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By Janet E. Halliwell

In keeping with the traditions of the Science Council of Canada - an independent and forward looking agency that applies broad and multidisciplinary analyses to the various issues it examines the author indulges in a holistic approach to the integration of the environmental, scientific, economic, and cultural concerns. This paper will characterize the changing conditions which the mining industry is facing. It will then explore the changing expectations of society with respect to environmental sustainability and how those attitudes in turn, must influence the strategic directions and attitudes of the industry, and within that, the role of science and technology.

Jan 1, 1991

A schematic overview of the variables which interact to determine ore reserves precedes consideration, in this context, of some recent views on the concept of a 'production cycle'. Political and governmental action, for whatever motives, is a greater obstacle to future mineral supply than technical problems.

Jan 1, 1979

THE Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties situated at 29 W. 39th St. in New York.

Jan 1, 1946

THE Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties situated at 29 West 39th Street in New York City.

Jan 1, 1946

Bloomfield Collieries Rix’s Creek Mine is an open cut coal operation located in the Hunter Valley region of Australia. The mine produces approximately 1.1 mt of saleable product per year and routinely employs cast-blasting practices for its unique dragline-truck overburden excavation method.

Jan 1, 2006

By S. R. Clifford

Organic contaminants can be removed from river sediment using conventional flotation methods. Organic contamination in sediments is one of the most significant pollution problems facing the Great Lakes region. Using conventional flotation, the majority of the organic contamination can be collected in a concentrate, leaving a "clean" tailings. This provides a cost savings by reducing the amount of material requiring further treatment. The concentrate can then undergo additional flotation stages, or other contamination removal procedures, to further remove the organic contaminants.

Jan 1, 1994

By Frank L. Bazzanella, Paul A. Weyler

A brief introduction to gravity concentration is presented, including some discussion on the more common minerals currently recovered. The important considerations in basic design of a gravity plant are mentioned and four currently operating flowsheets are presented. The plants discussed in detail include the Climax Molybdenum Co. By-Product Plant and the Canada Tungsten Ltd. Plant. Plants briefly highlighted include the Palabora Mining Co. Uranium Recovery Facility and the Bridge Hill Ridge Heavy Mineral Recovery Plant of Mineral Deposits Ltd.

Jan 1, 1978

By M. E. Fine, A. A. Hendrickson

The critical resolved shear stress and the strain rate dependence of the .flow stress are reported for Ag base A1 single crystals up to 6 at. pct A1 over a temperature ralzge of 4.1° to 470°K. At room temperature the solid solution strengthening is attributed brinciballv to an increase in the dislocation density on alloying. At 42°K the alloys are relatively stronger because the dislocations widen on alloying and are more difficult to cut. In a previous paper, the authors reported the characteristics of strain aging in Ag base A1 alloys.' The variation of the magnitude of the strain-aging yield drops on aging time, aluminum content, and testing temperature strongly indicated that the phenomenon is due to the Suzuki mechanism. In the present paper, the critical resolved shear stress (CRSS) and the strain rate dependence of the flow stress are reported for Ag base A1 single crystals as functions of testing temperature (4.2" to 470") and A1 content (0 to 6 at. pct). Observations on the substructure and measurements of the effect of crystal growth rate are also given. The experimental re- sults appear explainable considering that aluminum additions increase the dislocation density and dislocation width. EXPERIMENTAL METHOD The methods of specimen preparation and tensile testing were described previously.' Briefly, single crystals were grown from the melt in a vacuum (1 x lom5 mm Hg), shaped into tensile samples by a combination of abrading and acid etching, annealed at 850°C in a vacuum (1 x 10" mm &Z) for several days, and furnace cooled to 200'. The testing was done on a model TM Instron using friction grips and a strain rate of about 5 x 106 per sec unless otherwise noted. The various testing temperatures were obtained by immersing the specimens in the following media: 1) 4.2': liquid helium using the apparatus of G. Byrne;' 2) 77°K: liquid nitrogen; 3) 200"K: dry ice and acetone; 4) 415' K: ethylene glycol; 5) 460' \ to 480' : molten Stanalax. In the determination of the CRSS above 296' K, a ratio method was used; the crystals were strained initially at the higher temperature, 0.1 pct shear strain, and then tested at 296' . The ratio of the flow stress between the two temperatures was then multiplied by the average CRSS at 296' K to obtain the value of the CRSS at the high temperature. (The test at 296' showed a yield point resulting from strain aging; the flow stress at 296' K was taken as the lower yield stress.) The ratio method, we believe, is more accurate than using different crystals since

