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By M. M. Fine

A laboratory mineral-dressing investigation of manganese ore from the Martin mine, Independence County, Ark., succeeded in recovering ferrograde manganese products. Sintered flotation concentrates analyzing 40.7 and 41.4 percent manganese at overall recoveries of 54.6 and 47.7 percent, respectively, were produced from preconcentrated feed, Preconcentration of the ore for flotation included treatment by magnetic separation and by a combination of magnetic separation and heavy-medium processing. The mineral-dressing study of the Martin mine rhodochrosite ore was part of a general program of the Bureau of Mines to develop domestic sources of strategic minerals, including manganese. Several such potential sources of manganese exist in the Batesville, Ark., district, one of which is represented by the Martin mine. Although the Martin mine area has not been delimited with respect to total reserve tonnage, it is considered to be one of the more important occurrences of manganese in the district. It is estimated that several 100,000 tons of manganese carbonate ore are present in this and similar properties.

Jan 1, 1954

By A. A. Cochran

Bureau of MinesThe Bureau of Mines studied the development of practical methods for recovering manganese from the extensive domestic resources of low-grade ores and open hearth slags. A one-step operation was developed on a laboratory scale in which manganese and iron compounds are treated with chlorine, volatilized, and separated by selective condensation. Manganese recoveries of 90 to nearly 100 percent were obtained from 9 of the most important domestic ores. Analyses of the manganese chloride product indicated that it was suit-able for aqueous electrolysis with little additional purification. A complete, integrated process that provides for the recovery and recycling of chlorine is proposed. This process appears to have distinct advantages over previously proposed manganese recovery processes, and, in sharp contrast to leaching procedures, it is applicable to practically any manganese-bearing material.

Jan 1, 1967

By T. M. Romslo

"The Keystone and St. George properties are in the so-called Johnson Camp area and adjoin a property that in recent years has become a steady producer of low-to medium-grade copper-zinc ores. The Keystone Copper Co. was active intermittently from 1908 to 1938 and during 1926 to 1937 produced a recorded 1,100 tons of 5 percent copper ore. There is no evidence that ore has been produced from the St. George property.In the Johnson Camp area both igneous and sedimentary rocks ranging in age from pre-Cambrian to Quaternary are exposed. The ore bodies are in the Paleozoic rocks and occur principally in the Abrigo formation, which is composed mainly of limestones and shales. The rocks of the productive zones are metamorphosed and are cut by systems of fractures and faults. Chalcopyrite and sphalerite, the principal ore minerals, replace altered limestones to form deposits locally called mantos and chimneys.Investigation of the Keystone and St. George deposits by the Bureau of Mines included topographical and geological mapping of the surface and the underground workings and diamond drilling from the surface. A total of 10,067.8 feet was drilled in 22 holes. The drilling started November 13, 1947, and was completed August 19, 1948.This report records factual information obtained during the course of the investigation."

Jul 1, 1949

By C. C. Hwang

The Bureau of Mines formulated a method for calculating the concentration of entrained dust from a dust deposit by a turbulent gas stream. In particular, a diffusion equation is used to calculate dust concentrations in a channel following an explosion. Dust leaving the channel walls was treated as originating from stationary or moving, and single or multiple material sources. Formulas and sample computations for various types of dust sources in circular and rectangular channels are given, based on experimental entrainment rates. The analysis predicts the dust concentration as a function of time and channel space. The results appear to agree with the physical characteristics of explosion-driven dust dispersion in a O.6-m-diameter, 50-m-long explosion tunnel. The analysis is also applied to simultaneous and consecutive dispersion of coal and rock dust from simulated coal mine surfaces (walls, floor, roof, and ribs).

Jan 1, 1974

By Fred D. Wright

This paper describes research at the Bureau of Mines experimental oil-shale mine at Rifle, Colo., to improve blasting techniques and reduce breaking costs. Many of the conclusions are applicable to any mining operation. Experiments Were conducted on many phases of blasting. The effectiveness of various grades of explosives was compared, and several different drill-hole patterns were tried in heading rounds. An experiment was conducted to determine the maximum effective burden for various diameter blast holes. High-speed motion-picture studies were made of blasts, and the time for initial movement of rock after detonation of the explosive was measured. Experiments with millisecond-delay detonators in heading rounds proved that, when used properly, these detonators result in improved fragmentation, economical use of explosive, and compact, easily loaded muck piles.

Jan 1, 1953

By R. H. Nafziger

Bureau of Mines research has shown that very low-sulfur pressure vessel steels with improved mechanical properties can be prepared by two melting processes. Four pressure vessel steels having sulfur contents ranging from 0.0008 to 0.0040 wt-pct, were produced by the electric-arc furnace or by the electroslag processes. Calcium carbide was used as a desulfurizer in the electricarc furnace. Fluxes containing at least 40 wt-pct CaO provided sufficient desulfurization during electroslag remelting. Element recoveries were higher for electroslag remelting than for metal melted in the electric-arc furnace. Bar rolled from electroslag-remelted ingots generally possessed higher tensile strengths and ductility than bar rolled from it t melted in the electric-arc furnace. Charpy V-Notch upper shelf energies were also improved as a result of electroslag remelting. The primary failure mode during impact testing was was microvoid coalescence. Sulfide inclusions were minimal, especially in the electroslag-remelted material.

