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By Walter W. Kaufman

This report summarizes a study conducted to determine the state of the art of various rock removal systems and their capabilities. The Objective of the study was to determine if currently manufactured equipment can adequately accomplish rock removal in surface mine reclamation applications. Evaluations of state reclamation regulations, with regard to topsoil rock content, were made to determine the rock removal requirements. The major categories of equipment studied are rock pickers and rock rakes. The impact of rock removal implementation on the reclamation operations is discussed in detail.

Jan 1, 1979

By K. C. Dean

During the investigation of the occurrence of manganese deposits in western United States, the Bureau of Mines collected 2-ton samples from three oxide manganese ores in the Columbia and Elberta Mining Districts, Tooelo and Juab Counties, Utah. To determine the amenability of these ores to standard ore-dressing methods: of concentration, extensive laboratory tests were made. The Wildcat property, one of those sampled, is 7 miles east of Fairfield, Tooele County, Utah. The ore is described as a replacement deposit and occurs along fracture and bedding planes of shale and limestone. Experimental work was done on a sample taken from a stockpile at the mouth of the shaft. The Wildcat manganese ore is intermediate in grade (25.7 percent manganese) and contains clay as the principal gangue constituent. A high-grade product was obtained with high recovery of Manganese by simple washing.

Jan 1, 1949

By Joseph Chalmers

[Stimulative methods of production, whereby the total recovery of oil from natural reservoirs is increased, have come into considerable prominence during the past 15 years. In many oil-producing areas properties considered ready for abandonment by ordinary producing methods have responded to some form of stimulation, and their economic lives have been extended. The stimulative method having widest application is the injection of air or gas into the reservoir formations through selected input wells and is commonly referred to as the ?gas drive." As a result of the many successful "gas-drive" operations operators are depending more and more upon this method for increasing the ulti¬mate recovery of oil from their properties. A number of factors influence the efficiency of different gases as propulsive agents in recovering oil from sands. Gases of high density and viscosity shrew a tendency toward a slightly higher efficiency than those of lower density and viscosity. The solubility of the gas in the oil also affects the efficiency of oil recovery. Not only does dissolved gas decrease the viscosity of the oil, but dissolved gas that expands from solution in the oil tends to increase the effectiveness of a "gas drive." Interfacial tension between the oil and the gas and its effect upon the recovery of oil by gas injection are factors of which little is known. Dr. A. G. Loomis5 expressed the opinion that interfacial tension probably plays a minor role in the recovery of oil, except under conditions that produce a gas-oil foam. In connection with the above physical properties that influence the action of a pressure medium, control of the injected volume of the pressure medium is perhaps the major factor. The rate ofg;as injection determines to a great extent the amount of slippage and the resulting efficiency of the operation. The importance of volume control is realized when one considers that frequently it is the only factor that is under complete control of the operator.]

Jan 1, 1930

By Paul W. Jeran

This Bureau of Mines report has been prepared to provide a means whereby mineworkers without specific geologic training can recognize and record the existence of potentially hazardous geologic features encountered in coal mines. Each geologic feature described in this report has been implicated in roof failure. Through the recording of the observations of mineworkers, based on this report, a geologic map of mine workings and the associated ground control problems can be compiled. From such maps, the trends of changes and features can be determined and projected ahead of mining. The face crew can be alerted to a potential problem and what to look for as the face is advanced.

Jan 1, 1983

By Frank A. Peters

With the current renewed interest in advancing the technology for producing alumina from domestic raw materials, revisions of previous cost estimates to provide planning data are urgently needed. Completely new cost estimates on a 1973 basis are included for four alumina-from-clay processes and one alumina-from-anorthosite process. These estimates are based on new or previously calculated material balances, recalculated heat requirements, and new equipment designs. The use of larger and more modern equipment has permitted a significant reduction in labor requirements as well as equipment costs. Chemical prices, labor rates, and utility rates typical of late 1973 are used in these cost estimates. In addition to the revised cost estimates, all 21 previously published alumina evaluations compiled by the Bureau of Mines were updated to show the effect of inflation using an inflation index and late 1973 chemical prices, labor rates, and utility rates.

Jan 1, 1974

By Eugene Frey

"INTRODUCTION The Good Fortune mine was sampled by an engineer of the Bureau of Mines in June 1944. Project 984 was set up under the strategic minerals program to make old workings accessible for this sampling program. Actual operations commenced June 1, 1944, and were completed June 30, 1944.The deposit was visited and discussed briefly by Sidney H. Ball 3/ of the Federal Geological Survey in the summer of 1906 and by H. M. Chance 4/ several times from 1887 to 1900.LOCATION AND ACCESSIBILITYThe Good Fortune mine is situated in the Hartville mining district in Platte County, Wyo., approximately 9 miles northwest of the town of Guernsey. The property is about 100 miles north of Cheyenne, Wyo. (fig. 1).ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metal¬lurgical Branch, O. C. Ralston, chief, analyzes samples and performs beneficiation tests."

