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By R. A. Ozerkevich, R. J. Voisey

"SherrGold's MacLellan V ne is located about five miles south east of Lynn Lake immediately to the east of the Keewatin River. (Figure # 1)The property is accessible by an all weather road, leading north from the provincial highway 391, which links Lynn Lake with the Town of. Leaf Rapids and the city of Thompson to the south.The MacLellan Mine (formerly the Agassiz property) was discovered in the early 1950's and optioned from Comiesa Corporation in 1979 by Sherritt. SherrGold Inc. was formed in September 1985. Sherritt then transferred the MacLellan Mine, 15 other gold prospects in the Lynn Lake area and the old Lynn Lake nickel-copper mill to SherrGold. At the same time Sherrgold entered into a management agreement with Sherritt whereby Sherritt would develop and operate the MacLellan Mine and conduct SherrGold's exploration activities.The ore body as outlined in the original feasibility study is expected to produce in excess of 300,000 ounces of gold and 450,000 ounces of silver over the next 5 years. However the deposit is open to depth and exploration is continuing on and around the main zone and the many satellite deposits.The start of construction of the MacLellan mine and mill was scheduled to phase in with the closure of the Fox copper-zinc mine located 30 miles west of Lynn Lake. The majority of the employees from the Fox Operation were either employed at the MacLellan mine or relocated to Sherritt's Ruttan Operation."

Jan 1, 1987

By Tassos Grammatikopoulos, Sarah Prout, William Mercer, C. Gunning

"The Nechalacho rare metal deposit is located in NWT, Canada. Avalon Rare Metals Inc. is now evaluating processing techniques for recovery of REE to be used in the industry. QEMSCANTM analysis coupled with whole rock, REE, Zr and Nb, and electron microprobe analyses were utilized to identify and quantify the mineralogy of the deposit, and define the REE distribution among minerals. QEMSCANTM mineralogy was performed on fifty intact drill samples using EXPLOMINTM that provided textural information for the mineralization; crushed samples were used to determine the variability of the ore and define REE domains, and composite samples to determine the liberation and association of the REE minerals. The sample matrix predominantly consists of biotite, feldspars, quartz, muscovite/clays, minor chlorite and amphibole, magnetite and hematite and carbonates. REE include in decreasing order of abundance allanite (3.6%), monazite (1.5%), synchysite (0.9%), columbite (0.9%), fergusonite (0.6%), bastnaesite (0.4%), and zircon 11.0%. The majority of the HREE are carried by fergusonite and zircon, and the LREE by monazite, allanite, synchysite and bastnaesite. QEMSCANTM mineralogical data is extremely valuable in assessing the mineralogy of the ore. The data have been implemented in defining the mineralogy of the ore body, support metallurgical test work, predict recoveries and grades, and finally calculate reserves of the deposit.INTRODUCTIONAvalon is in the unique position of owning and developing one of the world’s largest rare earth deposits in the Northwest Territories of Canada.The term Rare Earth Elements (REE) is used to describe the 15 lanthanide elements or metals and, more recently, the metals yttrium and scandium, which display similar physical and chemical properties. REE are not particularly rare and have a similar abundance in the earth’s crust to nickel, tin or tungsten. Unlike these better known metals however, the rare earths have little tendency to become concentrated into commercial ore deposits. When they do become concentrated, deposits of REEs usually display enrichment in one of two groups. The most commonly occurring deposits of REEs contain a sub-group of elements referred to as the “light rare earth elements” (LREEs), which include lanthanum, cerium, praseodymium, neodymium, and samarium. Less commonly, deposits of REEs contain the much more valuable sub-group of elements referred to as the “heavy rare earth elements” (HREEs), which include europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Yttrium and scandium most commonly occur in association with this second HREE sub-group. Generally, LREEs are produced from the mineral bastnaesite, and the HREEs have been produced from the minerals xenotime and monazite. LREEs continue to be produced from bastnaesite, however in the 1980s, China started production of HREEs from unique laterite clay deposits. China now produces approximately 95% of the world’s rare earths."

