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By M. Normandin

The performance of various polymers and other macromolecules used to flocculate red mud particulate materials in the Bayer process can be evaluated on the basis of their efficiency to achieve adequate settling velocity and turbidity level, The Jar Test is widely used in the mineral industry to determine the efficiency of solid-liquid separation processes, particularly for gravity settler of the Bayer process. However, a high level of variability is found in the data obtained by this methodology, In this study, different parameters of the cylinder test procedure are evaluated to determine their role in the overall variability of the method, As demonstrated by laboratory testing, the overall variability can be considerably reduced by good laboratory practices.

Jan 1, 2005

By S. W. Asihene, K. Osseo-Asare

The thermodynamic data necessary for the quantitative treatment of Metal-NH3- H2O systems at elevated temperatures are lacking in the literature. As a result discussions of the chemical basis of high temperature processes, such as leaching and hydrogen reduction, have tended to rely on low temperature thermodynamic data. In this paper a critical review is presented of the available high temperature data for metal ammine formation in aqueous systems, and methods are suggested to enable extrapolation of elevated temperature stability constants from low temperature thermodynamic data. Predictions of the Van't Hoff Lsobar, the simple cation Correspondence Principle (whereby metal ammine complexes are treated as simple cations) and Helgeson's Electrostatic-Nonelectrostatic Model are compared with the available high temperature stability constants for nickel ammines. Up to 80 °C all three estimation methods yield results which are in agreement with experimental data. However, serious deviations occur at higher temperatures; the various models overestimate the stability constants in the order Van't Hoff Isobar > electrostatic-nonelectrostatic model > simple cation Correspondence Principle. Using the experimental nickel data as a basis, a method is presented which permits reasonable estimates to be made of the stability constants of metal ammine complexes for temperatures above 80 °C.

Jan 1, 2004

By M. J. Gagnon

The agglomeration of particulate materials is used in many mineral processes to enhance the settling of the fine particles, Depending upon many physical and chemical parameters, the aggregates demonstrate specific density-size distributions, In this study, a fractal model of the agglomeration process is introduced, Based on reliable experimental data and on physical calculation, the model presented helps to envisage the initial formation of the micro-flocs, and to interpret the subsequent interactions between the aggregates in terms of either coagulation or flocculation, Data from different sources, materials and different agglomeration processes are analysed and compared in the light of the proposed model.

Jan 1, 2005

By H. Kroog

"This contribution reports recent mineral sorting experience and lists the possibilities of the newest generation of automatic mineral sorters with a special focus on electromagnetic detection, optoelectronic technology and the latest innovative X- Ray transmission units. In industry, mineral and ore are still hand-picked and current automation potential is only utilised in a handful of specific applications. Recently a number of technological developments took place that may increase sorting potential, save mill costs and lead to lower overall tonnage costs. The mentioned technologies provide automatic dry separation of minerals and rock as an alternative for conventional processing. The MikroSort technology is environmentally friendly:•,The remaining waste is free of contaminations•,The dump volume is reduced•,The concentration of the high grade material•,at an early stage saves resources"

Jan 1, 2005

By W. L. Ennis

Introduction This paper outlines the causes of underground fires at Noranda Mines and the precautionary measures taken to guard against such fi res. Shafts There are six shafts (Figures and lA) on the property, of which N os. 1 and 2 are abandoned. Nos. 3, 4, and 5 are the present working openings from surface and No 6 is an internal shaft. No. 3 is used primarily as a service shaft, while Nos.?1 and 5 are the main hoisting shafts. Orebodies The orebodies are of two distinct types. There are the massive sulphide bodies, and the areas of mineralized rhyolite containing gold values and a silica content high enough for fluxing purposes. The massive sulphide bodies contain chalcopyl'ite, pyrite, pyrrhotite, and minor amounts of sphalerite and magnetite. The concentration of particular sulphides varies even within the same body. It is the areas high in pyrite, and to a lesser degree those, high in pyrrhotite, that are of particular interest.

