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By Mayumi Ito

Mineral processing of rare-earth ore from the Dong Pao deposit, Vietnam, was investigated. The ore contained bastnaesite, (REE (rare earth element)) CO3F, as the valuable mineral and barite, quartz, and fluorite as gangue. To establish a mineral processing flowchart, selective comminution, size classification, and magnetic separation were tested. Bastnaesite shows brittle properties and selective comminution was applied to improve the purity of products. The crushed products were classified by decantation, and the overflow product showed high purity of bastnaesite indicating that bastnaesite becomes fines by crushing and that selective crushing can be used to concentrate the bastnaesite. Magnetic separation for the sink product was carried out and the mag-product showed high recovery rates of bastnaesite, indicating that the combination of size classification and magnetic separation is effective.

Aug 1, 2013

By B. Ignasiak

Laboratory studies suggest that improvements of coke strength brought about by pre-heating caking coals before carbonization accrue from inadvertent oxidation rather than from other low-temperature changes in the coal mass. Controlled oxidation of highly caking coal, followed by laboratory carbonization, produces cokes which, in terms of a laboratory scale tumble test index, are equivalent to those obtained from prime metallurgical blends. Appropriately formulated blends of exhaustively oxidized and fresh caking coal similarly yield cokes with strength indices comparable to those of cokes made from the same coal after oxidation under optimum conditions.

Jan 1, 1979

To determine the optimal circuit configuration for gravity gold recovery consideration should be given to a range of factors in addition to the efficiency of the gravity circuit, including capital costs, ease of operation and impact on comminution. The most common gravity gold circuits utilise a centrifugal concentrator treating a portion of the hydrocyclone underflow. This paper will examine this option and alternative circuit configurations to illustrate the effect of various gravity circuit feed and tailings configurations on the equipment sizing, capital costs, operating costs, water balance, comminution efficiency and gravity gold recovery. The optimum circuit configuration can provide reduced capital and operating costs, maximise gravity gold recovery and improve comminution efficiency.

Jan 1, 2011

By Matthew S. Hall

Gold/iron oxide catalysts have been prepared and their catalytic performance evaluated for low temperature CO oxidation. The method and temperature used to dry the sample has a significant effect on their catalytic activity. Analysis by TEM revealed the catalysts contained Au particles, although catalysts with high and low activity did not always differ in their microstructure as evidenced by TEM. Catalysts were characterised using XPS and the difference between the Au(4d) and C(1s) binding energies measured; in general the greater the difference, the higher the catalytic activity of the material.

Oct 1, 2003

By S. Kashani-Nejad

The formation of oxides during the dehydration of MgC12,6H20, Bischofite, was studied by heating the bischofite over a range of time and temperatures in ambient atmosphere. Using a methanol-leaching technique developed by authors, the oxides that formed were isolated, identified and assayed. Three distinct regions of oxide stability were identified. The oxide produced at dehydration temperatures less than 300 °C was Mg2(OH)3C1,2H2O; at 300 °C, mixtures of MgOHC1 and Mg2(OH)3C1.2H2O were formed and at 400 °C, MgOHC1 was the only oxide produced. The presence of MgO observed in the products of the dehydration of bischofite at temperatures above 400 °C was due to the thermal decomposition of the MgOHC1 that was formed while the sample was heating to over 400 °C.

Jan 1, 2006

"THE OTTAWA BRANCH, CIM, each year holds a symposium on a subject of topical interest. The symposium this year was on Canada's Offshore Mineral Resources, at which papers were presented by: Dr. Donald G. Crosby, chief, Resource Administration Di-vision, Department of Energy, Mines and Resources, Ottawa; John A. Beesley, head, Legal Division, Department of External Affairs, Ottawa; and David W. Smith, man-ager, offshore exploration and production, Shell Canada Limited, Calgary. Because of the interest which this topic holds for our members, and because of the wealth and significance of information presented, the three papers -representing the first comprehensive review of our offshore resources -are reproduced herewith. The opening remarks of the Chairman, Dr. F. K. North, Professor of Geology, Carleton University, are also recorded, together with a few of the questions asked by the large attending audience. The symposium was held February 13th, and was organized by Dr. W. M. Tupper, chairman of the Branch Program Commit-tee. Differences in the extent of the continental shelf will be noted in the papers. These differences are related to slightly different definitions of the continental shelf by the authors."

