problems of sample reliability, some of these examples may also be applicable to quality control. Several possible applications of results developed in parts 1 and 2 are outlined. These include tests for random data, degree-of-mixing indices, and particle-fineness indices.

Jan 1, 1966

By Carl Fisher

A microseismic roof fall warning system was field tested in Western and Eastern coal mines in the United States to better define the capabilities and limitations of the microseismic method in predicting roof fall. Microseismic event and energy type data were obtained and documented for twenty-three coal mine roof falls, Field test results indicate that both the microseismic event and energy methods, as applied in this development effort, have a high probability for successful application in a commercially practical roof fall warning system. Based on the results and experience obtained during field testing, a commercial prototype microseismic roof fall warning system was designed and constructed. Although it was the intent of the program to field test the commercial prototype system, delays in equipment fabrication and contract time limitations did not permit field testing.

Jan 1, 1980

By P. G. Winchell, M. Cohen, J. Woodilla

The kinetics of stabilization have been studied with respect to the isothermal component of the martensitic reaction in ivon-nickel alloys. Although the carbun (or nit-vogen) content may be very low in these alloys, it plays an important vole in the stabilization phenomenon. In fact, if these interstitial elements are removed by moist-hydrogen treatment, no evidence of stabilization is found. In the pvesence of 0.007 wt pct C, the activation energy for the stabilization process is comparable to that -for the diffusion of carbon (or nitrogen) in ferrite) rather than in austenitc. This suggests that the interstitial diffiision controlling the stabilization occurs within the martensitic embryos rather than in the matrix of the parent phase. The kinetics furthev indicate that the interstitial atoms tend to diffuse -from the embryos toward the suvroundings, thereby immobilizing the interface. This appears to be the origin of the stabilizing effect -found in these alloys. PHILIBERT' has shown recently that interstitial elements play an important role in the stabilization of martensitic transformations in iron-base alloys. However, determination of the temperature dependence for this stabilization process has produced values (- 11,000 cal per mol) that cannot be readily identified with the activation energy for diffusion of carbon (or nitrogen) in either ferrite or austenite. In the present work, the isothermal mode of the martensitic reaction was employed to derive the activation energy for stabilization, and this was found to agree fairly well with that for diffusion of carbon (or nitrogen) in ferrite. An iron-nickel alloy with 30.8 wt pct Ni and 0.007 wt pct C was used in these experiments, the specimens being in the form of rods 0.074 in. in diam and 2 1/2 in. long. The specimens were sealed in evacuated vycor tubes and austenitized at 1100°C for 1/2 hr prior to quenching in water. A second series of specimens was decarburized (and denitrogenized) prior to the above austenitizing treatment by annealing in moist hydrogen for 182 hr at 1215°C. In order to achieve a "standard" condition in the austenitic state, all the specimens were transformed to martensite by cooling to - 195°C before the final austenitizing. Both the 0.007 pct C and the decarburized series then had an Mi temperature of about - 30°C. The isothermal martensitic transformation was carried out at a reference temperature of -88"C, and was traced by means of electrical resistance measurements. Each resistance value was normalized by dividing by the resistance of the austenitic specimen at O°C, thus giving a resist- ance ratio R. The rate of decrease of the resistance ratio (-dR/dt) provided a measure of the transformation rate. It was found that a plot of R vs log t at the reference temperature resulted in a slightly curved line which could be closely approximated by two straight lines intersecting at a time of 10 min, as shown in Fig. 1. If G = dR/dlogt is the linear slope of either straight segment, the rate of transformation at any given time is: The ratio of G for 1 less than 10 min to that for t greater than 10 min was 1.19 for the 0.007 pct C series and 1.24 for the decarburized series. These ratios made it possible to compute the transformation rate at any time greater than 10 min, knowing the transformation kinetics prior to 10 min. The stabilization treatment was introduced by up-quenching from the reference temperature, usually after 10 min of isothermal transformation: to one of four stabilizing temperatures between 0" and 22"C. After holding for various times, the specimens were down-quenched to the reference temperature for additional isothermal transformation. In this way, it was possible to compare the transformation rate (- dR/dt), immediately after stabilization with the transformation rate (- dR/dt)U in the unstabilized condition. The degree of stabilization was defined as: Ordinarily, Gs and Gu would be measured after the same time of prim isothermal transformation.