Aug 1, 1947

By A. B. Needham

This report describes the exploration work done in 1941 in connection with the search for strategic minerals as authorized by the Strategic Materials Act approved by the President on June 7, 1939. It deals with the various manganese deposits and showings in the Tombstone mining district of Cochise County, Ariz. The exploration project comprised a study of the geology, mapping of the areas, and exploration of various mines and deposits by sampling old drifts, crosscuts, and scopes, supplemented by diamond drilling from underground stations. The Federal Government's manganese-purchasing programs have revived interest in occurrences such as the scattered deposits near Tombstone. Because of this, the Bureau of Mines project report on the Tombstone district, prepared originally in 1941 but not published, has been revised and now is being made public.

Jan 1, 1956

By M. J. Dailey

This paper is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The property of the Silver King Coalition Mines Co. is situated in the western past of the Park City mining district, Utah, about 1 ½ miles southwest of the town of Park City, The elevation at the collar of the main shaft is 8,137 feet above sea-level.

Jan 1, 1930

By Carl Rampacek

The conversion of dilute sulfur dioxide gas into sulfuric acid by autoxidation in mechanical cells of the flotation or gas absorber types was investigated. Bench-scale tests were made with sulfur dioxide-air mixtures to determine the influence of several factors on autoxidation of sulfur dioxide, using iron and manganese salts as catalysts. The laboratory investigation subsequently was extended to pilot plant acid-making tests, using a modified turbomixer gas absorber having a 12-inch-diameter impeller. Sulfur dioxide gas was produced for the tests by roasting pyrite in a fluidized-bed reactor. In the better tests, made with manganese sulfate as the catalyst, the equivalent of 1,000 pounds of anhydrous H2SO4 was produced per 24 hours as a 10-percent solution; power consumption was 0.2 kwhr per pound of equivalent anhydrous acid synthesized. The batch and continuous tests demonstrated the technical feasibility of producing dilute sulfuric acid by autoxidation of sulfur dioxide gas in mechanical cells when converting pyrite roaster or waste smelter gases.

Jan 1, 1963

By L. D. Tracy

For many yeirs natural gas has been the principal fuel used in the he·1 ting furnaces in those mills located in the. Pi t-c;s. b.urgh district· \7hich manufacture bolts ., nuts, rivets, pick$, mattocks and srr.&11 for6ine;s. For a nUI.1"'.::>er of years the steady supply of this fuel has been more or less interrupted owing to the increased4and f·or d9mes tic use and to the increasing difficulty in securing an ad.eq_ua te c.1mount of natural gas. This condition has led a number of the steel compa.nies to substitute -oulvsrized coal a.s a fuel for the.furnaces. Elaborate irista.llations have been made for pulverizing tne coal ar!d _ coriveyi16 i -c to the fur:waces. • Soon after the furnaces ·-:commenced .. to operate ·,Vi th :pulverized coal, large quanti ties O::f.' fine dust beg.::in to accumulate on the platforms over the fu:rna. ces, the. roof trusses, on the outside of the va.rious· pip·e ·line electric cables a.i.1.d even on the roofs of the buildings. Some of tha comi:,a.n:;.0s, becomin·g alarmed, requested the Bureau of ;Unes to rr.c1ke an investigation to ascertcliin the.· licibili ty of this dust to cause an explosion.· Nhi le conducting this inves ti ga ti on,· an explosion· occurr-2! d in a.nothe:2 nill ·,7hich caused he death of one man and severely burned t;io others. Eleven sc1nrcles of the dust (which for convenience has been termed "mill d.ust 11 ) from various locations in the different mill' buildings were taken and submitted to chemical analyses, microscopic examination and also to flame and explosion tests. From the chu,1ica.l analyses it was found that· the volatile matter in th..:: dusts xanged -from 6.3 per cent to 23,54 per cent, fixed carbon from 50.88 per cent to 67.08 per cent and ash from 32.29 per cent to 32.16 per centw

Dec 1, 1919

By G. V. Sullivan

This report summarizes the results of a preliminary study concerning manganese extraction from low-grade dolomitic materials from the Philipsburg district in Montana by the Dean-Leute ammonium carbamate process. Studies were made to determine the relationship between the variables involved in treating these materials by a roast-leach process and the amount of manganese extracted. The variables studied were the roast temperature, the roast particle size, the molar ratio of NH3 to CO2 in the leach solution, the liquid-solid ratio in leaching, the leach time, and the size of the particles being leached. The roast-leach studies were statistically designed, and the experimental results were evaluated by an analysis of variance.

