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By I. H. Warren, Forward F. A

The reduction of aqueous slurries of uranyl carbonate at elevated temperature with compressed hydrogen m the presence of metal catalysts and certain organic promoters has been shown. to yield uranium dioxide. The reduction takes place in a sequence of steps. The purity and sintering properties of the dioxide make it of interest as a starting material for fuel element production. Simple control can be exercised over the surface area and oxygen/uranium ratio of the product during reduction. URANIUM dioxide for fueling atomic power reactors 1s conventionally produced as a powder by simultaneously decomposing and reducing ammonium diuranate with hydrogen in a furnace at high temperature. Fuel elements are then generally made from this powder by compacting and sintering ( 1). In order that elements approaching theoretical density may be obtained,

Jan 1, 1961

By John Loui Porathur

Highwall Mining has been recently introduced in India. The first Continuous Highwall Mining extraction in India started operating at Ramagundem Opencast Project-II (OC-II) of Singareni Collieries Company Ltd. (SCCL) in December 2010. A new hybrid empirical and numerical modelling approach has been devised to design web pillars for the initial Highwall Mining sites in India, considering the complex geology, such as existence of thick seams and multiple seams in close proximity. This paper gives the scientific elucidation of a comprehensive design methodology adopted for the above mentioned Indian Highwall Mining sites. The design technology includes web pillar design for multiple seams using hybrid empirical and numerical methods, slope stability assessment, ground movement monitoring, and recommendations for conducting blasting operations in the vicinity of Highwall Mining extractions.

Aug 1, 2013

By F. Habashi

Magnesium is the eighth most abundant element in the earth's crust, It occurs in nature in sea water, brines, and a number of minerals, Metallic magnesium was first isolated by Humphry Davy (1778-1829) in England in 1808 via electrolysis of anhydrous magnesium chloride with a mercury cathode, Antoine Bussy (1794-1882) in France extracted the metal in 1828 by reducing fused magnesium chloride with metallic po¬tassium vapour, The first industrial production of magnesium by electrolysis of molten carnallite began in 1886 in Hemelingen in Germany, In 1940 Lloyd M, Pidgeon (1903¬1999) in Canada pioneered the first industrial metallothermic magnesium extraction plant based on the reduction of dolomite with ferrosilicon under vacuum, Since then the magnesium industry developed further and a variety of processes are presently used.

Jan 1, 2006

By Lawrence Melis

Fission Uranium Corp.’s Triple R Uranium Deposit at its Patterson Lake South Project is located in northwest Saskatchewan in Canada’s Athabasca Basin. As part of pre-feasibility studies for the project a detailed metallurgical test program was completed to provide process design criteria. The testwork program encompassed preparation and analysis of test composites, comminution testing, uranium acid leaching, liquid-solid separation, solvent extraction of uranium, precipitation of uranium yellowcake products, tailings and effluent treatment, tailings physical and chemical characterization, and environmental testing of prepared tailings, as well as investigations of gold and silver recovery from the mineralization. The paper provides mineralogical information, testwork methodologies and test results which were used to arrive at process design criteria and the selection of the process flowsheet for the project.

Jan 1, 2020

By A. P. Paiva

The solvent extraction properties exhibited by some /V,N'-tetrasubstituted malonamides to efficiently and selectively recover iron(III) from concentrated chloride leaching solutions can be found in the recent literature. The iron(III) extractive chemistry exhibited by some of these derivatives is revisited, in order to compare their chemistry with that shown by a few of the new malonamide compounds. The generally good extraction efficiency towards Fe(III), from >4 M hydrochloric acid solutions, and the relative ease of Fe(III) stripping by distilled water are remarkable findings that are confirmed for the malonamide derivatives described in this work. Furthermore, additional data regarding their selectivity towards Fe(III) extraction over several base metal ions and their behavior when subjected to successive Fe(III) extraction-stripping tests are also presented and discussed.

