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By K. Osseo-Asare

"The molecular structural and solution chemical characteristics that underlie the surface activity of solvent extraction reagents are highlighted, with particular emphasis on the tendency towards reverse micelle and microemulsion formation. The physicochemical factors that lead to microemulsion-enhanced solvent extraction with chelating extractants are elucidated. Membrane-based contactor systems are described which are uniquely suited for enhanced solvent extraction with microemulsions. The possibility of combining solvent extraction with microemulsion-mediated materials synthesis is discussed. IntroductionThe discovery of new selective extractants has resulted in major breakthroughs which have helped to establish solvent extraction as a versatile separation technology (1-3). A complementary strategy towards new process development is to seek new ways of using the available reagents. This paper explores this second approach. From a molecular structural standpoint, an extractant may be viewed in terms of two components: a polar functional group and a hydrocarbon radical. In the conventional view of solvent extraction, this molecular structure serves two main purposes: The polar functional group provides the binding sites for complexation of metal ions, while the organic group is needed to render the resulting metal-extractant complex organic-soluble. But are these the only properties of the organic and the polar groups that are relevant to the solvent extraction process?In this paper, attention is directed to the fact that solvent extraction reagents possess the molecular structures of amphiphiIes; that is, they are characterized by the presence of spatially separated hydrophilic and hydrophobic groups on the same molecule. A case is made for the view that this amphiphilicity offers interesting opportunities to develop new separation processes which collectively may be described as enhanced solvent extraction (4-6)."

Jan 1, 1996

By F. Baldini, M. S. Borges

"The proposed method emphasizes the optimization of waste management with regard to the exploitation of raw materials incorporated in the remains of industry, as well as the economics of natural resources as an environmental impact assessment. This system [tool] allows: (a) the conversion of an environmental liability into an asset by finding a line of appropriate research for each type of waste and the development of new materials applicable to other industries, (b) the performance of internal control of the waste generated (production, storage, final destination) as well as legal conformity.Objectives:1.1 General objective:To design a collaborative system for socio-environmental management of industrial waste.1.2 Specific objective:Develop evidence of concepts;Evaluate the deployment of the inventory of waste in an industry;Enable the conversion of an environmental liability into an asset by finding a line of research appropriate to the waste: a case study;Evaluate the environmental legislation in the legal mechanisms that influence company decisions.IntroductionThe global economy is undergoing major changes, among these changes; it should be highlighted those related to technological progress and environmental quality.While the industrialized countries and higher levels of economic growth dominate modem technology, developing countries are identified by a different growth pattern, using the annual growth rate of Gross Domestic Product per capita [3, 18].Growth is when the GDP grows, in percent, over the previous year. Development, on the other hand, is when the countries change their technologies and improve their internal structure. Thus, the growth considers the accumulation of wealth, while the development is concerned with the distribution of wealth, improvement of the quality oflife and environmental quality [3, 18].As the UNESCO report shows (1999), the biggest problem is between consumption and development, what is produced and the end that is given to the product. Therefore, product and by-product have equal importance in the quantity produced [29].On one hand there is a positive relationship between indicators of economic growth and technological progress, however, on the other hand, these transformations are a paradox, confirmed by the dramatic use of environmental resources and the lack of technologies for recycling of industrial scrap."

Jan 1, 2011

By H. Schunnesson, H. Fredriksson, D. Johansson, E. Söderström, S. Manzoor, A. Gustafson, M. Danielsson

Fragmentation analysis is an essential part of the optimization process in any mining operation. The costs of loading, hauling, and crushing the rock are strongly influenced by the size distribution of the blasted rock. Several direct and indirect methods are used to analyse or predict fragmentation, but none is entirely applicable to fragmentation assessment in sublevel caving mines, mainly because of the limitations imposed by the underground environment and the lack of all the required data to adequately describe the rock mass. Over the past few years, measurement while drilling (MWD) data has emerged as a potential tool to provide more information about the in-situ rock mass. This research investigated if MWD can be used to predict rock fragmentation in sublevel caving. The MWD data obtained from a sublevel caving mine in northern Sweden were used to find the relationship between rock fragmentation and the nature of the rock mass. The loading operation of the mine was filmed for more than 12 months to capture images of loaded load-haul-dump (LHD) buckets. The blasted material in those buckets was classified into four categories based on the median particle size (X50). The results showed a stronger correlation for fine and medium fragmented material with rock type (MWD data) than coarser material. The paper presents a model for prediction of fragmentation, which concludes that it is possible to use MWD data for fragmentation prediction.