Jan 1, 1950

By R. B. Allen, E. E. N. Smith, B. C. MacDonald

"LocationTHE MAIN PROPERTY and townsite of Eldorado Mining & Refining, Limited, Beaverlodge Operation, is on the north shore. of Beaverlodge lake, •about seven miles north of the deserted town of Goldfields on lake Athabasca, and four hundred and ninety air-miles equidistant from Prince Albert, Saskatchewan, and Edmonton, Alberta. Both Eldorado Airlines •and Canadian Pacific Airlines maintain scheduled flights from Edmonton to the 4,000-foot airstrip on the north boundary of the Company property. Bi-weekly flights are made by Saskatchewan Government Airways from Prince Albert. Men and priority freight are flown by Company aircraft direct from Edmonton. From June to-September, when the waterways .are ice-free, freight is carried by barge from the •railhead at McMurray, Alberta, down the Athabasca river to Chipewyan, and across lake Athabasca to• Bushell, the terminal on Black bay, lake Athabasca, a total distance of 265 miles.The Eldorado Operation has been connected by a 12-mile, all-weather highway to Bushell. Where the highway crosses the park-land along the Fredette river, the townsite, Uranium, is under construction to provide services to the uranium-producing district. Spur roads have been built to the Ace, Fay, Eagle, •and Martin mines of the Eldorado operation, and to the properties of Pitch-Ore Uranium Mines, Ltd., and Rix Athabasca Uranium Mines, Ltd."

Jan 1, 1954

By Georges Houlachi, Akram Alfantazi, Michael Mahon, Maysam Mohammadi

Corrosion resistance of the lead-based anodes directly influences the purity of the final product in the zinc electrowinning process. The anodic MnO2 layer that is electrodeposited on the anodes during this process can protect the anodes against corrosion. Sand-blasted anodes generate a uniform, adherent and shiny MnO2 layer, which gradually blisters and eventually sloughs off after several weeks. In this study, we attempted to develop a new method to stabilize the MnO2 protective layer on the anodes during the electrowinning process by providing suitable nucleation sites for electrodeposition of this layer. MnO2 particles (P80=40µm) were used as seed material for this purpose. Different techniques of galvanostatic and cyclic voltammetry polarizations, scanning electron microscopy (SEM) and atomic absorption spectroscopy (AAS) were employed to investigate the performances of the MnO2-seeded lead anodes. The experimental results showed that growth of the MnO2 layer is influenced by the MnO2 seed particles on the anode surface. The MnO2 layers electrodeposited on the MnO2-seeded lead anodes were uniform and strongly adherent to the substrate. This layer was more stable than those formed on the PbAg anode without MnO2 seeding. This could provide the anode with a higher level of corrosion protection. Moreover, formation of undesirable MnO2 mud in the electrolyte and the rate of manganese consumption were decreased when the MnO2-seeded lead anodes were polarized. These observations could be attributed to the different properties of the electrodeposited MnO2 layer on this anode in comparison with that formed on the PbAg anode.

Jan 1, 2016

By D. Kalumba, S. Jjuuko

"Thin Spray-on Liners resist relative small deformations (< 1 mm) between rock blocks or fragments in terms of a combination of shear, adhesive and tensile-bond strengths. Shear-bond strength addresses the ability of a thin liner to resist stresses that act parallel to the rock-liner interface. Therefore quantification of shear-bond strength is essential in the formulation of design standards and requirements for Thin Spray-on Liners. In this paper Thin Spray-on Liner support mechanisms are reviewed. In addition previous methods of Thin Spray-on Liner shear-bond testing are discussed. The paper also explains the research being carried out at the University of Cape Town to investigate the effect of different parameters on the shear-bond strength.INTRODUCTIONRock surface support is widely used to combat rockfalls and resulting injuries and fatalities in the vicinity of active faces (Potvin, 2002), where workers spend most of their time (Adams & Baker, 2002; Potvin, 2002; Lacerda, 2004). The conventional (traditional) surface support systems in underground rock support include passive methods such as mesh and lacing and active methods such as shotcrete. However, rockfall sources between 1990 and 2000 in Nevada gold mines showed a steady increase in rockfall injury associated with mesh support as shown in Figure 1 (Lacerda, 2004). The conventional methods also negatively impact the mining operations with regards to costs, logistics and mining cycle times due to large material volumes (Tannant, 2001; Ozturk & Tannant, 2010; Ferreira, 2012). Therefore, these systems need to be substituted, with enhanced methods, in order to realize the business target of the mining industry of providing the planned return on investment made without harm and within budget."

Jan 1, 2015

By F. Hosseini

Shaping of metals by thixoforming relies on the unusual flow behavior of semisolid slurries containing nondendritic solid phase. The Flow behavior of metallic alloys containing both solid and liquid phases is investigated in the low solid fraction range (, 55%). This behavior depends on both the solid fraction and the shear rate. Four different shear rates is applied using back extrusion technique and flow stress versus true strain in different solid fraction is compared. It is well accepted that the flow stress s of alloys in their semi-solid state obeys to a thixotropic behavior, due to agglomeration and dissagglomeration phenomena during forming. The load-displacement curves produced from the tests may show an initial peak, believed to originate from a skeletal structure which rapidly breaks down under shear. Apparent viscosity obtained from this method is compared with other works and the proper power law of pseudo plastic state is introduced.

