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By B. P. Martinez

A process for regenerating spent pickle liquor is proposed in which some of the water is evaporated at atmospheric pressure and ferrous sulfate is precipitated as monohydrate crystals..Equilibrium conditions are set for a slurry of crystals in a mother liquor containing 5 percent FeS04 and 45 percent E2S04, by weight, and boiling at about 235° F. The slurry is pumped continuously to a filter, and the mother liquor from the filter is pumped back for reuse in the pickling tanks. The net result of the process is to remove ferrous sulfate in the regeneration plant at the same rate ac it is produced in the pickling tanks. This process is integrated with the steel-pickling operation and controlled by the pickling requirements for particular steels. Spent pickle liquor is removed for regeneration continuously from both batch and continuous picklers at higher acid concentrations than would be dumped to waste because no acid is neutralized or discarded. However, the process is not designed to keep a sulfuric acid concentration stronger than 25 percent in any pickling tank. To retain flexibility in the pickling operation, all acid makeup is added to the pickling tanks. Rinse waters are used as water makeup for the pickling tanks. To further minimize waste of acid in the rinse waters, improvements of rinsing practices are outlined.

Jan 1, 1953

By A. K. Schellinger

1. In the United States, the industrial application of centrifugal force for separating phase constituents has been confined almost entirely to aqueous systems at room temperature. This paper presents results for experimental tests on the use of centrifugal force for separating the liquid and solid phases in molten nonferrous alloys. 2. The development and use of a small centrifuge for treating molten metals is described. The centrifugal apparatus was, in essence, a 3-inch diameter spinner pot, which revolved, within -a gas -fired furnace, at speeds up to 3,000 r.p.m.

Jan 1, 1953

By M. W. Von Bernewitz

Corduroy is used for saving gold in small Land large milling plants throughout the world. Investigations by the Metallurgical Division of the Bureau of Mine indicate that corduroy blankets, used with or without a trap or jig in the mill classifier circuit, often are effective in concentrating gold and sulfides, especially if the gold does not amalgamate readily and if not enough sulfides are present to warrant the use of a shaking table, flotation cells, or cyanide plant. Most cold-mining countries include several or many small miner, that produce siliceous ores low in sulfides and gold, which can easily be amalgamated or caught in traps or jigs or on corduroy and shaking tables. At these mines the ore is crushed by stamps or bill mills, and the flow sheets include plates, flotation cells, and cyanide treatment, yet probably nearly as much of the pair minerals may be recovered by the less expensive plant. A well-known western maker of mine and mill equipment asserts, as the result of considerable observation of installed plants, that old and other valuable minerals should be caught as soon as they have been released by a mill, end recommends jigs to do this. A supplier of corduroy has informed us that at some mines this material is being replaced by jigs that catch gold as fine as 400-mesh. But for the small operator, inexpensive equipment such as a corduroy table may be better adapted and give a good recovery of gold and associated minerals.

Jan 1, 1939

By N. N. Moelbs

The U.S. Bureau of Mines is conducting research on many topics relating to the hazards of coal mining, increased production, and protection of the environment. One area of research that has received scant attention in recent years is that of water inflows, probably because few fatalities in the United States have been attributed to them. As mining goes deeper, the problem of water in 1ow could increase dramatically because of adjacent or overlying mines in which huge water pools are impounded. Inaccurate mine maps and ineffective barriers can constitute a serious problem for operators both from gradual inflows and sudden inrushes of water. This report describes a wide but ineffective barrier that permitted an average 240-gpm inflow to a developing mine from an adjacent mine. The anomalous geologic structure that facilitated this leakage is described, demonstrating that size, alone, is no assurance against serious leakage. Some recommendations for managing serious water inflow are included.

Jan 1, 1989

By H. F. Yancey

This report, dealing with the separation of coal from its associated impurities by means of a pulsater-type jig, continues the series of reports that have been issued by the Bureau of Mines, in which detailed study has been made of the efficiency and mechanism of separating coal and impurities in various coal-cleaning appliances. The previous reports have dealt with the piston jig, coal-washing table, pneumatic table, and Baum-type jig. Such studies of the separation accomplished by any form of concentration device are essential and necessarily preliminary to any intelligent attempt to improve the performance of such equipment Object and Plan The pulsator-type jig was developed recently by G. A. Vissac. Although two articles(2) describing plants using this typo of cleaning unit appeared in 1936, both dealt principally with plant design and layout rather than with plant performance The object of the stork described in this report was to determine the efficiency of the separation made by the pulsator jig on a sized feed, the specific gravity at which the separation between coal and impurity was effected, and the influence of the specific-gravity composition of the coal on the character of the separation made.

