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By Mike Samuels, John Starkey

"This paper examines test results and grinding mill design for the recent Fortune Minerals’ NICO Project, located in the Northwest Territories. SAG milling and rod milling options are compared. Rod milling is clearly shown to be the best option because of the ore’s extreme resistance to breakage in a SAG mill environment.Surprisingly, the Bond Ball Mill Wi was 13 kWh/t for this ore. The Bond Rod Mill Wi was 20 kWh/t, whereas the SAG pinion energy to grind the ore to T80 1.7 mm was 30 kWh/t. The existence of ore with this ratio of SAG hardness to Bond BM Wi has not been previously observed. If not considered, this critical relationship may adversely impact the accuracy of mill design. This paper substantiates the significance of these findings to achieve successful grinding design on ore that is macro-competent during primary size reduction, but relatively normal during secondary grinding.INTRODUCTIONThe NICO Cobalt-Gold-Bismuth-Copper deposit is located 160 km northwest of the City of Yellowknife, Northwest Territories. It is the largest IOCG-type deposit (aka Olympic Dam-type) currently recognized in Canada with Mineral Reserves of 21.8 million tonnes contained within a larger 57 million tonne, lower-grade Mineral Resource. The project, owned 100% by Fortune Minerals Limited, has been assessed in a positive definitive feasibility study, subject to underground test mining and pilot plant testing, and is now in the permitting stage to develop a combined open pit and underground mine and process plant. An updated process flow sheet incorporates conventional crushing, grinding and bulk flotation, followed by filtration for shipment of a concentrate to a purpose-built refinery proposed to be built near Saskatoon, Saskatchewan. At the refinery, separate bismuth and cobalt concentrates will be produced following regrinding. The hydrometallurgical process methods include: pressure acid leach, precipitation, ion exchange, and electro-winning for recovery of cobalt as 99.8% cathode; solvent extraction and electro-winning of by-product copper cathode; ferric chloride leach and electro-winning for recovery of bismuth as 99.5% cathode; and cyanidation of the leach residues for recovery of gold as doré."

Jan 1, 2010

By Wayne Phillips, Anatalia Silva, Robert Henderson, Tondo. Luis

"Kinross’ Paracatu Mine has 20 years of operational success as one of the lowest grade milloperated gold mines in the world. At year end 2005, Paracatu’s Proven and Probable Reserves were 1.18 billion tonnes at a grade of 0.40 g/t Au, containing a total of 15.2 million ounces of gold.In 2005, the plant processed 17 Mt of ore and produced 180,519 ounces of gold at a cash cost of US$274/oz. An investment of US$470 million has been approved to expand production to 61 Mtpa in 2009 which will extend mine life to 2036. During the period from 2009 to 2013 the project is expected to produce an average annual output of approximately 557,000 ounces of gold at an average cost of sales of approximately $230 per ounce.The soft, friable ore containing readily leachable gold associated with sulphides lends itself to simple processing. The process flowsheet consists of crushing, grinding, gravity recovery, flotation, concentrate leach and carbon adsorption to produce bullion bars. This paper describes the current operation, the deposit’s unique metallurgical features and the future expansion plant that has been designed to optimise recovery of gold.INTRODUCTIONRio Paracatu Mineração (RPM), a wholly owned subsidiary of Kinross Gold Corporation, operates the Paracatu mine. The mine is located in Brazil, 230 km south west of Brasilia in the north west portion of the State of Minas Gerais. The city of Paracatu, which has a population of 83,000 people, is just 2 km south of the mine."