Jan 1, 1979

By George H. Holmes

This paper is one of a series being prepared by the Minerals Division of the Bureau of Mines on mining and milling methods and practices at various mines in the United States. It describes such methods at the Caselton mine of the Combined Metals Reduction Co. The Caselton mine and mill are in secs. 28 and 29, T. 1 N., R. 67 E., M. D. B. & M., Lincoln County, Nev., about 10 miles by paved highway south- west of Pioche, Nev. (fig. 1). the history of the district and company This circular summarizos operations, describes physical features, labor and living conditions, the geology, ore deposits, and the ore. Prospecting and exploration methods are outlined, and shaft sinking, drifting and crosscutting, and raising are covered under development methods. In the soction on mining mothods, stoping and slushing are discussed, following which are descriptions of underground transportation, hoisting, ventilation, drainage and sampling, and surveying. The surface and crushing plants are described, and milling practices are presented in dotail with explanation of the filter plant and assay office. Safoty practices and the company organization are described in the concluding sections of the circular.

Nov 1, 1950

By S. L. McGill

The U.S. Bureau of Mines has determined the microwave heating rates for a suite of minerals and reagent-grade compounds. Maximum temperature achieved for the samples and the time required to reach temperature are reported. Heating rates of powdered samples are presented as a function of incident powers up to 3,000 W at 2,450 MHz. Descriptions of the microwave cavities, test cells, and a thermocouple assembly used to measure temperature in the microwave field are given. Many minerals of value heated in the microwave field, whereas host rock or gangue materials did not. In general, heating rates increased as incident power was increased. Exceptions to this were some very good (CuO, Fe304, and PbS) and very poor (CaC03 and SiO2) microwave-absorbing materials that showed negligible changes with increased power. Applications demonstrating the use of microwave energy in mineral processing that are described herewith include oxidation-reduction reactions, mineral liberation, and mercury retorting-vaporization. Microwave data on mineral heating rates will provide insight to possible chemical and mineral processing applications as well as assist in predictions of processing parameters.

Jan 1, 2010

By C. Harry Benedict

This paper, describing the leaching practice at the Calumet and Hecla mills, Lake Linden, Mich., is one of a series on milling methods and costs being published by the United States Bureau of Mines. GENERAL DESCRIPTION The reclamation plant is located along the shores of Torch Lake at a slightly lower level than the concentrator itself. The entire location of the original concentrator, in connection with the present reclamation plant, has been ideal, lore particularly as the leaching and flotation departments are common to both units. After 15 years of operation and with the reclamation sands just a little more than half exhausted it would appear that the remaining life of the deposit could be worked by the present plan, without decided changes or renewals of plant or equipment.

Jan 1, 1930

By C. R. Kuzell

This paper, describing the concentrator practice of the United Verde Copper Co., is one of a series being prepared by the Bureau of HISTORY The United Verde concentrator was constructed in accordance with recommendations based on certain novel reasons which were quite different from those usually justifying the expenditure of such an amount. Concentrator operations started in March, 1927, although the metallurgical staff had considered for several years the eventual addition of a concentrator department.

Jan 1, 1930

By David T. Couillard

Task training is increasingly important in mining operations because of the ever-accelerating pace of technological innovations and the concomitant increasing complexity of mining equipment. This Bureau of Mines report describes two successful task training program In use in two open-pit taconite operations in northeastern Minnesota. The programs are different in approach, but both have improved safety and in- creased productivity while lowering costs. Methods of training both before and after passage of the 1977 Mine Safety and Health Act are described, and the impact of this act on task training at each operation is discussed. The report identifies four common principles that have contributed to the success of the two training programs and presents plans each operation has for improving future training through new technology.

Jan 1, 1984

By D. S. Harper, C. O. Carman

A German coal planer was put in operation in the Keystone mine of the Eastern Associated Coal Corp. , Keystone , W. Va . , in August 1960 . At present , the planer is mining in the fourth panel . The blocks of coal mined were 340 by 1,900 feet in panel 1 , 340 by 1,660 feet in panel 2 , 590 by 1,900 feet in panel 3 , and panel 4 , currently being mined , is 590 by 1,900 feet . Almost one- half million tons of coal have been mined from these four panels . An 11 - man crew handles the complete planer operation and produces an average of 500 tons of clean coal per shift . Self - advancing hydraulic props are used to support the roof over the entire face . Roof control and action on all of the panels has been highly satisfactory . During periods of extreme pressure , some additional support is required in the tail entry where evidence of weight from the retreating longwall extends about 200 feet outby the face . The time lost from production by moving equipment between panels has been reduced steadily . The move from panel 3 to panel 4 required 5 days , but it is believed that even that time could be reduced .