Jan 1, 1969

"As part of a series describing the nickel operations of Vale Canada (formerly known as Inco), this paper focuses on the 1973 to current operations of the Copper Cliff nickel refinery in Ontario, Canada. The process used there employs the formation of Ni tetracarbonyl at high CO (gas) pressure and its subsequent decomposition at somewhat elevated temperatures to produce highly pure Ni pellets and powders. Personal sampling of workplace aerosol dusts is reported, with information on specific Ni compounds in the aerosols.RÉSUMÉ Dans le cadre de la série d’articles décrivant les opérations de nickel chez Vale Canada (anciennement Inco), le présent article cible les opérations de 1973 à ce jour à l’affinerie de nickel de Copper Cliff en Ontario, Canada. Le procédé utilisé à cette usine est la formation de tétracarbonylnickel sous une pression élevée de CO (gaz) et sa décomposition subséquente à des températures plutôt élevées pour produire des granules et des poudres de Ni pur. Un échantillonnage par l’auteur des poussières en aérosol est présenté ainsi que de l’information sur les composés spécifiques de Ni dans les aérosols."

Jan 1, 2015

"This document establishes standards and guidelines for scientific and technical disclosure by Issuers listed on the TSX Venture Exchange on their mineral properties. It incorporates and expands upon the minimum standards prescribed by Securities Laws and applies to all oral statements and written disclosure made by an Issuer or on behalf of an Issuer involving mineral properties.1. Introduction1.1 General(a) This Appendix establishes standards and guidelines for scientific and technical disclosure by Issuers on mineral properties. These standards and guidelines should be applied prudently and with common sense by those Issuers in conjmction with the applicable requirements of section 1.2.(b) This Appendix incorporates and expands upon the minimum standards prescribed by Securities Laws and applies to all oral statements and -written disclosure made by an Issuer or on behalf of an Issuer involving mineral properties.(c) This Appendix is not intended to be exhaustive or all-encompassing and greater detail may be appropriate and required in certain situations. Issuers are encouraged to contact Exchange technical staff where they are not certain about the requirement for disclosure on mineral properties."

Jan 1, 2003

By Marc C. Bétournay

A number of successful proof-of-concept projects have been carried out to replace conventional power application, such as diesel and rechargeable batteries, in underground mine vehicles. This has led to the development of the world?s first fuelcell production vehicle, a mine locomotive. A mine loader project has also started and several other projects are planned. These projects are providing the mining industry with the required information to make this technology shift possible. The application of fuelcell power will yield several important benefits such as the elimination of underground diesel emissions, significant reduction in the primary extraction?s sector greenhouse gas emissions and support for a more productive scenario. This article reviews these successes, discusses ongoing and potential projects and presents the technology application benefits that could be possible for mining operations.

May 1, 2003

By L. H. McKay

Tailing Dams Three types of dam have been structed to impound tailings from the Allenby mill: 1.- By classifier unit 2.- By earth dam 3.- By direct deposition of tailings The first type, which includes two dams, was built across a shallow valley which sloped down to Similkameen river, just below the mill site. Two earth embankments, one below the other, were built across the valley. Tailings were then piped to Akins classifiers mounted on wooden wheels. The classifiers were set up at one side of the valley and gradually moved ahead on the sand embankment created by the sand discharge from these classifiers, the slime overflow going to settli.ng ponds formed by the dams. Decanting wells were built in the settling ponds by placing four six-by-six timbers vertically in the ground, two feet apart, to which two-by-six tongue-and-groove boards were nailed. The elevations of the ponds were raised, as required, by nailing additional two-by-six boards on the well and bolting on more six-by-six timbers when required. The bottoms of the wells were attached to a covered launder made of three-inch lumber laid on a one per cent grade. This launder carried the overflow through the dam. The second type of dam was built across a long, narrow valley, known as Hitchen's Flat, the upper ~n d of which was about 2½ miles north of the mill. This valley, an ideal tailings site, was 4,000 feet long and from 600 to 800 feet wide. An earth embankment with a concrete spillway through the top was built approximately 28 feet high across the lower end of this valley. Tailings were then dumped into the upper end of valley, with no further expense until the basin was filled up to the level of the flume where this entered the valley. When the upper end of the valley was filled to this point there was still room for more tailings at the lower end. Therefore, a pump was installed to elevate the tailings to build a wall around the upper end of the valley by depositing sands from a launder built up on 20 foot supports and sloping both ways from the pumping station around the upper end of the basin.