Jan 1, 1962

By F. E. Cash

Among petroleum refinery employees and officials throughout the United States there has been marked effort to reduce accident frequency and severity. For the interest and benefit of refineries both in Louisiana and in other petroleum-refining States it has been possible to obtain from five refineries, representing 70 per cent of the production of Louisiana, tae accident experience for the past 3 to 6 years. The companies concerned have requested that their names be not used. For tide reason the four plants listed and discussed are designated as refineries A, E, C, and D. The size of the plant as regards largest to smallest number of employees is indicated by the alphabetical order.

Jan 1, 1933

By R. E. Campbell

Uranium metal of improved purity was prepared by electrorefining commercial magnesium-reduced uranium in a molten sodium chloride-uranium trichloride electrolyte. The best operating conditions for the preparation of refined metal were established as follows: an electrolyte containing 8.7 to 13.3 weight-percent uranium; initial cathode current densities from 300 to 1,500 amp/sq ft; and a molten salt temperature of 860° C. Ingots produced from electrorefined uranium crystals prepared with these operating conditions were substantially free of metallic impurities. The only impurities in the refined and consolidated metal were present in low or undetectable amounts.

Jan 1, 1965

By C. C. Anderson, H. H. Hinson, H. J. Snhroeder

"INTRODUCTION The Eunice field is one of a group in southeastern New Mexico producing oil and gas from so-called limestone-type reservoirs in which the productive strata are dolomite or dolomitic limestone ordinarily, wells in reservoirs of this type show wide differences in their productive characteristics, indicating erratic variations in porosity and permeability. Often there is a large difference in total footage of actual ""pay"" penetrated in neighboring wells and the vertical distribution of the ""pay"" within the productive strata varies. In the Eunice field there are few easily recognizable geologic markers to indicate true structural conditions of the oil-productive section, due to horizontal and vertical gradation in chemical compositions and lithologic characteristics of the strata. Geologic markers are found some distance above the oil-producing zones in this field and consequently they indicate only the general structure. Furthermore, no direct relation has been found between the general structure and the accumulation of oil within the reservoir.Many problems in well-completion and production practice have been met in the Eunice field because of erratic variations in porosity, permeability, in vertical distribution of ""pays,"" and the apparent departure from ordinarily accepted relations of oil accumulation to structure. A detailed study of the position and characteristics of the oil- and gas-producing zones aids production procedure. The methods employed in studying the Eunice field, discussed in this paper, may be applicable to other limestone-type reservoirs."

Jul 1, 1939

By B. K. Cantrell, K. L. Rubow

"The US Bureau of Mines and the University of Minnesota have developed design and performance criteria for a personal diesel exhaust aerosol sampler for underground coal mines. These are based on the premise that size can be used to separate diesel exhaust aerosol, which is mostly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. The sampler has three stages: a respirable aerosol preclassifier, a 0.8-um aerodynamic diameter inertial impactor to collect mineral dust and a final filter to collect the diesel aerosol. Using a sample flow rate of 2 L/min and gravimetric analysis to within 0.1 mg, the measure sub-0.8 um diesel aerosol has an a-priori limit of detection of 0.3 mg/m3.A miner working in an underground coal mine with diesel equipment is exposed to a wide array of pollutants from the diesel exhaust. These include CO, CO2. NO, NO2, SO2, diesel exhaust aerosol, and a variety of hydrocarbon compounds. A quantitative definition of the health risk resulting from these exposures remains elusive. During the past several years, though, progress has been made in defining the problem.Results from epidemiological studies by Garshick et al. (1988 ), animal inhalation studies by Mauderly eta). (1986), Iwai et al. (1986), and Brightwell et al. (1986) and in vitro studies by Lewtas et al. (1986) have provided sufficient data for the National Institute of Occupational Safety and Health (NOSH) to recommend that ""whole diesel exhaust be regarded as a 'potential occupational carcinogen,' as defined in the Cancer Policy of the Occupational Safety and Health Administration"" (NIOSH, 1988). NIOSH further stated that ""though the excess risk of cancer in diesel-exhaust-exposed workers has not been quantitatively estimated, it is logical to assume that reduction in exposure to diesel exhaust in the workplace would reduce the excess risk.""The Mine Safety and Health Administration (MSHA) has also been directed by an advisory committee to establish a diesel exhaust aerosol standard and to establish regulations to minimize exposure to diesel pollutants in underground coal mines (MSHA,1988). Both reports point out the need for development of measurement techniques for respirable diesel aerosol.In the past four years, the US Bureau of Mines (Cantrell,1987 and Cantrell, et al. 1987), in cooperation with Marple, et al. (1986), at the University of Minnesota's Particle TechnologyLaboratory (PTL), have studied the use of size-selective sampling techniques to measure the mass concentration of diesel aerosol in underground coal mines. Results from these studies have been used to develop design and performance criteria for a personal diesel exhaust aerosol sampler for use in underground coal mines.These criteria are based on the premise that size-selectivesampling techniques,can be used to separate diesel exhaust aerosol, which is predominantly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. In addition to the performance criteria, this paper discusses the laboratory and field test data used to develop the criteria."