Jan 1, 2006

By J-F. Magnan, M-A. Thibault, R. Boulianne, C. Gauthier, J-P. Gagné, G. Dufour

During the production of aluminium in smelters, the anodes used in electrolysis cells have to be replaced frequently. Anode butts are usually placed on anode trays for transportation and cooling, a practice during which Hydrogen Fluoride (HF) is emitted in large quantities. Covers developed in 2000 by Alcoa Deschambault to fit on the anodes trays were implemented, resulting in significant reductions of HF emissions. However, the covers are expensive to maintain and use short-life consumable parts. In January 2004, STAS and Alcoa decided to develop a more efficient design of cover, with lower maintenance costs and no need for consumable materials (like soft cushions). This paper presents a summary of the work performed to develop the new design as well as a summary of the test results.

Jan 1, 2006

By G. T. Lapidus, R. Zárate-Gutiérrez

Selective leaching of lead from a Pb-Ag-Zn concentrate with hydrogen peroxide in citrate solutions was studied at room temperature. Leaching tests were performed, varying the H2O2 concentration and the solid-liquid ratio, holding the solution pH constant at 7, and the citrate concentration at 1 M. Lead extractions of 100 % were achieved with 4 and 5 times the stoichiometric quantity needed to form elemental sulfur, with only a small amount of metal impurities dissolved (Ag, Zn and Fe). The lead solubility limit at those conditions was found to be ~21 g L-1. X-ray diffraction analyses of the leach residues were free of galena (PbS), while other metal sulfides, such as sphalerite (ZnS), chalcopyrite (CuFeS2) and pyrite (FeS2), were basically unaffected.

Jan 1, 2014

By Eiichiro Mizushima

Catalyst systems comprising (Ph3P)AuCH3 and acid co-catalysts were found to be highly efficient for hydration of alkynes to give ketones. Methanol was the best choice of solvents. Introduction Hydration of carbon-carbon unsaturated bonds is one of the environmentally benign routes to the carbon-oxygen bond formation. Hydration of alkynes forming carbonyl compounds, an important variation in this category, is a well known reaction which has been extensively studied. The reaction by acid-catalysis is the most conventional method, while it is applicable only to electron rich acetylenes to obtain satisfactory yields (1,2). The hydration of simple alkynes usually requires another catalyst (co-catalyst), typically a mercury(II) salt (3), which is inconsistent with the guiding principle of Green Chemistry (4).

Oct 1, 2003

By G. R. MANSON

The Brisco Barite Mine lies 70 km south-southeast of Golden, British Columbia. Barile mineralization occurs in a northstriking brecciation zone within Ordovician-Silurian Beaver/ oot dolomites and quartzites. Brecciation was caused by faulting related to the Mount Forster-Steamboat Fault. The main barite vein occupies a fault zone and is up to 12 m wide and over 250 m long. It is light grey to white, fine grained and compact; BaSO4 content is 9/. 70 per cent. Production started in 1945 and has continued to the present. Barile originally was removed from an open pit; later, an adit, begun in 1957, reached more than 240 m along the vein, 15 m below the pit floor. Today ore is hoisted from a decline resting some 37 m below the pit floor.

Jan 1, 1984

By Roussos Dimitrakopoulos

Conventional approaches to estimating reserves and optimizing mine planning and production forecasting result in single, often biased forecasts. This is largely due to the non-linear propagation of errors in understanding orebody attributes from a limited finite number of drilling data, throughout the chain of mine planning and mining. A new mine planning paradign is considered herein to include two interacting and potentially fusing elements: stochastic simulation and stochastic optimization. These two elements provide an expanded mathematical framework that allows the modelling of orebody uncertainty and its direct integration to mine design, production planning and valuation of mining projects and operations. This stochastic framework has shown to increase the value of production schedules in the order of 25%. In addition, case studies show that stochastic optimal pit limits are about 15% larger in terms of total tonnage, compared to the conventional (deterministic) optimal pit limits. This difference extends life of mine and adds approximately 10% of net present value (NPV) to the NPV reported above from stochastic production scheduling within the conventionally optimal pit limits. Furthermore, results suggest a potential new contribution to the sustainable utilization of natural resources.