Jan 1, 1960

By William I. Nissen, Richard Havens

Continuous flotation studies were made at a 50 - lb - per - hr feed rate to confirm the effectiveness of a batch - scale procedure for concentrating phenacite and bertrandite minerals from Mount Wheeler ores that contained , in percent , 0.47 , 0.78 , and 4.7 BeO . The procedure for selective froth flotation of the beryllium minerals from a gangue composed chiefly of calcite , fluorite , and mica comprised closely controlled preconditioning with sodium fluoride and sodium hexametaphosphate in a series of small mechanically agitated tanks and use of a mixture of oleic acid with kerosine , fuel oil , or turpentine as a collector . It was difficult to adapt the laboratory flotation procedure to continuous operation . The principal problem of achieving adequate conditioning to depress calcite and fluorite ultimately was resolved by conditioning in series . Thereafter , three ore samples of different grades treated on a continuous basis yielded concentrates containing from 12 to 25 percent Beo from these relatively complex and difficult ores . Recoveries , on a BeO basis , ranged from 75 to 88 percent . Losses , which primarily were due to incomplete liberation , probably could be lowered in a commercial operation .

Jan 1, 1964

By A. T. Coumbe

The first national survey covering sales of fuel oil by States and principal uses was made in 1926 by E. B. Swanson of the Bureau of Mines (then under the U. S. Department of Commerce) under a cooperative agreement with the American Petroleum Institute. This annual study, covering the market for fuel oil, was made through 1930 with the financial help of the institute bat has since been continued by the Bureau up to the present time. The scope and coverage of the survey have gradually changed over the years as new uses for fuel oil have been found and new products have come into importance resulting in market expansion. Range oil (No. 1 fuel oil or kerosine) came into use for cooking and space-heating daring the depression era in New England, and it was first reported as a total in the 1931 survey. In 1934 the sales were compiled on a State basis. State totals for distillate fuel oil, Diesel fuel, and residual fuel-oil sales were first shown for 1934 and by principal uses and States in 1937. Kerosine deliveries by States and main uses were also released for the first time in 1937.

Jan 1, 1952

Declines for both access and rock haulage are replacing shafts for mining relatively shallow deposits of down to 1000 m below surface. Where the orebody does not outcrop and where surface access may be restricted, it is often necessary to drive long dead end headings before a connection can be made back to surface and a ventilation circuit created. In hot tropical areas and where large diesel powered equipment is used for mining, heat may also be a problem at these relatively shallow depths. The normal design criteria based on statutory limits and good practice used to evaluate ventilation and cooling requirements in terms of air velocity, dust, gases, diesel exhaust dilution, re-entry after blasting and heat stress are described in this paper. These are then used to design and cost alternative auxiliary ventilation systems that include leakage based on general fan performance curves and typical duct systems. The implications of the current European Community recommendations regarding nitrous fumes are also briefly considered. The actual problem relates to a 2100 m long decline that may have to be extended to 3000 m long without a connection to surface or through ventilation and is located in a hot tropical area where the surface wet bulb temperatures may exceed 25¦C for more than a third of the summer period. Once the preliminary ventilation design is completed, the auxiliary ventilation system can be modelled and simulations undertaken that incorporate heat and moisture transfer routines with the objective of determining the cooling load and amount of refrigeration required. Cognisance is taken of cyclic diesel operations and the thermal flywheel effect of the surrounding rock on the wet and dry bulb temperatures resulting from these operations.A suitable modular cooling system located at the portal is described and optimised with capital and operating costs of both the ventilation and cooling systems provided.

Jan 1, 2005

By T. Narita

The diffusion barrier coating system (DBC system) was designed to suppress interdiffusion between alloy substrate and coatings in addition to ensuring slow oxide growth at high temperatures. In this report the concept of the DBC system will be introduced, and the results obtained for various heat-resistant alloys are presented. In this DBC system the s-phase of the Re-Cr-Ni system was selected as the barrier and is formed by electroplating Re-Ni and Ni films from aqueous solutions, followed by Cr and/or Al pack cementations. A typical DBC system consists of Ni-base superalloy / triple s-Re based alloy layer / ?’-Ni3Al and/or ß-NiAl (with or without Pt addition) / a-Al2O3. It was found that the DBC system maintained its structure for long time exposures because the s phase has tie-lines with the ? and ?’ alloy substrate and the ?’ and/or ß coating. The s-Re based alloy can suppress both the inward Al diffusion and the outward diffusion of alloying elements. The DBC system was successfully applied to various heat-resistant alloys such as Ni-Mo and Fe-Cr-Al based alloys, and these alloys with the DBC system were creep-deformed slowly under external applied stresses. A simultaneous diffusion coating process for Al and Hf was developed using Hf+NH4Cl+Al2O3 pack cementation. To obtain reliable and long-life coatings the combination of alloy substrate, coating, and external scale should be considered as a total system, to optimize oxidation resistance, structural stability, and mechanical properties.

