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By D. W. Frommer

Mineral dressing research was conducted by the Federal Bureau of Mines under a cooperative agreement with the St. Joseph Lead Co., on three samples of iron ore from the Pea Ridge deposit in central Missouri. The objective was to provide information on how to upgrade these submarginal ores and produce marketable concentrates. Samples were prepared from drill-hole cores of similar composition and character to produce (1) a medium-grade mixed hematite and magnetite, (2) a high-grade mixed hematite and magnetite, and (3) a high-grade magnetite. In all three ores phosphorus and sulfur constituted objectionable impurities; excessive amounts of silica were also present in the medium-grade ore.

Jan 1, 1960

By A. C. Fieldner

"Purpose and Nature of Tests:The rapidly increasing use of motor vehicles and trucks in the United States is creating an entirely new problem in the proper ventilation of tunnels, subways and other confined spaces through which such machines must pass. This problem has become of immediate importance because a tunnel 3,000 ft. long is being designed to pass under the Hudson River between New York City and New Jersey. Another tunnel at Pittsburgh 5,700 ft. long through the South Hills, is already under construction, and a third tunnel, 6,000 ft. between Boston and Past Boston is proposed. It is probably that other tunnels will be started in various parts of the United States in the near future.The ventilation of such tunnels is a serious matter, on account of the poisonous nature of automobile exhaust gases. It not uncommon to read about finding a man dead in his garage. Generally this happens on a cold, winter morning, after he has been running the engine with the doors and windows closed."

Mar 1, 1920

In 2007, a total of 278 metal mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Metal mines were the smallest mining commodity sector, comprising 1.9% of all mining operations. ? Gold mines comprised 44.6% (n=124) of all metal mining operations. Other common types of metal mines were iron ore (n=36; 12.9%) and copper ore (n=35; 12.6%). ? Nevada had the largest number of metal mines (n=45; 16.2%), followed by Alaska (n=28; 10.1%).

Aug 1, 2009

By J. S. Dunning

Recent developments in energy conversion, mining and minerals processing, pollution control, and chemical equipment have placed in-creased demands on heat-resistant alloys. Higher corrosion rates from oxidation, hot corrosion, and sulfidation have increased consumption of materials that contain critical and strategic minerals and in many cases have limited productivity. The Bureau of Mines is conducting re-search on substitute materials having greater resistance to high-temperature corrosive atmospheres above 6000 C compared to austenitic stainless steels such as AISI 304, 316, and 310, with the goal of conserving critical metals such as Cr and Ni. The substitute materials are based on Fe-Cr-Ni-Al compositions. Aluminum additions to Fe-Cr-Ni alloys significantly improve high-temperature corrosion resistance, particularly sulfidation resistance. In the alloy, devised by Bureau researchers, aluminum additions are held in the form of a second-phase precipitate, 8NiAl. Minor additions of Ti, Mn, and Si improve workability.

Jan 1, 1984

By D. L. Yopps

In research conducted by the U.S. Bureau of Mines, platinum-group metal (PGM) flotation concentrate from the Stillwater Complex, MT, was subjected to biooxidation using Thiobacillus ferrooxidans in an effort to break down the sulfide minerals and liberate the associated PGM's for subsequent chemical leaching. Bacterial preleaching oxidized up to 94 pct of the sulfide present, destroyed the PGM-bearing pentlandite [(Ni,Fe)9S8] mineralization, and dissolved most of the nickel in the concentrate. Cyanidation at 80° C proved to be the most attractive chemical leachant, removing 34 pct of the platinum, 76 pct of the palladium, 94 pct of the rhodium, and 97 pct of the gold from the biooxidized concentrate. Research also indicated that increased sulfide oxidation during the preleach phase led to improved PGM recovery in the subsequent chemical leaching phase.

Jan 1, 2010

By Donald P. Mickelsen

The raining and quarrying trends data shown in this report were reported to the U.S. Bureau of Mines (USBM) by mining and quarrying companies on the Mine Information Supplement survey, as well as by mineral producers on 58 annual USBM production and consumption surveys covering 59 nonfuel mineral commodities. The 1993 data presented in the tables of this chapter, were processed for the first time using the USBM Automated Mineral Information System. Domestic mining of nonfuel mineral materials totaled 3.7 billion metric tons in 1993, including 2.2 billion tons of crude ore nun& or quarried and 1.5 billion tons of mine waste and ore from development. This \vas an overall increase of 11% over that of 1992. These data do not include construction sand and gravel which until 1993 has been surveyed biennially. Starting in 1994, construction sand and gravel and the stones, which were also surveyed biennially, will be surveyed annually.