Jan 1, 1962

By Yue hua Hu, Wei Sun, Pan Chen, Li Wang, Runqing Liu, Central South University

"The flotation separation of muscovite from quartz was investigated using mixed sodium oleate/dodecylamine (NaOL/DDA) collectors. The flotation experiments were conducted on single minerals and their collecting performances were studied by means of adsorption amounts and molecular dynamics simulation. Flotation results show that muscovite presents good floatability while quartz exhibits poor floatability in alkaline condition. Adsorption amounts show that both NaOL and DDA can absorb onto surfaces of muscovite and quartz in presence of mixed surfactants. Molecular dynamics simulation indicates that DDA plays an important role in the adsorption of mixed surfactants on these two mineral surfaces. The molecules of mixed NaOL/DDA are arranged in a rigid and well-ordered packing on muscovite (001) surface. Only a few DDA adsorb on quartz directly, and rest DDA and NaOL molecule exist near by the quartz surface, forming a hydrophilic cylinder-like structure. This study may provide guidance for the flotation mechanism and application of mixed anionic/cationic collectors.INTRODUCTIONIn the past decades, there has been an ever-increasing demand for muscovite (KAl2(Si3Al)O10(OH)2) because of its potential applications in cosmetics, construction and metallurgy industries (Barlow & Manning, 1999). Besides, muscovite is an important carrier for some rare metals, including vanadium, titanium and lithium (SsuerrN, 1979). Quartz (SiO2) occurs as the main gangue mineral in muscovite ores, which results in a low purity of muscovite and limits its wide applications. Therefore, there is an urgent need for the beneficiation of low grade muscovite ores. Many studies remove quartz by screening and gravity separation in virtue of their differences in shape, hardness and density. However, these methods undergo poor efficiency in case of small particle size (below 50µm) of muscovite and quartz (Liubakka, Sullivan, Lamphere, Corradi, & Dykhuis, 2011; Santos, Franca, & Ogasawara, 2011)."

Jan 1, 2016

By M. Coleman, M. E. Reed

The control of feed delivery quality to the flash furnace remains an unsolved problem. Many operations around the world still have limited control of feed quality to their flash furnace. Schenck Process and WorleyParsons continue to work towards the ‘holy grail’ of simple quality feed delivering both radial feed distribution and pulseless feed delivery. Ten years ago they joined forces to offer a system based on then Clyde Process RotoFeed system which could deliver ground level installation, online mixing of materials, pulseless feeding direct to the burner, with good radial distribution. Unfortunately, this proved to be too large a step for the Flash Smelting community and met with resistance from the process owners. Since then the community has developed a range of options some of which have been implemented over this period. Despite these improvements there are still areas of concern including safety issues associated with concentrate leaks and spills, uncontrolled variations in feed rate including massive flooding events, intermittent distribution improvement and set up of the burner continues to be trial and error and hard to repeat the success in each burner campaign. These continue to impact flash furnace performance globally on a daily basis. Following the community reticence to pursue the complete solution a number of interim steps are now available to pave the way to the ultimate feed system. The mixing of material has been installed and is delivering line blended materials on a daily basis. This paper will investigate the developments over the last 10 years and discuss the pros and cons of this incremental step process for overall furnace control. INTRODUCTION Schenck Process and WorleyParsons have continued to interact and observe changes in the flash smelting industry and to consider application of the Clyde RotoFeed now incorporated in the Schenck Process ProStreamTM range for delivery of feed directly to the concentrate or matte burner. Schenck Process pneumatic injection from the Clyde Process range, ProStreamTM, utilises two types of volumetric feeders to accurately control the feed of material into an injection pipeline. These are referred to as the RotoFeed and RotoScrew technologies and the choice of feeder type is dependent on the characteristics of the material to be handled. The RotoFeed is generally used for finer, granular and powdered materials which cannot be accurately handled with a screw such as pulverised coal and copper concentrate, whilst the RotoScrew is particularly suited to coarser lump materials, particularly abrasive of cohesive materials like zinc powder, electronic scrap and metal ashes. Both units can operate at high pressures and many systems work at 3 to 10 bar with the occasional system working at 20 or 30bar for carbon to gasifiers. For the Flash furnace the ProStreamTM units can be used to deliver each of the furnace feed materials into a single line, mixing the materials homogeneously and live to the burner.