Jan 1, 2010

By David D. Hottinger

Only a minimum amount of illumination is generally provided for many types of mobile surface mining equipment. This condition presents a hazard to operating personnel working on and around such equipment. To reduce this hazard MSHA has proposed safety regulations requiring minimum levels of illumination for hazardous zones on and in the immediate area surrounding surface mining equipment. This report describes a Bureau of Mines sponsored project demonstrating the feasibility and effectiveness of providing dragline illumination in compliance with the proposed MSHA regulations. A description of the computer aided design, on site installation and field evaluation of individual lighting systems for each of three different size draglines is presented

Jan 1, 1981

By C. Babcock

When a flat-lying mineral deposit such as a coal seam is mined, some coal is left to separate the roof and floor so that miners and machines can safely mine the seam. The mineral left is in the form of mine pillars. If too much is taken, support problems and unsafe working conditions result. If too little is taken, the mining operation will be unable to compete economically with other mines. Therefore, one must select pillars of the optimal size to maximize mining recovery and minimize risk to miners and equipment. Later, if the pillar support is no longer needed and the surface can be allowed to subside the thickness of the coal seam, then the pillar support can be removed to increase mining recovery, and initial pillar size is not as critical. Only a small part of the information available on pillar design can be presented here. The purpose of this report is to summarize some of the work done by the U.S. Bureau of Mines and others on pillar design, which is reported in the literature from 1833 to the present, and present rock mechanics test results that aid in understanding mine pillar behavior. The variable names used are those of the authors cited. This results in multiple use of some variable names.

Jan 1, 1994

By K. F. Anderson

The increasing number of oil-productive reservoirs in the Ellenburger formation has emphasized the need for information pertaining to the hydrocarbon recoveries that may be obtained from such reservoirs. Most of the space available for accumulating hydrocarbons in the Ellenburger formation is derived from fractures, which makes it difficult to estimate reserves or probable recoveries. The Ellenburger reservoir in the Big Lake field was selected for study because it is one of the few near-depleted reservoirs in the area. The experience gained in operating and developing this reservoir has been and should continue to be a helpful guide to operators both in predicting recovery and establishing methods of development and operation In similar reservoirs. Development and production data were gathered from different sources. The writers have compiled and interpreted these data to estimate the ultimate recovery of hydrocarbons. In addition to the estimates of ultimate recovery, the report contains sample calculations and estimates of theoretical recovery based on different methods of operation. The calculations presented in this report indicate that the Ellenburger reservoir is 95 percent depleted and that the ultimate recovery of hydrocarbon liquid from the oil reservoir and gas cap combined will he 4-0 barrels per gross acre-foot of reservoir rock. An estimated 32 barrels of condensate per gross acre-foot of reservoir rock in the gas cap has been recovered, and the estimated ultimate recovery of crude oil will be 47 barrels per gross acre-.foot of rock in the crude-oil reservoir.

Jan 1, 1954

By C. P. Bowie

"It is well known by all who are familiar with the oil industry in America that the oil pipe line is as fundamentally a part of this industry as the railroad is of most other American industries. The oil pipe line was first introduced about 56 years ago, and since that time has so demonstrated its superiority as a means of carrying crude oil froze the well to the refinery, that this method of transportation has largely superseded all others. This has made possible the building of refineries in or near the large consuming centers, rather than at the wells, which are usually remote from the centers of population.The pipes for conveying the oil are laid on the surface of the ground, or at a depth varying from 18 inches to 3 feet beneath the surface, and the main lines are generally eight inches in diameter. The oil is forced through the pipes by means of pumps operated either by steam or by internal combustion engines. The pump stations are located from 1 1/2 to 90 miles apart, varying with the condition of the country through which the pipe lines extend, and the viscosity of the oil to be handled.Some of the larger pipe-line systems and hundreds of miles in length. It is estimated by the U. S. Geological Survey that the total mileage of oil trunk lines in the United States today is approximately 34,000, and that the gathering systems, which are a fundamental part of the trunk systems, aggregate about 11,500 miles in length, making a total of 45,500 miles.Using those figures as a basis, some general conclusions as to the investment represented will be made. At the time most of the lines were constructed, the average cost per mile based on eight-inch pipe was about $6,500. The cost of the average pump station at that time varied from $130,000 to $250,000. The cost at the present time, on account of the increase in price of labor and materials, would be much in excess of these figures. The fixed investment in pipe lines is, therefore, very extensive. It corresponds closely with the actual cost of the property, and is estimated to be approximately $500,000,000."

