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The Florida phosphate industry currently produces more than 80 pct of the total U.S. marketable output of phosphate rock. Because phosphate is one of three principal nutrients used in formulating a complete fertilizer, it is imperative that an uninterrupted supply of this material be available to meet the agricultural requirements of the United States while maintaining a viable phosphate industry which is competitive in world markets. As a result of an evaluation made by the Bureau of Mines, five areas were identified that affect the overall production and projected growth of the phosphate industry in Florida. These areas relate to the technological ability of the industry to comply with environmental regulations and performance standards by using the best available technology. The most significant technical problem facing the industry is the management of the clay fraction rejected during the beneficiation of phosphate ores. Other areas of concern are environmental restrictions and regulatory requirements, issues associated with mining and reclamation of wetlands, reclamation of other disturbed lands, and consumptive water use. Each of these areas is reviewed, with major emphasis placed on the current state-of-the-art processes for treatment and management of phosphatic clays.

Jan 1, 1983

By Robert P. Vinson

This Bureau of Mines report presents the results of tracer gas studies conducted at three facilities where bagger hoods had been installed several years ago to remove airborne silica dust from the vicinity of the bagging operator. The studies indicated that for optimum benefits makeup air must be evenly dispersed, the hood enclosures and duct systems must be as airtight as possible, the average intake air velocity of each hood should be at least 200 fpm, and the hoods and duct systems must be properly maintained.

Jan 1, 1981

By D. Eugene Rannels, Sarah E. Dunsmore, Cara Martinez-Williams, Yu-Chen Lee

"Dunsmore, Sarah E., Yu-Chen Lee, Cara Martinez Williams, and D. Eugene Rannels. Synthesis of fibronectin and laminin by type II pulmonary epithelial cells. Am. J. Physiol. 270 (Lung Cell. Mol. Physiol. 14): L215-L223, 1996.Previous investigations demonstrated that type II pulmonary epithelial cells regulate extracellular matrix deposition as a function of time in primary culture. In those studies, the matrix fraction was analyzed as a whole. The present work focused on two components of the type II cell matrix, fibronectin and laminin. These glycoproteins have differing effects on differentiation of type II cells in primary culture. Fibronectin synthesis was quantitated between day 1 and day 6 in the cells, matrix, and medium; laminin synthesis was quantitated only in the cells. Although total fibronectin synthesis was regulated as a function of time in culture, reaching its greatest value on day 2, the average proportion of newly synthesized fibronectin in the cells (35%), medium (50%), and matrix (15%) remained constant over a 6-day interval. Between day 2 and day 6, the relative abundance of fibronectin messenger RNA increased 6.5-fold. Rates of cellular laminin synthesis did not vary with time in culture. These results support a role for differential regulation of fibronectin and laminin synthesis to determine the composition of the type II cell extracellular matrix. INTERACTIONS BETWEEN THE pulmonary epithelium and alveolar basement membrane may play a role in the physiology and pathophysiology of the lung. Pulmonary epithelial cells and the alveolar basement membrane form one component of the blood-gas diffusion barrier. Integrity of this barrier is crucial to normal lung function. Specific domains of alveolar basement membrane components have been proposed to determine localization of type I and type II pulmonary epithelial cells during lung growth and development, as well as during repair of the alveolar surface after injury (13). In the injured lung, the extent of damage to the epithelium and the underlying basement membrane is thought to be a key factor to determine subsequent repair or fibrotic scarring (3)."

Jan 1, 1998

By Wilbert J. Huff

[This is the fifth of a series of annual reports of the explosives Division, Bureau of Mines, United States Department of the Interior.3/ It deals particularly with work done during the period July 1, 1939, to June 30, 1939. The writer and the respective unit leader to whom credit is indicated have directed the various studies outlined.]

