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By J. C. Allan

THE purpose of this paper is to outline the pogress made in the development o the gravity separation method o ore dressing known as Sink-and-Float, which, in the opinion of the writers, has now reached a stage justifying the claim that this new method marks a highly important advance in the technique . The essential feature of the newest development of this process is the extremely accurate separation achieved. This is responsible for higher extraction in the sink-and-float unit on coarse sizes and, in consequence, for substantially higher overall recoveries. Whilst this is the most remarkable feature of the new process, it has further important contributions to make to ore dressing under the following heads: (1) The introduction of the sink-and-float separator as a buffer helps to iron-out irregularities in the mill feed. By supplying a concentrate of constant grade to the flotation section, the process also indirectly improves overall recovery. (2) The addition of a sink-and-float unit to an existing mill results in substantial increase in capacity at low per ton capital cost. (3) Where the plant can be installed underground for the pre-treatment of low-grade ores, there is a saving in hoisting costs, and excellent 'fill' is provided near the point of use. ( 4) Low-grade mixed oxide-sulphide copper ores may be pre-concentrated, thereby producing a flotation feed sufficiently rich to render the oxide residue from such flotation economic for subsequent treatment by leaching or other methods. (5) Application of the process eliminates hard gangue constituents which cause high grinding costs, or gangue constituents which adversely affect flotation. The plant is compact and easily controlled. No highly skilled operators or expensive reagents are required, and the labour and power per ton are low. The separator is extremely flexible, working equally efficiently on any throughput up to its maximum capacity.

Jan 1, 1940

By Jehan Rondot

Les trois intrusions alcalines de Suzorite en haute Mauricie, bien que non datees, son! sans doute d ,attacher aU)( nombreuses autres intrusions alcalines dispersees sur les blocks Grenvillia et Laurentia et datees de I 050 Ma =t= 10%, done reliees d l'orogene grenvilien. L 'utilisations de la Suzorite est liee d sa forte proportion de phlogopite (>50%). Le rapport Mg/Fey varie de 3 d 7. Sa mineralogie et sa composition particulieres (forte proportion de Mg, Ket H20) en font son attrait.

Jan 1, 1984

By C. C. Walden, A. Bruynesteyn

"Chemical and biological aspects of the formation of acidic effluents from sulfide waste materials are discussed. Test procedures to determine the acid producing potential of waste materials, as well as the characteristics of such acidic effluents, are presented. Practical applications of the test procedures are discussed with reference to predictior of environmentally unacceptable drainage and to estimation of metal recovery by dump leaching.INTRODUCTIONNatural leaching of sulfide minerals, exposed to the atmosphere, has been occurring for geological time. For centuries, man has been aware of the acid drainage originating from coal workings, copper mines and waste dumps. With the advent of the technical sciences, the processes involved in acid mine drainage production were considered to be solely chemical in nature. However, in 1947, it was shown (1) that a specific microorganism, called Thiobacillus ferrooxidans, was responsible for acid mine drainage from coal workings. It was demonstrated that under suitable conditions - this bacterium oxidized pyrite and marcosite in the coal to ferric sulfate and sulfuric acid. Numerous studies have subsequently demonstrated that - under suitable conditions - Thiobacillus ferrooxidans can attack most sulfide minerals, producing weak sulfuric acid, oxidizing ferrous to ferric iron and solubilizing other metals present (notably copper and zinc) as their sulfate salts."

Jan 1, 1980

By H. Tan

The effect of carbonaceous matter on gold extraction was investigated in cyanide systems with pure gold as well as pre-robbing sulfide gold ores. Auger studies demonstrated that the carbonaceous matter preferentially smeared on iron sulfide rather than aluminosilicate surfaces during wet or dry grinding. During mechanically mixed leaching, coating of sulfides and silicates and stripping of carbonaceous matter occurred simultaneously. TEM and XPS studies indicated preferential coating in the form of elemental (graphitic) carbon at the edges and the defect sites of particles. Interestingly, carbonaceous matter extracted from the gold ore was predominantly graphite and not preg-robbing in a solution with a high KCN concentration. However, the carbonaceous coating had a significantly detrimental effect on gold dissolution when gold was pre-ground with the gold ore. Artificial coating on gold surfaces with the natural carbonaceous matter from the ore was also found to substantially retard gold dissolution. With the addition of the natural carbonaceous matter from the gold ore, gold extraction from two non preg-robbing sulfide gold ores was inhibited owing to carbonaceous coating. The presence of carbonaceous matter significantly reduced the current density for gold oxidation and increased the current density for pyrite oxidation. This could explain the fact that carbonaceous coating hindered gold dissolution while enhanced sulfide preg-robbing.

