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By M. Timmins

Campbell Mine operates a 100 tpd gold autoclave that treats sulphide concentrates at 305 psi and 200 °C. Autoclave feed consists of fresh pretreated concentrate, an acidic oxide slurry recycle as well as other high arsenic sources. The brickwork that is used to construct the five compartments of the vessel must be inspected and repaired periodically. Shutdowns are scheduled to inspect this brickwork and at times replace entire sections of the brick walls or lining. It also provides an opportunity to repair or replace other internal features such as agitator blades or oxygen spargers. Mechanics and contractors are scheduled around the clock to perform the maintenance requirements. There are many safety considerations and precautions that must be taken in order to protect the well-being of the workers and minimize damage to sensitive pieces of equipment. Heat, arsenic and lead contamination and confined space issues are just a few of the hazards involved. The following paper will describe how these safety concerns are addressed and will serve as a guide for future autoclave shutdowns.

Jan 1, 2004

Pilot plants for pressure hydrometallurgy represent special design and project execution challenges unique to the industry and to the pilot- and demonstration-scale. Pilot plant projects have different objectives and shorter timescales than commercial plant projects. Design considerations and strategies, and project execution methods that meet the special needs of pilot plant projects, are discussed. Specific guidance is given for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical process equipment, and for the selection of materials of construction for pilot-scale equipment. The balance between the need for process similarity with future commercial operations and the realities of pilot-scale equipment is also discussed.

Jan 1, 2004

By M. Pearson, J. Irvine, L. Mercer, P. Lauzon

Severe service ball valve performance has a direct impact on the mechanical availability of high pressure oxidation and leach plants. The primary function of these valves is to isolate the autoclave for maintenance. Valve failure has historically contributed significantly to the maintenance downtime of these process plants. An understanding of the root causes of valve failures is the first step in increasing the reliability of the severe service ball valves. A rigorous failure analysis practice has been developed by Hatch for investigating refractory failures in furnaces and kilns based on Kepner-Tregoe methodology. The method has also been modified for valve failure analysis. From a root-cause failure tree analysis of each of the valve components, a list of all potential valve failure mechanisms was developed for ranking and evaluation, along with recommendations for further valve development. The purpose of this paper is to present the reader with the modified Kepner-Tregoe method and examples of this analysis.

Jan 1, 2004

By G. A. Bezuidenhout, J. Davis, S. Lefume, J. P. T. Kapusta, D. K. Chibwe

"Although the centennial of the Peirce-Smith (PS) converting process has recently been celebrated, the technology has essentially not changed much since its inception. PS converting is used extensively in the Cu, Ni and PGM industry to remove iron and sulphur from a molten matte phase. A typical PS converting process would use low pressure air supplied by a blower to bubble air through the molten bath. This bubbling injection regime is inherently inefficient from a process and energy consideration. In the late 70’s and early 80’s, Brimacombe and co-workers demonstrated at both laboratory and plant scales that sonic injection (jetting regime) into copper or nickel converters could reduce or eliminate the above hindrances characteristic of PS converting. Since then, in spite of these successes, very little industrial applications have made headway in the converting process of non-ferrous metal mattes on a commercial scale. As part of its operational improvement and energy reduction program (process efficiency), Lonmin Platinum decided to conduct a full scale industrial evaluation of sonic injection using air only to establish if punchless, high efficiency sonic injection was feasible in its small 3.05 × 4.57 m converters (10’ × 15’). A plant trial was run for four weeks in one of its three converters. This paper discusses the plant demonstration with a focus on the experience acquired by Lonmin together with the key learnings from the trials. Reference will also be made to the commercial aspects of a full scale implementation of sonic injection in all three converters in the smelter. INTRODUCTION AND OBJECTIVESAlthough the centennial of the Peirce-Smith (PS) converting process has recently been celebrated (Peirce and Smith, 1909; Southwick, 2009), the technology has essentially not changed much since its inception. PS converting is used extensively in the Cu, Ni and PGM industry to remove iron and sulphur from a molten matte phase. A typical PS converting process would use low pressure air supplied by a blower to bubble air through the molten bath. This bubbling injection regime is inherently inefficient from a process and energy consideration."