Jan 1, 1940

By Eric E. Cather

Approximately 270,000 cu yd (20[0],000 cu m) of inferred subeconomic auriferous gravel resources were estimated in three Tertiary deposits in the Polk Springs study area (fig. 1 and table 1). These resources are exposed between tuff-breccia and lava flows of the Pliocene Tuscan Formation and Paleozoic or Mesozoic metamorphic rocks which suggests that although no deposits were identified in the other RARE II areas, they may be concealed beneath the Tuscan Formation. Difficulty in choosing drilling targets will make the likelihood of resource discoveries small. The development and production of these deposits would also be prohibitive under current economic conditions due to the thick covering of volcanic rocks. Recent stream gravels of Deer Creek in the Polk Springs study area contain enough gold to attract gold hobbyists; however, the stream gravels do not have sufficient volume to be considered a resource. Potential exists for additional auriferous gravels near the Occidental Mine in the Polk Springs RARE II area.

Jan 1, 1983

By Peter P. Kopas

Study, analysis, fabrication and testing for canopies on Roof Bolters and Shuttle Cars in coal seams under 48?.

Jan 1, 1980

By McHenry Mosier

Mechanical loading, adopted long ago in open-pit, coal, and non-metal mines, was not used extensively in underground metal mines until the World War. In less than a decade it became standard practice in underground work in many mining districts. In 1924 the Missouri School of Mines and Metallurgy, in cooperation with the Federal Bureau of Mines, published a bulletin entitled "Mechanical Underground Loading in Metal Mines," which was prepared by Charles E. van Barneveld, mining engineer, Bureau of Mines.

Jan 1, 1940

By Harold A. Watson

A method for measuring leakage of vapors into a chemical-cartridge half-mask facepiece during simulated use is described. The respirator, fitted with high efficiency cartridges, is worn in a dichlorodifluoromethane (CC12F2)--air test mixture while a series of timed activities (facial movements, varied breathing, exercise, etc.) is performed. Complementing other tightness tests, this method is useful particularly for studying face fit and the effect of facial movements on leakage. The concentration of CC12F2 within the facepiece is monitored continuously to observe the immediate effect of physical activity on leakage. A composite sample is collected simultaneously in a plastic bag as a measure of average leakage during the 18-minute test period. Leakage, reported as percent, is calculated from the concentrations of CC12F2 within the facepiece and in the test atmosphere.

Jan 1, 1970

Significantly increase the amount of fresh air that sweeps the face in front of a continuous mining ma-chine, in order to prevent methane gas buildup. Approach Water sprays are mounted along the sides of a continuous miner and behind the cutter head to help push ventilating air along the required path, and prevent its short circuiting. How It Works A continuous miner is fitted with two sets of water sprays, one of which is used at a time. The set of sprays shown in the diagram, helps move the ventilating air forward along the left side of the miner and across the cutter drum from left to right. That air is then drawn into the exhaust air passageway located along

Jan 1, 1978

By Albert L. Toenges

The production of bituminous coal by stripping methods has become an important factor in some areas, especially in the Central and South Central States. In the latter, production at strip mines exceeds that at deep mines. Table 1 shows the tonnage produced at strip mines and the percentage of the total production for 1924 to 1935, inclusive, for the States in which the mines described in this circular are situated.4/ Following are references to earlier Bureau of Mines publications on strip mining of bituminous coal: Cash, F. E., and von Bernewitz, M. W., Methods, Costs, and. Safety in, Stripping and Mining Coal, Copper Ore, Iron Ore, Bauxite, and Pebble Phosphate: Bull. 298, Bureau of Mines, 1929, 275 pp. Kiessling, O. E., Tryon, F. G., and Mann, L., The Economics of Strip-Coal Mining: Econ. Paper 11, Bureau of Mines, 1931, 32 pp. Turner, Scott, and Bureau of Mines Staff; Mining Bituminous Coal by Stripping Methods: Inf. Circ. 6383, Bureau of Mines, 1930, 23, pp.