Jan 1, 1993

By John C. Feeley

This paper is the result of a field study of prospect drilling in the Florida phosphate fields. The objective is to describe the drilling methods employed . . Since the general policies of the operating companies in the land - pebble area do not permit the dissemination of prospecting information and costs thereof , the writer has carefully avoided mentioning names and locations except by reference to existing publications ,

May 1, 1949

By A. W. Khair, M. Ahmad

"Bit wear has been proven to have a significant effect on respirable dust generation in coal cutting system. The mechanism of bit wear can be adhesion, abrasion. oxidation, or diffusion. depending on cutting conditions. This paper presents a portion of an extensive ongoing series of studies to better understand the principles of bit wear and dust generation. Used bits collected from underground coal mines were analyzed to identify the basic principle of bit wear in coal and rock cutting. Distribution of weight loss and conical height loss of worn bits were studied and bit wear was divided into four stages according to weight loss. Utilizing these worn bits, Laboratory experiments have been carried out to study the effects of bit wear on coal cutting system and respirable dust generation. An Automated Rotary Coal Cutting Simulator was use to perform the experiments. Acoustic emission monitoring is applied to study the effect of bit wear on fracture formation and dust generation. INTRODUCTIONContinuous miners were introduced in the 1950’s and became the major equipment in underground coal production. Now the larger production in the coal industry has increased the demand for continuous miners and their use. It is well known that serious dust problem is also introduced with the use of continuous miners, especially with recent increase in productivity. On the other hand, legal restrictions are made ·more strict by the Mine Health & Safety Administration for the respirable dust generated by the continuous miners to prevent coal workers from incidence of pneumoconiosis. The incidence of pneumoconiosis depends on dust concentration, exposure time, and physical properties of dust. Of them, dust concentration is the best parameter for the assessment of the risk of pneumoconiosis. Although a lot of research work has been done to reduce dust concentration substantially, some areas are still required further investigation to meet the strict regulations. One of the areas is about bit wear and dust generation. In this area, the principles of bit wear and effect of bit wear on dust generation are major concerns."

Mar 1, 1992

By Glen C. Ware

The Bureau of Mines determined the factors involved in the corrosion of starting sheets used in the production of electrolytic zinc with the ultimate purpose of adapting zinc starting sheets to commercial practice . Under present practice , zinc is electrodeposited on aluminum cathodes and subsequently stripped for melting . The use of zinc instead of aluminum would eliminate the need to strip the deposit , thereby reducing the cost of handling and melting it , but zinc has not been suitable because it was too vulnerable to the corrosive attack of the electrolyte . Serious attack was found to be limited to the areas of the cathodes situated immediately above the surface of the electrolyte and to re - entrant corners . It was possible to avoid solution - level corrosion by immersing the starting sheets completely , exposing only a relatively heavy suspension member to solution - level attack . Zinc starting sheets could be made as reliable as aluminum and could be continued in residence for periods up to 39 days . Periods as long as a week were feasible under conditions similar to those found in commercial practice . A test of zirconium as a starting - sheet material showed that it promoted corrosion of the deposit to a lesser extent than aluminum and that the deposit adhered less tenaciously . These two properties lend themselves to the development of ways to strip deposits mechanically from zirconium starting sheets . Titanium was unsuitable for use as a starting - sheet material .

Jan 1, 1963

By J. S. Browning

Laboratory and pilot-plant tests of spodumene-beryl pegmatites of the Kings Mountain, N. C., area resulted in development of a new and improved method by the Bureau of Mines for separating and recovering spodumene, mica, and beryl. The process was successfully applied to other domestic pegmatites and a spodumene flotation-plant tailing containing about 0.5 percent beryl. The method comprised soap flotation of the spodumene, using combinations of sodium fluoride and lignin sulfonate as conditioning agents to recover 80 to 85 percent of the contained lithia in concentrates assaying over 6 percent Li20. About 80 percent or more of the beryl was retarded in the spodumene tailing. The beryl subsequently was activated, floated, and cleaned in a secondary circuit to yield beryl concentrates containing 6 to 7 percent BeO. The tests also demonstrated that a good recovery of high-grade mica could be produced.

