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By Brian Hart, Zhe Chen, Liuyin Xia, Mana Pourdasht, Stamen Dimov

"Gold losses related to carbonaceous matter (CM) during processing are a significant problem in the gold processing industry. Inherent CM in gold ores can behave similarly to activated carbon in its ability to adsorb gold cyanide. This phenomenon is termed preg-robbing as the surface adsorbed gold cannot, for the most part, be recovered. Research has identified that gold adsorption by inherent CM is linked to the specific surface area, pore structure, degree of C disorder and surface functional groups. One of the strategies to inhibit CM preg-robbing prior to leaching is a chemical oxidation; a process linked to modification of the surface functionality. In this study, the variability in gold cyanide adsorption due to oxidation with different reagents has been investigated. Variability in gold cyanide adsorption by CM is examined in relation to structural and surface modifications using TOF-SIMS, XPS and Raman spectroscopy.INTRODUCTION A major obstacle for effective gold recovery during carbon in leach (CIL) or carbon in pulp (CIP) processes carbonaceous gold ores is the presence of carbonaceous matter (c-matter) which has the ability to adsorb, or preg-rob gold from the cyanide leach solution. It can be responsible for poor recoveries as the carbonaceous materials (CMs) within the ore competes with activated carbon used during the leaching and adsorption phase of processing (Cay, 2014). Preg-robbing capacity can vary significantly with mild preg-robbing ores showing absorption capacities of less than 1 g Au/t ore, while severe preg-robbing ores may have CM with the capacity to preg-rob more than 500 g Au/t ore (Dunne, 2007). Research by a number of groups have shown that the degree of C disorder has some influence on the ability of the carbonaceous material to adsorb Au(CN)2- (Miller et al, 2005, Helm et al, 2009, Hart et al, 2010). It is also apparent the adsorption characteristics of carbonaceous material is affected by changes in surface chemistry (Dimov, 2016). Various treatment including; flotation to remove the carbonaceous material (Wills, 2010), addition of surface blinding agents (for example kerosene) to passivate or blanket the carbon surfaces (Dimov, 2016), addition of strong adsorbents (eg. activated carbon or resin) to compete with the carbonaceous material and passivation or surface coating by oxidation (pressure, roasting, chlorination and biological oxidation), have been employed prior to leaching in an attempt to minimize the gold losses (Dunne, 2013)."

Jan 1, 2017

By Mingxia Liu, Hao Li, Qi Liu

"Laboratory batch flotation tests were carried out on fine (-20 µm) hematite to investigate the non-polar oil’s influences when sodium oleate, octyl hydroxamic acid, or oleyl hydroxamic acid were used as a collector. Batch flotation tests were performed with artificial mixed minerals (hematite:quartz = 1:1) under natural pH condition and kerosene was utilized as the model oil. The experimental results showed that kerosene emulsion behaved differently when used in conjunction with the three collectors. Kerosene helped improve the flotation when sodium oleate or oleyl hydroxamic acid was used as a collector. Nevertheless, it reduced concentrate weight yield, grade and recovery to a noticeable extent when octyl hydroxamic acid was used as a collector, especially at low dosages. In addition, single hematite batch flotation kinetics tests coupled with water recovery measurement were carried out to study the role of kerosene at different collector dosages. It was observed that water drainage and the resulting froth destabilization by kerosene was dominant at low collector dosages, especially in the flotation using octyl hydroxamic acid. At higher collector dosages, the water drainage and froth destabilization effect by kerosene was possibly counter-balanced by the higher hematite hydrophobicity and bubble surface tension gradient, which led to more stable froth layer.INTRODUCTION The minerals industry is facing a steady decline in ore grade, compounded by increasing complexity of mineral dissemination. As a result, the ore has to be ground sufficiently fine to have a suitable degree of mineral liberation, which produces large percentages of fine and ultrafine particles outside of optimal size range for ore dressing. Due to the unique characteristics of fine particles, i.e., small mass, high specific surface area, and problems such as increased solubility of complex minerals (Finkelstein, 1997; Finkelstein & Allison, 1976; Fornasiero & Ralston, 2005), high reagent consumption, fast surface oxidation in the case of sulfides (Collins & Read, 1971; Klassen & Mokrousov, 1963), severe particle entrainment (Subrahmanyam & Forssberg, 1988; Warren, 1984), low flotation rates (Glembotsky, 1953; Philippoff, 1952; Ye & Miller, 1988), slime coating (T. K. Mitchell et al., 2005; Parsonage, 1984), etc., flotation performance of these finely ground ores is very poor in terms of low concentrate grade and recovery."

