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By Alla D. Mah

The heat of formation of scandium sesquioxide (Sc203) has not been measured previously, and existing values for gallium sesquioxide (Ga203) are subject to large uncertainties. As a consequence, thermodynamic calculations involving these oxides hare lacked scientific exactness. This paper reports newly determined values of the heats of formation of gallium and scandium sesquioxides at 298.15° K., by combustion calorimetry. The corresponding free energies of formation are derived from heat and entropy data.

Jan 1, 1962

By W. L. Crentz

San Juan County, which occupies the extreme northwest corner of New Mexico, contains large reserves of coal in the Fruitland formation and in the Menefee formation of the Mesaverde group. The coals have bright luster, are brittle, and break easily in handling. All mines sampled are in the La Plata-Fruitland and Rio Chaco districts of the Durango-Gallup coal field. This large area, all within San Juan County, contains numerous coal beds 5 to 15 feet thick. Ellis2/ mentions the Carbonero (Fruitland in this report) bed in the La Plata-Fruitland district attaining a thickness of 36 feet. This bed has been correlated with the Carbonero bed, formerly mined at Carbon Junction, near Durango, Colo. During the field investigation covered by this report, no operating mine in the Fruitland bed was working a bed thickness of more than 15 feet.

Jan 1, 1957

By d&apos, Kathleen J. Amico

THIS SUAMMARY is shown in Minerals Yearbook volumes I and III of this series on mineral production in the United States, its island possessions, the Canal Zone, and the Commonwealth of Puerto Rico, and on the principal minerals imported into and ex- ported from the United States. The several commodity and area chapters contain further details on production. A summary table comparing world and U.S. mineral production also is included. Mineral production may be measured at any of several stages of extraction and processing. The stage of measurement used in the chapter is normally what is termed "mine output." It usually refers to minerals in the form in which they are first extracted from the ground, but customarily includes for some minerals the product of auxiliary processing operations at or near mines.

Jan 1, 1962

By Roger M. Turpening

This study was performed to examine the feasibility of using seismic shear waves to detect the presence of abandoned coal mines. !he Antiquity Coal Mine near Antiquity, Ohio was used as a region of known voids. No attempt was made here to accurately locate the mine tunnels if detection was obtained. The results of this study were positive. Sharp changes in the amplitude of the received shear waves were clear indications of the presence of a fluid (gas or liquid) filled region between the source and receivers. When moving the source showed no change in the received signals it was concluded that the voids existed beneath the sensors. Prior to these tests drilling (SM-3) had determined that a void did exist in this area. This void was confirmed by this shear wave test and two additional voids were found.

Jan 1, 2012

By J. L. Holman

The Bureau of Mines has extended its previous development of cast Mn-Cu damping alloys to powder metallurgy (P/M) consolidation of alloys containing 55 to 75 wt-pct Mn. Blends of minus 200-mesh elemental powders were compacted cold in directional and isostatic presses. With 1 pct binder, typical green densities ranged between 76 and 80 pct of theoretical when pressing at 30 or 48 tsi. Green strength increased with compacting pressure and copper content. As-sintered tensile strengths ranged to 60,000 psi fox a hydrogen, sintered 60Mn-40Cu alloy, along with 5-pct elongation. Sintered densities ranged between 90 and 96 pct of theoretical. Sintering (a as effective when holding for 1 hr at maximum temperatures of 900° to 1,040` C, dependent on composition. Strength and ductility were considerably lower than for equiva¬lent cast alloys. When aged to the damping condition, alloys containing 60 to 70 pct Mn exhibited >40 pct specific damping capacity (SDC) at 5,000-psi stress, considerably higher than values reported for equivalent cast material. Effects of 1 or 3 pct Sn or Zn additions on SDC and other properties were assessed. Trials were conducted on consolidating rings and gears of the 65Mn-35Cu alloy on industrial-type P/M equipment.

Jan 1, 1979

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations beginning with No. 4251, of which this is the third. The data are accompanied by maps showing the location of holes drilled and deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township-map. The description of each half township is followed by a description of each deposit developed in that half township.

Jan 1, 1948

By Francis E. Federspiel

Based on the investigation by the Bureau of Mines, tungsten is the principal metal found in the study area; gold and silver were the primary metals found at one property. Tungsten occurs in tactite zones formed near contacts of calcareous metasedimentary with granitic intrusive rock. Gold and silver were found primarily along quartz veins in granitic rocks; small amounts of those petals also occur in the tactite zones. Since 1856 approximately 200 lode claims or relocations have been recorded, mainly in the southwest corner of the study area. Tungsten production in this part of the area has been inure than 7,800 short ton units (70,800 kg) of tungsten concentrates; about 4,800 short ton units (43,500 kg) were from the Mud Lakes Mine; and 3,100 short ton units (27,200 kg) were from the Rainbow Mine 1/.