Sep 1, 1920

By W. N. Hoskins

This report covers the final results of a two-phase contract study conducted between July 1974 and October 1976. A comprehensive summary of the initial phase of the study is included. Phase I of the study involved the investigation and evaluation of all potential candidate underground systems for mining the deeper deposits of oil shale and associated minerals in the Piceance Creek basin of northwestern Colorado. Phase II called for the refinement and the detailed technical and economic analysis of the most promising system, or systems, thus disclosed. Of the several systems initially investigated and evaluated, four showed considerable merit for exploiting the deeper deposits: (1) chamber and pillar mining with spent shale backfill, (2) sublevel stoping with spent shale backfill, (3) sublevel stoping with full subsidence, and (4) block caving mining using LHD's. Final refinement and analysis of these four systems indicated their technical feasibility over at least part of the range of conditions expected in the deeper deposits. Their economic feasibility also was indicated under certain operating and market conditions. A variety of engineering, production, and cost information is provided on each of these systems.

Jan 1, 1976

By O. C. Blade

This survey report, the first for this type of fuel, is issued to provide information on the characteristics of the burner-fuel oils now manufactured for sale. Reports of surveys of diesel fuel, conducted under a cooperative agreement between the American Petroleum Institute and the Bureau of Mines, United States Deportment of the Interior, have been published annually since 1950.2/ This survey of burner-fuel oils is similar to the diesel-fuel surveys In pattern and has been conducted under an extension of the same agreement at the request of the Oil-Heat Institute of America and the petroleum industry. It is not intended to conflict with the diesel-fuel survey but rather to supplement it. Burner-fuel oils, also specifically referred to as heating oil, range oil, furnace oil, "Bunker C," and fuel oil, are sold in increasing volumes for use in this country and for export. Sales of all grades of fuel oil in the United States have increased from 340 million barrels in 1926Y to over a billion barrels per year. 4/ Distillate fuel oil sales, in proportion to total fuel-oil volume sold, increased from 42 percent in 1950 to 50 percent in 1954. Sales of distillate and the heavier residual oils during recent years are shown: [ ] It must be realized that the data given are not accurate indications of the use of these materials as burner fuels. Some burner fuel, used as range oil, is kerosine, which is not included above. A large volume of fuel oil--approximately 30 percent of the distillate type and some residual fuel oil--is sold as diesel fuel. Smaller

Jan 1, 1955

By R. L. Bruening, N. E. Izatt, S. R. Izatt

The need for selective metal separations has increased as the mining industry encounters more complex ore bodies and demand for higher performance end products expands. The Molecular Recognition Technology (MRT) process uses highly selective SuperLig® resins to remove desired metals from a variety of solutions in the mining and metals processing and recovery industries. MRT separation processes efficiently produce high purity metal products. In this paper, applications of MRT to metal recovery at mg/L to multiple g/L concentration levels are presented and discussed. Specific examples in the precious metal, nickel, cobalt, zinc, copper, and rare earth industries are given.

Jan 1, 2014

By J. M. Singer

Thermal, mechanical, and physical properties of virgin and heat-treated Pittsburgh seam coal were determined as part of a comprehensive study of combustion of monolithic coal block. The information was sought to help characterize pyrolysis and combustion processes in underground coal mine fires but should also prove useful in the study of in situ and surface coal gasifiers. Measured properties include thermal conductivity, specific heat, thermal expansion, density, compressive and tensile strength, porosity, and permeability. The transport property data were obtained (when feasible) in two mutually perpendicular directions of the anisotropic virgin coal material, and coal samples carbonized for 5 hours at temperatures of 350° C, 475° C, 500° C, 650° C, and 850° C. Other coals (Pocahontas No. 3, Sewell, and Illinois No. 6 seams) were investigated for porosity and relative permeability. Interdependence among all properties was evident from the results; however, only a few correlations could be developed owing to inhomogeneity of coal material and specimen variation, which had the effect of reducing the accuracy of measurement and increasing data scatter.

Jan 1, 1979

By G. J. Hartman

The Fort Cady in situ borate mining project involves recovery of boron from a mineral deposit located over 1400 feet below the surface. The resource recovery method is being developed using in situ mining technology employing weak acid solution injected directly into the ore body. As the acid contacts the calcium based ore (primarily natural colemanite), the contained borate values are digested as boric acid. This boric acid solution is then pumped to the surface by use of submersible pumps. At the surface the borate values are recovered as a finely divided solid white powder after a series of chemical reactions and precipitations resulting in the production of calcium borate. The refined product is then sold under the trade name CADYCAL 100.TM All environmental permits for up to a production rate of 90,000 tons per year have been obtained. These permits required an Environmental Impact study (EIS) for federal lands and an Environmental Impact Report (EIR) for the private portion of the property. Regulatory permitting required over 5 years to obtain all the various authorizations for this project. The ore body has an average thickness of 118 feet extending over 273 acres. At a production rate of 90,000 tons per year with only a 70 percent resource recovery allowance, in place reserves are sufficient to sustain production for over one hundred years.

Jan 1, 1997