Jan 1, 2017

By S. Kelebek, B. Ingram, C. Gibson, T. MacNeil, M. Aghamirian

"The beneficiation and upgrading of pyrochlore from its ores is carried out through flotation. In industrial practice, upgrading is conducted in a two-stage flotation process in which pyrochlore flotation is carried out after gangue mineral pre-flotation (carbonate, silicate, sulphide or phosphate reverse flotation). In this study, the flotation of pyrochlore from a low grade carbonatite ore was performed at the laboratory scale following a two-stage flotation process in which carbonate minerals were floated in advance of niobium minerals. In parallel, a simplified flotation process was developed in which pyrochlore was floated directly from gangue minerals at increasingly acidic pH. Laboratory results indicated that both two-stage and direct flotation provided similar results in terms of niobium grade-recovery. Based on these results, a large scale, integrated pilot plant was conducted using a direct flotation flowsheet. While the elimination of reverse gangue flotation resulted in flowsheet simplification, the dissolution of carbonate minerals and the subsequent effect of dissolved cations on the floatability of pyrochlore added an element of complexity. A comparison of results from locked-cycle laboratory testing and pilot plant testing highlights the challenges of scaling up a complex flowsheet. A case is made for the direct flotation process and the key parameters to achieving success in large scale direct flotation of pyrochlore are discussed.INTRODUCTIONPyrochlore (Ca,Na)2Nb2O6(OH,F) is a niobium bearing mineral which has been the primary global source of niobium since the first pyrochlore mine commenced operations in the late 1960s (Gibson et al., 2015a). Preceding the discovery and development of high grade pyrochlore deposits in North and South America, the majority of global niobium supply came from gravity concentration operations of columbite (Fe,Mn)Nb2O6, across Africa (Perrault and Manker, 1981)."

Jan 1, 2016

By Herbert D. Drechsler, James B. Stephenson

"AbstractThe paper identifies the major components of price change which affect the determination of the internal rate of return of a mining project. It illustrates several price indexes which may be used to measure general price increases, identifying techniques which might incorporate them into mine valuation procedures. The ""hurdle rate"" for new investment is discussed.IntroductionDECISIONS regarding the value of an orebody and whether or when to mine an orebody are based on an estimate of the cash flows which would be associated with its exploitation. These pro-forma cash flows represent cash in or out of a possible mineable deposit and include exploration and construction costs, sales revenues, operating expenses, taxes, debt borrowings, interest and debt repayment. It has long been recognized that when combining the cash flows occurring over the life of the mine, dollars received or paid out early have greater value than those received or paid out later. This time value of money has been incorporated into mine evaluation calculations through the use of present-value or discounting techniques. Another factor affecting mine valuation, inflation, is not accounted for by valuation techniques now in use. In recent years, price changes have become more volatile. In the past, price change could easily be ignored when evaluating potential mines. Today, the combination of larger investments and greater price volatility leads to great concern about the effects of price change on mine valuation."