Jan 1, 2007

By D. du Plessis, R. Stobbs

The Canadian Clean Power Coalition (CCPC) was created in 2001 to protect and enhance Canada’s vast coal and other carbon-based resource wealth, and to ensure that environmental public policy decisions recognize that these resources are a Canadian asset, not an environmental liability. To achieve its mandate, CCPC has undertaken to demonstrate technologies for use in new coal-fired power plants to control air emissions including carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxides (SOx), mercury (Hg), and particulates (PM). The first phase of the demonstration project assessed three existing technologies for coal-fired power plants that reduce all emissions, including CO2, to levels equivalent to or below that of gas-fired power plants. The technologies considered in this phase included integrated gasification combined cycle (IGCC), ‘oxyfuel’ combustion, and amine scrubbing of pulverized coal. These technologies were evaluated with three coal types: Eastern bituminous, western sub-bituminous, and lignite coals. This paper presents the studies, conclusions concerning the capital and operating costs of these technologies, the cost of electricity produced (with CO2 removed), and the cost per tonne of CO2 avoided. It also discusses the potential for using captured CO2 for enhanced oil recovery, and possible technology enhancements for improving the competitiveness of gasification of low-rank western Canadian coals. The second ongoing phase of CCPC’s work includes the design and construction of a commercial-scale plant to demonstrate the feasibility of integrated gas combined cycle (IGCC) and/or polygeneration technologies and the potential for using the CO2 generated for enhanced recovery of conventional oil.

Jan 1, 2006

"Horizontal grinding mills have been used in the mining industry for more than a century, and due to their operational and maintenance simplicity they remain a widely used technology for various stages of comminution. The relative ‘efficiency’ of horizontal grinding mills compared to other comminution equipment is often debated, and efforts to improve the energy efficiency of these mills is an on-going area of attention for process engineers.The discharge arrangement design affects the material transport characteristics within a horizontal grinding mill. Material transport plays a significant role on efficiency of horizontal grinding mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a Greenfield milling operation at Mirabela Mineração’s SantaRita Nickel operation in Brazil. This grinding circuit was commissioned in October 2009, which was designed as a typical SABC circuit to grind 4.6 mtpa (575tph) to produce a P80 of 125um with 10-12% ball charge in SAG mill. The nameplate design capacity has been achieved in few days in ABC circuit without grinding media in SAG mill, and has been operating in ABC mode. The through has gradually increased to an average of 800 tph and recently 7% ball charge has been introduced to increase the throughput to +900tph.This paper investigates improved material transport using Outotec’s TPL™ (Turbo Pulp Lifter) technology and the opportunities this technology presents when designing horizontal grinding mills. Operational data, with particular reference to energy and throughput optimization, is presented."

Jan 1, 2013

By Sunil Koppalkar, Liming Huang

"Since late 1980s the research group led by late Professor Andre Robert Laplante at McGill University undertook fundamental studies and applied research of the Knelson Concentrator (KC) and developed a sustainable method to correctly estimate gravity recoverable gold (GRG). In the early time a concept of ‘free gold’ was used, it was defined as the gold that could be separated and recovered from gold ore by amalgamation. Due to health and safety hazards, its practical use had declined. Around 1994, a methodology using a 3-in Knelson Concentrator to measure gravity recoverable gold was established at McGill University. Through more than 10 years’ improvement and optimization, this technique had become a standard method to evaluate GRG for gold ores, gold plant streams and platinum group metals. Until 2006, about 200 GRG tests had been carried out at McGill University for the ores from all over the world. Recently, a modified version of GRG test (short test) with the advantages of reduced processing time and lower cost had been developed for the mundane needs of gold industry.INTRODUCTIONGold gravity recovery has evolved significantly over the past twenty-five years, mainly because of the advent of the Knelson Concentrator (Knelson 1988, 1990, 1992, Laplante 2000). Now, a series of Knelson Concentrators for different applications are manufactured and used in gold industry all over the world (Knelson Concentrators 2004).In 1980s the Knelson Concentrator gained acceptance from mining industry as an effective device for the recovery of gold from grinding circuit. Knelson Concentrator became the obvious choice because of its design features: a relatively long processing time without concentrate discharge (compared to some other centrifuges, such as Falcon Concentrator and Chinese Yunxi Centrifuge at that time), large throughput capacity, treating a wide size range of material, yielding a high grade concentrate with small mass that could easily be smelted. As more and more Knelson Concentrators were accepted in gold industry, mineral processing engineers faced with challenges: what are the separation mechanisms of the Knelson Concentrator? How much gold can be extracted for an ore if a Knelson Concentrator is installed? For answering these questions, a laboratory scale Knelson Concentrator was created."