Jan 1, 2011

By D. W. R. George, J. L. Stewart

Developments in the last decade, which have contributed to increased productivity and decreased coke rates in the iron blast furnace, are reviewed. Future progress in blast-furnace practice is also considered.

Jan 1, 1966

By K. E. Barnes

"The IsaMill was developed for fine-grained ores that required at least double the grinding efficiency of ball or tower milling to be economic. This was achieved, but in practice, the benefits of using inert media (eg sand, slag, ore, ceramic) have proven to be at least as important as the higher grinding efficiency. Flotation selectivity and rate was improved for all particles, particularly fines. This allowed a dramatic simplification of the Mount Isa lead zinc flotation circuit – adding 6 MW of ultrafine grinding power reduced reagent addition and flotation volume and increased plant energy efficiency. This was quite unexpected.This paper examines four orebodies that were enabled by inert grinding – McArthur River, George Fisher and Black Star Open Cut Mines (complex fine-grained lead zinc orebodies in Australia), and the Western Limb Tailings Retreatment plant (a PGM operation in South Africa). In a unique case history, the operating performance of the Mt Isa lead zinc concentrator is explained by size-by-size mineralogical data collected over 25 years, systematically explaining the impact of declining ore quality, and the effects of additional conventional grinding, inert grinding, and circuit and reagent redesign.The mineralogical case histories are so compelling that it is argued that the advantages of inert grinding should not be confined to difficult, fine-grained orebodies. The availability of largescale efficient inert grinding mills could have profound impact on circuit design for many orebodies.INTRODUCTIONThe IsaMill was developed by MIM (now Xstrata) to enable the development of the McArthur River Orebody in the Northern Territory of Australia. This ultra-fine grained ore needed a grind size of 80% passing 7 microns to produce a saleable concentrate. Such a fine grind was not economic with conventional ball or tower milling. Below about 25 microns the low energy efficiency and high media consumption of these mills is prohibitive. Critically, the high steel consumption and associated change in pulp and surface chemistry also seriously affects flotation metallurgy."

Jan 1, 2006

By Michael Young, Josh Rubenstein, Michael Cooper, Tom Shouldice, Dan Curry

"Xstrata Nickel Australasia’s Cosmos plant in Western Australia is currently implementing a debottlenecking project to increase nickel output while maintaining metallurgical performance and a low unit cost for production. Mineralogical analyses indicated that the processing bottlenecks could be removed by simply reconfiguring portions of the circuit as well as adding capacity with technical advancements – notably an IsaMill™, Jameson Cell, Wemco® SmartCell™ and Larox Filter.The Wemco® SmartCell™, which is particularly suited for coarse mineral flotation, and Jameson Cell, which is particularly well suited for fast floating and fine minerals, combine as rougher scalpers to complete the main stream portion of the flotation circuit. Addition of the two new cells meet the required flotation capacity to handle the forecast increase in nickel feed grade and tonnage.The addition of an IsaMill™ for regrinding allows the SAG mill to produce a coarser primary product, thus enabling increased throughput. The advantages offered by the IsaMill™ include operation in open circuit (internal classification), an inert grinding environment (ceramic media) for better downstream flotation (“clean” new surfaces), compact footprint (easy to retrofit into existing plant) and energy efficiency. With the new rougher capacity addition, the remaining original plant cells were reconfigured to suit the new regrind mill and cleaning requirements. The existing 24 m2 Larox pressure filter was replaced with a larger 32 m2 unit to dewater the increased concentrate output.The paper describes the upgrade at the Cosmos concentrator with particular emphasis on the mineralogical data and metallurgical benefits associated with the changes.INTRODUCTIONThe Cosmos concentrator is located 680 km northeast of Perth in Western Australia. The deposit’s development and operations were started in 1999 by Jubilee Mines NL, Cosmos’ previous owner, with the first production of nickel concentrate in April 2000. The Cosmos concentrator treats a komatiite hosted high grade nickel sulphide ore, with sulphides being predominantly pentlandite and pyrrhotite with lesser amounts of pyrite and chalcopyrite."