Jan 1, 1977

By B. F. Haanel

IN the fall of 1929, a paper was presented at the Annual Western Meeting of the Institute entitled The Fuel Research Laboratories at Ottawa and the Scope of Their Investigations. At that time, the equipment of the laboratories had not been completely installed, but the regular routine work was being carried on as usual, and several large-scale investigations were being conducted. It is now five years since that paper was presented, and it seems fitting that a brief description of the investigations which have been undertaken, together with results-especially those which have reference to western Canadian fuels-be presented at this Annual Western Meeting. The coal mining industry of western Canada has, within the past few years, suffered many unfortunate vicissitudes. The replacement of coals by oil, for bunkering ships, for operating railway locomotives, and for heating, has weighed heavily on the coal mining industry of British Columbia and Alberta generally, but more particularly in the Crowsnest Pass area and Vancouver-and hydro-electric developments have also left their impress. With a full appreciation of these conditions, the Department of Mines planned research and large-scale investigations which it was considered would be of the greatest benefit to the coal industry, and the results have amply justified the plans and anticipations. The fact, however, must not be lost sight of, that the application of the findings of certain of these investigations would not have been feasible had not the Federal Government assisted the transportation of coal by the application of railway subventions. These subventions permitted Canadian coals to compete at competitive points with United States coals, and it must be admitted also in this connection that certain of the collieries which have benefitted, both as a result of the railway subventions and the investigations conducted by the Fuel Research Laboratories of the Department of Mines, made special efforts to produce a coal which was capable of competing with the American product, by special preparation at the mines.

Jan 1, 1936

By Kurt F. Weitz

"The number of materials that can be classified as fillers covers an extremely wide range: this paper outlines those fillers of the industrial mineral type that find extensive application in the paint and plastics industriesIn the paint industry, mineral fillers are known as extender pigments. Extenders are added to paint and plastic compositions to (1) lower the cost and (2) rein-force or modify the physical properties of a composition.Commonly used extenders are classified according to chemical type and discussed in terms of the change in physical properties that they impart to a paint or plastic film. Available cost reductions and data on the consumption of extenders in the Canadian paint industry are also included."

Jan 1, 1970

By Jaeheon Lee, Junmo Ahn, Doyun Shin

"Many alternative leaching systems including bacterial leaching have been introduced to avoid passivation on the surface of chalcopyrite and to increase the leaching efficiency of copper from chalcopyrite. Recently, glycine, one of the simplest amino acids, has been emerging as an efficient and environmental-friendly lixiviant to recover copper. In the present study, an alkaline glycine–peroxide lixiviant system was used to leach copper from chalcopyrite concentrate and the leaching mechanisms were also investigated by a suite of kinetic studies under different conditions. The chalcopyrite concentrate contains 28.8% copper with 30.8% sulfide sulfur. The effect of concentration of glycine and hydrogen peroxide of the leaching solution was investigated. Glycine concentration was varied from 0.5 to 1.0 M and the hydrogen peroxide concentration was changed between 3 to 5%. Leaching time and pulp density were also varied. Hydrogen peroxide is an oxidant of the system and the leaching efficiency with periodic additions of the peroxide was also studied. A mineralogical study was performed using XRD and SEM. To investigate the surface of the residue materials, XPS was used to see if any passivating layer was formed during the leaching. Detailed results from mineralogical, chemical, and metallurgical studies will be presented and discussed.INTRODUCTION The greatest global resource of copper is low-grade chalcopyrite and heap bioleaching may be the only economic option for its processing. However, formation of a passivating layer on the surface of chalcopyrite slows down the oxidation reaction and reduces the efficiency of the process."

Jan 1, 2017

Reaction between xanthate ions in solution and oxidized compounds present on the surface of galena to form lead xanthate is considered to be a side reaction not contributing to flotation, although accounting for some consumption of reagent. The direct reaction of lead sulphide with xanthate and oxygen to form lead xanthate is the most significant to flotation. Coadsorntion of dixanthogen is also involved. Previous work has shown lead recovery in lead rougher flotation to be a function of m [H+] where: m = concentration of xanthate in solution rHl = hydrogen ion concentration. A plausible explanation for this relationship is suggest-ed. Likewise, the experimental findings that the amount of xanthate adsorbed under certain conditions is a function of m'[H+] are explained in terms of reaction between xanthate ions and soluble basic lead salts such as PbO.PbS04? It is also shown that m[H+] should have a constant value in lead cleaners operating at a higher pH than the roughers. This conclusion is confirmed by plant data, and the value of the constant agrees well with the calculated value. The finding is useful in mill control.