Jan 1, 1938

By H. F. Yancey

This report, dealing with the separation of coal from its associated impurities by means of a pulsator-type jig, continues the series of reports that have been issued by the Bureau of Mines, in which detailed study has been made of the efficiency and mechanism of separating coal and impurities in various coal-cleaning appliances. The previous reports have dealt with the piston jig, coal-washing table, pneumatic table, and Baum-type jig.5/ Such studies of the separation accomplished by any form of concentration device are essential and necessarily preliminary to any intelligent attempt to improve the performance of such equipment Object and Plan The pulsator-type jig was developed recently by G. A. Vissac. Although two articles(2) describing plants using this type of cleaning unit appeared in 1936, both dealt principally with plant design and layout rather than with plant performance The object of the stork described in this report was to determine the efficiency of the separation made by the pulsator jig on a sized feed, the specific gravity at which the separation between coal and impurity was effected, and the influence of the specific-gravity composition of the coal on the character of the separation made.

Jan 1, 1938

By J. B. Zadra

After the discovery of the rare-earth mineral deposit in the Clark Mountain area near Mountain Pass, San Bernardino County, Calif., two samples wore obtained through the Mining Division of the Bureau of Mines for investigation of possible method of concentration. Three other samples were received later from different locations in the same area. The rare-earth mineral in this ore had been identified by E. T. Schonk as bastnaesite, a fluocarbonate of the rare-earth metals containing cerium, lanthanum, praseodymium, thorium, uranium, etc. Associated with the bastnaesite were barite, silica, and some calcite. The bastnaesite contained a small amount of iron as a coloration and some manganese. Twenty to fifty percent of the weight of the samples studied was bastnaesite, or ten to twenty-five percent total rare-earth oxides; about half was cerium oxide. Apparently, none of this mineral occurred in pure form. Even the highest-grade particles 'wore contaminated by fine, interlocked grains of barite, calcite, and silica; barite contamination predominated, and the barite was interlocked with varying amounts of bastnaesite. While the specific gravities of pure bastnaesite and barite (approximately 5.0 and 4.50 respectively) differ enough to allow separation by gravity, the interlocking of the minerals nullified this difference. Consequently, only a partial separation could be made by gravity concentration. The extremely fine grained texture of most of the ore prevented grinding to a size that would make concentration by flotation practicable; a partial separation of barite by this means was effected.

Jan 1, 1952

By Changwoo Lee, Jan M. Mutmansky

"This paper results from the research at The Pennsylvania State University into establishment of standard procedures for characterization of respirable coal dust performed by the Generic Mineral Technology Center for Respirable Dust and supported by the U.S. Bureau of Mines and the Mining and Mineral Resources Research Institute at The Pennsylvania State University. The research performed within this particular project is oriented primarily toward standard methods of sampling and characterizing respirable coal mine dust underground so that the chemical, physical, and morphological characteristics are known and can be related to the incidence of coal workers' pneumoconiosis (CWP) in Pennsylvania.The research was initiated by con¬ducting a search of the literature to determine what coal and geologic variables may be related to CWP. The effects of coal rank, free silica content, the mass of respirable dust, and the level of trace elements were the major variables studied. It seems to be evident that the free silica content, the rank of coal, and the mass of respirable dust are the major concerns in defining the causes of CWP. However, based on the literature survey, the authors have concluded that verification of the causes of CWP is a multivariate problem and must be analyzed in an appropriate statistical manner.The results of a multivariate analysis of ten trace elements recorded on Pennsylvania coals are presented. Five of these trace elements were found to be of use in differentiating one coalfield from the others. Of these five elements, chromium and zirconium showed a strong positive correlation with the rank of coal while strontium showed a negative correlation.The design of the field sampling work and its application in future research is the final topic discussed. The sampling plan is oriented toward continuous miner sections with eight-stage impactors as the collection equipment. All of the field work will be conducted in the coal measures of the Allegheny Formation and above with both dust and channel samples being collected in the same mines.Coal workers' pneumoconiosis has been an important topic of concern to miners, mining engineers, and epidemiologists for decades. The general cause of the dis¬ease, the inhalation of coal mine dust, is well known, but the specific coal and geologic variables that affect the incidence and severity of the disease are still subject to debate and study. The primary objective of this study is to identify those variables of Pennsylvania coals that contribute to the CWP problem. To accomplish this task, a field sampling program is to be conducted to relate the characteristics of the coal dust, the coal seam properties, and the geologic variables to the occurrence of CWP.The first year of this study has been involved with both a literature review and experimental work oriented toward identification of causal variables related to CWP. The results of this work are presented here along with plans for implementation of the findings in future research.The previous studies of CWP causal variables have been conducted by scientists, engineers, and medical personnel. Many different types of studies have been performed with emphasis on interpreting the effects of dust mass concentration, mineralogy of the coal, the rank of the coal, and trace element concentrations upon the incidence of CWP in various coalfields. Most of the research has been conducted during the last two decades, with the British Isles, West Germany, and the United States being the primary countries involved.The review of the literature was conducted to determine which variables are likely to warrant further study in Pennsylvania. Previous research studies have related CWP to free silica and other mineral content, the rank of coal, the mass of dust in the working place, and the trace elements in the coal and lung dust. In the following sections, each of these topics will be discussed and analyzed."