Jan 1, 2007

By K. M. Tompson, R. L. Armstrong, C. I. Godwin

"Tungsten skarn deposits on the Clea property in the Selwyn Mountains, Y. T., are related genetically to a quartz monzonite stock, about 500 metres in diameter at the surface. Lower Paleozoic sedimentary rocks are metamorphosed for a distance of 3 km from the stock. Tungsten-bearing skarn mineralization within the altered sedimentary rocks is of two types: sulphide-rich pods and calc-silicate beds. The most significant scheelite concentration is in calc-silicate beds near or adjacent to the quartz monzonite stock. Discordant K-Ar and Rb-Sr isotopic dates indicate that the stock is probably of early Late Cretaceous age, 94 Ma or slightly older, and that it cooled slowly. High initial 87Srl86Sr ratios and disequilibrium relationships between K-jeldspar phenocrysts and groundmass minerals in the porphyritic phase of the granitic rock , and between different granitic rock specimens, indicate contamination of crystallizing magma by old sialic continental crust which extends westward under the Selwyn Basin.This study is significant to regional tungsten exploration. Granitic rocks associated with tungsten deposits, in this part of the Canadian Cordillera at least, appear to have specific isotope characteristics that indicate they were generated at a specific time and in a particular way.IntroductionThe Clea tungsten skarn property (Fig. I) is owned by Canex Placer Limited, and lies in the Selwyn Mountains (Bostock, 1948) near the eastern margin of the Selwyn Basin (Wheeler and Gabrielse, 1972), Yukon Territory. The property covers a 20-square-mile area centered near latitude 62°47 ' north and longitude 129°52' west, and is accessible by helicopter. An airstrip and the terminus of a summer-use gravel road at MacMillan Pass, Yukon, are about 20 miles to the northnorthwest.This paper deals mainly with the geochronemetry of granitic rocks from a stock associated with tungsten mineralization on the Clea property. We show that these rocks have specific characteristics that not only define the genesis of this stock, but also have significance for regional tungsten exploration around plutons in the Canadian Cordillera."

Jan 1, 1980

By John Russell

"The South American mining community leads the world in recognition and adoption of the latest grinding mill relining technologies. Clearly this region has recognised the benefits of improved relining performance.Six of the seven RUSSELL TWIN 8 Mill Relining Systems, ordered to date, are either operating or being manufactured for South American mine sites.This paradigm shift, towards very short relining times, aims at displacing mill relining activities from the critical path of concentrator maintenance shutdown schedules.The first uses of the RUSSELL TWIN 8 Mill Relining System have seen some of the highest SAG mill new liner placement rates ever observed by RME, as would be expected with two, independent Machines working simultaneously in the one mill.The liner-replacement-rate, averaged over the whole reline, is good (27% improvement over single Machine System in the same mill) but short of full potential. This modest result can be attributed to reline crews unfamiliarity with RUSSELL TWIN 8 System operation.This paper compares a sample of conventional (single machine) RME Mill Relining System performance data with one ‘double head’ mill liner handler by others. Early performance of Escondida’s new RUSSELL TWIN 8 System performance is then compared with recent single Machine data from Escondida, immediately prior to RUSSELL TWIN 8 commissioning. RME and Escondida look to constantly improving RUSSELL TWIN 8 System performance as full operational familiarity is achieved.Also, the preparation of this paper revealed a need to develop a global industry standard for mill relining data collection. A web based platform, to develop and then distribute standardised data collection templates, is discussed in Annexure 1."