Jan 1, 1961

By M. M. Fine

Small-scale laboratory mineral-dressing studies were made on a total of nine individual or composite samples of manganese-bearing material from the west-central Arkansas, or Mena, district. Of these, only three yielded concentrates that would probably be acceptable for purchases by the Federal Government fur the National Stockpile. Concentrates from some of the other properties, however, contained more than 40 percent Mn and might be merchantable to other purchasers of manganese ore. In most instances, a too-intimate association of manganese oxides and gangue is conducive to low grade, low recovery, or both, so that mechanical concentration processes do not promise much for this district.

Jan 1, 1956

By Marvin E. Lane

This paper , which describes the mining methods and practices at the Hayden Creek lead mine of St. Joseph Lead Co. in southeast Missouri , 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 Hayden Creek mine is in the W 1/2 sec . 7 , T. 36 N. , R. 4 E. , St. Francois County , Mo. , about 1 mile southwest of the town of Frankclay ( fig . 1) . The mine is on the west edge of the mining district known as the Lead Belt . However , neither the ore body nor the underground workings are connected with those of any other mine in the district . In contrast with most operations in the district , underground haulage is entirely trackless , and nearly complete delineation of the large , well -defined ore body by drilling permitted comprehensive planning of development and mining in advance of shaft sinking . The ore differs in character and occurrence from that of the main ore deposits in the Lead Belt in that the lead mineral , galena , occurs in the dolomitic matrix enclosing granite boulders instead of in dolomite limestone .

Apr 1, 1957

By Albert L. Toenges, Louis A. Turnbull, Henry E. Dekay, James N. Scudder

A preliminary survey of coke and steel plants conducted by the Bureau of Mines in cooperation with the Office of Solid Fuels Coordinator and under the auspices of the Coke Production Committee indicated that a very appreciable increase in pig-iron production would be obtained if pres- ent blast furnaces were supplied with a more uniform coke. Control of the sulfur and ash content of coal used for making coke is an important factor in producing uniform coke and thus increasing blast- furnace efficiency. In some mines producing metallurgical coal, the analysis of the coal bed shows a wide range of sulfur and ash content. To obtain production of coal with minimum deviation in sulfur content sampling, grading, selective mining, blending, and surface preparation are practiced at some mines with satisfactory results. The mines selected for this study have developed these methods and are successfully producing coal of uniform sulfur and ash content. The systems employed at different mines vary according to the physical character- istics of the coal bed, the manner of occurrence of impuritites in the coal, the development plan and mining system, surface preparation and the acceptable impurity content of the prepared coal. The ash content of the coal can be controlled by face preparation and in the cleaning plant. The introduction of some method or practice at other mines might make possible the use of coal for inetallurgical purposes that otherwise could not be used for making coke because of the wide variation of sulfur and ash content.

Dec 1, 1943

By M. A. Lucas

The Bureau of Mines has developed a computerized mathematical model to predict the distribution of accessory elements throughout a metallurgical process. The model can be used to determine process conditions that effect better accessory element control consistent with continued high primary metal recovery. The model presented is specific for determining the bismuth distribution in lead smelting but can be adapted to most extractive metallurgical processes. Thermodynamic, kinetic, and process parameters form the base for the model. Its logic and structure are described in detail.

Jan 1, 1983

By William M. Thornton

[Owing to the comparatively high freezing point of nitroglycerin (14, 15, 16, 17, 18, 23, 37, 38)3/ - 1.9° C. and 13.0° C. for the labile and stabile modifications, respectively, as determined by Hibbert (16) - manufacturers of dynamites have incorporated into the liquid portion of these composite explosives various substances capable of participating in an explosion, to depress the above-mentioned freezing point. Aromatic nitro-compounds, chiefly nitrobenzenes, nitrotoluenes, and nitronaphthalenes, have been used to a considerable extent (11), but such nitrosubstitution products have not proved altogether satisfactory, as has been shown clearly by Naoúm. (14). Consequently there has been a strong tendency in recent years to replace them with one or more of several nitric esters, among which the following (29, 35) have been prominent: Dinitrochlorhydrin (monochlorhydrin dinitrate); nitrosugars, for example, sucrose octanitrate (19); tetranitrodiglycerin (diglycerin tetranitrate); nitroglycol (ethyleneglycol dinitrate); and diethyleneglycol dinitrate (13, 46, 47). Of these, nitroglycol (33, 4l, 45, 48, 49, 65) is outstanding in importance. As the Bureau of fines is naturally interested in the analytical chemistry of the "explosive oils," it seemed desirable to bring together in this report the widely scattered experimental work covering the problem of differentiation that has appeared in various chemical and physicochemical publications.]