Jan 1, 1988

By H. R. Shell, Robert C. Johnson, Wilbur H. Warwick

Alpha silicon nitride fibers , Si3N4 , were successfully grown in graphite crucibles by a new method utilizing silicates and silicon ( S in equations below) as sources of silicon and using carbon , aluminum , and silicon as reducing agents (R in equations below ) . The basic reaction mechanism is believed to be generally as follows : 1,300 - 1,500 ° C S + R + N₂ SiO + RO + N₂ › 3Si0 + R + 2N₂ _1,300 - 1,500° C 3RO + Si¸N • ( 1 ) ( 2 ) A build - up of coatings on the solid raw- material particles hindered the evolution of silicon or silicon monoxide vapor and thereby slowed down further formation of silicon nitride fibers . Free oxygen in the crucible caused the formation of amorphous silicon dioxide ( SiO2 ) fibers . This problem was solved by passing , entering , and exiting gases through layers of lump graphite inside the reaction vessel . The silicon nitride fibers grew best around 1,400 ° C. Nitrogen flow rates from 4 to 6 liters per minute were adequate . The fiber widths were generally only a few microns whereas their lengths sometimes reached one - quarter inch or more . Chemical and X- ray analyses indicated that bulk fiber samples were usually 80 to 90 percent Si3N4 . The fibers had good oxidation resistance to about 1,260 ° C. Thermal shock resistance was excellent . Electrical resistance was determined .

Jan 1, 1964

By John K. Alley, Robert C. Johnson

The primary objective of the research was to grow aluminum borate whiskers or fibers and to determine their properties . Molten salt bath and vapor deposition methods were used for synthesis . Whiskers exceeding 25 mm in length were grown . The best results were obtained by vapor deposition and most of the data presented were determined on whiskers produced by this method of synthesis . Three different aluminum borate compositions ( 4.8A1203 B₂03 , 3.8A1203 B203 , and 2.5A120, B203 ) were identified by X- ray and chemical analyses . The aluminum borates 4.8A1203 B20, X- ray diffraction pattern was indexed . Optical data were obtained on the three aluminum borates . In addition the following whisker properties and growth factors were determined : ideal atmospheric dewpoint for vapor deposition method , near 65 ° F ; temperature range of whisker formation , 1,000 ° to 1,400 ° C for the molten bath method of synthesis , > 1,000 ° to < 1,400 ° C for the vapor deposition method ; whisker growth rates by the vapor deposition method , maximum 12 mm per hour ; raw material vaporization , 50 to 60 percent of the fluoride lost in 1 hour ; tensile strength , maximum obtained 174,162 psi ; melting points , ranged from 1,675 ° to 1,795 ° C.