Oct 1, 2009

By Joseph Carlston

With environmental regulations continuing to restrict the discharge of phosphorus from wastewater treatment facilities, traditional methods of phosphorus removal are proving inadequate. To achieve the phosphorus control necessary, a new coagulant used for phosphorus removal, cerium chloride, has been studied in several municipal and industrial wastewater treatment facilities that must meet a phosphorus discharge limit of 0.5 mg/L or lower. These studies demonstrated the high phosphorus removal capabilities of cerium chloride, with the results illustrating the ability for cerium chloride to reduce phosphorus to low concentrations in the effluent using a lower volume of product as compared to traditional coagulants, such as ferric chloride. This reduction is due to the unique ability of cerium chloride to remove phosphorus as cerium phosphate, whereas iron- and aluminum-based coagulants rely on adsorption and co-precipitation.

Jan 1, 2014

By Kristie Tarr

Portland cement is primarily used to solidify backfill in underground mine workings and it represents a major cost in mining operations. CANMET-MMSL has invented an alternative binder technology that does not contain any amount of Portland cement and is made using waste materials, such as development rock and smelter slag. The technology has been successfully tested with many types of base metal and ferrous slag. Research conducted in collaboration with several mining operations in Canada has shown that the CANMET-MMSL binder has considerable potential as a replacement for Portland cement in mine backfill. An integral part of the overall mining operation, backfill is used for two main purposes: safety and environmental remediation. Depending on the mining method used, backfill provides a working surface, stabilizes stope and pillar walls, as well as the surrounding rock mass, and controls caving of stope backs. There are several benefits associated with the replacement of Portland cement in backfill, including reductions in (i) the footprint by placement of slag waste underground, (ii) the environmental effects and long term liability resulting from disposal and containment of slag waste on surface such as acid rock drainage, (iii) GHG as a result of reduced Portland cement usage (the production of 1 ton of Portland cement produces 1 ton of GHG), and (iv) the significant costs associated with reduced Portland cement usage.

Oct 1, 2010

By Patrick Pelletier Jr., Pierre-Alexandre Bossé, Gianni Bartolacci, Ian Orford, Steve Parent

"Over the last decades, many authors have shown the importance of froth in the flotation process. Mineral recovery is related to froth recovery and flotation. Selectivity is affected by froth characteristics, especially structure and loading. The characteristics of froth textures could therefore be used for diagnosing flotation.Machine imaging, especially image texture analysis, allows on-line measurement of important froth characteristics and process state classification. The measured characteristics include froth texture, loading and stability indicators. To extract information from images, texture analysis tools are used as well as a block-matching algorithm (BMA). For process state classification, images are analyzed with the same tools and clustering is done with multivariate data analysis algorithms.Two case studies, Brunswick Mine Concentrator Cu/Pb circuit and LaRonde Mine Zn circuit, are presented to show that these indicators may be used for diagnosis and control. The influence of manipulated variables on measured froth features is shown as well as the relationship between froth characteristics, mineral recovery and flotation selectivity.INTRODUCTIONImaging is a way to depict abstract characteristics of a scene or an object; it is often related to other types of scientific observations, chemical component concentrations, for example (Geladi and Grahn, 1996). In this paper, the scene is flotation froth. Imaging can be especially useful in applications where it is difficult to obtain the measurements needed for process analysis – froth flotation, for example."

Jan 1, 2006

By Megan Becker, Aubrey Mainza, Indigo Research Laboratories, Jenny Wiese, Gaynor Yorath, Lucy Little

Particle shape characterisation has an important role to play in mineral processing, to clarify effects of shape on rheology, equipment wear rates, comminution, classification, sizing and flotation. However in industry, shape characterisation is not routine, and the most commonly used shape descriptor in the field (circularity/ angularity/ sphericity) is not invariant. This study aims to investigate shape measurements for a fine particulate ore sample measured with different analytical devices. Two Automated Scanning Electron Microscopy devices with Energy Dispersive X-ray Spectrometry (FEI QEMSCAN® and Zeiss Mineralogic®), and a camera based image-sizer using dynamic image analysis (Retsch CAMSIZER® XT) were compared. Each device was used to analyse the shape characteristics of specific particles in both a coarse sample (–212/+150 µm) and a fine sample (-53 µm) of UG2 platinum ore. Circularity and Roundness frequency distributions obtained from the three devices were then compared. For selected individual particles, circularity showed higher variability than roundness, and the sample circularity distributions obtained by the three devices were completely different. It is clear that circularity data from different studies relying on different devices should not be compared on an absolute scale. The shape parameter roundness was found to be a more robust descriptor than circularity, and it can give a stronger indication of a particulate sample’s shape characteristics on an absolute scale. However, there were still significant differences in the roundness measurements obtained by the CAMSIZER XT and the two Auto-SEM devices, which was attributed to the dissimilar mechanisms of image capture.