Jan 1, 1941

By Richard N. Appling

This compilation presents information obtained through investigation of manganese deposits and a reconnaissance of potential manganese-bearing areas of southwestern Oregon and Del Norte County, Calif., from October 1952 to September 1955. The report includes maps, assays, and preliminary examination data on 39 manganese deposits distributed throughout Curry, Coos, Douglas, Josephine, and Jackson Counties, Oreg., and 1 deposit in Del Norte County, Calif. On the basis of mineral content the deposits can be divided into three groups: 1 Manganese silicate deposits, manganese oxide deposits, and manganiferous iron de-posits. Generally the oxides occur along the coast in the Curry-Coos County area, the manganiferous iron deposits are in the Josephine-Douglas area, and the manganese silicates are found in both the Josephine-Douglas and Jackson County areas. The deposits are characteristically irregular in form and usually small. Most silicate and manganiferous iron deposits are in metasediments of Triassic (?) age; oxide deposits are in sediments varying in age from Jurassic to Eocene.

Jan 1, 1957

By John S. Dunning

This paper is one of a series describing methods and costs of recovering sand and gravel from deposits in the United States and deals directly with the operations of the Atlas Sand, Gravel and Stone Co. at Farmington, Conn. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local expenditures only and not total production costs. It is recognized that publication of total costs might in some instances cause embarasement to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations may ensue.

Jan 1, 1933

By Welton J. Wenger

Apparatus for the analytical distillation of crude oils under an artificial pressure of 760 mm. of mercury has been designed and constructed. This apparatus enables laboratories at high altitudes to make Bureau of Mines routine analyses of crude oils with results similar to those obtained by laboratories at sea level. This is especially important for laboratories in the Rocky Mountain region, where barometric pressures of approximately 600 mm of mercury are encountered. During the past 30 years, the ?Bureau of Mines has made several thousand analyses of crude oils from various parts of the United States and from foreign countries. The first part (stage 1) of the distillation for the analysis is made at atmospheric pressure, and as most petroleum laboratories are near sea level, comparable results are obtained ordinarily. However, the increased use of the method by .laboratories at high altitudes has caused difficulty, as the analyses cannot be accurately compared with analyses from laboratories at sea level. For instance, laboratories at 7,200 feet generally report 2 to' 4 percent (based upon the crude oil) more gasoline than sea level laboratories. The use of the pressurized apparatus developed by the writers makes it possible for these high-altitude laboratories to duplicate analyses made at sea level.

Jan 1, 1949

By C. M. McCulloch

The natural vertical fracture system in bituminous coalbeds is called cleat. Cleat orientation commonly controls the direction of mining with major development paralleling the face cleat. Previous researchers have categorized the origin of cleat as endogenetic, relating the origin of cleat to compaction and coalification, and exogenetic, relating the origin of cleat to tectonic forces. In the coalbeds studied for this report it was found that tectonic forces were the controlling factor of cleat formation. Face cleats were formed as extension fractures during structural deformation, and butt cleats, as release fractures during erosion and uplift. The face cleat of the Pittsburgh coalbed rotates from N 80° W in north-western West Virginia to N 57° W in southwestern Pennsylvania; the face cleat maintains a perpendicular orientation to the shifting axial trend of local structures. Cleat orientation in other bituminous coalbeds in Virginia, Utah, Oklahoma, and Central Pennsylvania showed a similar relationship to local structure. Directional permeability of coal is directly related to cleat. Holes drilled perpendicular to the face cleat yield from 2.5 to 10 times the amount of gas released as compared with holes drilled perpendicular to the butt cleat.

Jan 1, 1974

By Paul G. Swanson

This manual of practice is to be used in combination with the final reports for the study of spoil stability in the Eastern Coal Province. The manual applies the predictive matrices developed in the parent study for use in evaluating the stability of typical mine spoil slopes. The values of internal friction and pore pressure coefficient are derived for many varied slope conditions. The results can be used in conventional stability analysis equations to assist the mine operator or regulatory personnel in evaluating spoil stability from very limited information.

Jan 1, 1983