Jan 1, 1965

By D. W. Butner

This report is concerned with the conditions affecting the methods and costs of mining phosphate rock in that part of the western phosphate field that is in Bear Lake and Caribou Counties in southeastern Idaho ( see fig . 1) . The area was selected because it contains most of the known phosphate reserve and because its geology has been studied more extensively than that of other sections . Deposits of phosphate rock on public land may be leased from the Government under the terms of the Mineral Leasing Act of 1920 , subject to the regulations of the Bureau of Land Management . Public interest in phosphate production is growing , as shown by an increasing number of applications for leases . Two mines are being operated steadily for the production of phosphate rock by companies that have also the necessary processing plants for the manufacture of fertilizer . Total western phosphate - rock production in 1947 is reported by the Economics Statistics and Division of the Federal Bureau of Mines to have been 1,193,000 long tons , mined in Idaho , Montana , and Wyoming . The average grade was 30.7 percent of contained phosphorus pentoxide (P205 ) ; the average value at the mines was $5.67 per long ton . Idaho contributed 905,000 tons , or somewhat more than 75 percent of western production . Western fertilizer plants took 23 percent of total production; 76 percent was exported . Strip mining accounted for 75 percent of the Idaho tonnage; the remainder was stoped from underground workings . Rock must contain a minimum of 30 percent P205 to be commercially useful for the production of superphosphate fertilizer by current acid treatment methods . Research by corporations and Government agencies has been directed toward the use of lower - grade ore . So far , only by smelting can rock containing as little as 25 percent P205 be used economically . Any development of processing or use pattern that would render the mining of , say , 20 percent rock profitable would have important effects in reducing the unit cost of mining . In the search for metallurgical improvements , consideration should be given to the saving of valuable components of the rock, such as vanadium and fluorine , both of which are present in the beds .

Oct 1, 1949

By A. F. Roberts

The subject of mine fires is a very wide one. To give reasonable coherency, the paper concentrates on the behaviour of fires in the ventilated airways of mines; spontaneous combustions are not considered. The following topics are considered in some detail: 1) Material selection: Performance requirements for mining materials in terms of flammability and smoke/fume production; methods of test and need for relevance to mining conditions. 2) Fire growth: The influence of material properties and method of use on the rate of growth of fire in a mine roadway; the influence of ventilation, slope, material orientation, proximity of walls and roof on fire behaviour. 3) The fire in the ventilation network: The influence of fire on the ventilation distribution; the circulation of fire products in the network. The influences of these topics in determining fire control strategy are then considered but topics such as fire detection and fire extinction methods are not reviewed in detail. An extensive Bibliography on papers relating to mine fires is included.

Jan 1, 1989

The 1967 Lignite Symposium was held at Grand Forks, N. Dak., on April 27-28, 1967. This was the fifth of these technical meetings and the fourth which was cosponsored by the University of North Dakota and the Bureau of Mines. These symposia have provided a meeting place where current developments concerning technology and utilization of solid fuels (lignite) are presented. There was a registration of 255 persons from 24 States, the District of Columbia, six Canadian Provinces, Germany, and India. Many segments of coal or energy oriented organizations at many levels were represented. During the meeting, 18 presentations were made covering developments in electrical power generation, mining, estimation of reserves, combustion, gasification, and chemical and speciality uses of low-rank coals; these are com-piled in this Information Circular to provide a record of the symposium and to permit wider dissemination of the information. Proceedings of the other meetings have also been published.3

Jan 1, 1968

By Carl H. Beal

The oil industry in the United States is further advanced than in any other country, because of American initiative and the development of industries dependent in some way on petroleum or its products. For this reason the output has constantly increased (fig. 1), and as a result this country has produced more than half of the total output of the world. Trw total past output of the world is approximately 7,000,000,000 barrels of 42 gallons each; of this the United States produced about 4,000,000,000 barrels, or about 57 per cent. The limit of production in this country is being approached, however, and although new fields undoubtedly await discovery, the yearly outpnt must inevitably decline, because the maintenance of a given output each year necessitates the drilling of an increasing number of wells. Such an increase becomes impossible after a certain point is reached, not only because of a lack of acreage to be drilled, but because of the great number of wells that will ultimately have to be drilled. According to figure 1, the daily production per well each year has increased during the last few years. However, this increase is abnormal, being caused by the new pools brought in. Although such a condition may continue for several years, the average production per well will finally begin to decrease on account of the lack of new pools to make up for the normal decline in production of the old ones.

Jan 1, 1919

This three-part report provides the results of an industrial engineering study that assessed the safety and efficiency of underground ore handling in U.S. metal mines. One of the primary findings of the study was the improvement needed in controlling muck size in the are handling stream. Oversize ore is causing much additional labor, creating work stoppages, and is a principal cause of accidents in metal mines. The specific objectives of the Present Systems Study were to determine and evaluate the productivity of existing ore handling systems in a representative group of underground metal mines, to relate the available historical accident record statistics of these selected mines to the specific operations in the overall ore handling operations, and to highlight the potential areas of improvement for each mine on the basis of productivity and associated hazardous index for each operation.

