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By L. J. Kane

While analyzing synthesis gas produced from coal, the Bureau of Mines found that conventional procedures for naphthalene determination were difficult and time consuming. The Bureau developed a rapid and sensitive turbidimetric procedure, which requires only simple instruments and hence can be used in plant-control laboratories. The gas is passed through a saturated aqueous solution of picric acid at 3° to 4° C. whose turbidity is then measured at room temperature. A dispersing agent is added to prevent coagulation of the suspension on warming. Only about 1 mg. (0.015 grain) of naphthalene need be absorbed, and precision and sensitivity are a few ten-thousandths of a grain, or a few hundredths of a grain per 100 cubic feet. The determination can be completed less than 10 minutes after absorption. INTRODUCTION One of the functions of the Branch of Coal Gasification, Bureau of Mines, Morgantown, W. Va., is to develop economical methods for manufacturing, from coal, a mixture of hydrogen and carbon monoxide for producing hydrogen, methane, and other gaseous fuels. This raw gas may contain many impurities, including naphthalene. This impurity is usually determined by first forming naphthalene picrate in a water solution of picric acid, separating the picrate, and titrating the unreacted picric acid or the picrate itself.

Jan 1, 1957

By J. Hadjigeorgiou, Y. Potvin

In a benchmarking paper published in the SAIMM Journal, Potvin and Hadjigeorgiou (2008) reviewed ground control strategies to manage large deformations in underground hard rock mines. Significant differences were identified in the design and acceptable tolerance between civil and mining engineering practice for squeezing ground conditions. Variations were also noted in ground support strategies between Australian and Canadian mines. In this paper we review progress in design methodology and ground support practice since 2008, including the availability of more effective deformation monitoring, new design tools, greater access to yielding ground support elements, and better installation practices. An improved understanding of technical and practical issues associated with squeezing conditions has led to the development of ground support guidelines for a range of squeezing ground conditions in hard rock mines.

Jul 5, 2023

By A. E. Lindquist

This Bureau of Mines publication identifies areas having sufficient coal reserves to support synthetic natural gas (SNG) development and summarizes those areas having the highest potential. Capital requirements, mining and coal cost factors, water availability, and coal-quality data pertinent to SNG production are presented. Evaluation of individual coal reserve blocks was based upon coal and water requirements of the Bureau of Mines Synthane coal gasification process.

Jan 1, 1977

By Carl F. Wingquist

Electrical resistance heating to effect thermal fragmentation of semiconductive rock was examined by the Bureau of Mines. Tests were carried out on copper-bearing ores of the Nonesuch Shale Formation in the laboratory and in the the field at White Pine, Mich. Fieldwork included primary and secondary breakage tests. Heating tests on in situ rock failed to produce thermal dam-age to an extent considered useful; however, boulders up to 30 ft3 were effectively broken by the method. Power input to the test rock was taken from a 50-kV, 5-amp dc power supply.

Jan 1, 1976

By Albert L. Toenges

This report is the second of a series describing methods and systems of mechanical mining; where operations are conducted on more than one shift. The first report, Information Circular 7014,4/ describes mining operations at 14 mines and the present paper describes operations at 11 additional mines. The purpose of this study is to analyze the advantages and disadvantages of the various types of equipment and mining systems now used where more than one shift is worked per day. Physical conditions vary in different and in the same mining districts and determine, together with economical considerations, the systems of mining and the types of mechanical loading equipment to be used. The information presented in this paper may be helpful to operators or others who may contemplate installing a mechanical mining system. The equipment used in the mines described comprises conveyors, scrapers, mobile loaders, mobile conveyors, and combination of these types. The description of the mining systems and practices at the mines investigated is detailed only as they relate to and affect mechanization. In computing the operating data in mines that are not totally mechanized, employees not working directly on production have been charged to output from mechanized sections in proportion to the percentage of mechanization. The operating data for comparing various systems are for an average working dry, as the number of men working on idle days varies greatly in different mines.