Jan 1, 2019

By E. Watkins, S. J. SCHATZEL, K M. AJAYI, V. Gangrade, Z. Khademian

A stochastic discrete fracture network (DFN) model is developed based on mine site core log data to predict the horizontal and vertical permeabilities from the surface to the top of the caved zone at a longwall mining site in southwestern Pennsylvania. One hundred DFN realizations were generated to determine permeabilities for the isolated zone over an abutment pillar after mining the second panel. The results from this study show that the vertical and horizontal permeabilities from the DFN model agree closely with field measurements, which indicates that the resultant permeability obtained from the field measurements is representative of the predicted permeabilities. With this agreement, the aperture data for other zones of the mine could be obtained from the geomechanical model — specifically, for the fractured zone over the gob. Based on the successful validation of this model, this model could be further developed to predict the permeability of the fractured zone over the gob with fracture aperture obtained from the geomechanical analysis. This will complete the fracture characterization of the overburden, which could be used to predict potential shale gas flow to the mine in the event of a breach. This prediction could provide information on the associated risk of a casing breach and determination of methods to proactively prevent such an occurrence.

Feb 1, 2023

By T. T. Quirke, L. C. McCabe

The object of the present investigation was to discover a physical basis for rank differentiation of coals, particularly the coals of the Illinois basin. Vitrainl was selected as the most appropriate coal material to use in the investigation, because of its homogeneity and ease of acquisition and handling. Previous Investigations.—Hoffman and Jenker2 have shown that their index of reflection is a characteristic of coal rank and that the Leitz slit microphotometer may be used in determining the different intensities of reflection. Zhemchuzhnikov3 measured the luster of several Russian coals with a color analyzer and found that the degree of luster was indicative of rank. Luster-volatile matter curves based on data from Sucan and Donetz coals were satisfactorily used for determining the rank or volatile content of other coals after the luster strength was determined. In 1934 Fisher4 reported refractive indices of 1.76 for bituminous vitrain and 1.87 for semibituminous vitrain. Investigation of Angle of Polarization.—Early in the present investigation several determinations of the refractive indices of the vitrains were made by immersing the minus 150 plus 200-mesh powder in oils. It was found that all the samples fell within the range 1.6 to 1.8. However, difficulty was encountered in securing oils in this high index range that were closely enough spaced to separate some of the coals. The writers made a number of determinations of the angle of maximum polarization from the polished surfaces of the vitrains and derived their refractive indices by the procedure described in the following paragraphs. Johannsen5 states the fundamental concepts underlying this procedure as follows: In general, in an isotropic medium light vibrates in all directions at right angles to the direction of propagation, and when it meets with another isotropic medium at an angle, part of the light is reflected and part refracted. It has been found that after reflection or refraction, the vibrations do not move with the same freedom in every