Jan 1, 2005

By B. Erdem, N. Çelebi

An important problem associated with tandem dragline systems is that of matching the productive capability of individual draglines in the combination. In this paper, a dependence mechanism among draglines in a tandem system is described, and possible consequential problems in a poorly-matched system are defined. The rate of linear advance and the cost of stripping are determined as two major indications for an efficient operation. The proposed decision criteria and the underlying mechanism to select a synchronous couple are introduced and used in simulating tandem dragline systems. The developed model is tested on a hypothetical strip mine where pullback stripping is applied with a tandem dragline system.

Jan 1, 1999

By G. Belzil, F. Robichaud, M. Fullam

"The Goldex mining and milling complex is operated by Agnico-Eagle Mines Ltd. and is located in the Abitibi greenstone belt of Northwest Quebec, Canada. The mill operates presently at a throughput of 8,250 tpd with gold grade varying between 1.8 and 2.2 g/t. The ore is very high in gravity recoverable gold (GRG) at about 92% and as such a significant emphasis was placed on the gravity circuit. Commercial production started in 2008. Average gold recovery is 93.5% with about 68% of gold recovery coming from the gravity circuit. Over the course of the first several years of production, several gravity audits were carried out. In 2009, a complete gravity audit was completed, including ore, classification, Knelson Concentrators, and the gold room. In 2011, an audit was undertaken of the flotation circuit to determine the efficiency by which GRG is floated. Large samples of flotation feed and tails were collected and process for GRG content. This allowed a link between gravity and overall recovery to be made. This paper presents results of the audits and the development of a model linking gravity and overall gold"

Jan 1, 2012

By Ian L. Price

Description of the Springhill Coal Field The Springhill coal basin, which lies in the approximate centre of Cumberland county, Nova Scotia, is of Carboniferous age, and forms a syncline plunging to the westward at an angle of 32° at the outcrop but gradually flattening to the dip. It contains several workable seams of varying thicknesses, a generalized section of the measures in descending order from the surface being: [] The 1,114 feet of strata is composed of shales and sandstones, and all of the coal seams mentioned, with the exception of No. 4 and No. 5, have been mined commercially. The coal is said to be the best steam and domestic coal in the Province of Nova Scotia.

Jan 1, 1946

By L. R. Plitt

A series of experiments were carried out in an effort to develop a universally applicable mathematical model of the hydrocyclone classifier. The design and operating variables studied were: cyclone diameter and height, the inlet, vortex finder and apex diameters, the feed pressure and the solids content of the feed slurry. The model consists of four basic equations which express the cut size ( dso), volumetric split between overflow and underflow, volumetric throughput, and sharpness of separation in terms of the operating and design variables. Although empirical, the model is nevertheless in general agreement with fundamentally derived models. The model clearly 1•eveals the effect of the major variables on the operation of a hydrocyclone. Because of its broad data base and the inclusion of all the major variables, the model may be used without experimental data to predict the operation of cyclones over a wide range of different operating conditions. With operating data, the equations may be modified to serve as an operational model.

Jan 1, 1976

By M. R. Saharan

A brief overview of rockburst control measures is presented. The paper then elaborates on one key rockburst control measure, which is known as destress blasting. A historical background of the technique is presented in order to understand different aspects of its field application. The publication enumerates key aspects of the technique as being used in practice in South Africa and North America. The paper also presents an analysis of three case studies in order to demonstrate difficulties associated with the field application of distress blasting in hard rock mines.