Jan 1, 1937

By Kenneth M. Maas

The Bureau of Mines inventoried the land availability for mineral exploration and development in northern Alaska and compared this land with known mineral terranes and mineral deposits, to quantify the potential for favorable location of mining claims for metalliferous mineral deposits. This report includes thirty-three 1:500,000-scale maps that depict land availability, and the accompanying text and tables relate availability acreage to areas of favorable mineral terranes. Three categories of land availability and ownership are identified, along with 12 subcategories of land status. Available land comprises approximately 14.5 million acres or 16% of the 90.3-million-acre study area; land available with restrictions accounts for 7.5 million acres or 8%; and unavailable land encompasses 68.3 million acres or 76%. Mineral terranes underlie 37.8 million acres or 42% of the study area; 5.3 million acres or 14% are available for mineral location, 2.8 million acres or 7% are available with restrictions, and 29.7 million acres or 79% are unavailable. There are 500 known mineral deposits or occurrences within the study area. This includes 271 lode deposits, of which 171 lie within a recognized mineral terrane and 55 are on available land. The remaining 229 are placer deposits.

Jan 1, 1987

By B. M. O'Harra

The residues resulting from the retort distillation of zinc ores have from 40 to 75 per cent of the weight of the original ore and contain from 5 to 15 per cent zinc . A rough estimate indicates that approximately 450,000 tons of residues are produced annually in the United States , containing about 36,000 tons of zinc . Besides the current production of residues there are at many smelter sites large accumulations from past operations which are available for treatment if this can be done profitably . In addition to their zinc content the residues contain much unconsumed coal , which has been carbonized during the distillation process , and those from most western ores also contain lead and silver . In this paper is summarized the information obtained in a survey , recently made by the Bureau of Mines , in cooperation with the Missouri School of Mines and Metallurgy , of processes which are in use or which have been suggested for the treatment of retort residues . The complete report of the survey is to be published as a Technical Paper of the Bureau of Mines .

Apr 1, 1923

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By E. R. Bauer

This report describes a U.S. Bureau of Mines investigation into the removal of gate road chain pillars in conjunction with longwall retreat mining. The research objective was to determine, through evaluations of the loads imposed on the gate road pillars and supplemental support elements in the entries, how the pillars, supplemental support, and entries were affected by the longwall abutment pressure. To achieve this goal, vibrating wire stressmeters and hydraulic flatjack pressure cells were installed in the support elements to monitor stress change caused by abutment pressure as a function of longwall face advance. The findings documented in this report are the result of information collected from instrumentation and observation at the mine. Pillar and support loading measurements and stability observations revealed that the roof and the sup- port elements remained stable during panel retreat, while the face progressed at a normal rate of advance. The ability to safely and efficiently mine chain pillars during panel retreat increases resource recovery and can provide several other benefits described in this report.

Jan 1, 1993

By Donna lynne Anderson

This report documents the status of a laser-based underground guidance system for tracking and controlling the movements of underground mobile mining equipment. This research is part of a multiple project effort at the U.S. Bureau of Mines to increase mine safety and efficiency by developing technology for computer-assisted mining. Guidance systems, which can track and control the movements of underground mining equipment, are essential during computer-assisted mining operations. A continuous mining machine at the Bureau's surface test facility served as the test-bed for initial development and experimentation of this guidance system. Subsequently, a continuous mining machine in an underground mine served as the platform for in-mine experimentation The first section of this report includes details of the laser sensors, communication network, and computer hardware. The next section includes experimental results, which show the system capable of accurately tracking and controlling the tram maneuvers of a continuous miner underground. The final section discusses conclusions and recommendations.