Jan 1, 1950

Introduction ?MT involves the measurement of naturally occurring magnetic and electric field oscillations. ?The ratio of E/H (wave impedance) is measured as a function of frequency to give resistivitydepth information. ?The ratio of vertical and horizontal magnetic fields (tipper) gives information about the location of (channeled) current systems.

May 1, 2008

By Henry Hengeveld

Are the IPCC results credible? The most recent IPCC assessment is??an admirable summary of research activities in climate science? US National Academy of Science 2001 report to President Bush Joint statement by Academies of Science from 17 other countries ? May 2001 ?The work of the?IPCC represents the consensus of the international science community on climate change science. We recognize IPCC as the world?s most reliable source of information?and endorse its method of achieving this consensus.?

Nov 1, 2002

By S. Kursunoglu

The aim of this study was to investigate the effectiveness of Ascorbic (C6H8O6) Acid (AA), Activated Carbon (AC) and Guar Meal (C6H12O6) (GM) as a reductant for the simultaneous complete dissolution of zinc (Zn) and manganese (Mn) from a spent and mixed Zinc-Carbon (Zn-C) and alkaline battery powders in sulphuric acid (H2SO4) leaching. AA was tested previously as a reductant by other researchers while AC and GM were tested as a reductant for the first time in battery recycling. The effects of H2SO4 concentration, AA/AC/GM dosages, reaction temperature and leaching time on the Zn and Mn dissolutions were investigated according to 2k full factorial experimental design and Central Composite Design (CCD) technique; then, a simple optimization study was carried out for comparing the reductants. The optimum reductive acid leaching conditions for AA were determined at 3 hours leaching time, 70°C leaching temperature, 0.5M H2SO4 concentration, 13 g/L AA dosage, 1/20 g/mL solid/liquid (S/L) ratio and 200 rpm stirring speed. Under these conditions, the dissolution efficiencies were 99.9% for Zn and 99.3% for Mn. The best reductive acid leaching conditions for AC were determined at 3h leaching time, 80oC leaching temperature, 1M H2SO4 concentration, 3 g/L AC dosage and 400 rpm mixing speed. Under above conditions, Zn and Mn dissolutions were not complete. At 2M H2SO4 concentration, 10 g GM dosage, 700C leaching temperature, 200 rpm stirring speed, 1/20 g/mL solid/liquid (S/L) ratio and 3 hours leaching time, full dissolution of both Zn and Mn was achieved. As a result, three different reductants were evaluated in this study for complete simultaneous Zn and Mn dissolutions. This paper also compared present test results with previous spent battery recycling studies for Zn and Mn dissolutions. Full valuable metals dissolutions from spent batteries were achieved at low H2SO4 concentrations with AA and high concentrations with GM. Selective precipitations of Zn and Mn from acid solutions were carried out using NaOH and KOH. Using 3M NaOH as precipitating agent at room temperature and at pH 8; 95.4% of Zn and at pH 10; 93.7% of Mn were precipitated from the leach solution. Under the same conditions, using 3 M KOH at pH 8; 91.6% of Zn and at pH 10, 96.4% of Mn were precipitated. Based on the experimental results obtained, an appropriate flow sheet was proposed to recover both Zn and Mn.