Jan 1, 1938

By T. T. Quirke, L. C. McCabe

The object of the present investigation was to discover a physical basis for rank differentiation of coals, particularly the coals of the Illinois basin. Vitrainl was selected as the most appropriate coal material to use in the investigation, because of its homogeneity and ease of acquisition and handling. Previous Investigations.—Hoffman and Jenker2 have shown that their index of reflection is a characteristic of coal rank and that the Leitz slit microphotometer may be used in determining the different intensities of reflection. Zhemchuzhnikov3 measured the luster of several Russian coals with a color analyzer and found that the degree of luster was indicative of rank. Luster-volatile matter curves based on data from Sucan and Donetz coals were satisfactorily used for determining the rank or volatile content of other coals after the luster strength was determined. In 1934 Fisher4 reported refractive indices of 1.76 for bituminous vitrain and 1.87 for semibituminous vitrain. Investigation of Angle of Polarization.—Early in the present investigation several determinations of the refractive indices of the vitrains were made by immersing the minus 150 plus 200-mesh powder in oils. It was found that all the samples fell within the range 1.6 to 1.8. However, difficulty was encountered in securing oils in this high index range that were closely enough spaced to separate some of the coals. The writers made a number of determinations of the angle of maximum polarization from the polished surfaces of the vitrains and derived their refractive indices by the procedure described in the following paragraphs. Johannsen5 states the fundamental concepts underlying this procedure as follows: In general, in an isotropic medium light vibrates in all directions at right angles to the direction of propagation, and when it meets with another isotropic medium at an angle, part of the light is reflected and part refracted. It has been found that after reflection or refraction, the vibrations do not move with the same freedom in every

Jan 1, 1938

By J. Muller

Keywords: Pyrometallurgy, blast furnace, slag viscosity, slag liquidus temperature, phase equilibria The viscosity of molten slag in blast furnace operations is an important process variable, influencing the rate and location of reactions inside the furnace, as well as the ease with which the final slag could be removed from the furnace. To optimize these processes, it is necessary to estimate the slag viscosity and liquidus temperatures as accurately as possible, and know the target values. Models to predict viscosities and liquidus temperatures, incorporating phase equilibrium calculations, have been developed and validated with measured data. Various diagrams have been developed to illustrate how the properties vary with composition and temperature, including pseudo-ternary diagrams of SiO2-MgO-CaO-Al2O3 for viscosity and liquidus temperature. Models were also applied and methodologies developed to analyse historical blast furnace operations and determine target values.

Jan 1, 2011

By Robin B. Steven

Rio Tinto's Kennecott Bingham Canyon Mine is one of the largest open pit copper mines in the world. In 1988 they completed a $400 million project using a conveying system to transfer the ore from an in-pit crusher to the concentrator. The longest conveyor, C-6, was 17,352ft long and ran in a tunnel through the mountain-side to the concentrator. The belt was removed after 14+ years after carrying 700 million tons of 10 minus ore. The paper discusses the original G6 belt's performance and new splicing methods used to achieve a 60% dynamic splice efficiency on the replacement belt.

Jan 1, 2004

By D. M. Muir, C. Cao

Many gold ores have copper mineralisation which presents problems in a carbon-in-pulp operation. Various types of copper-gold ores and ways of tackling the problem are discussed. In some cases copper and gold can be upgraded to a concentrate by flotation; otherwise, copper or gold can be selectively leached. When both copper and gold cyanide are present in solution, it is possible to minimise copper loading onto carbon or to selectively strip the copper from the carbon. Alternative leach solutions like thiourea and bromine are discussed and results obtained with the ammonia/cyanide system are presented in the light of our present understanding of the chemistry involved.

Jan 1, 1989

By N. O. Johnson, R. A. Westin

Polychlorinated biphenyls were the basis of non-flammable askarel dielectric liquids wed in electrical equipment made between 1929 and 1978. Although PCBs were widely used in mine electrical equipment, the toxicity and environmental persistence of this chemical led Congress to ban its manufacture and use. Bureau of Mines Information Circular 8838 summarizes the regulations imposed by the EPA on the use and disposal of PCBs, and describes the limitations of available substitutes. Recent changes in the regulations will impose additional requirements on the use of PCBs by the mining industry. This paper is an update of the material presented in the Bureau of Mines information circular.