Oct 1, 2011

By James S. Redpath

"AbstractThis paper is an attempt. to outline the present status of underground mining contracting in Canada, and to present certain facts concerning the writing and administration of underground mining contracts which, hopefully, may be useful to those intending to engage a mining contractor . The paper is based on the author' s experience as a contractor and also as a consulting engineer advising others in the purchase of contractors' services.HistoryIN THE early days of mining contracting in Canada, the contractor was primarily a labour contractor. He was expected to bring a good crew of men that normally followed him, and to perform certain work under his own direct supervision. The owner usually looked after all other details including financing, payrolls, withholding taxes, etc , computing and paying the contractor his profit. In the pre-World-War II years, most work was done on this basis.Over the years, the contractor was called on to supply more in the way of services, and the present-day situation evolved.Labour contracts are still used, but now the contractor is expected to carry out his own administration. Most contracts now call for the supply of special tooling required to do the work. In most cases, some, if not all, supplies are the contractor 's responsibility and , in a growing number of cases, the contractor is responsible for such items as design and surveying. The ultimate in this direction is the execution of projects on a turnkey basis. Under this system , the contractor carries the project to a stage where it is turned over fully operational to the owner."

Jan 1, 1977

By A. Roy MacLean

This paper outlines the changes in modern-day coal mining that have been brought about by the increased cost of labour and the use of new and highly efficient equipment. In the latter category are mentioned the ramp-plate, the Bretby cable carrier, armoured face conveyors and the shearer-loader. Greater productivity and increased safety are emphasized.

Jan 1, 1969

By S. Kelebek

Efficient separation of minerals is the essence of mineral processing. Separation of hexagonal pyrrhotite in processing of Ni-Cu sulphide ores was investigated together with particle size effects with respect to selective flotation recovery of pentlandite and nickel. The recovery by size response was compared for sodium metabisulphite (SMBS), triethylenetetramine (TETA) and their combinations with amyl xanthate as a collector. The pyrrhotite recovery for all sizes was lower than that of pentlandite for the blank case as well as individual cases with SMBS and TETA. For pyrrhotite, the recovery by size relations in the case of individual uses of reagents were mainly determined by recovery losses at coarser size range (>74 um), which occurs at a coarser size for pentlandite (>212 um). The combined use of SMBS and TETA, and the associated synergistic effect very significantly knocked down the pyrrhotite recovery to less than 7% that was a maximum for the –10 um (attributable to hydraulic entrainment). High recovery of pentlandite in a wide range of intermediate sizes and drastically low recovery of pyrrhotite resulted in a very efficient separation of pentlandite from pyrrhotite in all sizes. Separation of this mineral is discussed in relation to fundamental functionality of the reagents used.

Jan 1, 2017

By R. Ghomashchi

Wear, fatigue and corrosion are the most widely encountered modes of failure in materials used in engineering applications, including aero-gas turbines. Although wear is distinctly classified as adhesive, abrasive, erosive, fretting and so on, there are usually more than one wear mechanism involved in the failure of components in service because there are many systems and materials variables active in materials wear that makes it more difficult to study. This is further complicated by the discrepancies between the results of laboratory tests and field data. The present investigation was set up to examine the wear characteristics of M50 and T1 high-speed steels at both room and elevated temperatures to draw a thorough understanding of the wear behavior of this class of high-speed steels. This article focuses on the mechanical and microstructural characterization of wear for T1 and M50 high-speed steels using a pin-on-disk wear machine.

Jan 1, 2005

By Staff

Introduction The Hedley mine, perhaps better known as- the Nickel Plate mine, is one of the outstanding properties of southern British Columbia. Discovered in 1898 by Woollison and Arundell, prospectors, the property was bonded in 1899 to M. K. Rodgers for the Marcus Daly Estate, of Butte, and development was started the same year. From the high grade of the ore outcrop, and its colour, due to oxidation of the arsenopyrite, it was not difficult to open up and trace the showing. The Nickel Plate ore-shoot, which apparently had been easy to follow on surface, was more difficult to trace underground. In 1903, prospecting on an adjoining property, the Sunnyside, showed commercial ore at surface, but it was only after two years&apos; work that the ore-body was defined and shipments started. From this property, $1,200,000 have been taken out. Prospecting was also carried on on the IXL, Climax, Copper Cliff, Mound, Bulldog, Exchange, Silver Plate, Gold Plate, and other properties, all of which had surface showings, but up to date only the Nickel Plate, Iron Duke, Morning, and Sunnyside have produced commercial ore. In 1904, the Bulldog looked like a very promising mine, but it failed to make good. In 1905, the Sunnyside No. 1 was in the limelight, but it also failed to make the grade. In 1906, an outcrop on the Sunnyside No. 3 looked interesting. Subsequent work. on this claim produced $840,000, and at the same time ore which yielded $400,000 was mined from the Sunnyside No. 4. In 1908, the Nickel Plate ore-body entered a lean zone and, as the diamond drill failed to give satisfactory results, the Daly Estate, after making a profit of $1,151,000, sold the property to the Hedley Gold Mining Company, Limited, for $760,000, retaining, however, a large interest.