Jan 1, 1939

By N. Morrison, I. Holl, R. Welyhorsky, A. Hempstock

ABSTRACT: The Victor diamond mine is located in the James Bay lowlands, 90 km west of the First Nations village of Attawapiskat. The project was the first of its kind in northern Ontario. The process plant was designed to produce a 95 to 98% by weight diamond concentrate through three stages of comminution, dense medium separation, and proprietary X-ray technology for final recovery. The plant was commissioned over a period of six months, commencing prior to substantial completion of construction. Through effective planning of the commissioning phase, the Victor mine start-up was safely completed nine months ahead of schedule.

Jan 1, 2011

By M. R. Grundy

The Robinson project is based on the porphyry copper and gold deposits in the Robinson Mining District, near Ely in Eastern Nevada. The district was mined from the late nineteenth century to 1978 by Kennecott Copper Corporation and its predecessors. Operations ceased when falling copper prices in the late 1970's made their outdated mill and smelter complex at McGill uneconomical. In October 1991, Magma Copper Company (Magma) acquired the many claims that cover the known porphyry copper deposits in the district These occupy a disturbed area about nine miles long and three miles wide between the towns of Ely and Ruth. Magma proposes to build a copper / gold mine and concentrator and expand the existing gold leaching facilities. Several pits, previously mined by Kennecott Copper Corporation, will be enlarged; the use of larger, more modem equipment will result in higher productivity and lower operating costs in general. ICF Kaiser Engineers, of Oakland, California, were awarded the con-tract for detailed design of the process facilities, which was essentially complete by the end of 1993. The project at present is awaiting completion of the environmental permitting process; state air and water permits are in hand, and the Bureau of Land Management's (BLM) current schedule indicates that the final obstacles to construction will be cleared by early fall of this year.

Jan 1, 1994

By A. Slotwinski, R. E. Barry, M. M. Menon, P. T. Spampinato

"A coherent FM laser radar based sensor for remote metrology of plasma facing material surfaces in a fusion reactor is described. The sensor is capable of 3-D mapping of surfaces, based on a series of precise range measurements from large distances (up to 20 m). Other features include the ability to operate under adverse environmental conditions involving very high gamma radiation (3xI04 Gy/hr), ultra-high-vacuum (<I0-5 Pa), and high temperature (200°C). The paper describes the basic principles of the sensor, together with experimental results obtained with the sensor. The ability of the sensor for remote rendering of ""visual quality"" images without the need for any external illumination is also illustrated.IntroductionMeasurement of the features of large area surfaces (-1500 m2) to sub-millimeter accuracy, from relatively large distances (20 m), is necessary in the case of the International Thermonuclear Experimental Reactor (ITER -a 1500 MW fusion reactor that is currently in the design phase). Furthermore, the measurements may have to be performed after the reactor is temporarily shut down. During such shut-downs, the ITER in-vessel environment will be highly radioactive due to neutron activation of the reactor wall (gamma radiation field of 3xl04 Gy/hr), the vessel will be maintained under ultra-clean vacuum conditions (<10-5 Pa), and the plasma facing surfaces will be maintained at elevated temperature (200°C). Therefore, the precision measurements must be conducted remotely, and because of the large dimensions of the fusion reactor and the limited number of access ports, the measurements must be done from large distances. The reactor vessel is a large toroid. Fig. 1 shows the cross section of the toroidal vacuum vessel, and the location of the metrology probe. Because of the very large surface area involved, fast scanning capability is also needed to reduce the reactor down-time."

Jan 1, 1997

By Gary E. Sherman

To aid the U.S. Army Corps of Engineers in their Resource Development Navigation Study of ten existing or proposed port sites in Alaska, the Bureau of Mines examined the potential for mineral development around three Alaska port sites: Iliamna Bay, Kotzebue, and Nome. The mineral deposits near Iliamna Bay include gold, copper, and iron. Development of minerals in this area will require the discovery of new deposits or the definition of additional are reserves at known deposits. The mineral deposits near Kotzebue are primarily gold, copper, coal, lead, and uranium. Based on the character of these deposits, it appears that development of a small-scale mine supplying coal for regional use is the most likely scenario in the near-term. The mineral deposits near Nome are primarily gold and copper. Development of small underground gold mines is possible, however it appears that expanded offshore gold dredging will have the greatest impact on the flow of freight and goods through the Nome port in the near term.