Jan 1, 2010

By M. Veiga

"Mining is an energy and water intensive activity. Increasing energy efficiency and reducing water consumption are two of the key requirements in moving toward a more sustainable mining industry. Water reduction, reuse and recycle options are reviewed, identifying cases where these options have been implemented. Then a novel mine water network design method is described, which analyzes a mine/mill water system in order to identify areas where water requirements and water system energy requirements can be reduced. First, a site water balance is determined and major water consumers and sources are specified. Next, multiple possible combinations of supplying water to mine and mill consumers are compared. Finally, low energy and water combinations are identified.INTRODUCTIONMining consumes vast quantities of energy: The whole mining and metals sector consumes over 12% of the world’s energy (DOE, 2009). Mining also requires large quantities of water, although mining water consumption is a relatively small portion of the overall world water use. Even in relatively dry, mining-intensive countries like Australia and South Africa, mine water consumption is only 2-3% of national water demand (Brown, 2003). However, at the local level, when mining takes place in areas where water is scarce, mine water consumption can severely impact local supplies. In addition, acid rock drainage, leaks from waste impoundments, or direct disposal of tailing into waterways can contaminate surface and groundwater (MMSD, 2002). Mine water systems can be large energy consumers, but better mine water systems can reduce both water and energy consumption. Improving water system design and practice are key strategic requirements in moving toward a more sustainable mining industry.This paper addresses conventional base-metal or precious-metal mine sites, which consist of an underground or open pit mine and a mineral processing plant, or mill. Ore is extracted and processed through the plant to produce a saleable product. Tailing, or waste material, is then deposited in a tailing storage facility (TSF). Any rock removed from the mine with no economic value, or waste rock, is stored without being processed."

Jan 1, 2010

By R. Pelton, Z. Dai, S. Yang

ABSTRACT Hydrophobic polystyrene nanoparticles were evaluated as potential flotation collectors for pentlandite. The flotation of hydrophilic glass beads demonstrated the nanoparticles’ ability to induce flotation. Deposition of nanoparticles on glass surfaces increased the contact angle and enhanced adhesion of the beads to air bubbles. High flotation recoveries were achieved when 5–10% of the bead surfaces were covered with nanoparticles. Surface functionalization—the addition of vinylimidazole to polystyrene nanoparticle surfaces—caused the nanoparticles to selectively deposit onto pentlandite surfaces in the presence of Mg-Si slimes. Ongoing work includes attempts to identify specific applications where nanoparticle collectors might be cost effective. _ KEYWORDS Flotation, Nanoparticle collector, Coverage

Jan 1, 2014

By James A. Brown, Marius Botha, Christopher A. Fleming

"The technical and economic feasibility or re-processing hundreds of millions of tons of tailings in a number of historic gold tailings dams in the Witwatersrand area of South Africa is being investigated. The objective is to recover uranium and residual gold from the tailings, as well as to oxidize the sulphides to eliminate long term environmental liabilities associated with acid mine drainage. The tailings from the re-processing plant will be re-deposited in a new area far from urbanization, allowing for the rehabilitation of the real estate currently occupied by these historic tailings.The first step in the process involves a mild-regrind and mild acid leach of the tailings (pH 2.5 to 3.0) to dissolve up to 40% of the uranium. This uranium is recovered directly from the pulp by resin in pulp (RIP) with a strong base resin. The RIP tails are then treated by flotation to recover a rougher pyrite concentrate, and flotation tailings that are discarded. The rougher concentrate is cleaned to produce a final pyrite concentrate and cleaner scavenger tailings, and the pyrite concentrate is oxidized in an autoclave to leach uranium and generate acid. The autoclave discharge is combined with the cleaner scavenger tails, and the acid and ferric ions generated in the autoclave are used to leach more uranium and oxidize more sulphide in the cleaner tails. The product from the concentrate leach circuit is processed by resin in pulp for uranium recovery, followed by neutralization, cyanidation and carbon in pulp for gold recovery.The rougher float tails may be further treated to recover gold that was not recovered in flotation, but which had been liberated from the old dumps by natural oxidation of some of the pyrite over many decades. The float tails would be neutralized and treated by cyanidation and CIL to recover this liberated gold.All parts of the flowsheet have been extensively tested in the laboratory, and the critical elements of flotation, pressure oxidation and resin in pulp have been demonstrated in pilot plants. The results of the hydrometallurgical investigations are presented here."