Jan 1, 1983

By J. C. Franklin

An experiment was conducted by the U.S. Bureau of Mines and the Canada Centre for Mineral and Energy Technology (CANMET) to measure the emanation rate of radon from cemented unclassified mill tailings in two dewatered stopes of a uranium mine at Elliot Lake, Ontario, Canada. The radon was monitored upstream and downstream and in both stopes to determine the concentration in the stopes and the amount exhausted from both stopes. The emanation rate was determined to be 0.55 pCi/cm2 sec-1 from the mill tailings, which is approximately 1,000 times higher than the average flux in the mine before backfilling.

Jan 1, 1982

Alexander Sutulov. Mineria Ghilena 1545-1975 (Mining in Chile 1545-1975). Santiago, Centre of Investigation of Mining and Metallurgy, 260 pp. (In Spanish). G. B. Rothenburg. Speciality steels. D.S.A., Noyes Data Corp., 1977. 270 pp. Witbank Middelburg Branch A General Meeting was held at the Wit bank Golf Club on 20th April, 1977, at 17h30. Treatment of waste water An International Research Symposium on New Processes of Waste Water Treatment and Recovery is to be held in London from 6th to 8th September, 1977. It NIM reports Report no. 1708 An examination of the suitability of various reducing agents for the production of ferrochromium. (27th Feb., 1975; re-issued May 1977). Report no. 1724 The preparation and reduction of chrornite pellets containing a reducing agent. (14th Apr., 1975; re-issued Mar. 1977). Report no. 1854 The interaction of pyrite, oxygen, and xanthate. (8th Mar., 1977). Report no. 1876 The ultrasonic determination of the mud level in a thickener and the resin level in an ion-exchange column. (6th May, 1977). Report no. 1878 The electrochemical dissolution of galena in aqueous solutions. (5th May, 1977). Report no. 1881 n-Octylaniline, a new extractant for noble metals.(28th Mar., 1977). Report no. 1883 The determination of iron, chromium, titanium, and tungsten by X-ray-fluorescence spectrometry. (31st Mar., 1977). Report no. 1889 Entropy relations in the formation of complexes of silver (1), mercury (II), and cadmium (II) with llwnodentate liyaruls. (5th May, 1977). Mechanics of granular materials A conference on the above subject is to be held in London on 8th and 9th September, 1977, under the auspices of the Institute of Mathematics and Its Applications.

Jan 1, 1977

Ancient volcanogenic Cu-Zn-Pb-Ag-Au massive sulfide ores commonly have associated with them along strike and in the immediate hanging wall a distinctive sediment that is thin, usually cherty and metal enriched, and generally referred to as an "exhalite horizon" or "tuffaceous exhalite". Typical examplks include the 13 Ma tetsusekiei of the Kuroko deposits of Japan (Kalogeropoulos and Scott, 1983, Econ. Geol.) and the 2700 Ma contact tuffs of Noranda, Canada (Kalogeropoulos and Scott, 1989, Can. J. Earth Sci.) and Key Tuffite of Mattagami, Canada (Liaghat and McLean, 1992, Explor. Min. Geol.). Attempts to use trace element distributions as lithogeochemical guides to ore have been largely unsuccessful. Exhalites have been considered to be the products of seafloor hydrothermal activity that is peripheral to the main ore-producing vents. However, large actively-forming polyrnetallic sulfide deposits at the Explorer mid-ocean basalt spreading ridge (1 850 m depth) in the NE Pacific and the eastern Manus back-arc dacitic spreading center (1650 m depth) in the western Pacific have demonstrated that the exhalite horizons are more likely produced by fallout of particulates from the main hydrothermal plume. In a typical hydrothermal plume, grains of >27 µm represent up to 97% of the mass (although only 2% of the population) of the particulates and are calculated by Stokes equations to fall from the plume to the seafloor within a few krn of their source. The particles are primarily composed of anhydrite, barite, amorphous silica, iron oxyhydroxides and metal sulfides and oxides. Plumes are subject to bottom currents which push them in preferred directions, just like smoke plumes in the atmosphere are subject to the vagaries of wind direction. Bottom currents in the deep ocean can be 50 m/min or

Jan 1, 1993