Mar 2, 2022

By K Akiro

Volcanogenic massive basemetal sulphide and gold mineralisation of predominantly low sulphidation style has been located within Lower Tertiary basaltic and felsic volcanic and sedimentary sequences at Ufuo, in the Left April River area, northwest Papua New Guinea. The four discrete massive sulphide bodies, which have been so far identified, occur within a 3 +5 km area situated within a north west trending structural corridor. The sulphide bodies are all localised on the margins of the corridor where the bounding major through going faults are transected by regional faults. Mineralisation is characterised by massive pyrite-bornite-sphalerite-barite-quartz-anhydrite deposition with later galena-tennantite-chalcopyrite. Minor phases include enargite, goldfieldite and bismuth sulfosalts. Jasperoidal silica lenses and bioturbated sediments are closely associated with the massive sulphides. Basemetal sulphide mineralisation is also closely associated with phyllic-style quartz-sericite- altered host rocks underlying the massive sulphide lenses. This mineralised phyllic alteration is localised to fractures, veins and breccias that cross-cut propylitic style alteration characterised by quartz, epidote, chlorite, adularia and zeolite. The mineralised system possesses several hydrothermal features consistent with a copper-rich submarine exhalative volcanic hosted massive sulphide (VHMS) system, ie discrete massive sulphide bodies with abundant barite, associated jasperoidal silica and bioturbated sediments. However, exploratory drilling of the alteration zone underlying each of the massive sulphide bodies has not identified a well-defined zoned alteration pipe that is characteristic of such systems. The alteration is also similar to that of a porphyry-related low sulphidation system in which phyllic alteration has overprinted a regional propylitic style assemblage. The presence of sporadic enargite (and ?tennantite/tetrahedrite) suggest there were intermittent pulses of acid fluids in the system probably derived from exsolved magmatic SO2 which flowed directly to the surface along reactivated faults. The occurrence of tellurium and bismuth minerals is also consistent with a magmatic contribution to the metalliferous hydrothermal fluids. It is proposed that the VHMS orebodies are the products of submarine exhalative deposition generated by a crystallising magma emplaced within crust of on-going tectonism. Ufuo mineralisation is similar to many VHMS deposits elsewhere in that it is unclear whether the metals are derived from the magma directly, or via seawater leaching of the wallrock. Additional studies such as oxygen isotope analysis may assist in resolving this issue. If the metals are shown to be of direct magmatic origin then there may be good prospects for discovering economic-grade porphyry-related mineralisation at depth below the massive sulphide deposits.

Jan 1, 1999

By Árpád B. Palotás, Adel F. Sarofim, John B. Vander Sande, Lenore Rainey Christian, J. Feldermann