Jan 1, 2010

By R. B. Rao, B. Das, J. K. Mohanty, D. S. Rao

Physical, mineralogical and geochemical characterization, along with some beneficiation approach to pre-concentrate the Ni content of the chromite overburden material of the Sukinda Valley, India, have been carried out in detail. Mineralogically, the overburden consists of geothite, quartz, hematite, magnetite and secondary silicates in varying proportions. A specific Ni mineral phase is absent in this material with the Ni and Fe being mostly enriched in finer fractions. Distribution of Ni and Fe in various size fractions and increase of Ni with increase in Fe (goethite content) indicate that goethite is the major Ni-bearing mineral phase. Quantitative estimation of goethite from chemical analysis and weight loss data indicates that the goethite quantity varies from 40% to 90%. Electron microprobe analysis (EPMA) indicates that Nirich and Ni-poor goethite are present in the overburden material. A sequential dissolution study indicates that more than 50% of the Ni are present within the goethite lattice as a lattice substitution. The results of pre-concentration studies (size classification, gravity, flotation and magnetic separation) indicate that Ni is richer in finer fractions. Further, the enrichment of Ni content is limited to 1.1% with 50% recovery by classification followed by hydrocyclone separation of the below 53 m m fraction.

Jan 1, 2000

This paper aims to increase our understanding about existing capacity-building approaches and their implications for obtaining a social license to operate in the mining industry. The notion of ?capacity building? is gaining increasing currency in the mining sector in developing countries due to a rapid rise in the globalisation of mining operations. Capacity-building is conceived here as a process that lasts after the mine-cycle, intended to provide local mining communities with tangible skills and knowledge to gain meaningful employment in mining or other industries relevant for the local economy. Building community capacity to understand and effectively respond to these transformations is vital for obtaining a social license to operate, as it promotes sustainable and locally relevant development. Accountability mechanisms such as global norms and international standards increasingly highlight the need to build capacity among stakeholders, particularly among local communities adjacent to mining operations. International frameworks and mining companies have embraced the notion of capacity-building as a driver to assist corporate social and operational performance. However, this narrow understanding of capacity-building through the prism of corporate social responsibility and ?best practice? is preventing the industry from meaningfully impacting communities and maintaining a social license to operate. This latter notion is being widely embedded across multiple industry sectors, as a social and economic reward from mining companies to compensate communities for natural resource extraction and gain social acceptance. Although both concepts are widely recognised in the minerals industry, insufficient attention has been paid to the implications of applying a top-down (mining-orientated) or a bottom-up (community-orientated) capacity-building approach for obtaining a social license to operate, or indeed how these two concepts are linked and applied in practice. At times, communities lack the necessary capacities in the form of education and skills to deal with mining-led livelihood transformations. This is preventing both mining companies and communities from forging sustainable livelihoods and responding to mining-led livelihood transformations, a situation that is creating discontent among communities and reducing the possibility of obtaining and renewing a social license to operate for the industry. Based on a review of current scholarly debates, accountability mechanisms in the mining industry and fieldwork findings in Colombia, this paper will contribute to an understanding of the implications of existing capacity-building approaches that support a social license to operate.