Mar 1, 1992

By Charles L. Harness

Fifty years ago, the belief that "fillers" were added to paints for the sole purpose of diluting and cheapening the pigment may have been justified; but paint technology has made tremendous progress since that time, and today both the manufacturer and the consumer know that the judicious use of fillers may add desirable properties to a paint that cannot be introduced in any other way. A growing respect for these accessory materials has led to the use of the more euphemistic term "extender." The names "extender" and "filler" are to a considerable degree synonymous. The newer term, "extender," is adopted in this paper, though it is actually no more descriptive than the older name. Stewart's3/ definition of extender is: "A cheap pigment, usually of an inert type, used to extend or increase the bulk of a paint, thus reducing its unit cost. Extenders are also used to adjust the consistency of a paint and to let down colored pigments of great tinting strength. The use of an extender in a paint does not necessarily mean the resultant product will be inferior. In fact, extenders sometimes, improve -certain characteristics of a film." All extenders are not cheap, as, for example, wet-ground mica and diatomite. Research in the, use of extenders (also sometimes called "inerts") has been one of the host active branches of study in the paint field; and many thousands of dollars have been spent in establishing the physical and chemical characteristics required of various natural mineral extenders for numerous paint formulas

Jan 1, 1943

By S. H. Lorain

This paper is one of a series on mining and milling method and costs being published by the United States Bureau of Mines. The Golden Messenger mine, operated by the United Gold Mines Corporation, is in the York-Confederate Gulch mining region in Luis and Clark County, Mont., 22 miles northeast of the city limits of Helena and about 1 mile north of the town of York. It is the first operation to exploit successfully the low-grade ores of the York-Confederate Gulch area. The unusual vein structure presents some mining problems that have been solved in ail interesting manner.

Jan 1, 1937

By John A. Organiscak

[Fugitive Just is generated alone unpaved mire reads from intermittent equipment traffic. Typically, the majority of such traffic consists of trucks hauling either mine product or waste [rum the surface mime pit and/or the processing plant. Fugitive dust generated along these unpaved mine roads includes particles of all sizes which become airborne. The potential hazards include the deleterious effects to human health of inhaled dust, traffic visibility hazards and environmental impacts on the localized area by the larger-sized visible airborne dust. Two held surveys were recently conducted to quantify fugitive dust generation and dispersion from truck traffic on unpaved and untreated mine haulage roads For these surveys., airborne glow sampling was conducted at multiple sampling fixations away from an unpaved haulage road at a limestone quarry/plant and at a coal mine preparation plant lo measure the size characteristics, concentrations. and dispersive behavior of the dust cloud generated from truck traffic- Results show that at least 80% of the airborne Just generated by haul trucks was larger than 10 µm- Airborne respirable, thoracic, and total dust concentrations all decreased and approached background concentrations 30.5 in (100 feet) from the road This report describes the average and instantaneous peak dust levels that were measured tip to 30.5m (100 feet) Iron the haulage road. Keywords: Unpaved mine road, fugitive dust, silica.]

Jan 1, 2008

By Raymond L. Lowrie

For many years it has been considered that an average of 50 percent of the coal in the deposits exploited has been recovered. Owing to many changes in mining methods during the past two decades, this study was initiated to obtain an up-to-date measurement of recovery percentage and thus establish part of the basis from which presently recoverable reserves may be estimated. Recovery percentages were determined within mined areas of 200 underground coal mines. These comprised a statistical sample selected to be representative of operating mines in relation to their significance to depletion of reserves. The results ranged from 29 to 91 percent and averaged 57.0 ± 1.7 percent (95-percent confidence limit). Six factors were identified mathematically as significantly affecting recovery percentages: (1) Pillaring system, (2) top rock and conditions, (3) bottom rock and conditions, (4) marketability, (5) coalbed thickness, and (6) productivity. Skill and attitude of mine operators toward recovery, although not measured, were probable factors. Five other variables that were tested did not show any significant relationship with recovery percentages. Also, five mining equipment features were identified, through discussions with mine officials, as affecting adversely recovery percentage at some mines.

Jan 1, 1968

By W. A. Cole

Underground mining methods at the Gray mine of Tri-State Zinc, Inc., are of special interest because of the low unit costs achieved through use of jumbos and loading equipment mounted un crawler-type tracks and of diesel trucks that haul from the stoping areas to the mill through inclined adits. The operating company, Tri-State Zinc, Inc., is a wholly owned subsidiary of Gold Fields American Development Co., Ltd., the latter being the American branch of New Consolidated Gold Fields, Ltd., a British-owned company.

Jan 1, 1957