Jan 1, 1992

By Don M. Coulter

"INTRODUCTION The Lookout Mountain coal deposits were examined by J.L. Stratton, an engineer of the Bureau of Mines in April and May 1943. The area investigated includes that part of southern Lookout Mountain in townships 4 to 8, south, ranges-9 to 11 east, and contains approximately 140 square miles in DeKalb and Cherokee Counties in northeastern Alabama (fig. 1.)Six coal seams having a minable thickness of 18 or more inches are represented in the area. The third seam, known locally as the Hill seam, has been correlated with the Upper Cliff No.1 seam and is referred to as such throughout this report. The preliminary investigation indicated that the Upper Cliff No. 1 seam is a low-volatile, high-grade coking coal. The work done on this project was confined principally to determining the amount and grade of coal in this seam.The only existing maps of mines in the area were one of the Lookout Fuel Co. at Lahusage, Ala. (fig. 2), and one of the Lookout Mountain Iron Co. at Battelle, Ala. (fig. 3), Consequently, to gain some knowledge of the grade and tonnage mined, surveys of the other mines were necessary. Many of them were caved, and many were filled with water, necessitating considerable preliminary work."

Feb 1, 1947

By C. Golumbic

Most early research on solvent extraction of coal has been concerned with the molecular structure of coal. Although rush work is continuing, practical aspects of the subject also are being emphasized. For example, development of the Pott-Broche extraction process resulted from the discovery of very efficient solvents for the pressure-extraction of coal. Recently, Orchin and Storch reported the use of even more efficient solvents under similar conditions. In addition to the discovery of more effective solvents, the possibility of efficient extraction at atmospheric pressure is obviously of practical interest. H. J. Rose observed that phenanthrene at its atmospheric boiling point readily dispersed 80 percent or more of Pittsburgh-bed bituminous coal. This fact served as the starting point of the present investigation, ill which determination of the chemical specificity of this solvent and the chemical nature of the resulting extracts was undertaken. This paper represents a progress report of the results obtained to date.

Jan 1, 1950

By J. J. S. Sebastian

The process development described in this report was carried out at the Morgantown Station of the U. S. Bureau of Mines in cooperation with West Virginia University. An experimental laboratory-scale pilot unit to gasify coal dust in entrainment was constructed on the Campus of the University in Morgantown. The enormously accelerated demand for liquid and gaseous fuels and utilization of our immense coal resources require that a low-cost process be developed for the gasification of a wide variety of coals. Such a process would be a major factor in lowering the cost of synthetic liquid fuels. None of the proc3sses developed in Germany prior to and during World War II, such as the Winkler process, the H. Koppers dust gasification process, the Wintershall-Schmalfoldt process, etc., meet all the requirements for a low-cost process under American conditions. Nor has any other process designed and experimentally operated at atmospheric pressure during the post-war period in this country appeared to fulfill all of the necessary conditions for a low-cost process.

Jan 1, 1950

By R. M. Creamer

Attempts have been made to electroplate titanium and zirconium from aqueous, nonaqueous, and fused-salt electrolytes. Metals were produced only in fused-salt electrolytes, the major product being sponge metal. All other electrolytes gave only partial reduction of the metal ions. Fused alkali borate electrolytes containing titanium salts gave titanium boride powders and coatings of poor adherence. Some of the problems encountered in the deposition of these metals and some of the aspects of titanium and zirconium chemistry involved are discussed. INTRODUCTION Titanium and zirconium are both relatively light, noncorrosive metals with both military and civilian uses. This has led to intensive investigations into the metallurgy of these metals. Both metals are high in the Electrochemical Displacement Series and are difficult to prepare in a pure state. At present they are prepared by reducing their chlorides, using magnesium. Electrolytic reductions have resulted in the preparation of fine powders or sponge of variable quality. It is believed that a good process of electroplating these metals on a baser metal would result in a very desirable product. The objective of the research summarized in this report was to investigate methods of electrodepositing these metals, with the idea of producing uniform, coherent plates. Most of the work was concentrated on titanium, the more abundant of the two metals. A system developed for titanium should be applicable to zirconium owing to their chemical similarity. Information gained from these experiments may also be applicable to the electro-winning of the metal.

Jan 1, 1954