Aug 1, 2013

By J. E. Nesset

"Significant progress has been made over the past few years on characterizing and understanding the hydrodynamic properties of frothers and collectors and their effect on flotation performance. This new understanding of the relationship between chemistry and hydrodynamics has dramatic implications for how flotation circuits should be controlled and optimized. Previous work has shown that choosing a frother of the right ‘strength’ is critical to the optimization process, and the work and discussion presented here serve to strengthen the argument. In addition, we know that collector chemistry will also influence hydrodynamic properties and needs to be taken into consideration. To achieve the desired outcome, the overall system of reagents and operating parameters must be considered. This paper describes and discusses some of the findings from recent research on frother and collector chemistry effects (on hydrodynamics), and how this knowledge can be used to improve flotation performance. Examples from plant experience are discussed.INTRODUCTIONFrothers perform various functions in flotation but the primary ones are control of bubble size in the pulp zone and stabilization of the froth zone. Laskowski (2003) was among the first to try to capture both roles in characterizing frothers in order to provide a basis for frother selection for a given duty, as well as to explore the link between function and frother chemistry (structure). The method he used requires bubble size data and a frothing index; the procedure has been simplified by Cappuccitti and Finch (2008) using gas hold-up to substitute for bubble size, and froth height (without overflow) as the froth stability metric. The gas hold-up/froth height relationship will be referred to as ‘hydrodynamic characterization’. Essentially, the gas hold-up parameter reflects the sum of the hydrodynamic conditions in the pulp phase (water in this case), i.e. the effect of bubble size plus the apparent impact of the water surrounding the bubble due to the frother (Finch, Nesset and Acuna, 2008). Similarly, the stable froth height parameter reflects the sum of hydrodynamic conditions in the froth, i.e. the effect of bubble size undergoing coalescence plus the influence of the water in the lamellae and Plateau borders between bubbles. It could be argued that the gas hold-up/froth height relationship is a superior one to simple bubble size/froth index for discerning differences in frother behaviour"

Jan 1, 2010

By Richard Peaker, Jens Lichter, Alexander V. Potapov

"The recent combination of Computational Fluid Dynamics (CFD) and Discrete Element Modeling (DEM) can provide considerable insight into the performance of flotation cells. One area of interest from a fundamental equipment design perspective has been the influence of flotation cell size and the inflow rate on the metallurgical performance of the cell. One of the specific design objectives when increasing the size of flotation cells, or increasing the feed flow to the flotation cell, is to ensure that the feed stream flowing into the cell does not have an opportunity to bypass the mechanism.This paper describes the initial modeling efforts to quantify the inter-relationship of cell size, inflow rates, and feed and discharge box placement, on the retention time distribution of solids in the flotation cell, and the fraction of particles that bypass the mechanism on a size by size basis.INTRODUCTIONThe great majority of newly installed cells in mineral processing plants world-wide are of the cylindrical tank design and this tank shape offers a number of hydraulic advantages over the older style of square cells. Cylindrical cells give symmetrical flow patterns and by careful design of the mechanism and tank internals, the flow patterns generated can concentrate the more intense mixing in the lower portion of the cell to promote good solids suspension and particlebubble contact. Simultaneously, cylindrical tank design gives a more quiescent upper zone for particle-bubble transport into the froth zone. These symmetrical flow patterns are naturally disturbed in normal operation by the slurry inflow and outflow from the individual cells. The challenge for flotation cell designers is to determine the magnitude of these flow disturbances, and to assess whether or when the inflow and outflow rates have a sufficient impact on the hydraulic flow patterns so as to potentially affect the metallurgical performance of the flotation cell."

Jan 1, 2007

Peñasquito is Mexico's largest gold producer, consisting of two open pits - Peñasco and Chile Colorado - containing gold, silver, lead and zinc. Over the next three years, mining activities in the pit are expected to be focused on lower grade ore in the upper parts of the Peñasco pit while stripping is emphasized to ensure an economically optimal pit shell design to maximize the net asset value of the operation. By 2019, Peñasquito’s gold production is expected to benefit from an improvement in mined grades as it recommences mining higher grades at the bottom of the Peñasco pit and significantly enhanced metallurgical recoveries with the planned completion of the Pyrite Leach Project ("PLP").