Jan 1, 1965

By Ron Light, Doug Applett

"HistoryThe Nanisivik mine began operation in October 1976 as the world's most northerly metal mine and the first permanent industrial project in the Canadian High Arctic. Located 700 km north of the Arctic Circle on Baffin Island's Strathcona Sound, exploration by Texasgulf Inc. between 1957 and 1970 had outlined the ore deposit. In 1974, Nanisivik Mines Ltd. was formed with Mineral Resources International, the Government of Canada, Metallgesellschaft and Billiton being shareholders, and Strathcona Mineral Services Ltd. providing project management. In 1996, Breakwater Resources purchased the mine from Alberta Energy Corporation Limited which had recently acquired the assets of then owners Conwest Exploration Ltd.Ore DepositThe main ore deposit is very flat, approximately 80 m in width and varying in thickness from 3 m to 16 m. The length of the deposit is approximately 3000 m with satellite zones located on the perimeter of the main zone. The economic mineralization is sphalerite with minor galena and silver. The sphalerite and galena are coarse grained and associated with pyrite as the main gangue component with minor inclusions pf dolomite and calcite within the deposit. The deposit being hosted in a permafi·ost environment creates a number of challenges. Dry drilling is employed in room and pillar production drilling. The permafrost aids in the stability of both the pillars and the back."

Jan 1, 2000

By Rejean Gagnon, Fernand Rochefort

"Haulage costs, in most operations, represent a large portion of total cost. Quebec Cartier Mining Company came to the conclusion t hat an electric trolley assist providing more horsepower than available from dieselgenerator sets presented the best oppor tunity for improvement. Accordingly, a testing and development program was carried out which resulted in the design, installat ion and application of a practical system. This paper describes the development of the system, the equipment used as well as the actual operation. A projection is also made to indicate further improvement in productivity. A comparison is made of truck operating data before and after activation of the trolley assist system in order to determine its economic impact."

Jan 1, 1972

By H. Z. Liu, J. M. Zhao, F. C. Wang

"Novel silicate-alginate composite beads containing 2-ethylhexyl phosphonic acid mono-2- ethylhexyl ester (P507) were synthesized and applied for the adsorption of Nd3+ from aqueous solutions. The adsorption amount of Nd3+ has been increased owing to the introduction of P507. The effect of equilibrium pH (pHe), the kinetic and isotherm experiments were investigated. The adsorption reaches equilibrium at 9 h and the maximum uptake capacity is up to 195.4 mg/(g dry adsorbent). The Langmuir isotherm equations are used to describe the adsorption process. Complete desorption can be realized with 0.2 M HCl within 20 min. INTRODUCTIONRare earth elements (REEs) have found various applications in different domains, such as metallurgy industry, ceramic industry, nuclear fuel control, photo-electro-magnetic functional materials owing to their unique properties. Neodymium (Nd), as a representative of all of the most valuable REEs, is widely used as catalysts, laser crystals, capacitors, rubber additives, Nd-Fe-B magnets, hydrogen storage and so on. Thus, the separation and purification of neodymium is significant. Unfortunately, Nd always coexists with other REEs and selective separation of the individual Nd from the REEs mixtures is still extremely difficult owing to their strictly similar atomic structures and chemical properties.Liquid-liquid extraction (LLE) and solid-liquid adsorption (SLA) are the most widely adopted techniques for the separation of REEs in the hydrometallurgical fields. The LLE process is well suited for large-scale continuous operation because of its inherent high capacity and fast kinetics. Nowadays, as a commercial extractant, 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) has been extensively studied for extraction and separation of REEs since it has considerably good extractability and high separation efficiency (Xu et al., 1992). SLA is one of the effective and green separation methods with some prominent advantages, such as easy regeneration of adsorbents, small footprint size, less industrial wastes, higher enrichment factors and column efficiency,rapid solid–liquid separation without emulsion and so on. Hence, the introduction of extractants with excellent performance into adsorbents will integrate the advantages of LLE and SLA (Lee et al., 2009)."