"Interest in the fine structure of soots and carbon blacks is motivated by a variety of possible applications. The structure provides information on the origins of the particles and on their adsorptive and reactive properties. This paper describes a method for quantification of the structure of soots and carbon blacks based on direct electron microscopic observation followed by image analysis of these materials. High-resolution transmission electron microscopy (HRTEM) provides a very detailed observation of particle structure. The differences in soot structure, because of its complexity, may not be easily quantifiable with the human eye; therefore, high-level computer software has been used to manipulate HRTEM images. This technique involves the application of fast Fourier transforms (FFT) to single particles and the measurement of characteristic parameters such as interplanar spacings and crystallite sizes from these particles. The methodology and application of this characterization technique are presented here. Results are shown for dif¬ferent samples obtained from soot and carbon black particles selected to illustrate the capabilities of the methodology. Quantitative information can be obtained on structural characteristics, e.g., interplanar spacing, circularity, orientation, elongation, and length distribution of lattice fringes, as well as on the fractional coverage of the extracted pattern. c 1996 Wiley-Liss, Inc.This paper presents a combination of techniques for recognizing and classifying different carbonaceous materials, using their structural morphology. A new method to assess and quantify the parameters which define such structures is proposed and discussed. The technique is based on the use of HRTEM (high-resolution transmission electron microscopy) and computational image analysis.It is well-known that carbonaceous materials like graphite, soots, coals, cokes, chars, etc. possess characteristic structural appearances which can vary from mostly random or amorphous to a perfectly ordered graphitic crystalline structure (Buseck and Bo-Jun, 1985; Buseck et al., 1987). The carbon structure has been variously described as turbostratic (Oberlin, 1989) or as crumpled sheets (Rouzaud et al., 1991) to indicate that parallel layering, reminiscent of graphite, is observed over dimensions of nanometers, but that these planes or crystallites show disorder over larger scales. The degree of order of such structures is strongly dependent on the thermal treatment of the material as well as on the composition of the source of the carbonaceous material. The value of the electron microscope in studying the morphology of such materials has been well-established, and abundant information is available (Ishiguro et al., 1991; Lahaye and Prado, 1978; Buseck, 1992).The use of HRTEM has brought further insight into this matter. Qualitative assessment of the structural order of such materials has been attempted over a long period of time in order to differentiate between various sources or treatments. There is, to date, no successful method available for quantifying the structural characteristics of various carbonaceous materials. This paper presents a technique which is able to recognize dif-ferent materials and to quantify the structural parameters of those materials using HRTEM and computational image analysis, including pattern recognition techniques.In the case of perfectly ordered graphitic crystals, electron diffraction is widely used for obtaining details on structure. Analysis of diffraction patterns can reveal parameters such as interplanar spacing, d002, crystallite size along the c-axis, Lc, crystal size in the plane of the layers, L., mean number of crystallites, Nc, etc.Complicated electron microscopy methods such as defocusing, tilted illumination, axial illumination, etc., often have to be used in order to characterize complex materials such as randomly oriented crystals in soots and carbons. Obtaining the right fo"

Jan 1, 1998

By Patrizio Damiano

Competitiveness in Electric Arc Furnace production is pushing steelmakers to increase the throughput at the lowest expenditure. The technological challenge is therefore to operate the existing facilities at their top capabilities and to exploit materials and energy sources at the upmost yield and efficiency. Moreover, seizing the opportunity offered from the price variability of metallic feedstock calls for flexible practices, versatile equipment and tools to rapidly tune the melting profiles without hindering steel quality and equipment lifetime. The innovative Danieli Q-MELT Automatic EAF system addresses these aspects implementing a centralized control system which interacts with multiple technological packages. Each of these cutting-edge technologies focuses on one aspect of the EAF cycle, increasing machine availability and resource efficiency, by means of electrode regulation and foamy slag control, charging optimization, off-gas analysis and closed loop injectors control. Moreover, these modules provide the process supervisor application (Melt Model) with important information regarding the process status, thus allowing the adoption of a unified control strategy. The supervisor implements a robust statistical approach to identify process deviations in real time. The first results and technology perspectives inferred from the field immediately after the start-up are described in this paper.

Oct 30, 2017

By T. A. Henrie

A technique was devised for measuring the rate of chemical reactions between reactive metals and molten-salt mixtures at high temperatures. The rate of the heterogeneous reaction between high-purity titanium metal and titanium trichloride in molten sodium chloride was determined. The reaction is surface-controlled, and the heat of activation is 8.29 kilocalories per mole TiC13. An active site or reaction nuclei is created by adsorbing a TiC13 molecule at the metal surface. Reaction of the second TiC13 species forms an activated complex that decomposes into three TiC12 molecules.

Jan 1, 1963

In 2005, data obtained from the Mine Safety and Health Administration (MSHA) indicated a total of 922 underground (6.3%) and 13,744 surface (93.7%) mining operations.1

Jan 1, 2008

By C. G. Clifton

The Oatman District produced approximately 2.2 x 10 6 ounces of gold and 0.8 x 10 ounces of silver between 1897 and 1942. A total of 3.8 x 10 tons of ore averaging 0.58 O/T gold and 0.17 O/T silver was extracted from eight major orebodies and a number of lesser deposits. Oatman lies at the center of a trachyte-latite-rhyolite volcanic complex which contains at least one resurgent caldera. The orebodies are typical epithermal quartz-calcite + adularia lode deposits which are very deficient in sulfur. Ore deposition has occurred within dilatant zones on faults which radiate from a common point within-the complex. Fischer-Watt Mining approached the Oatman District with an integrated exploration program utilizing four basic procedures to define the characteristics of past productive areas the results of which were applied to unexplored portions of the vein system. These procedures, listed in their order of usefulness, in defining known and prospective mineralized zones are: vein contouring, detailed alteration mapping, fluid inclusion temperature determinations, and geochemical sampling.