Jan 1, 2011

By Christian Wögerer

For material or process development as well as for quality checking of materials, thermal diffusivity measurement may be the tool of choice in many applications. Especially if diffusivity is measured locally resolved, a lot of information can be read out of such a ?diffusivity image?. This paper explains the method to measure coplanar specimen like plates and lists some interpretations of diffusivity images, like inhomogeneity of sintered materials, structural voids or inclusions. Diffusivity is a material property, describing transportation of heat in solids in spatial and temporal terms. With thermo cameras it is possible, to measure diffusivity of larger areas simultaneously. The result is an area of diffusivity values that may be plotted or displayed like an image. Locations with lower diffusivity values could be caused by the presents of structural differences in the material, by decomposition of the material components or by inclusions of other material like air.

Jan 1, 2009

By J. L. Hoffman, F. W. Wood, R. A. Beall, W. E. Anable

For melting and purifying reactive and refractory metals , two electronbeam furnaces have been constructed and operated on the principle of highpowered vacuum diodes . It was necessary to design the vacuum and electrical systems , mechanical features , and operating procedures to cope with dynamic conditions . Vacuums of 10-5 torr , tens of kilowatts of power at 5 to 10 kilovolts , and the evolution of impurities at thousands of liters per minute constitute a challenging combination . The furnaces have been used to melt either button specimens weighing several hundred grams or , by feeding material as a consumable electrode , small ingots weighing several kilograms . Hafnium is among the metals that can be purified . For example , hafnium starting material with Rhn 94B was softened to Rhn 70B after 2 hours of melting under a 25 - kw electron beam , and impurity levels were reduced as follows : Oxygen , from 700 to 350 ppm ; nitrogen , from 71 to 20 ppm ; hydrogen , from 6 to 1 ppm ; aluminum from 75 to < 20 ppm ; chromium , from 80 to < 10 ppm ; iron , from 100 to 40 ppm ; and silicon , from 40 to < 20 ppm .

Jan 1, 1963

By Arno C. Fieldner, Howard I. Smith, J. W. Paul, SAMUEL SANFORD.

Many mine samples of coal are analyzed each year in the laboratories of the Bureau of Mines. The analyses are made in connection with investigations relating to fuels belonging to or for the use of the United States Government, the causes of accidents in coal mines, the geologic relations of coal beds, and the character and the value of the coal and lignite in the public lands. The systematic collection and analysis of such samples in connection with fuel investigations was begun in 1904 at the Government fuel-testing plant at the Louisiana Purchase Exposition, and was under the direction of the United States Geological Survey for six years. Descriptions of the coal samples collected between the beginning of this work, July 1,1904, and the transfer of the fuel-testing and mine-accident investigations to the Bureau of Mines, July 1, 1910, were compiled and published in Bureau of Mines Bulletin 22.a Descriptions and analyses of samples collected during the fiscal years 1911 to 1913 were published in Bureau of Mines Bulletin 85.b The present bulletin presents analyses and descriptions of samples collected during the fiscal years 1913 to 1916. In order that the material in this bulletin may be used to supplement that presented in Bulletins 22 and 85, the same plan of geographical classification has been followed, the analyses and descriptions of the samples being grouped in alphabetical order according to the State, county, and town near which the mines or prospects sampled are situated.