Jan 1, 2012

By J-F. Béland, N. Parson

Aluminum extrusions are widely used for automotive crash management systems due to their superior specific energy absorption capabilities, as compared to steel. The Al-Mg-Si alloy series can be readily extruded into complex multi-hollow profiles, as required in crash systems, and can be used to target a range of desired strength levels. This paper focuses on the development of an axial crush test protocol and evaluation of the crush performance of common 6XXX series alloys for a variety of tempers. The observed crush behaviour is then compared to tensile test results.

Jan 1, 2015

By L. Lorio, B. Hilscher, P. Nayak, N. Yoon

"Mining has been a staple to technological advancement ever since the dawn of time. By harnessing the different physical and chemical properties that each mining commodity brings to the table, more and more innovation is developed and manufactured. As these non-renewable resources continue to be extracted, the industry as a whole faces a challenge in finding the next economical deposit as well as declining grade at the current operations. By means of pre-concentration, ore sorting aims to separate the barren material from the valuable ore to reduce energy consumption and tailings generation, while increasing the feed grade, concentrate grade, mill recovery, and revenue. In addition, ore sorting allows the modification of deposit geometallurgy in order to allow the creation of an optimal mill feed. This paper evaluates the applicability and challenges of ore sorting by utilizing the results from four different mines, and reviews them in detail. The mines include one underground and three open pit mines that are precious metal operations. In order to understand the applicability of ore sorting in these operations, initial rock-by-rock test results and different types of assays (atomic adsorption [AA], inductively coupled plasma [ICP], and fire assay) are utilized. Using the assay results, the grade recovery curves for ore sorting are generated and they are further improved by using and developing an ore sorting algorithm, which is discussed in this paper. The application and evaluation of ore sorting in greenfield and brownfield properties will also be discussed. The state of the art ore sorting technologies for both rock-by-rock and bulk sorting are also reviewed in this paper. The future technologies on the horizon, including different combinations of sensors, are explained. The sorting technologies include X-ray transmission (XRT), X-ray fluorescence (XRF), colour, infrared, electromagnetic, and laser induced breakdown spectroscopy (LIBS)."

Jan 1, 2017

By N. A. Duke, R. L. Carpenter

Abstract - The West Meliadine area is underlain by structurally interleaved panels of mafic and minor ultramafic metavolcanic rocks and metasedimentary rocks that occur along the northern margin of the Neoarchean Rankin Inlet greenstone belt. Three structural and metamorphic domains are recognized: (1) the easterly Wesmeg domain; (2) the central Barracuda-Ridge domain; and (3) the westerly Peter Lake domain. The Wesmeg domain is characterized by a series of southeast-trending, north-dipping, foliation-parallel panels of greenschist facies mafic metavolcanic and metasedimentary rocks. The Barracuda-Ridge domain is comprised of greenschist to amphibolite facies mafic metavolcanic rocks that define an east-northeast-trending structural grain. The Peter Lake domain consists of amphibolite facies mafic metavolcanic rocks and minor metasedimentary rocks intruded by a monzonite pluton. West Meliadine hosts the economically significant Wesmeg gold deposits, as well as other important gold showings across the Barracuda-Ridge and Peter Lake domains. The geological setting of the Wesmeg gold deposits resembles that of a break or fault zone. The Pyke Break is a major geophysical discontinuity (>65-km strike length) and is the first-order structural control on gold mineralization at West Meliadine. It is several kilometers wide and characterized by polyphase deformation and shear zone development accompanied by lode-gold mineralization. In general, gold concentration is related to quartz and iron-carbonate veining, iron sulfides (mainly arsenopyrite and pyrrhotite), and accompanying silicate alteration minerals that overprint favorable chemical and structural traps late in the history of deformation.