Jan 1, 2012

By Alessandro Navarra, Roberto Parra, Boyd Davis, Frank Mucciardi

A smelter scheduling algorithm has been developed, which allocates the oxygen production between the smelting furnace and the converter aisle, so as to maximize copper throughput. The algorithm is intended for daily operation planning, controlling the sequencing of the converter cycles, and the oxygen drawn by these cycles. In some cases, it may be worthwhile to decrease converter oxygen allocation in favour of the smelting furnaces. Thus, a better utilization of the oxygen plant can increase primary copper throughput by several percentage points. This principle is demonstrated through sample computations. The approach presented in this paper can be incorporated into smelter management software.

Jan 1, 2015

By R. B. Ellestad

Introduction Lithium has been known since 1817, when it was discovered by the Swedish chemist, Arfvedson, while working in the laboratory of Berzelius on the chemical analysis of the mineral petalite, LiAl(Si205)2. Development of the chemistry of lithium proceeded slowly, following the early work of Davy, Gmelin, Bunsen, and Matthiessen. Approximately seventy years elapsed before lithium products assumed any commercial importance, and for a considerable period it was a' very minor industry. Their chief early use seems to have been in medicine, and in the production of lithiated water. Other more important uses were gradually discovered, and the industry has had a slow but steady growth. Chemistry Lithium is classified as an alkali metal, along with sodium, potassium, rubidium, and cæsium. Like these, it is a silvery-white metal, which can be cut with a knife; it is harder than sodium, but softer than lead" It is remarkable in having a density of only 0.53 gram per cubic centimeter, which makes it the lightest metal. On ignition in air, it burns intensely to form chiefly lithium monoxide, Li2O. Like the other alkali metals, lithium reacts vigorously with water to form hydrogen and lithium hydroxide. The later is a strong base, and reacts with acids to form salts. The salts of lithium are in general analogous to those of the -other alkalies, but many of them have unique properties. For example, lithium chloride and bromide are extremely hygroscopic, and have a very high water solubility. Lithium fluoride, phosphate, and carbonate, on the other hand, are all relatively insoluble, unlike the corresponding sodium and potassium compounds. In this instance, lithium exhibits its frequent tendency to resemble the alkaline-earth group of elements (calcium, strontium, and barium). Many of the special and valuable properties of lithium are related to the extremely small size of the lithium ion.

Jan 1, 1948

By Celine Y. Zhang, Chloe J. Feng, Charles Q. Jia, Donald W. Kirk

Oil sands petroleum coke (OSPC) is a by-product of coking - a high-temperature process that converts the mined bitumen to the synthetic crude oil (SCO). For every barrel of the SCO produced, about 20 kg of OSPC are generated. Over 70 million metric tons of OSPC have been produced and stockpiled as a result of the development of oil sands industry in the past few decades. Unlike conventional petroleum coke, OSPC has uniquely high impurity contents, particularly sulphur (~ 7 wt%) and metals (e.g. vanadium at ~0.15 wt%), which has hindered its large-scale applications as a solid fuel. Vanadium is a valuable metal that is widely used as an alloy for strengthening steels. The stockpiled OSPC contains about 100,000 tons of vanadium, while the world’s production in 2013 was only 75,600 tons. At the current price of $25US/kg, the OSPC-bound vanadium represents a total value of $2.5 billion US dollars. In this work, we investigate the technical feasibility of extracting vanadium from OSPC. The work focuses on the characterization of vanadium in OSPC and the conditions for effective extraction of vanadium from the OSPC.