Jan 1, 1918

By A. Dutta, B. Devulapalli, A. Mukhopadhyay, E. W. Grald

"Computational Fluid Dynamics (CFO) has matured over the past two decades as an analysis tool for conducting virtual experiments with significant time and cost savings. It complements and reduces physical testing. CFO has penetrated the diverse materials industry in much the same way as Computer Aided Design (CAD) did more than a decade ago. As the basic numerical algorithms used in CFO have steadily improved, so have the reliability, consistency and user-friendliness improved significantly, too. Other recent trends have also contributed to the rapid growth and widespread adoption of CFO. In this presentation, CFO applications from several materials processing industries will be presented using case studies. Emphasis will be on metals, glass and semiconductor applications.IntroductionThe term materials processing covers a diverse array of industrial applications and products today. From the continuous casting of steel, to the deposition of semiconductor materials atom by atom, to the extrusion of molten polymers, materials processing applications span an incredible range of length scale, process times, pressures, temperatures and velocities. The properties of the materials themselves, in terms of density, viscosity, thermal conductivity, etc., can be complex functions of temperature, shear rate, chemical composition and time. And the processing equipment may be very complicated in geometric shape.Computational fluid dynamics (CFD), the technique of solving the governing equations of fluid motion and other related phenomena using a computer, has enjoyed widespread and rapid growth, which started in the aerospace and automotive industries. More recently, CFD has also been successfully applied to a great many materials processing problems, in spite of the challenges described in the previous paragraph. The reasons for the growing usage of CFD in materials processing are many. Using CFD to test design options and reduce the number of physical prototypes can decrease the time and cost associated with new product and process development. CFD gives insight and provides detailed predictions of operating conditions in lieu of difficult, intrusive and often expensive experimental methods. CFD can be used as an aid to scale-up processes from lab or pilot scale to full production. Troubleshooting the performance of existing equipment is often carried out with the help of CFD. Determining how an existing piece of process equipment will operate under new conditions, or with new input ,materials, is also a common task for CFD."

Jan 1, 2004

By P. Koskinen

Outokumpu Oy has 30 years&apos; experience in nickel production. It is mainly based on the technology developed within the company. The production chain starts from the mines reaching to the high-grade cathode nickel and the stainless steel manufacturing. As a multi-metal producer Outokumpu has the advantage to exploit from nickel raw materials also other valuable metals and intermediate products which can be processed at the company&apos;s various plants. The main source of nickel concentrate is nowadays the Enonkoski Mine started up in early 1986. It is the most modern mine in Finland being provided with the latest Finnish high-tech systems. Nickel concentrates are smelted at the Harjavalta Works using Outokumpu&apos;s internationally well-known flash smelting method. Also nickel containing residues and secondaries&apos; are used as raw materials. The high-grade nickel matte from the smelter is then refined at the nickel refinery in a hydrometallurgical process, which was also developed by the company&apos;s own research staff. These processes have been continually improved and capacities gradually enlarged to 18 000 mtpy of cathode nickel. Besides plating, melting and superalloying purposes part of the nickel ends in stainless steel at the Tornio Works. The production was started in 1976 and has reached an established position on the European market.

Jan 1, 1988

By J. W. Paul

This circular is one of a series of reports on coal mining methods and cost s which are being prepared by the U. S. Bureau of Mines for the purpose of making available to those interested in the industry a knowledge of the mining methods employed in mines where mechanical and hand loading is practiced and the cost data on the several operations pertaining to the removal of coal from the working faces and its transportation to the tipple for loading into railroad cars. The methods employed are influenced by the natural local conditions with respect to the thickness and character of the coal beds and the overlying strata, the means employed for roof support and its control, and the disadvantages incident to the development of mines in thin coal beds.

Jan 1, 1929

By H. Ranjbar

The Darrehzar porphyry Cu deposit is situated in the Urumieh-Dokhtar magmatic suite of Central Iran. The REE and trace element data suggest that the deposit lies within a continental margin setting. Phyllic and propylitic alteration are pervasive in the area but potassic and argillicalteration are not readily recognized on the surface. This is possibly the result of super gene weathering of the surface rocks or because of an intense phyllic overprint. Poor soil development and abundant outcrop make the area suitable for a case study of lithogeochemical exploration technique for Cu deposits. A total of 262 rock samples was collected over the area and analyzed for 15 elements. The geochemical data cor-relate with the mineralogical composition of the rocks with the phyllic zone being marked by high-er concentrations of Si, Al, K, and by a high sericitization index while Ca, Mg, Sr, total Fe and Mn are more abundant in the propylitic zone. The lithogeochemical study indicates a metal zonation from a Cu + Mo-rich core to a Zn + Pb ± Ag-rich outer zone. Principal component analysis is useful for separating element associations, which in turn reflect the alteration halos. Principal components 1 and 2 depict alteration zoning, where-as 3 shows an association of Cu and Mo, that roughly defines the mineralized area.