Jan 1, 2006

By N. C. Carter, Wm. H. White, J. E. Harakal

"Of twenty-one ore deposits in British Columbia which are either in production or advanced stages of exploration, five have potassium-argon ages in a range of 165-205 m.y., eight are in a range of 44-55 m.y. and the remainder are either ca. 140 m.y. or ca. 100 m.y. old. Deposits of the oldest group have generally similar geological environments and radiometrically indistinguishable ages of magmatic and hydrothermal minerals. Deposits of the youngest group also have similar geological environments, with successive magmatic and hydrothermal events closely intermingled in time and place. Such deposits find no comfortable home in existing classifications of ore deposits. 1t is suggested, therefore, that those epigenetic deposits which can be shown by radiometrie and/or geologie means to be coeval with genetically related magmatism be designated as ""paramagmatic deposits."""

Jan 1, 1968

By X. Gu

Mining operations, especially surface coal mines, have great impacts on the local ecosystem and the environment. However, it has been a common practice in mine design that the economic evaluation considers only the operating and capital costs, while the costs incurred due to ecological damage are left out. Such practice underestimates the total cost of mining and ignores the difference in ecological impacts between different mine design alternatives. With growing interest in sustainable development, the mining industry is under increasing pressure to operate not only based on economic and engineering principles but also on principles of sustainability. Therefore, estimating ecological costs of mining and considering such costs in the mine design process is an important step towards reducing ecological impacts at the design stage. The objective of this paper is to quantify the ecological costs of open pit coal mining and to demonstrate the influence of such costs on the ultimate pit design. The ecological costs of mining are estimated based on the areas and types of land damaged by mining activities and the carbon emission from energy consumption. Four major components of ecological cost are identified, namely, lost value of direct eco-services, lost value of indirect eco-services, prevention and restoration costs, and the cost of carbon emission from energy consumption. Necessary equations are given for estimating these costs. An algorithm is described for ultimate pit optimization in coal deposits with near-horizontal coal seams. A case study is presented in which the ultimate pits with and without ecological costs are optimized and compared to show the influence of ecological costs on the pit design outcome.

Aug 1, 2013

In this study, flotation of fine galena, chalcopyrite and pyrite was performed after grinding with different extent of oxidation-reduction condition adjusted by grinding media. Sodium dithionite and iron ions were added in mill to simulate pulp potentials and iron oxidation species produced by grinding media, respectively. The types and quantities of the metal oxidation species on mineral surfaces were determined by EDTA extractions, while the surface electrical properties of minerals and interaction of different types of metal oxidation species were studied by zeta potential measurements. It was found that the nature and concentration of the absorbed metal oxidation species were dependent on oxidation atmosphere controlled by the iron amount of grinding media. These species interacted with each other and had an important role in determining flotation of fine galena and chalcopyrite as well as activation of fine pyrite by lead and copper.

Jan 1, 2006

By Paul Guliov

Industrial clays, including a variety of bentonites and kaolinbased clays in southern Saskatchewan are hosted by Late Cretaceous and Early Tertiary sediments. Ofparticular significance are the deposits of swelling bentonite in the Cretaceous Bearpaw Formation and the kaolinitic clays of the Cretaceous Whitemud and Paleocene Ravenscrag Formations. Swelling bentonite is currently produced in the Wilcox-Truax area by Canadian Clay Products Inc. and yields at least seven different commercial products for a variety of applications. Kaolinitic plastic clays, including ball clay, stoneware and earthenware clay, as well as kaolin in southern Saskatchewan, have a long history of development and use. Products include common and face brick, refractory bricks and other shapes, chinaware, pottery, sewer pipe, chimney flue linings and tiles. Currently clay production is for out-of-province brick manufacturing and for pottery. Recent research and improved technology combined with expansion in certain areas of the global clay industry generally hold promise for a resurgence of a clay-based industry in Saskatchewan. Products of particular promise include: clay tiles; kaolin fillers and extenders; and aluminum as well as related by-products from kaolinitic clays based on the carbochlorination process.

Jan 1, 2001

By Chris Cross

A working group from Anglo American, BHP Billiton, Rio Tinto and Xstrata reviewed supply and demand for graduates from mining education departments in countries where they normally recruit: Australia, Canada, Chile, Western Europe, South Africa and USA. Departments are typically small and increasingly unsustainable, resulting in a steady rate of closure. Supply and demand for graduates in the minerals industry is cyclical, with supply lagging behind demand and trending downwards. Currently, supply is tight and the industry is trying to expand with an ageing workforce. Greater collaboration between universities and within the industry is recommended to address these issues.