Jan 1, 2015

By Chris M. Healey

"Abstract- The Jasper Gold mine in northern Saskatchewan produced a total mill feed of 140 127 tonnes at an average grade of 19.0 g/t Au. Both diamond drilling and chip samples from under­ ground workings returned extremely high values, up to 12 851 g/t (375 oz/I) Au over 0.10 meter from a chip sample. In the presence of such extremely high grades, the accurate estimation of reserves is a major problem.ln the first part of this study, production data from the mine were used to evaluate the results of a variety of reserve estimation techniques in this environment. In two out of three cases studied, indicator kriging with assays cut to 342.9 g/t (10 oz/I) gave extremely good results. In the third case, however , indicator kriging gave unacceptable results. Instead, lognormal kriging of uncut data gave the best results.Secondly, from the same database, a number of drill-hole spacings were simulated, and reserves estimated from the simulations. As may be expected, the results of this analysis show increasingly better results with tighter drill-hole spacing. However, even with a 5 m by 5 m spacing the variation from actual grade was quite large. This is not a systematic under- or over-estimation of grade, rather a random scatter of results .The results of this study show very clearly the problems of deriving good estimates of reserves when extremely high-grade samples are encountered. There is a high degree of randomness to this database, so reserve estimation in this situation will remain a high-risk operation."

Jan 1, 1993

By L. Tafaghodi, S. Sarbishei

"Following the depletion of nickel sulfide ores, laterites are considered as one of the main sources for producing nickel and cobalt. One of the primary steps in pyrometallurgical extraction of nickel from laterites involves partial reduction of the ore at temperatures below 1000°C. Studying the kinetics of laterite reduction provides valuable information on reducibility of nickel laterites using coal as a reductant. The present study investigates the reduction behavior of a nickel laterite by thermal gravimetric analysis and differential scanning calorimetry. Non-isothermal reduction tests and X-ray diffraction analysis were performed to find the main reactions that occur during the process. The kinetic parameters were calculated by Coats-Redfern method. The general model of simple reaction f(a)=(1-a)n was used for calculating kinetic parameters.INTRODUCTION Nickel (Ni) naturally occurs in the form of sulfide and laterite ores. Laterite ores are mainly available in tropical regions. Weathering phenomena during millions of years has led to the formation of several layers with specific mineralogy (Butt & Cluzel, 2013). The three main layers downward are limonite, smectite, and saprolite (Crundwell et al., 2011). Although laterites are the most available nickel ore resource (70%), their share in the overall Ni production is limited to 40% (Crundwell et al., 2011). The main reasons for not materializing the full potential of laterites are as follows (Ray et al., 1985): •,Laterite ores contain high water content (free and combined) which in turn results in high energy consumption of the extraction process. •,As Ni is present in the form of solid solution in laterites, physical upgrading methods such as flotation are not effective in increasing the Ni content before the extraction process. •,Extracting Ni from sulfide ores involve exothermic reactions which are beneficial due to decreasing the overall energy requirement of the process, however there is not efficient release of energy in the process of extracting Ni from laterite ores."

Jan 1, 2017

By Grant D. Nicholas

This paper compares an integrated evaluation approach to decision-making with more traditional sensitivity analysis and Monte Carlo simulation. The primary objective is to highlight the differences in NPV that can arise from using these evaluation methods in a top down and bottom-up approach. Results from three resource scenarios, derived from sampling a "virtual" ore body (reality) on grid spacings of 75m, 50m and 25m, are analyzed and compared.