Jan 1, 2004

By Bernard Vigneault

Les critères de qualité de l?eau pour les métaux visant à protéger la vie aquatique sont présentement basés sur les concentrations totales. Cependant, la complexation (association de ces métaux avec des ligands en solution) peut diminuer de façon importante la toxicité des métaux sur les organismes aquatiques. Pour évaluer l?importance de la complexation pour diminuer la toxicité des métaux dans les effluents miniers et métallurgiques, nous avons étudié la spéciation des métaux et la toxicité chronique de différents effluents miniers et métallurgiques. La phase dissoute des effluents a été échantillonnée à l?aide de la dialyse in situ et la spéciation du cuivre, du zinc et du cadmium a été calculée à l?aide du modèle d?équilibre chimique WHAM. Les concentrations de métaux libres ont également été mesurées à l?aide d?une technique d?échange ionique. Les concentrations de métaux libres calculés et mesurés indiquent que la complexation est importante dans les effluents miniers, particulièrement pour le Cu. Pour relier la spéciation des métaux et la toxicité chronique, nous avons mesuré en parallèle l?inhibition de croissance de l?algue Selenastrum capricornutum et des larves du poisson Pimephales promelas de même que l?inhibition de la reproduction du cladocère Ceriodaphnia dubia. (tests de toxicité chronique inclus dans le programme de suivi des effets environnementaux du règlement fédéral sur les effluents de mines de métaux). En absence de thiosels, aucune mortalité a été observée pour l?ensemble de ces tests et il n?y a pas eu également d?inhibition la croissance de la larve de poisson P. promelas. L?inhibition de la croissance de l?algue S. capricornutum, n?est pas reliée aux concentrations de métaux traces mais plutôt par aux concentrations de calcium. Les inhibitions de la reproduction du cladocère C. dubia sont reliées aux concentrations de métaux dissoutes et libres et non pas aux concentrations totales de métaux, démontrant l?importance des effets de la spéciation chimique sur la toxicité des métaux. Nos résultats indiquent que l?inhibition de la croissance de l?algue l?algue S. capricornutum est due aux concentrations élevées de calcium retrouvées dans les effluents miniers et que les concentrations totales de métaux ne peuvent être utilisées pour prédire la toxicité chronique vis à vis le cladocère C. dubia.

Nov 1, 2002

By K. C. Corin, Z. G. Song, J. Y. Liu, M. W. Zhang, State Key Laboratory of Mineral Processing-BGRIMM, J. G. Wiese