May 1, 2006

By V. Barranco, K. Yliniemi, A. Hubin, B. P. Wilson, D. Janas, M. Lundström, P. Hannula

Typical copper electrorefining electrolyte contains tens of grams of copper, some nickel and a wide variety of impurities. Some of these impurities comprise trace amounts of dissolved precious metals like Ag, Pd and Pt that currently are not fully exploited. This study presents an electrochemical method to recover precious metals via a combined electrodeposition-redox replacement (EDRR) process, where energy is used only to deposit copper during the ED-step, while the RR-step relies on the spontaneous replacement of copper by the precious metals (i.e. cementation). In order to conduct the recovery successfully, process parameters such as deposition potential (EDE), deposition time (tDE), redox replacement time (tRR) and the number of cycles (n) was adjusted. Investigations performed in synthetic electrolyte (40 g/L Cu, Ag = 10 ppm) proved the possibility to recover a high purity silver. Short deposition times (tDE) were found to result in small Cu particles that provided a suitably high surface area for silver cementation. In addition, experiments performed in real industrial electrolytes containing 44 g/L Cu and 54 ppb Ag (Boliden Harjavalta, Pori), demonstrated that EDRR could attain Ag recoveries of between 46–67% in an energy efficient, additive-free manner. INTRODUCTION The raw materials used in the state-of-art primary and secondary copper smelters contain mainly base metals, but also notable amounts of Ag, Pt and other precious metals. These valuable metals distribute mostly into the copper matte during the pyrometallurgical treatment (Tirronen et al., 2017) and end up into the cast anodes. During the electrorefining stage, metals more noble than copper such as gold and platinum, are not dissolved but enrich into the anode slimes. In contrast, silver may dissolve slightly and thus, minor chloride addition is used to retain silver in the slime as sparingly soluble AgCl. Moreover, other metals less noble than copper may also dissolve, such as nickel. Therefore the electrolytes used in electrorefining typically contain substantial amounts of copper, nickel and even arsenic as well as minor metals such as antimony and bismuth. In the Boliden electrorefinery these were reported to be in the magnitude of 51.2– 60.4 g/L of Cu, 10.9–15.8 g/L Ni, 7.2–15.9 As, 0.2–0.4 Sb and 0.1–0.4 Bi with an associated sulfuric acid concentration of 139–155 g/L (Lehtiniemi et al., 2018). Copper is the most noble of the dominating base metals in the electrolyte and is thus deposited on the cathode as 99.99% purity LME-A grade. Anode slimes are collected and subjected to precious metals treatment e.g. via pressure leaching—selenium recovery— Doré smelting—Ag refining—Au/Pt/Pd leaching and reduction process (Ludvigsson & Larsson, 2003). The Pori refinery, operating in Finland since 1941, not only produces 133 000 t Cu cathode and 2300 t nickel sulphate annually but also 66 t silver, 4.6 t gold and palladium and platinum (in year 2017).

Jan 1, 2019

By Steve Lalancette

Centre Jardin Lac Pelletier (CJLP) has been a leading actor in the revitalisation of closed mining sites in northern Québec for over 20 years. Over that period, CJLP developed a cost-efficient technique that transforms sterile mining residue into a substrate able to support a resilient ecosystem. Using a unique mix of organic matter, fertilisers and selected plant species, this technique rapidly builds a microorganic fauna and a layer of humus that will sustain the creation of vegetation coverage. The coverage is composed of over 13 different plant species, each having a unique role in the development of a resilient ecosystem, from soil stabilisation to nitrogen fixing. Considerably less expensive than traditional methods using civil engineering techniques, it does not require the use of heavy machinery or the spread of topsoil. This technique has been successfully used to restore over 20 sites in Québec such as Joutel, Yvan Vézina and Louvicourt. It is a proven technique that has passed the test of actual implementation. The presentation will review the biological, production and economic aspects of the technique through the revitalisation of the Joutel site.