Jan 1, 1980

By Joseph Hirschi, Behrooz Abbasi, Harrold Gurley, Yoginder P. Chugh

"The research goal was to assess if analytical tool/s can be developed to quantify displacements around a geological fault as longwall face moves toward it and past it. A company was faced with crossing a 2-3 m (6-10 ft.) normal up-thrown fault in the development entries and the face while mining a 375 m (1,200 ft.) wide longwall face. A field monitoring and numerical modeling study was performed to develop data. Field measurements consisted of roof-to-floor convergence and rectangular rosettes in the immediate roof. Numerical modeling consisted of constructing a 3-D structural model using the FLAC3D software with the fault plane incorporated as ubiquitous joint. Based on analyses and field observations data, the coal company was informed of impending movements along the fault plane and likely impacts on the development entries. Additional stiff supports were installed in head gate entries around the stage loader and equipment about 60 m (200 ft.) outby of the longwall face (solid). As the longwall face approached the fault, predicted displacements were documented and manifested by severe loading on the installed supports.BACKGROUND AND STUDY OVERVIEWThis paper summarizes results of a cooperative study aimed at improving longwall mining operations in Illinois. More specifically, the study focused on: 1) In-mine measurements in development entries while mining ahead of and behind a faulted zone, 2) Making observations on stability of pillars and entries while mining through the fault, and 3) Developing simplified analytical structural models using FLAC3D to assess if predictive techniques can be developed to plan mining operations through fault zone. Available data on geometry of the fault with estimates of the cohesion and frictional parameters were used for modeling."

Jan 1, 2015

By D R. Seaman, Y Peng, F Burns, D J. Bradshaw

Telfer Gold Mine is a gold-copper mine in the eastern Pilbara of Western Australia, owned and operated by Newcrest Mining Limited. TelferÆs ores are processed by a dual train, 21 Mt/a, concentrator where gold is primarily recovered by gravity concentration and the flotation of a gold-bearing copper concentrate. A minor portion of TelferÆs gold is also recovered to a pyrite concentrate that undergoes treatment via carbon-in-leach (CIL) cyanidation. The gold recovery of the CIL circuit is below the industry standard and operates with a high reagent consumption rate.With a new fine-grinding facility, the Telfer process plant will have the ability to liberate copper and gold from the pyrite concentrate and recover these by flotation prior to the existing leaching circuit. This process will improve overall gold and copper extraction, while reducing reagent consumption in the CIL circuit.This article is an overview of the development of this methodology. Size-by-size analysis and mineralogical studies of monthly composites identified factors limiting the CIL gold recovery and the causes of high reagent consumption. Laboratory studies confirmed a relationship between the regrind product size and gold leach recovery. The addition of an intermediate flotation stage ensured that the regrind circuit will improve overall recovery while at the same time reducing operating costs. Without the addition of a flotation stage, the additional reagent consumption from regrinding alone would be prohibitive towards increasing recovery. Pilot scale studies confirmed the conditions required to selectively recover gold and copper from the pyrite concentrate as well as establishing the full scale regrinding energy requirements. Construction of this facility at Telfer is currently underway.CITATION:Burns, F, Seaman, D R, Peng, Y and Bradshaw, D J, 2012. Development of a pyrite regrind circuit at Telfer Gold Mine, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 45-52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The first record of coal discovery in Australia dates back to 1791 when escaping convicts found coal in the banks of a creek just south of Newcastle. Development in the Newcastle Coalfield was the sole source of supply for the colony and for export until the 1850s when mines were established in the Southern & Western Coalfields. The important Hunter Coalfield was not discovered until 1873 when coal was found at Rixs Creek near Singleton: The first exploration drillholes were commenced in 1799 using drilling equipment obtained by Sir Joseph Banks. From 1820 to 1850 several famous geologists (naturalists), including the Rev W. B. Clarke, J. D. Dana and Strzelecki, wrote reports on the coal measures in New South Wales. The first Government Geo- logist, Samuel Stutchbury, was appointed in 1850. The major coal deposits of the State are contained in Permian Coal Measures in the Sydney-Gunnedah and Oaklands Basins. Coal quality ranges from high volatile, high moisture thermal coal at Oaklands to low volatile hard coking coal in the Southern Coalfield. Most coalfields can provide a range of steaming and coking coals.