Aug 1, 2013

By M. Jiang, X. Fan, W. X. Chen, Z. K. Guo, H. H. Zou

"Some improvements are carried out for elasto-plastic model by taking the shear dilation effects and relaxation effects of deep rocks into accounted. The high pressure equations of states with Mie-Grüneisen form are also introduced to describe the relation of pressure-volumetric strain. Numerical simulations of free field responses for deep underground explosions are conducted by using the user subroutines which compiled by means of the secondary development functions of LS-DYNA9703D codes. It is indicated that the dynamic responses of free field are well simulated based on this improved elasto-plastic model, and the analytical results are in good agreement with the data of U.S. Hardhat nuclear test.INTRODUCTIONDynamic behaviors of deep rocks for underground explosions are obviously different from that of shallow underground explosions and have aroused great attentions of international experts who work for rock engineering. The dynamic models of deep rocks could be roughly divided into classic elasto-plastic model and fracture damage model according to different theoretical foundation. M. E.Kipp and D. E.Grady et al. are the outstanding representatives who engaged in the researches of fracture damage mechanics. Researches of dynamic problems for geomaterials were carried out by C.C.Grigorian and the conclusion that incompressible elasto-plastic medium model could not be used to solve the problems of closed underground explosion was derived, and therefore C.C.Grigorian model was proposed. In this model, C.C.Grigorian assumed that the average hydrostatic pressures and the densities of medium had one to one relationship, and the path of loading or unloading is different from each other. For shear deformations, analytical solutions of the problems were derived according to the model which was slightly different from Prandtl-Reuss model, the constitutive equations were closed by Mises-Schleiher constitutive model. However, the analysis showed that there were two inadequacies in C.C.Grigorian model. Firstly, the shear dilation effects of fractured medium after wave front could not be considered. Secondly, the relaxation characteristics of the rocks in fractured region were not taken into account."

Jan 1, 2015

By Brent Robertson

Failure to meet quality objectives during the execution of any industrial project has lasting negative impacts on facility life cycle performance. Cost overruns, schedule delays, and rework are characteristics of project quality issues that arise during the project. Commissioning and start-up problems, low production, production bottlenecks, breakdowns and the necessity for operational work-arounds are characteristics of project quality issues that appear after project completion. Risks such as production facility downtime, shortened equipment life, and potential HSE violations must be clearly identified and addressed during project planning phases. Appropriate Quality Assurance (QA) and Quality Control (QC) focus must be placed on identified high-risk areas. In order to be effective, quality systems must be flexible, non-confrontational, consistent, and adaptable to projects of any size ? from capital mega-projects to small maintenance projects. All project participants must be aligned in how they are approaching quality and the difference between QA and QC must be clear to everyone on the project. Emphasis must be placed on QA activities to minimize project cost, reduce rework, manage change, and reduce the production facility operational risk. QA is focused on the work processes used to generate the design and confirming that the processes are present and being followed. Issues in the work processes guarantee that the output drawings and specifications will be less than optimal. The identification and monitoring of quality-critical processes provides a focus for QA activities. QC activities are then used to generate proof that the project was implemented correctly and become a key part of the turnover.

Nov 1, 2011

By lchimura. R. .

Japan Oil, Gas and Metals National Corporation (JOGMEC) and Centro de Investigation Minera y Metalurgica (CIMM) commenced a five year project from 2001 to modify the treatment of the furnace dust from Teniente converter containing harmful elements like arsenic and lead. The project was supported by Japanese and Chilean governments, and a demonstration plant was installed and operated at Las Ventanas Smelter and Refinery (Division Ventanas CODELCO). The basic and detailed engineering was made by Mitsui Mining and Smelting Co., Ltd (MMS) based on the joint study among JOGMEC, CIMM and Division Ventanas CODELCO. Arsenic in flue dust is lixiviated by sulfuric acid and fixed as crystalline ferric arsenate, where leachability of arsenic will be lower enough than the regulation, 5mg/I by TCLP (Toxicity Charactaristic Leaching Procedure) of USEPA. On the other hand, the recovered copper from the dust will be fed to the copper production process at Las Ventanas Smelter and Refinery, while zinc will be recovered as the exportable product. As introducing the crystallization and growing stage, the stable crystalline ferric arsenate formation can be achieved under the normal pressure.

Jan 1, 2007

The rate of liquid copper deoxidation during top blowing of reducing flames has been investigated using a high capacity thermogravimetric unit at 1200 °C. For 1 kg copper samples, it was observed that the rate of deoxidation was proportional to the flow rate of the reducing reagent (H2 or CO). Under similar experimental conditions, it was found that H2 is more effective than CO even though both have similar thermodynamic potential to deoxidize liquid copper. The rate of deoxidation of liquid copper with reducing 0 2/CH4 flames was measured for 0 2/CH4 molar ratios of 1.5 to 2. The deoxidation rate depends on the 0 2/CH4 ratio and decreases as it approaches the stoichiometric ratio (02/CH4 = 2). Estimation of the rate of deoxidation of liquid copper with top blowing flames based on the thermodynamic composition ofH2 and CO in the product gases, agrees well with measured values.