May 1, 2011

By Ben R. Bjorkman

The future is here ? or at least that?s what Mine Planners predicted some 15 years ago ? that by 2004 we would have man-less mines running themselves using space-aged technology. Truthfully, though, there hasn?t been much change in mining methods in the past decade, but thankfully that?s all about to change. The benefits of autonomous ? even Tele-operated mining (especially in narrow-vein ore bodies) are wellknown: increased production hours by eliminating travel time to and from the face, continuous production at the face while crews screen and bolt behind the working equipment, less liability for workers? safety in certain areas, etc. But when plans are put in place to accomplish this vision, things stagnate and production carries on as before. This paper examines the components necessary to make that vision a reality. First we?ll detail the technology required to enable Tele-operation ? even autonomous operation of mining machinery, then we?ll look at what?s wrong with the current way we?re mining, and finally conclude with a critique of the machinery itself.

Oct 1, 2004

By Stephen P. Quin

One of the most prospective undeveloped greenstone belts in Canada, the Hope Bay greenstone belt extends over 80km in a north-south direction and is between 7 and 20km wide. The belt lies on the arctic coast and comprises mafic meta-volcanic and meta-sedimentary rocks that are bounded by Archean granite intrusives and gneisses. The greenstone package has been deformed during multiple events and is transected by major northsouth trending shear zones that appear to exert a significant control on the localization of mineralization. The Hope Bay belt contains a number of significant gold deposits hosted in a typical Archean greenstone belt and which occur in several geologic settings, including shear-hosted, lode-style and breccia-associated. Combined, the deposits host a measured and indicated resource of 1.6 million oz of gold averaging 15.7 g/t plus an inferred resource of 2.7 million oz of gold averaging 12.3 g/t. All deposits remain open to expansion. Exploration in the period 2000-2002 by Miramar includes more than 110,000m of drilling to more fully define the nature of the known deposits, while regional exploration has focused on identifying and evaluating new targets. In carrying out its programs, Miramar uses a number of techniques to improve its chances of exploration success. Activity in 2003 includes 43,000m of drilling focused on expanding resources in the Madrid area, testing the Boston deposit at depth and continuing the hunt for more discoveries. Meanwhile Miramar is advancing one of the deposits towards a production decision, based on a low capital, high return development scenario.

May 1, 2003

By D. W. Tully

Sedimentary and volcanic rocks of the Timiskaming series trend west-ward across the property of the Upper Canada mine, forming part of the north limb of a regional syncline which is truncated on the south by the Larder Lake fault zone. A wide zone of schistosity strikes east-west through the sediments and volcanics. The central portion of this zone is occupied by a system of narrow gouge-filled fractures in highly altered rocks, mainly tuff, trachyte, trachyte porphyry and syenite porphyry. The alteration zones have developed through repeated stages of deformation and accompanying metamorphism. The initial stages were marked by carbonatization and sericitization, followed by silicification and the introduction of minor amounts of sulphide minerals. Gold was finally de-posited in relatively late fractures within silicified zones and pyrite. Repeated movements along the Up-per Canada break have offset post-ore dykes of minette and diabase, and have resulted in minor displacements within the orebodies.

Jan 1, 1963

By D. A. MacLeod

DURING the past fourteen months, dust surveys have been made at thirty-six mines in the Province. These surveys are made to determine the concentration of dust in the mine atmosphere, the flow of air through the mine, the methods adopted to prevent the generation of dust, and the measures taken for its elimination. When high concentrations of dust are encountered, suggestions are given for its prevention ?and elimination wherever possible. Dust sampling is absolutely necessary to determine the effectiveness of any measure taken in the prevention and elimination of dust in the mine workings. Consequently, more time has been spent on this phase of the work than on any other. The apparatus used is the Devers circular konimeter and Zeiss microscope. At various mines, the Zeiss konimeter is used, and the dust counts taken by the two instruments have given results that are closely comparable; so much so that either instrument can be used with confidence and the results obtained will compare in accuracy with those obtained by the methods used in Ontario and South Africa. Before the Workmen's Compensation Act Amendment Act was passed in November, 1936, most of the mine operators were already keenly interested in the prevention of silicosis. This interest has been intensified at all the mines, and measures have been adopted to decrease the amount of dust in the mine atmosphere. Several operators have spent a large amount of time and money in bettering these conditions, and have met with decided success. Practically all others are adopting the known methods of prevention, suppression, and elimination of dust, that apply to their ?particular mines. To prevent the production of dust in underground workings should be the first, as it is the most important, aim, especially during the time the men are underground. An atmosphere free of dust cannot be obtained, but measures can be adopted to lower the concentration that is found? in the average mine.

Jan 1, 1939