Jan 1, 1988

By M. Misra

The dielectric properties and flotability of different ranks of Argonne Premium Coal samples are presented. The flotability of different ranks of coal are correlated with the dielectric properties and intrinsic moisture (or bound water) content. Measured dielectric properties of as-received coals and other constituents are incorporated into a mixture equation to calculate the dielectric properties of bound water present in the different ranks of coal. The nature of bound water present in low-rank hydrophilic coals is significantly different from that present in high-rank hydrophobic coals. The water molecules present in low-rank lignite have an oriented dipole-dipole interaction and are tightly bound to the surface. For high-rank coals, the water molecules are not bound to the surface and have a randomly distributed clathrate ice-like structure. Controlled thermal treatment can modify the structural nature of bound water present in low-rank hydrophilic coals and increase their flotability.

Jan 1, 1990

By C S. Walker

This paper analyzes the physical, operational and economic site conditions which were conducive to the design of a diesel-electric power plant wherein the over-all use of the thermal energy of the fuel exceeds 80 per cent. The heat energy supplied to the diesel engines is recovered in power generation, vapour phase cooling, waste heat boilers, air to exhaust gas heat exchangers and lubricating oil coolers. Electric boilers are also integrated into the plant design to enable the ratio of electric power output to heat recovery to be varied to suit the seasonal and daily variations. The criteria relative to thermal and electric power design requirements are discussed, and the design details of some parts of the plant which conform to these criteria are illustrated. Some data in regard to the actual operation of the plant over a short period are also included. Introduction THE Cantung mine (Canada Tungsten Mining Corporation) is located some 180 miles north-east of Watson Lake, Yukon Territory. It is situated on the upper reaches of the Flat river at an elevation of about 3,700 feet.

Jan 1, 1965

By J. J. Scott

As a Rock Mechanics investigator, the author has, Over his career, attempted to use his best knowledge in developing better rock control fixtures. Based on the experience of nine years of development of friction rock stabilizers, in 1980 he decided to launch a new investigation to develop a unique roof support fixture which would fit the coal mining market. The largest single user of roof bolts in the world is the American coal mining industry, historically using up to 100 million fixtures per year. In 1989 they used approximately 82 million fixtures.

Jan 1, 1990

By Edgar Roque, Edwin Cereceda

El presente trabajo pone en evidencia las ventajas de emplear el método de explotación por Bench and Fill, en lo que respecta a costos y rentabilidades. Dada la importancia de atender al control de la dilución y fragmentación tomando en consideración las variables generadas en la voladura, este artículo explica a los planificadores de minería —antes de diseñar, perforar y cargar un bloque de producción— cómo predecir y optimizar los efectos de la voladura en los costos de operación evaluando el comportamiento del macizo rocoso y zonificando los niveles a minar.

Apr 30, 2019

By Ronald M. Van Noy

A reconnaissance study of kyanite-group mineral deposits in the Northwest has revealed large exploitable reserves of the mullite-forming raw materials in the Woodrat Mountain and Goat Mountain districts of north-central Idaho. Potential coproducts or byproducts are garnet and muscovite mica. The Woodrat Mountain district contains garnet-kyanite-mica schist, which has been traced for 6 miles and may extend farther. Surface samples average 29 percent kyanite and contain up to 15 percent garnet. Inferred reserves of strippable ore with a low waste-to-ore ratio, and containing more than 15 percent kyanite, are more than 3 billion short tons. The Goat Mountain district contains several kyanite-mineral zones. Samples of the richest zones average from 10 to 20 percent kyanite minerals and represent about 200 million short tons of strippable rock. Beneficiation tests indicate that the kyanite minerals and garnet can be concentrated by a combination of gravity, flotation, and electromagnetic methods. Reserves in these deposits are sufficient to satisfy any foreseeable domestic and export demand. However, the freight tariff to reach the nearest major users of kyanite (located in the Midwest) has discouraged development of western kyanite resources. Western demand of a magnitude to support a moderate to large milling operation has not yet been developed. However, there is some foreign market potential. If a garnet byproduct could be prepared and sold for coated abrasive products or as grinding grains, an offset possibly could be gained to a por¬tion of the mining and milling costs for the Pacific Northwest producer. Such byproduct values would offer a means for expanding the geographic market areas as well as the regional market potential.