Jan 1, 2017

By Norman O. Lotter

Drill core is preferred as the sample material for metallurgical and mineralogical characterisation and flowsheeting of an orebody. The question arises as to how to do this at the economic optimum, since geologists have several other strategic uses for their drill core. The limiting factors are the cost of extra drilling for the metallurgical testwork and the need to preserve the drill core record. In this study, the representative sampling of drill core at an economic optimum for metallurgical testing is addressed. This phase of the drill core work is preceded by earlier drill core characterisation - for which other appropriate sampling protocols are used - that has provisionally categorised the orebody into geometallurgical units. In stratified sampling of drill core, use is made of a version of the stratified approach to compound distributions proposed by Cochran in 1946. Use is made of Gy’s 50-piece minimum sample mass model to estimate minimum requisite sample mass. In the case where sampling and testwork are required on a Lifeof- Mine blend of a given ore deposit, whereby defined ore types or geometallurgical units are present, the sample mass requirement is significantly reduced by working from drill-core at the geometallurgical unit level. A case study using Raglan drill core is discussed. Using nickel as an indicator paymetal, and sampling at a fundamental variance level of 8%, the minimum sample masses for disseminated sulphides, net-textured sulphides, and massive sulphides are 3.80, 7.37 and 4.39 kg respectively. When the same drill-core is sampled as a Life-of-Mine mixture without knowledge of the geometallurgical units, the minimum sample mass increases to 84.28 kg. It is thus possible to assemble a representative Life-of-Mine sample of drill-core more economically, at the same time validating its representativity. Equivalent calculations for copper, platinum and palladium are discussed, with outcomes consistent with this finding. When all four paymetals are considered, one selects the largest minimum mass out of all four cases. This results in minimum sample masses of 11.67, 74.90 and 175.16 kg for disseminated sulphides, net-textured sulphides and massive sulphides respectively. The simulated Life-of- Mine blend would require a minimum sample mass of 377.33 kg to cover all four paymetals.

Jan 1, 2010

By Chris Fleming, John R. Goode, James Brown

"Data will be produced from two uranium feasibility studies that were conducted in 2008, both involving uranium recovery from leached slurry by resin-in-pulp (RIP) with strong base resins. Excellent metallurgical results were produced in RIP pilot plants in both studies, and the loaded resins were eluted with strong sulphuric acid and recycled to RIP in an integrated process. Resin losses by either abrasion or mechanical breakage were immeasurably low.Metallurgical results from these two campaigns will be presented, along with an economic analysis of RIP versus the alternative process of CCD or filtration and solvent extraction.INTRODUCTIONThe recovery of uranium directly from pulp with strong base resins in RIP contactors was practiced commercially in the USA in the 1960s, but the process never established itself as a viable alternative to solid/liquid separation and solvent extraction. This was due mainly to the necessity to do a sand-slime separation partially resulting from the unavailability of coarse resin beads, inadequacies in the design of the RIP contactors and screens to separate resin from pulp, as well as problems with the strength and durability of resins in agitated pulps.There have been significant advances in the last 30 years in each of these areas. All the commercial resin manufacturers are now producing very tough, durable, strong base resins, and are manufacturing them in a large bead size that is better suited to RIP applications. In addition, with the emergence and wide spread implementation of the carbon in pulp process in the gold industry in the 1980s, many innovative techniques for preparing leached slurries and separating carbon from pulp have become firmly established. These techniques have proven to be equally applicable to resin separation from pulps in RIP contactors."