Jan 1, 1997

By J. J. Bean

The development drilling program of the Copper Cities mine indicated that the molybdenum content of the ore would be about 0.011% MoS2&apos; The molybdenum content of the Miami mine at the same time was about 0.025% MOS2&apos; The Miami mill had a very successful molybdenum operation which used bleeder turbine steam from the Miami power plant for the steaming operation. The much lower grade of the Copper Cities ore, the absence of a source of low cost steam and the use of sodium aerofloat as the copper collector which Miami experience indicated did not respono readily to the steaming technique made very doubtful the success of a similar operation at Copper Cities. However, the relatively few pounds of copper that could be recovered from the low grade Copper Cities heads made very desirable the recovery of the molybdenwa,as a source of additional revenue. Accordingly, shortly after the Copper Cities mill began operation, a research program was instituted to develop a suitable method of molybdenum recovery. This program explored first, the successful steaming process then in use at Miami and as expected, found it unable to decompose the sodium aerofloat copper collector. The known chemical depressants were then tried without much encouragement. Finally the copper concentrate was dried, not roasted, to 2-3% mOisture and this along with sodium ferro-cyanide and cyanide resulted in sufficient copper depression that a final molybdenum concentrate containing 1.0% CU could be made. The bench scale testing was followed by pilot plant testing. Sixteen

Jan 1, 1972

By Yury V. Kulikov, Rakan Rahbani, Arkady Y. Senchenko

"The relevancy of complex minerals treatment is constantly increasing taking into account mineral resources depletion. Different refractory ores and concentrates, oxidized and polymetallic ores, as well as metallurgical products (slags) can be assigned to such mineral type. The treatment of such products via conventional flowsheets requires considerable capital and operational costs and does not always provide high recovery level of valuable components into a saleable product. Therefore, considerable amount of ores and metallurgical products are not treated, or treated inefficiently. One of the most promising approaches that allows economic treatment of refractory products is their ultrafine grinding down to 5-20 µm with subsequent processing or hydrometallurgy. Horizontal bead mills - the IsaMillTM, developed by Xstrata Technology, received their wide application in mining industry. Standard testing is performed under laboratory conditions in an M4 IsaMillTM (volume - 4 liters) to define the parameters of fine grinding. This mill completely simulates the operation of full scale industrial mills up to 50 m3 in volume (up to 8000 kW motor). The paper describes fine grinding technology performed in bead mills, and the importance of testing according to a certified method for industrial equipment selection. The paper contains description of promising directions of fine grinding technology application for several projects in Russia and Kazakhstan."

Jan 1, 2014

By R. R. Brown

The solubility and the activity of aluminum chloride hexahydrate, A1C13?6H2O, in aqueous solutions were determined as a part of the Bureau of Mines, U.S. Department of the Interior, research to improve mineral processing technology for recovering alumina from low-grade domestic resources. The solubility of A1C13 in pure water was found to be 31.09 and 31.77 wt-pct at 25° and 85° C, respectively, and decreased drastically to 10 and 0.1 wt-pct when the respective amounts of 20.3 and 37 wt-pct hydrochloric acid (HCI) were added in solution. The equilibrium constant for the solubility of hexahydrate, activities, and activity coefficients of A1C13 and H2O were calculated and compared with the results from the available methods of estimation. The results were shown to be useful in leaching nonbauxitic ores for extraction of alumina by changing the solubilities of component salts upon addition of HC1. Simultaneous solubilities of A1C13, FeC13, KC1, and NaC1 in solutions of HC1-H2O were also determined and their effects on the purity of A1C13?6H20 crystallized from mixed salt solutions are briefly discussed.

Jan 1, 1979

By Steven E. Mischler, Jay F. Colinet

The study analyzes the impact of the Continuous Personal Dust Monitor (CPDM) on reducing overexposures to coal mine dust. It compares compliance sampling data before and after the implementation of the CPDM and the 2014 MSHA dust rule. The results indicate a significant reduction in the percentage of samples exceeding the dust standard for various mining occupations, highlighting the effectiveness of the CPDM in improving miners’ health and safety.

Feb 22, 2022