Jan 1, 1963

By John E. Rourke, O&apos

A survey of existing and developing field permeability test methods was conducted in order to identify and specify capable methods to be used in feasibility investigations or performance monitoring for in situ leaching of ore deposits. Geologic settings of leachable deposits are discussed, as well as representative techniques used for the in situ leaching operation. Subsurface investigation techniques including drilling, core recovery, and down-hole inspection methods relevant to field permeability investigations are discussed. Field experience is examined and capable field permeability test methods are identified. Specifications for test borehole preparation, test performance. and methods of analysis are given. The test methods are comparatively rated in a matrix with respect to costs ease of use, and data effectiveness' for a broad range of conditions. Well Pump and Packer test methods receive high ratings. Recommendations are made for needed developments in field permeability test methods and a comprehensive bibliography is given.

Jan 1, 1977

By P. T. Brooks

Semipilot scale tests were made to demonstrate a newly developed electrorefining process which could be extrapolated to commercial scale in producing high-purity nickel and cobalt from crude nickel metal and high-grade ferronickel. The new process comprises application of solvent extraction techniques to remove and separate cobalt and iron from nickel and the electrodeposition in diaphragm cells of pure nickel and cobalt from chloride-based purified electrolyte. Using water insoluble organic amines, the solvent extraction operations enabled production of commercial-sized nickel and cobalt cathodes of higher purity than that of commercial electrolytic metals. The solvent extraction operation for separation of cobalt from nickel was made simpler than the conventional method. Furthermore, the solvent. extraction operation for iron removal made possible the electrorefining of ferronickel without the prohibitive loss of nickel resulting from the method ordinarily used for iron removal.

Jan 1, 1970

The Department of Interior, U.S. Bureau of Mines performs the task of estimating the quantity of coal reserves existing in each state on a county by county basis. As a part of Information Circular 8655, the Bureau of Mines established the criteria for the uniform estimations of coal reserves and listed the most recent estimates of coal reserves by county and by seam. At the same time however, the Bureau recognized that these figures represented the upper bound with regard to the estimated actually usable or obtainable reserves. Recovery of these reserves are subject to the mining methods used and to the resolution of such problems as the use of poor quality coal and competition provided by conflicting land use. These problems, in practice restrict the recovery of the estimated quantities of coal reserves listed in IC 8655. Another impact, the subject of this manual, is the impact resulting from previous mining activities. In particular, many of the reserve seams included in the reserve estimates overlie or underlie mined-out coal beds. Portions of these reserve seams may therefore be unmineable or at best may have a reduced quantity of extractable coal. In order to improve the accuracy of the coal reserve base estimates, the Bureau of Mines funded an effort1 to develop a systematic methodology for estimating the coal loss associated with the impact of previous mining activity. The coal loss calculation model (CLCM) described in this manual is a result of that effort and addresses the percentage of coal loss in reserve seams due to previous overmining or undermining.

Jan 1, 1976

By Steven R. Ruggieri

This report documents the work performed and the results obtained during the field demonstration of the Remote Sealing System at the USBM's Jenny Mine near Inez, KY in the Fall of 1978. Although various portions of the Remote Sealing System had been used on a number of prior occasions, the field demonstration at Jenny Mine marked the first use of the complete upgraded system including the use of the inert gas generating system for seal placement and the first application of the new froth foam system. The objective of the field demonstration at Jenny Mine was to demonstrate the complete system by emplacing and evaluating several complete underground seals under conditions representing those of a mine fire situation. Several critical sealing conditions were identified including: ? High entry airflow ? Standing water (1 to 2 ft) in the entry ? Flowing water (150 gal/min) ? Irregular roof ? Sealing a 4-way intersection. Four seals were successfully placed under the conditions mentioned above. The demonstration served to verify proposed techniques to handle these conditions as well as to dispel any doubts about the system's capabilities. As a result of the successful field demonstration, the Remote Sealing Equipment is now under the jurisdiction of MSHA's Mine Emergency Operation ready for a mine fire emergency.

Jan 1, 1980

By R. O. Dannenberg

The Bureau of Mines conducted laboratory investigations with the objective of developing an alternative process for recovering cobalt and copper from complex sulfide concentrates. Processes currently used depend largely upon precipitation techniques to remove impurities and recover cobalt from sulfate liquors prepared by oxidative pressure leaching of the sulfide concentrates. The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H202 oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic acid extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 pct Cu.

Jan 1, 1987

By John M. Devine

The severe corrosion of equipment that is caused by the presence of hydrogen sulphide in oil and gas has been described in detail by several authors. Such corrosion, termed "low-temperature hydrogen sulphide corrosion", presents a somewhat different problem from the "high-temperature hydrogen sulphide corrosion" that is encountered in refinery operation and which has been described by various-investigators of refinery corrosion.

Jan 1, 1932

By H. M. Smith

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Jan 1, 1927

By Mark Sheppard

[Considerable research work hi been done on secondary crushing and coarse and fine grinding, and the literature on the general subject of Crushing contains many references to the work of investigators on the laws governing end the factors entering into the economical production of fine materials. However, little information on primary crushing in available The literature deals mainly with problems and practices in ore dressing, end in this field the engineer or investigator is concerned largely with the production of fine material and the unlocking of minerals in the ore. Under such conditions close control of screen sizes of primary-crusher products is a secondary consideration and has received very little attention.]

Jan 1, 1938