Jan 1, 2007

By Denis Labrie

Résumé Cent soixante (160) câbles d'ancrage ont été installés au toit de la rampe à la Mine-laboratoire de CANMET à Val-d'Or, Qué bec, Canada, pour prévenir toute dégradation suite à l'élargissement de la voie de roulage dans un secteur tournant à 180 degrés, communément appelé Virage Santa Barbara. Le roc à cet endroit est de nature bloqueuse et stratifiée, et son épaisseur au toit de la rampe est limitée à environ dix (10) mètres, le tout sous une couche de terrain meuble saturée en permanence. Le soutènement mis en place a été conçu pour former une zone de compression et supporter une strate de roc d?environ quatre (4) mètres d'épaisseur. Les critères de conception et les méthodes d'installation sont présentées. Un contrôle de qualité rigoureux a été effectué au moment de la mise en place du support, notamment en ce qui concerne la mise en tension des câbles eux-mêmes et la qualité du béton utilisé lors de l'injection. Des instruments de mesure seront mis en place sous peu pour dépister tout mouvement éventuel au toit de la rampe. Abstract Design and installation of an active mine ground support using tensioned cables at the Experimental Mine, Val-d?Or, Québec, Canada. One hundred sixty (160) cables were installed at the back of the ramp at the CANMET?s Experimental Mine located in Val-d?Or, Québec, Canada, to prevent any degradation of the ground after the enlargement of the roadway in a sector turning at 180 degrees, usually called Virage Santa Barbara. The nature of the rock mass in this area is blocky and stratified, and its thickness above the ramp does not exceed ten (10) metres. Eight (8) metres of soil, mostly saturated, cover the bedrock on top of the ramp. The ground support was designed to form a compression zone at the back, aimed to carry a strata of rock of around four (4) metres thick. The design criteria and the methods of installation of the ground support are described in the paper. A strict control of the quality of the grout used for injection and the tension placed in the cables was carried out during the installation of the support. Ground monitors will be installed soon, to detect any movement that could take place above the ramp.

May 1, 2001

By W. F. Harkness, D. Hodgkinson

"A non-destructive testing program was established at Crows Nest Resources (C.N.R.), Line Creek mining operation following an in-service fatigue failure of a front wheel spindle on a large haulage truck.This failure identified a definite need for improvements in the ultrasonic techniques used during the mandatory spindle integrity examinations. Initial investigations using common mining industry ultrasonic examination techniques showed that the smallest detectable cracks were 75 mm in length for the spindle types in service at the C.N.R. site. The Initial findings indicated that inadequate inspection technique design was the cause of the poor performance. To improve inspection reliability it was identified that improved ultrasonic techniques were required. Results using designed ultrasonic techniques were encouraging, with the detection of simulated and natural cracks 12 mm long achieved. The cost benefits associated with the extended spindle life, following the removal of these small fatigue cracks, far exceeded those of the expertise and effort necessary to implement and conduct the N.D.T. program.Introduction During 50 years of evolution, non-destructive testing (N.D. T.) has progressed from a laboratory curiosity to a well accepted and invaluable tool used in the assessment of material integrity. Unlike destructive testing, N.D.T. does not deform or render the material useless. Non-destructive tests may involve many applications, from the determination of a corrosion prevention coating thickness to the examination of a raw material for internal and external deformities.Within the mining sector, highly-stressed components will normally have been subjected to some form of non-destructive test during their manufacturing cycle. These tests are used to ensure the component does not contain material flaws whichmay be detrimental to its service performance.While the component may have assured quality when produced, deterioration by fatigue may occur during an aggressive service life. Large dynamically-loaded components such as haulage truck front wheel spindles are , in particular, prone to this service related problem."

Jan 1, 1987

By E. Benguerel, G. Monteith, L. Centomo, S. Pelletier

In early 2007, it became apparent that with changing concentrate feeds, the magnesium (Mg) load projected for CEZinc starting in 2009 and beyond would quadruple and overwhelm the current Mg process bleed capacity. A project was started, following design for six sigma (DFSS) standards, to select both the optimal process and to evaluate its target capacity for the Mg bleed circuit. The economic and process risks of under or over-designing while Mg reduction efforts were underway at the mines also needed to be evaluated. This paper describes the project methodology, the impact on the plant, and some potential optimizations for CEZinc's basic zinc sulphate (BZS) Mg bleed process.

Jan 1, 2008