"In the present study effect of grinding media on flotation of two mineral systems have been investigated, viz. sulphide minerals (including a pure chalcopyrite and pyrite mineral, and two different base metal sulphide ores), and oxide minerals (quartz, hematite and cassiterite). It was shown that mild steel media milling produced lower recoveries in the case of chalcopyrite and pyrite, as compared to the case of milling using ceramic media. For oxide minerals, the effects of using mild steel media as opposed to ceramic media were not as significant as was for the sulphides, although, after mild steel milling, at acidic pHs their recoveries were significantly reduced. For two base metal sulphide ores, viz. Nkomati and Dexing ores, the differences resulting from different milling media , although marginal, were opposite for each of these ores.For oxide minerals XPS showed that oxides and hydroxides of iron (e.g. FeOOH) adsorbed on the surfaces of the minerals. In the case of the Nkomati ore, adding Fe2+ or F3+ ions after milling with chrome steel media resulted in reduced talc (gangue) recovery, but increased water recovery and reduced concentrate grades. Further investigations are currently in progress to examine the Fe ions effect on the talc surfaces and froth properties.INTRODUCTIONGrinding of ores is necessary to liberate the valuable minerals from its gangues to allow for their selective recovery during mineral processing such as flotation. The grinding process inevitably involves contact of the ores with the surface of the grinding device and the grinding media. Accompanied by grinding, several phenomena can occur including the grinding medium wear, formation of precipitated species on the ore surfaces, chemical reaction, galvanic effects, changes in the Eh of solution, etc. There is a considerable body of literature on the differences observed in the flotation of various ores after milling using various grinding media. Laboratory studies have used balls or rods made from mild steel, ceramic, stainless steel or chrome steel to investigate the effects of different grinding media on mineral flotation. It is found that the interactions between the ore and the grinding environment can affect flotation separation of sulphide (Wei and Sandenbergh, 2007; Bruckard, 2011), oxide (He et al., 2014) and carbonate minerals (Song, 2009 and 2010). For example, mild steel milling produces relatively high concentrations of Fe ions in the pulp, affecting the recoveries of minerals compared to the case of ceramic media. On the other hand, the stainless steel media or chrome media are reported to be beneficial to the recovery of sulphides, when compared to the cases of using mild or carbon steel media (Rey and Formanek, 1960; Peng et al., 2003a,b; Huang and Grano, 2006; Bruckard, 2011). It is not clear, however, whether these Fe ions may affect the surface properties of the minerals involved or the general pulp/froth behaviour and hence their floatability. In addition, in the study of an low-S PGE ore carried out by Miettunen et al. (2012), forged media grinding in the CO2 atmosphere led to the highest Pt and Pd grades and recoveries, but the high chrome grinding media gave lower flotation recoveries than those using the forged media."

Jan 1, 2016

By G. P. van Greunen

"The rehabilitation of underground excavations has been undertaken as long as mining has existed. The conventional methods have proven to be dangerous, time consuming and expensive. During the construction of Styldrift Mine at Royal Bafokeng Platinum several vertical and horizontal excavations had to be rehabilitated. With a zero tolerance attitude towards working in unsafe conditions, together with a non-negotiable timeline to construct and ramp up the mine, the project team could not rehabilitate these excavations using conventional methods. This paper details the approach used to rehabilitate excavations using remote methods and how it was adapted to suit varying operating conditions and requirements - ensuring that no person ever entered an unsafe excavation before it was fully rehabilitated and safe. INTRODUCTION Styldrift Mine is an expansion project of the Royal Bafokeng Platinum group. It is located in South Africa in the North West Province some 10 km south of the Sun City resort (Figure 1). The mine consists of a twin shaft system (Main Shaft and Services Shaft). Capital construction of the shaft and associated infrastructure started in 2009 and is projected to be completed during 2020. The designed steady state production capacity of the shaft is 230 ktpm of Merensky ore. Production ramp-up commenced in 2017 with steady state production set to be achieved 36 months later in the fourth quarter 2020.Merensky Reef was intersected at a depth of 600 m below surface and the shaft design has a mean mining depth of 630 m. The project was approved for execution in 2008 on the basis of a suitable mine design and bankable feasibility study. One of the main excavations that required rehabilitation was an underground reef silo, Silo 4. It is a key piece of infrastructure on the critical path to allow steady state production at Styldrift Mine to be achieved. During construction excessive scaling within the silo along its 64m length necessitated urgent rehabilitation to be able to meet the ramp-up schedule. The criticality and urgency of these excavations prompted the project team to reduce the risk of failure while ensuring safe and cost-effective rehabilitation. This paper will focus on the rehabilitation of Silo 4 while capturing the essence of the learnings of all the excavations that were rehabilitated remotely."