Jan 1, 1970

By David R. Delling

Tenneco is a large, diversified, energy-based company which has grown rapidly during its forty year life. We're the youngest corporation among Fortune's top 20 companies. Tenneco Minerals Company is the division of the Corporation responsible for nonfuel minerals exploration, development and operations. Tenneco Minerals Company is headquartered in Lakewood, Colorado. Exploration offices are in Colorado, Nevada, Alaska, and Perth, Australia. We currently operate two gold mines in Nevada and a large underground trona mine and soda ash processing plant in Wyoming. The latter has a capacity of 907 000 tonnes per year of soda ash and is the subject of my presentation today.

Jan 1, 1984

Granduc lies near the Alaskan border in British Columbia, about 600 miles (960 km) north of Vancouver. Prospecting in the area must take place in the short summer months of fog and rain because the winter is bitter cold, with snowfall up to 960 inches (24.4 m) accompanied by avalanches. Despite these difficulties, the mineral ized area was discovered in the 1920's. By 1956, Newmont Mining Corporation had developed mineable ore reserves estimated at 32,500,000 tons of 1.93% copper. Newmont and ASARCO, in a joint venture, then began development of the ore body, which was partially covered by glaciers. It was apparent a concentrator could not be built at the mine site where overland access was impossible due to the weather conditions and the terrain. Years of engineering studies of all possible access routes finally dictated the driving of an 11 mi long (17.6 km) tunnel passing under three glaciers and three mountain ranges to the nearest feasible concentrator site at Tide Lake. Even then, a mountain road subject to an average snowfall of 800 in. (20. 3 m) had to be built 32 mi (51 krn) from the concentrator through Alaska to Stewart, British Columbia, the nearest port. At Stewart, which is located at the head of a fjord 120 mi (192 krn) from the Pacific Odean, a fully equipped marine terminal was built. The tunnel, the lifeline between mine and mill, was to be driven from both ends; however, in 1965, an avalanche occurred at the Leduc portal, killing 26 crew members and wrecking much of the camp. The tunnel was then driven from one heading adjacent to the concentrator site at Tide Lake, a distance of 53,744 ft (16,381 m) to a point under the ore body. The remote location, type of terrain, and bad weather made supply of crews, equipment, and construction materials difficult; but in spite of these extremely adverse conditions, the tunnel crews set many world records. Mineralization throughout the ore zone is generally uniform in grade and composition and is primarily chalcopyrite and pyrrhotite associated with pyrite. Mining is mainly by sublevel caving. After blasting, rubber-tired load-and-haul equipment moves from level to level by means of an internal connecting ramp system on a 15% slope. At the gathering haulage level, 15-ton bottom-dump cars deliver the ore to a 600-ton pocket equipped with a Hudson "Rock-Flo" dump. The bottom of the ore pocket forms the feed chute to the primary

Jan 1, 1978

By G. M. Molinda

The U.S. Bureau of Mines conducted an investigation to determine the nature and frequency of coal mine roof failure beneath valleys. A mechanism for this failure and suggestions for controlling this problem are presented. Hazardous roof conditions identified in some mines were positively correlated with mining activities beneath stream valleys. Mine maps with overlays of unstable roof and locations of stream valleys show that 52 pct of the instances of all unstable roof in the surveyed mines occurred directly beneath the bottom-most part of the valley. The survey also showed that broad, flat-bottomed valleys were more likely to be sites of hazardous roof than narrow-bottomed valleys. Evidence of valley stress relief was found beneath several valleys in the form of bedding plane faults and low-angle thrust faults. This type of failure, previously believed to be only a shallow phenomena, was found at mining depths as great as 300 ft. In situ, horizontal stress measurements beneath a valley and the adjacent hillsides, confirmed valley stress relief. Numerical analysis of 13 valleys overlying one mine property showed the effect of the valley excavation on horizontal and vertical stress.

Jan 1, 2010