Jan 1, 1929

By D. A. Garland, A. D. Jackson

"Alanx ceramic/metal composites are proprietary products developed by Lanxide Corporation who joined with Alcan to form Alanx Products L.P. in 1988. Alanx ceramic/metal composites are composed of silicon carbide in a combined alumina and metallic aluminum matrix. In laboratory slurry wear tests conducted by Alanx ceramic/metal composites have shown to perform well against other wear resistant materials. At the Kidd Creek Concentrator Alanx CG896 ceramic/metal composite was tested in two pumping applications, the primary cyclone feed pumps and the filter feed pumps. In both instances the wear rates of the parts made of Alanx CG896 were far less than the gum rubber parts traditionally used. As of year to date September 1992 the unit cost to repair primary cyclone pump parts has dropped 58% from 1991 figures. For the filter feed pumps the unit cost to maintain the pumps has dropped by 33% as compared to 1990 figures. The total savings represented by implementation of Alanx wear parts, based on projected year end unit costs for 1992, as compared to 1991 costs for primary cyclone feed pumps and 1990 figures for filter feed pumps, is $166,753. INTRODUCTIONAt the Kidd Creek Concentrator the cost to maintain the primary cyclone feed pumps and the filter feed pumps was a constant concern. Rubber wear part consumption was quite high and the manpower required was considerable. For 1991 the total cost to maintain five primary cyclone pumps was $244,062. The cost to maintain the filter feed pumps in 1990 was $72,076. A wear material was needed that would increase the time between repairs and that would increase the reliability of these pumps between scheduled shut downs."

Jan 1, 1993

By N. Lecuyer

"During early 1980, pre-production work commenced at the ""Les Mines Gallen"" project, north of Noranda, Quebec. As a result of the acid mine water associated with this property, a major pre-production phase included the installation of a water treatment plant to render the water environmentally suitable.This paper emphasizes the planning, installation and operational factors of the treatment plant necessary to the success of the mining operations and the maintaining of a clean environment.Introduction,T he Gallen Project is a zinc, gold and silver open-pit mining operation approximately 10 kilometres north of Noranda, Quebec. This property has a long history, with initial diamond drilling done in the early 1930s and underground mining taking place between 1953 and 1962. This property was reactivated in 1980, with production scheduled a t a rate of 45,000 ton s per month.Included in the reactivation plans for the property was the installation of a water treatment plant to treat the acidic mine water.Plant DesignThe requirements for the Gallen water treatment plant were two-fold. Firstly, it was necessary to neutralize the acid water and secondly to produce a sludge containing metal hydroxides and sulphates which would be stable when stored, and a clarified overflow meeting governmental regulations to be discharged to the environment.The flow sheet (Fig. I) will explain the process in treatment of the acid water.Acid mine drainage is treated with lime to increase the pH to 9.50. Metals in solution are precipitated as metal hydroxides and the 504 as calcium sulphate. The precipitate slurry is then aerated to convert ferrous iron to ferric iron, which is more stable for storage and disposal.The precipitate is next flocculated with a polymer flocculant and settled in the thickener to produce a sulphate/Hydroxide sludge and a final effluent discharged to the environment."