Jan 1, 1981

By John R. Benham

In 1979 and 1980, the U.S. Bureau of Mines and U.S. Geological Survey conducted a mineral survey of the 20,500 acre Black Butte RARE II area (No. 5102) in the Los Padres National Forest (fig. 1). The work by the Bureau of Mines indicates that the potential tor mineral resources in the area is low. Samples of outcrops and stream channels contained no economic minerals. A mercury deposit near a granodiorite-sedimentary rock contact occurs 2 mi northeast of the study area, but similar deposits have not been discovered within the area. Geothermal potential exists near Tassajara Hot Springs, but no thermal springs occur in the area; nor have oil, gas, or coal resources been found.

Jan 1, 1982

By Thomas O. Glover

The mining industry of Cameroon continued to be dominated by crude petroleum. Crude petroleum production has become the most important facet of Cameroon's economic development. Oil production was estimated to be 6.3 million tons in 1983 compared with 5.2 million tons in 1982 and 4.3 million tons in 1981. Over two-thirds of its export income was attributed to crude oil. The country's only refinery, dedicated in 1981, has a production capacity of 2 million tons. Cameroon has become self- sufficient in petroleum products since commissioning the refinery. The oil sector contributed approximately 13.5% to Cameroon's gross domestic product in 1982-83. Oil production was expected to rise from 125,000 barrels per day in 1983 to 156,000 barrels per day in 1985 when output peaks. Cameroon's ultimate recoverable reserves have been calculated at 100 million tons, or 750 million barrels of oil.

Jan 1, 1985

By R. H. Grau, S. B. Robertson, R. B. Krog

The National Institute for Occupational Safety and Health (NIOSH) has conducted research to improve the ventilation of large-opening mines. Large-opening mine ventilation is unique for the following reasons: (1) it is challenging to keep airflow velocities high enough to effectively remove or dilute airborne contaminants, (2) large air volumes can be moved through the mines with little static pressure drop, and (3) stoppings to direct ventilation airflows are costly to construct and maintain. The research results suggest that by incorporating ventilation planning into the mine planning process, using propeller fans, developing new stopping materials and construction methods, and using long pillars to eliminate crosscuts where possible, the ventilation of large-opening mines can be significantly improved. The ventilation improvements created by incorporating these various techniques into the ventilation plan will help reduce the exposure of mine workers to airborne contaminants in underground large-opening mines.

By E. P. Carman

In this report, the Federal Bureau of Mines presents a summary of the occurrence, properties, and uses of some natural bitumens, using the layman's or dictionary definition of bitumens - that is, naturally occurring hydro-carbons. Emphasis is on the less common solid and semisolid bitumens, particularly those occurring or used to some extent in the United States. This comprises data from many sources and references to these sources for more detail than is given in this summary. This paper was prepared primarily to answer questions about some of the less known bituminous materials. The word hydrocarbons could just as well have been substituted in the title for bitumens, but bitumens was used, since an abstract of the paper was presented at a meeting where the major emphasis was on bituminous materials. The reader will realize that coals, of which only the more unusual such as the cannel coals and torbanites are discussed in this paper, are primarily mixtures of bituminous materials and carbon. The amount of bituminous material, or volatile matter, in coals is greatest in the lower rank coals and the unusual types described in this paper, and decreases as coal rank increases. However, since no method other than destruction of the original coal substance by heat is known that will separate the volatile matter from the carbon, it appears reasonable to classify the coals with other bituminous materials, particularly since bituminous coal - the most widely used coal - by its name indicates the combination of bituminous materials and carbon.

Jan 1, 1961

By J. R. Thoenen

In Progress Rerort 1,4/ a number of facto were demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By John Redington

This paper describing the milling practice at the Coniaurum Mine is one of a series of papers on milling methods, practice, and costs prepared in cooperation with an published by the United States Bureau of Mines. The 500-ton will of the Coniaurum Mines (Ltd.) is located at approximately the center of the company's property and a little more than a mile from the town of Schumacher, Ontario. The main shaft through which all the ore is heisted is adjacent to the mill so that the ore hoisted in a 3-ton skip is dumped directly into a 15-ton bin at the crusher.