Jan 1, 1974

By Norman] [Seldle

This report describes the development of a mine machinery training system from initial conception through a task and skill analysis, a training system analysis, implementation of a prototype system, and initial validation of the prototype system. The objectives of the training are to improve safety and productivity simultaneously via complete, thorough training. A task and skill analysts was executed for shuttle cars, continuous miners, cutters, loaders, face drills, tractors, and scoops. The prototype training system is for shuttle car operator training.

Jan 1, 1976

By Paul M. Tyler

The technology of clay and the manufacture of ceramic products therefrom, and also the clay resources of most of the individual States, are already covered by a voluminous literature. The present resume touches these matters only briefly; its purpose is essentially to bring together in small compass certain of the elementary factors affecting the potential commercial value of a clay deposit. In its preparation the author made extensive use of the annual chapters on Clay in Mineral Resources of the United States and in the two annual issues of the Minerals. Yearbook that succeeded them. For careful review and constructive criticism of the manuscript, the author is indebted to Hewitt Wilson. GENERAL DESCRIPTION The term ?clay? includes a great variety of substances that may differ widely in chemical mineralogical and physical properties. No two clays are exactly alike. All of them however, have the prominent characteristic of becoming more or less plastic when wet. Nearly all of the useful clays can be molded into articles, will hold their shape while being dried, and can be converted into a hard, rocklike substance by heat. Clay may, and in fact usually does, consist of a number of minerals among the commonest of which are kaolinite, quartz, feldspar, iron oxides, mica, bauxite, calcite, and manganese oxides. Organic matter is often present. Pure kaolinite, which has the formula A1203. 2 SiO2. 2H2O, is ordinarily, considered to be the parent "clay substance," butt most clays contain other hydrated mixtures of alumina and silica (aluminosilicic acids) along with indefinite amounts of sand and other nonessential minerals3/ Even, this so-called inert matter affects the plasticity, drying shrinkage, ease of drying, and final density, and at high temperatures may react chemically with the clay substance.

Jan 1, 1929

By Michael A. Anuta

This report describes the potential for utilization of satellite observations for remote sensing of mine waste disposal areas. Four study sites consisting of metal and nonmetal mining areas in different climatic and physiographic regions of contigous United States were used in this investigation. The mine waste disposal sites consisted of mining of phosphates in Florida, copper in Arizona, silver in Idaho, and coal in West Virginia. Landsat satellite multispectral scanner observations were used together with aerial photographs, ground surveys, U.S. Geological Survey maps, and other ancillary information. Landsat digital data were categorized using automated supervised classification algorithms and an image analysis system. Detailed description of automated classification techniques employed and the accuracy attained is provided together with the results of manual interpretations. The inventory of areas distrubed for phosphate mining and a change detection investigation for-Polk County Florida were also undertaken during this study.

Jan 1, 1982

By J. R. Thoenen

The enormous and constantly increasing demand for limestone to supply a multitude of uses is a remarkable feature of the mineral industries. As approximately 130,000,000 tons of limestone are produced annually, it is not surprising that deposits at or near the surface are gradually being exhausted and that less advantageous supplies are being worked. Quarries are becoming deeper and wider year by year, and in many places the volume of overburden that must be removed to allow open-pit work has increased alarmingly. Quarrymen are also gradually learning how expensive it is to sort and clean stone from a deposit overlain by poor material. As such conditions confront the limestone industry, the natural tendency is to seek some modification in method whereby the handicaps of increasing cost may be met and overcome. Operators, some of them unwillingly, have been forced to conclude that underground work in drifts and tunnels is the most logical solution of the problem. The unwillingness of some is largely due to unfamiliarity with mining and to the unfounded fear that costs must increase and dangers multiply when mining is undertaken.

Jan 1, 1926

By Gordon E. Green

This report addresses remote monitoring of coal waste impoundments for stability. Existing automated geotechnical monitoring systems are described and reviewed along with details of instruments suitable for such systems. An impoundment in West Virginia which was in the construction stage was instrumented and monitored between July 1979 and may 1981. Sensors which measure surface and subsurface parameters including settlement, horizontal deflection, surface tilt, pore water pressure, seepage, pond level, and meteorological parameters were installed. Data from the 37 sensors were collected by on-site logger and transmitted by telephone to a central processing station in Seattle for recording and interpretation. Difficulties were encountered with telephone and powerline outages and malfunction of electronic units. Detailed descriptions of the design and performance of the system are provided along with evaluation and comparison with other systems. Recommendations for improving and expanding the capabilities of the monitoring system are given.

Jan 1, 1982