Jan 1, 2019

By Bob Drew, Goran Vukovic, Bojan Zivanovic, Klaus Gamweger

Reaction bath temperature is a major factor in processing liquid metals and in many applications where a balance between process duration and temperature has to be found to run a procedure efficiently. Also extremes of temperature can decrease the output of a process if too cold or even make it impossible, conversely overheating can be detrimental to both the product and furnace integrity. With the help of the new online temperature measurement system very accurate monitoring of the process is possible in contrast to the current routine practice where the temperature is measured periodically with dip thermocouples. The system works with a digital, fiber optic pyrometer, which is embedded in a refractory housing. Installation in the lining is possible below liquid level as nitrogen is blown to keep the system open and to ensure continuous sight from the optical head of the pyrometer to the molten metal through the tuyere. This permanent temperature measurement gives optimal process control with the potential of taking appropriate actions at an early stage enabling proactive process control. Therefore energy savings and even process endpoint detections can be realized.

Jan 1, 2015

By T. Gerritsen, R. MacRosty, R. Pula, P. Gebski, W. L. Ying

Furnace run-outs can cause extended furnace downtime for repair, while leaks or more severe failures in the cooling system can lead to brick hydration or in severe cases, steam explosions. These incidents can result in lost production, damage to equipment, injuries and casualties. To prevent such incidents, reliable and accurate techniques to monitor the critical components of the furnace such as refractory lining, furnace structure, taphole integrity and main water circuits are required. This paper describes several advanced methods that have been developed to assess the condition of furnace integrity, refractory lining, tapholes and cooling water circuits.

Jan 1, 2015

By Christiaan Zeilstra, Jan van der Stel, Koen Meijer, Gerard Louwerse, Tim Peeters

The steel industry is producing about 5% of the world wide CO2 emission. Therefore the European steel industry has defined a research program to reduce the CO2 emission by 50% per ton: ULCOS. Since its start in 2004 ULCOS has identified four technologies for further development. Two of these technologies which produce liquid hot metal are discussed. The ULCOS blast furnace is based on recycling of decarbonated topgas and the capture and storage of CO2. The concept has been demonstrated during three campaigns at LKAB EBF in Luleå, Sweden. The smelting reduction process HIsarna is a combination of the cyclone-technology and Hismelt. The process has been demonstrated successfully in four campaigns at a pilot installation on the IJmuiden steelmaking site.

Jan 1, 2015

By S. P. Cashin, D. Kashuba, W. Esplin

Barrick has had 6 autoclaves in operation at the Goldstrike Mine, North of Carlin Nevada, since 1993. The 6 autoclaves operate in parallel, processing slurry of gold ore. The gold in the ore is predominantly associated with, and encapsulated by, sulphide minerals. It is necessary to oxidize at least 90% of the sulphide mineral before the gold can be concentrated using a cyanide/carbon-in-leach (CIL) circuit. Sulphide oxidation chemical reactions occurring in the autoclaves are exothermic; however, the sulphide content in the ore is not high enough to operate the autoclaves in an auto-thermal mode. Heat from steam is added to the first 2 of 5 autoclave compartments to initiate the sulphide oxidation reactions. The steam used to heat the autoclaves is supplied by three boilers, which are fuelled with propane gas. The completion of a few operations and maintenance projects in the last 2 years has resulted in a 50% reduction in propane energy requirements. The autoclave operating temperatures were minimized. Excess oxygen addition was held as low as possible. The material of construction for the compartment walls inside the autoclaves was changed from brick to Titanium metal. And, the speed of the autoclave slurry agitators was increased. All of these activities had an impact on the propane energy requirements of the autoclaves. Presented below is a description of the autoclave systems, and a discussion of how the energy needs were reduced, resulting in significant operating cost savings.