Jan 1, 1983

By G. Heinrich

Size by size recoveries and pentlandite liberation data from image analysis were used to evaluate plant tests of pentlandite flotation and pentlandite/pyrrhotite middlings flotation from pyrrhotite in a circuit treating low grade magnetic intermediates at the Strathcona Mill. Raising the pH with lime gave improved selectivity for liberated pentlandite but there were major losses of middlings unless the circuit was pulled hard indicating the need for finer regrinding. However, size by size recoveries at the normal regrind showed that, while the pentlandite recovery improved in the finer ranges, the pyrrhotite recovery also increased leading to little selectivity in any size range. A much finer regrind gave greatly improved selectivity in all size classes suggesting that 'surface polishing' as well as liberation effects were being seen. Using liberation data from image analysis of the products, surface polishing accounted for over 99 % of the improvement in selectivity. Unreasonable recoveries of more highly liberated particles were observed for liberation analysis by volume fraction but showed the expected trend in recovery when the analysis was based on surface liberation. The surface liberation data showed that the improved pentlandite recoveries after finer regrinding were to more than 90 % caused by improved liberation with the remainder contributed by surface polishing effects. The practical implications of this work are that i) the comparison of particle grades with product grades allows to estimate the effect of regrinding on co-flotation/entrainment, ii) surface liberation models should be used for evaluating recoverabilities by flotation and iii) regrind circuits may be set up to ensure that all particles go through the mill or that only the coarse fraction is reground depending on the surface scrubbing found to be required.

Jan 1, 1993

By D. O. Tansey

This paper will describe the mechanisms involved in delay blasting and how they are applied with the use of D.S.B. It will examine the control of potential damage resulting from detonations, and show how good fragmentation and efficient recovery of this material blasted can be achieved.

Jan 1, 1979

By D. R. Griffiths

"Oxidation of pyrrhotite prcxiuces sulphuric acid which in turn leaches out heavy metals, resulting in acidic contaminated seepages. The establishment of a marsh on top of the pyrrhotite would result in an anaerobic sediment, which should prevent further oxidation of the pyrrhotite. Initial data indicates that concentrations of sulphates and heavy metals in the seepage water are greatly reduced. Further hydrogeological studies are required however, to determine if metal and acidic loadings to the environment have increased.L'oxidation du sulfure de fer produit de l'acide sulfurique qui a son tour attaque les métaux ayant pour resultat une contamination d'acide et de métal des eaux d'infiltration. L'etablissement d'une couverture faite de boue et de vase au-dessus du depot du sulfure de fer réduit les effets de l'oxidation.Les données initiales indiquent que les concentrations de souffre et de métaux dans les eaux d'infiltration sent grandernent réduites.Des études plus poussées sent nécessaires pour déterminer si les quantités de souffre et de métaux dans les eaux d'infiltration ont augmentées.INTRODUCITONPyrrhotite tailings are readily oxidized through a combination of precipitation and atmospheric oxygen causing acidification of the unsaturated zone above the water table. This reaction is usually catalyzed by the bacteria, Thiobacillus ferooxidans. As the pH decreases, heavy metals become more soluble resulting in contaminated seepages to ground and surface waters.By creating a marshland on top of the pyrrhotite, an anaerobic intermediate layer should form between the organic covering and the tailings, preventing the oxidation process from progressing.In September 1986, Falconbridge Limited implemented a tailing reclamation project that involved creating a marshland on top of pyrrhotite tailings. The following paper will discuss and illustrate the preliminary results obtained during the sampling period of May to September 1987."

Jan 1, 1988

By H. H. Wober, P. J. Morgan

"The proposed classification of ore reserves based on geostatistical and economic parameters is designed to be used as a communication tool to identify for investors, bankers, and financial analysts the degree of risk associated with a specific class of ore reserves. The class designation identifies the degree of accuracy of the estimates for tonnage and grade of annual production volumes of ore. It thus enables decision makers to quantify the risks and uncertainties inherent to the ore reserve in achieving over-all economic goals and annual financial objectives.IntroductionDuring the evaluation, in 1980, of the Creede silver deposit in Colorado, U.S.A., as a potential bulk mining project, the authors were faced with the problem of conveying to senior management the risks and uncertainties that are implied by using common or conventional classification systems to categorize ""ore reserves"". The estimated numbers for tonnages and grade of the projected ore reserves represented the only entry for future revenue from the project. It was, therefore, necessary to convey to management the level of risk associated with those numbers when implementing further stages of development, and to convey what impact significant differences would have on the profitability of the project. The desire to quantify these risks led to a revised definition of ""ore"" and to a re-examination of the classification system of ""ore reserves"". Traditional methods for estimating tonnage and grade of reserves do not include a quantification of the errors of these estimates. The advent of geostatistical methods made this quantification possible. The proper application of geostatistical methods, with adequate geological input and a reliable set of sample data, is essential to its validity.Others have proposed a classification of ore reserves based on geostatistical parameters. Diehl and David (1982) recognized ""that concepts of proven, probable and possible have to be linked to the production rate or time horizon"". Royle (1977) had also addressed this problem. Forsyth (1987) pointed out that bankers are concerned with ""the probability that the variability will fall within a certain degree of accuracy"" especially for grade estimates, and would like to see grades expressed together with the error of the estimate at the 950Jo confidence level."

Jan 1, 1993