Jan 1, 1931

By Wadaw Cybulski

The problem of coal dust explosions: Basic information about the explicability of coal dust: Main parameters of the explosibility of coal dust; Main parameters of the explosibility of coal dust; Limit explosibility of coal dust and its dependence upon the basic parameters: The effect of the initiator of the explosion-on-the explosibility of coal dust: The dependence of the course of an explosion upon the distribution of coal dust in the workings, upon the dimensions of the workings, the length of zones, the direction of the development of explosions and upon the content of firedamp in the air of the workings; Con-sequences of coal dust explosions; The ways of suppressing the danger of coal dust explosions; Stopping the developed coal dust explosions; The explosibility and explosions of lignite dust of xylite structure

Jan 1, 1975

By Philip W. Holland

This U.S. Bureau of Mines (USBM) report describes a chromatographic method that is used for rapid field determinations of carbon dioxide in natural gas streams at a USBM helium production facility. The method employs a commercially available portable gas chromatograph that is equipped with a 10-m fused-silica capillary column coated with a porous polymer. The instrument operating parameters permit determinations to be performed over a concentration range of 10 ppm to 10 pct with a frequency of 20 samples/h. The speed at which determinations can be performed is an important factor when evaluating efficiency or troubleshooting processes at the helium facility.

Jan 1, 1994

By Thomas W. Camm

The U.S. Bureau of Mines has developed a system for estimating mining and processing costs as a function of process feed rate with the objective of applying this system to abandoned mine tailings and to evaluate the benefits, if any, of metal recovery. Cost analysis was applied to the mine wastes of Smelterville Flats: an extensive area of mine tailings in the Bunker Hill Superfund Site with high concentrations of lead, zinc, and other sulfide minerals. Results from previous site characterization and metallurgical processing studies were used as the input for the cost analysis. This analysis indicated that processing this site at an optimum production rate of 3,500 short tons per day (st/d) could generate a positive cash flow.

Jan 1, 1993

By J. R. Hoskins

A recent survey of 23 vein-type metal mining operations in several western states discloses that some of the more serious deficiencies in ventilation technology are associated with inordinately high levels of mine resistance. This problem has progressively increased over many years of operation (without adequate remedial action) as mines have become extended in depth. Where two shafts form the downcast and upcast airways of a relatively deep mine, the whole of the mine air volume must pass through each shaft in turn. Since at least one of these shafts contains hoisting equipment, structural members are necessary to support the rigid guides and shaft walls. These offer high aerodynamic resistance. In some deep mines, a single shaft of this nature may represent upwards of one-half of the total mine resistance. The second shaft, depending upon its design, may represent an additional one-third of the mine resistance. Therefore, the various working levels throughout the mine contribute only the small remaining amount of the total mine resistance.

Jan 1, 1972

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations No. 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the fifth. The data are accompanied by maps showing the location of holes drilled and deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township. The 14 half-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project except the deep holes drilled to test the geophysical anomalies. The locations of those holes show on figure 13 in Volume I. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each half township is given with the discussion of that area.

Jan 1, 1948

By Eric E. Cather

A mineral survey of the Fisher Gulch RARE II area (A5299), Trinity County, California was conducted by the U.S. Bureau of Mines and U.S. Geological Survey. The Bureau of Mines was responsible for detailed examination of mines, prospects, and mineralized zones; the Geological Survey conducted geological, geochemical, and geophysical studies of the area. The area is underlain by the Salmon Hornblende Schist. Tonalite stocks 1.5 mi (2.8 km) to the east and northeast of the area intrude the schist and are closely associated with the nearby nines (Cox, 1967). The mines have quartz veins containing sulfides and gold in shears trending east to north past in the schist and tonalite (Hotz, 1972). Strewn and terrace gravel s occupy most of the drainages, many have yielded substantial quantities of gold.

Jan 1, 1981

By J. C. Gerdeen

SAP-S information on the following element types are included in this appendix: Type 1. Three-Dimensional Truss and Bolt Element Type 4. Two-Dimensional Finite Elements Type 8. Variable-Number-Nodes Thick Shell and Three-Dimensional Elements Type 9. Two-Dimensional Joint Element (to be used with Type 4 elements) Type 10. Three-Dimensional Joint Element (to be used with Type 8 elements) Additional SAP4 elements, Types 2, 3, 5, 6, 7 and 12, are also contained in SAP-S and information on these elements is readily available in any SAP4 user's manual. These elements are as follows: Type 2. Three-Dimensional Beam Elements Type 3. Plane- Stress Membrane I-r .n Elements Type 5. Three-Dimensional Solid Elements (8 Node: Brick) Type 6. Plate and Shell Elements (Quadrilateral) Type 7. Boundary Elements Type 12. Three-Dimensional Straight or Curved Pipe Elements

Jan 1, 1976