Jan 1, 2004

By A. B. Irwin

Abstract The techniques used in recognizing, recording, and interpreting structures in the Slocan sedimentary ceries in the West Kootenay district of B.C. are presented here in the hope that they will be of use to others working in complexly folded areas. The general pattern of folding in the Central Slocan area is obscured by lack of outcrop over a large part of the country, lack of marker horizons, local complexities of folding, and several systems of faulting. 1t was found necessary to observe and record in great detail all primary and secondary structural features and to analyse those observations on a statistical basis. The determination of bedding tops as well as bedding attitudes proved to be of fundamental importance in determining the pattern of folding. The interpretation of secondary linear and planar structures confirm:; this pattern. Accordingly, the thickness of the Slocan sedimentary series is computed to be several times that formerly postulated. Introduction The data upon which this paper is based were collected largely during the field seasons of 1947 and 1948 when the writer was employed by the British Columbia Department of Mines on detailed mapping in the Slocan mining camp. Additional observations were made by the writer during 1950 when engaged in property examinations for the Geological Survey of Canada. This presentation is largely a condensation of part of a more comprehensive thesis (5) and is restricted to observations and conclusions pertaining to the mapping of complex folds, stripped of any hypothetical discussion. Except for some unique occurrences of primary structures, there are no features or techniques described here which are not presented in standard textbooks on structural geology. It is felt that the major contribution of this paper is the method used in applying these standard techniques to a specific field problem and in interpreting the results.

Jan 1, 1951

By J. -M. Lalancette, D. Lemieux, C. Chouinard

"A gold bearing concentrate containing 107 g/T of gold, 9.3% copper and 706 ppm of mercury was processed at the demonstration scale for the extraction of gold and copper using a cyanide free process. The concentrate was generated through flotation to upgrade the gold and copper grade, but also showed contamination with mercury. This concentrate was submitted to the DST process demonstration plant. The concentrate was first oxidized using a fluidized bed to produce a calcine. The mercury was volatilized during the oxidation stage with an efficiency higher than 98%. The mercury was condensed and removed from the sulfuric acid using a thiosulphate process. Copper was extracted from the calcine as copper sulphate using diluted sulfuric acid. The solid remaining after acid leaching was submitted to the DST chlorination process for gold extraction. Under optimized conditions, a gold extraction of 97.3% was achieved in the chlorination reactor. Gold was recovered from the pregnant brine by precipitation on silica using a DST proprietary process.INTRODUCTION Dundee Sustainable Technologies Inc. (DST) offers proprietary metallurgical processes for the treatment of material from the mining industry. DST processes enable the extraction of precious metals and for the removal and stabilization of contaminants, such as arsenic, from ores and concentrates. DST provides environmentally-friendly, viable and efficient processes, capable of handling complex and refractory ores which cannot be processed with conventional approaches due to metallurgical issues or environmental considerations. Several mining jurisdictions around the world have banned or restricted the use of cyanide. DST has developed a closed loop chlorination process as an alternative to the conventional cyanidation process for the extraction of precious metals from minerals. The tailings from the process are inert from toxic substances such as cyanide and organic compounds, are sulphide depleted which means they do not generate acid, and thus, meet and/or exceed environmental norms. The process has demonstrated excellent gold recoveries within a fraction of the time needed for cyanidation to obtain similar results. Moreover, the closed loop process does not generate any liquid effluent and does not consume much water: it only requires a water make-up to compensate for moisture leaving with the tailings and by-products, and seawater may be used. The improved environmental footprint of the DST process has been certified by the Environment Technology Validation program (ETV) which provides an independent evaluation of the performance claims of innovative technologies."