Jan 1, 2016

By A. Liem, R. L. Johnson, C. Sturgess, E. Kuzub

New challenges in mineral processing arise as high-grade ores become less available and the mining industry is forced to exploit lower grade ores. One of the challenges in beneficiating lower grade ores is the liberation of mineral particles while maintaining control over material management. Lower grade ores need fine grinding to free valuable minerals, but finely divided particles can cause severe problems, such as dustiness and flowability, in subsequent stages of material management. There are at least two approaches that can be taken to resolve this dilemma, both of which relate to particle size enlargement. First, the application of a dust suppressant can be used to control that aspect of material management. The optimal choice of dust suppressant agent depends on effectiveness and cost, both of which can be strongly influenced by the selection of application method. Second, agglomeration combining small particles into larger units-can reduce dust and improve the flow characteristics of the material at the same time. There are several mechanisms that can be employed to agglomerate mineral materials. Although agglomeration adds a new processing step, it is often cost effective. This paper describes these two approaches and their respective challenges, as they relate to a mined ore. We report on modified or newly developed procedures for characterizing mineral ores with respect to material management. On the same material, we use agglomeration processing to capture fines within larger particles and show how dustiness and other aspects of material handling are affected. We conclude by discussing their specific application in accordance with the mineral properties and processing needs.

Jan 1, 2004

By E. Ghali, W. Zhang, G. Gabra, N. Sorour, G. Houlachi

The additives polyacrylamide, 1-Butyl-3-methylimidazolium chloride, Tetra-butylammonium bromide, Benzalkonium chloride and chitin are evaluated during zinc electrolysis from synthetic acidic sulphate electrolyte containing Mn2+ ions, in absence and in presence of 0.0055 mg dm-3 of Sb3+ ions. Galvanostatic polarization tests for 2 hours at 50 mA cm-2 and 38oC were carried out to determine the cathodic and anodic potentials, and current efficiency of the deposited zinc. Potentiodynamic polarization and cyclic voltammetry tests have also been employed to study the electrochemical behavior of each additive on the zinc deposit on aluminum electrode. Results showed that, in presence of Sb3+, adding 1 to 3 mg of 1-Butyl-3-methylimidazolium chloride increases the cell voltage by ˜0-7 mV. Current efficiency is increased by ˜4.90-6.40%; power consumption is reduced by ˜147-173 kWh t-1 by adding 1-3 mg, respectively. However, in absence of Sb3+, cell voltage is decreased by ˜7-28 mV, current efficiency is increased by ˜0.70-1.50%; power consumption is reduced by ˜41-47 kWh t-1 by adding 1-3 mg. The effect of the other additives on cell voltage, current efficiency, lead content and morphology of zinc deposit has also been examined. Surface morphology and crystallographic orientation of the deposit was studied using scanning electron microscopic (SEM) and X-ray diffraction (XRD), respectively. The content of lead in the deposit has also been measured using inductively coupled plasma spectroscopy (ICP).