Jan 1, 2010

By The Honourable George Prudham

"I AM PLEASED indeed to be present with you here today and to be taking part in the proceedings of your convention. You have been greeted and welcomed to the Province by Premier Manning who is also provincial Minister of Mines and Minerals, and to this City by Mayor Hawrelak. As Minister of Mines and Technical Surveys in the federal government and as Member of Parliament for Edmonton West, I have been asked to share the honour of extending greetings and a cordial welcome to all.It is a happy coincidence that this representative national gathering, indicative of the growing strength and significance of a great basic Canadian industry, is taking place in the Macdonald Hotel, the new addition of which marks another important step forward in the progress of this City and district.This happens to be the third national convention of the C.I.M. that I •have had the pleasure of attending and I trust that I am not presumptuous in expressing the hope that I will have the opportunity of attending many more conventions of the Institute in my present capacity.Dr. Kidd has bestowed on me a high honour by asking me to be Co-Chairman of this Inaugural Session of the Convention and thus to share with him the responsibility of presiding over the proceedings of this afternoon."

Jan 1, 1953

By Arnaud Faucher, Claude Bazin, Marilène Renaud, Mohamed Mai Manga

"Grinding circuits are operated in the presence of disturbances due to ore changes and equipment malfunctions. One of the challenges faced by the operators is the detection of a disturbance, the identification of its origin and of the action needed to minimize its impact on the process. Hydrocyclones overloading, worn or partly plugged apexes of the units of a nest, surging and internal liner detachment may cause a loss of classification capacity and quality. Recovery losses in downstream leaching or flotation circuits justify the effort in developing techniques for the detection of hydrocyclone malfunction. Two approaches for the detection of hydrocyclone fault are presented in this paper. The first proposed method uses the conventional sensors available in a grinding circuit allowing real time detection of hydrocyclone abnormal operation. The second technique is based on the use of vibration sensors installed on the hydrocyclone of a nest. This last technique enables the classification of the hydrocyclone malfunction as surging, overloading and plugged apex. The two techniques can be combined to increase the robustness of the problem detection.INTRODUCTIONHydrocyclones are used for many purposes ranging from water separation, fines removal and obviously for the preparation of the feed for subsequent concentration circuits in a mineral processing plant. The strategic role of the hydrocyclones for the preparation of the feed to the concentration circuit is often underestimated because of their simplicity of operation and robustness (Napier-Munn et al., 1996; McIvor, 1988). It remains that despite their simplicity, hydrocyclones have been studied extensively from 1970 to 1990 with the objective of developing mathematical models of their operation to be incorporated into grinding circuit simulators (Napier-Munn et al., 1996; Lynch, 1977; Flintoff et al., 1987). Such a development effort is already an acknowledgement of the importance of these units in a mineral processing plant. Several authors (Del Villar et al., 1996; Plitt and Kawatra, 1979; Casali et al., 1998) proposed soft sensors to estimate the classification efficiency of hydrocyclones using sensor measurements. However, few of the proposed sensors are used in the industry. More recently several papers were published to discuss the application of 3-D modelling of the hydrocyclones (Narasimha et al., 2005; Cullivan et al., 2004) and sensors (Bond et al., 1999; Neesse et al., 2003; Hou et al., 1998; Olson and Waterman, 2004; Williams et al., 1995; Willams et al., 1997) to help in the detection of hydrocyclone malfunction."

Jan 1, 2010

During the hydrometallurgical processing of the major base metals Cu, Zn, Ni and Co, the presence of iron is normally a serious complication, and iron separation from the pay metals usually constitutes one of the main challenges for the metallurgist. There are many instances, however, where the presence of iron is beneficial, or is even required. Two cases are presented where iron is required during the processing of base metals. The first example deals with the use of ferric sulphate to oxidize sulphides, more particularly copper and zinc sulphides, under atmospheric conditions. The results presented confirm that ferric ion leaching is efficient, particularly when the oxidant is regenerated during the process. The second case is the use of iron to solubilise refractory cobalt oxide minerals; examples, including pilot plant results, are presented for various ores from Africa and Central America. In both cases, this paper reviews the basic concepts involved and provides details of their application.

Jan 1, 2006