Jan 1, 2017

By R. Clarkson

"Free gold particles occur in many base metal and precious metal mines throughout the world. Due to the high density and malleability of gold, large circulating loads of free gold particles can build up over time in grinding circuits. This gold is often deposited in unintended traps throughout the mineral processing system.These unidentified free gold deposits represent a serious security risk as well as an inaccessible inventory of gold. Deposits of free gold particles often remain undetected by mine management until they are accidentally discovered while repairing mill equipment.Nuclear tracers have been used to determine the free gold recovery efficiency of gravity recovery equipment, drills, and sampling equipment (Clarkson, 1994, 1995; Walsh and Rao, 1986; Walsh and Kelly, 1992). In November, 1993, the author inspected the grinding circuit at La Mine Doyon in Rouyn-Noranda, Quebec and made recommendations to recover coarse gold and to eliminate gold traps from the circuit. In 1995, the author salted mineral processing circuits with radioactive gold particles. The gamma and X-ray radiation from gold’s nuclear isotope (Au198) were detected through steel, in pipes, and in moving equipment using scintillometers. The radiotracers proved to be a safe, rapid and accurate method of identifying gold traps and improving security.Nuclear TracersWhen particles of gold are placed in a nuclear reactor, some of the gold atoms (Au197) absorb another neutron in their nucleus to form gold’s radioactive isotope (Au198). In the process of radioactive decay, this isotope emits high energy gamma rays and X-rays which are easily detected (even through steel) with scintillometers.Radioactive gold (Au198) has a very short halflife of 2.7 days. At the relatively low activity levels used for tracing, the particles remain detectable with a small hand-held scintillometer for about 10 to 14 days. After 14 days the irradiated gold is close to background levels and within two months it is essentially non-radioactive. The radiation has no effect on the recovery characteristics of the gold particles. The gold radiotracers are very safe due to their very low level of radiation, short half-life, and their inherent physical and chemical stability. However, the use and possession of even mildly irradiated gold is strictly licensed and regulated."

Jan 1, 1997

By M. M. C Jiménez, J. A. S Ténorio

For the recovery of valuable materials and for the protection of environment, recycling process of printed circuit board is an important subject of study. Moreover, the popularization of the computers and its technological evolution has generated a large number of waste electrical and electronic equipment. This paper presents a study of synergistic solvent extraction of copper, nickel and zinc from a sulfuric leaching liquor of printed circuit boards (PCB’s). The percent extraction of copper, nickel and zinc from dilute aqueous sulfate media besides synergistic effect of mixture of the .extractants Cyanex 272 and D2EHPA have been studied. Furthermore, different conditions such as temperature, pH of the feed solution have been examined. The results suggest that the synergistic effect of the .extractants mixture enhance the extraction efficiency of nickel.

Jan 1, 2014

"Pilot plants for pressure hydrometallurgy represent special design and project execution challenges. Over the past twenty years, Zeton has designed and fabricated a variety of world-class pressure hydrometallurgical pilot-plant facilities, and this paper discusses design considerations and strategies related to such projects. Project execution methods are also discussed, and guidance is given for the selection of materials of construction and for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical pilot equipment. The paper concludes with a discussion of the need for process similarity with future commercial operations and the realities of pilot-scale equipment.INTRODUCTIONThe process technology developer or owner and the designer/fabricator of a new pilot-plant facility are faced with some difficult technical choices even after the decision to build a dedicated plant has been taken. A pilot-plant project is usually on the critical path of a large commercial project involving investments many multiples greater than the capital cost of the pilot plant. Schedule savings in the design, manufacture, and commissioning of the pilot plant or in a rapid completion of the experimental program can be disproportionately beneficial to the overall development project. However, inappropriate shortcuts resulting in major oversights can be disproportionately problematic.A number of considerations and suggestions for both the project execution approach and the process engineering design of pressure hydrometallurgical pilot-plant facilities are presented as a guide for potential owners and operators of new pilot-plant equipment and facilities."

Jan 1, 2012

By F. Ford, Z. Dai, A. W. Lee

ABSTRACT: As high-grade nickel sulphide ores are being depleted and processing laterite ores continues to pose challenges, the future of nickel extraction lies in low-grade ultramafic ores. Canada has large resources of low-grade ultramafic nickel sulphide ores in the Thompson Nickel Belt. Most of the deposits are high tonnage and open pittable, but have high MgO content. The main challenge in processing low-grade ultramafic ores is the presence of serpentine. Chrysotile, one of the three polymorphs of serpentine, is the most common form of asbestos. In addition, the high slurry viscosity associated with ultramafic ores makes grinding and flotation possible only at a very low solids percentage.

Jan 1, 2011