Jan 1, 2015

By G. A. McGuffin

"IntroductionWITH the increase in quantity of sour gas reserves in the Province of Alberta, and the wider market for sulphur brought about by mounting world demand and restrictions placed on the principal supply, it was inevitable that this important source of sulphur would be .developed. In the light of these facts, it seems timely that a general paper on sulphur recovery from petroleum gases be presented. This, then, is the purpose of the following text. A short discussion of each of the following subjects is presented:(1) Properties and uses of sulphur(2) Existing sources(3) Market research(4) The recovery process in Turner Valley(5) Hazards of sulphur productionNo pretext of originality of material is made since innumerable reports have been prepared on this and related topics and information contained in these has been used quite liberally.Properties and uses of SulphurSulphur is a non-metallic element having an atomic weight of 32.06. The stable crystalline form at atmospheric temperature is referred to as 'rhombic' sulphur. It is bright yellow and has a specific gravity of 2.05, equivalent to 129.2 lb./cu. Ft. Above 204°F. sulphur has another stable crystalline form, referred to as 'monoclinic'. This is reddish-brown and is slightly less dense than the rhombic variety (122.4 lb./cu. Ft.). Sulphur in bulk form weighs 84 to 90 lb. per cu. Ft. Sulphur melts at approximately 240°F. to a straw coloured liquid which is quite viscous."

Jan 1, 1952

By Elizabeth Gardiner

Tailings and water management facilities are integral components of mine and mill operations. They must be managed for the long term to ensure that safe and environmentally responsible stewardship is achieved. The Mining Association of Canada (MAC) has developed and published two manuals to provide guidance to mining companies on sound practices for the safe and environmentally responsible management of tailings facilities: ???A Guide to the Management of Tailings Facilities; and ???Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. The Guides were designed to help companies develop and implement tailings management systems that include environmental and safety criteria, to improve the consistency of application of sound engineering and management principles to tailings and water management facilities through their full life cycle, and to demonstrate this to regulators and the public.

May 1, 2003

By Henri-Loui Jacob, Suzie Nantel

"Depuis la fin des annees 1800, la province de Grenville represente pour Ie Quebec une source importante et diversifiée de minéraux industriels. Le Ministère de l'Énergie et des Ressources du Québec, dans Ie cadre de I'entente auxiliaire Canada-Québec, et les compagnies minieres y ant multiplié, surtout depuis 1983, leurs travaux d 'exploration, de cartographie, et d'évaluation pour les minéraux industriels. Ces travaux ant conduit ala découverte et ala mise en valeur de gisements de granite architectural, de graphite, de dolomite et ant aussi permis de repertorier des gîtes et des indices prometteurs de wollastonite, de silice, de calcite. de dolomite, de silicates d'alumine et de terres rares. Les gisements récemment découverts sont actuellement exploités au sur Ie point de l'être et les gîtes et les indices les plus prometteurs ant été jalonnés.ABSTRACTSince the late 18oos, the Grenville Province in Québec has been an important and diversified source of industrial minerals. The Ministere de l'Énergie et des Ressources du Québec, under the Canada-Quebec Mineral Development Agreement, and the private sector have put an emphasis on exploration, mapping and evaluation programs in the Grenville Province for minerals, particularly since 1983. These programs have led to the discovery and the development of deposits such as architectural granite, graphite and dolomite, and have also led to inventories of occurrences and prospects of wollastonite, silica, calcite, dolomite, alumina silicates and rare earths. The deposits discovered lately are presently being quarried or will be in the near future. The most promising occurrences and prospects have been claimed."

Jan 1, 1990

By Karl J. C. Harries

"The following is an outline or check sheet of some things that might be looked at when considering the concept of a royalty or royalty provisions. It is not intended as a guide to what is right or wrong (that is for the parties to decide). It does not replace the discussions in this work and is not intended to be a complete or exhaustive compilation of matters to be considered. It presumes that you are familiar with the basic concepts of royalties and has been included as an aide memoire only. Use it as such, with caution and common sense, and amend it to suit your needs. Remember also that brevity can result in inaccuracy or imprecision. This is a danger in many points below.The section references are for the sections where the matter is the main subject of the section – see the index for other sections.Royalty TypesNet Proceeds [§§ 5.8.; 11.4.]• No accepted or understood meaning within industry.• Literal meaning, if not defined, would imply “net operating profit”.• Often defined as net profit with revenue base of proceeds from sale of product.• Should not be used without detailed and clear definition. Net Operating Profit [§§ 5.8.; 11.4. – referred to only]• Net profit without recoupment of pre-production expenditures.• Revenue base: usually proceeds from sale of product.• Operating costs deductible.• Some reserves may be permitted.• Recoupment of some post-production capital expenditures may be permitted.• Not often seen as basis for royalties in Canada."

Jan 1, 2003