May 1, 2007

By Bunting S. Crocker

This paper reviews the trends in the past two years in autogenous grinding throughout the world. It covers rock grinding in South Africa, Sweden, Canada, the United States, Finland and Germany. To properly orient the discussion on this subject, the paper attempts to define and classify the scope of autogenous comminution. As this is a relatively new subject, there is often considerable confusion regarding the various practices, which sometimes differ widely. By clarifying the types and forms, we hope to help clear up this con-fusion. Autogenous grinding is being carried out, throughout the world, either in mills grinding in water or solution or in dry mills using air classification to remove the finished material. The wet grinding, particularly, can be divided into: (1) (2) (3) Primary autogenous grinding, or "run-of-mine" grinding. Secondary autogenous grinding or semi-autogenous grinding or rock pebble grinding. Combination processes. -This covers plants in which pebbles made in the primary mill are re-moved and used as grinding media for fine grinding in secondary mills.

Jan 1, 1963

By Davood Moradkhani, Maryam Rasouli

"The present study reports solvent extraction and separation of zinc from concentrated nickel sulfate solution. In our previous study, Zn and Cd in cold filter cake (CFC, 45-55% Zn, 11-16% Cd, and 2.5-4% Ni) were extracted by alkaline leaching followed by electrowinning processes respectively. The strip solution from electrowinning process, was a pregnant liquor solution (PLS) containing 16.8 g/l Ni and 4.2 g/l Zn. In this work, PLS is subjected to the solvent extraction process for separation of traces of Zn from high grade nickel. The zinc free raffinate containing 16.6 g/l Ni sulfate solution will flow to nickel electrowinning plant for cathode production. Di-(2-ethylhexyl) phosphoric acid (D2EHPA) is the organic phase used in this study. The effects of various parameters such as organic phase concentration (10- 40 % v/v), pH (1.5-3), and temperature (25 and 45°) are investigated. Zinc over nickel separation factor increases by increasing pH from1.5 to 3. The results show that 98.7% of Zn was loaded at25°C O/A ratio of 1, pH 3, and 10% vol. D2EHPA. A 10 M NaOH is used for pH control. However, replacement of pH controlling agent with ammonia solution (25%. v/v) results in interesting observations. Ammonia addition, reduces the solubility of Ni2+ cations in solution. Nickel starts to precipitate from raffinate in a crystalline bluish-green form. The obtained crystals are characterized by XRF and identified to be nickel-bearing analog of boussingaultite, a rare sulfate mineral of nickel with chemical formula of Ni (NH4)2(SO4)2.6H2O. The crystallization rate of crystals is studied. It is a slow precipitation process with 75% in 4 days.INTRODUCTION Annually, many hydrometallurgical processes such as electrowinning, solvent extraction and leaching are applied to waste filter cakes in Zanjan, Iran. These additional processes on filter cakes are critical from both environmental and economic points of view. CFC (cold filter cake) is a toxic but valuable filter cake (45-55% Zn, 11-16% Cd, 2.5-4% Ni, and 0.2-1.5% Cu) produced in many zinc production plants. Our research group at Research and Engineering Company for Non-ferrous Metals (ReCo.), developed a series of hydrometallurgical methods for extraction of zinc, cadmium and nickel from CFC (Moradkhani, & Rasouli 2012). The recovery of zinc and cadmium with alkaline leaching and electrowinning was successfully studied. The strip sulfate solution from cadmium electrowinning unit, contains high concentration of nickel with some traces of zinc impurity. This pregnant liquor solution (PLS) was analyzed and reported to contain 16.8 g/l Ni and 4.2 g/l Zn. In this work, PLS is subjected to the solvent extraction process to separate Zn from nickel (Fig. 1). The organic phase stripping solution containing 4.2 g/l zinc and 200 ppm nickel can be circulated and used in the acidic leaching step. This generates nickel solution with high purity suitable for nickel cathode production."

Jan 1, 2017

By Tom Setterfield

Conclusions ?Canada is a prospective place to explore for IOCG deposits ?Time distribution of IOCG mineralization in Canada mimics that in the rest of the world ?Canada may have been the first country to start mining IOCG deposits ?Production from newly discovered IOCG deposits in Canada may start soon

May 1, 2006