Jan 1, 2010

By K. Iturralde

The topic of this article is the automation and robotization in refurbishment processes of industrial buildings. The need to mold these production spaces is quite universal. Particularly in the regions with a high industrial development and with a lack of buildable land, there is a need to convert this kind of spaces into an improved production system. The latest developments can be a useful tool for achieving a more efficient way of reforming this type of construction. On the one hand we have the digital or computerized 3D Laser Scanning (Computer Aided Measurement) that allows an accurate 3D modeling of the entire building. On the other hand, the project management using BIM (Building Information Modeling) could provide an easy design of each of the elements of the refurbishment. Finally, through the production of construction elements using robotics as jig or for CNC (Computer Numerical Control) we achieve a neat production of each element. How can be all those technologies applied in the refurbishment or expansion of industrial buildings? The research takes a first approach and analyzes industrial buildings that can be called generic or not specialized. To narrow the field of refurbishment, three major factors are defined. The first is to minimize the bill of the energy consumption of the buildings. This could be done either insulating the envelope, reducing the waste-volume to be conditioned climatically or creating facilities for energy production. The second is that the refurbishment or expansion of industrial buildings should try not to interfere on the production process that takes place in the building. In other words, the assembly of the elements in the construction site should be quick and easy, causing the least of disturbance at the workplace. Finally, the research makes an approach towards a robot integrated industrial or productive building .

Aug 1, 2013

By Robert Strachanm

The East Kootenay coal-field, situated close to the boundary between the provinces of Alberta and British Columbia, is composed of four small areas locally called the Crow's Nest Pass, the Upper Elk, the Flathead and Crown Mountain, and comprises an area of about 3 78 square miles. From eleven to twenty-five seams have been exposed of two feet and over in thickness, with a total thickness of about 200 feet of coal, and reckoning about one hundred feet to be workable, gives an estimate of coal available of about thirty-seven billion tons. The coal is a high-grade bituminous, occasionally tending towards anthracite, and the majority of the seams furnish a. very good quality of coking coal as well as an excellent steam coal. The coal-field is found in the mountain ranges in long narrow strips. The age of the fonnation and the thickness of the covering beds have had considerable influence on the character of the coal, and lateral pressure and disturbances in the process of mountain-building have wrought great changes. With such an abundance of coal, it has been a disappointment that the East Kootenay field has not figured larger industrially. So far only one portion of the coal-field has been utilized. This is the Crow's Nest, where, in 1898, the Crow's Nest Pass Coal Company commenced development. Access to the coal seams was easily obtained, the mountain creeks having eroded away the covering, and mines were driven into the coal seams. In that year about ten thousand tons of coal were produced from the mine at Coal Creek.

Jan 1, 1924

By Paul J. Sylvester, Yeonuk Choi, Mike Nelson, Louis J. Cabri, Mike Tubrett

"The development and characterization of sulphide standards containing as many as seven precious metals has increased the efficiency and comprehensiveness of micro-analyses for deportment studies using laser ablation microprobe inductively coupled plasma mass spectrometry (LAM-ICPMS). Because trace precious metals occurring in solid solution or as sub-micron inclusions in sulphides, arsenides, and sulpharsenides are often heterogeneously distributed, a significantly large number of analyses are required. Using well-prepared samples it is possible for up to 120 analyses per day, far more than by other comparable methods. Examples will be discussed from projects focused on the deportment of Au and the platinum group elements (PGE).INTRODUCTIONBecause gold and the platinum-group elements (PGE) occur as both discrete minerals and in trace quantities in a variety of minerals (mostly sulphide, arsenide, and sulpharsenide minerals), specialized trace analytical methods were developed and applied to determine the deportment of precious metals in ore deposits, requiring sensitivities ranging originally from about hundreds to presently tens of ppb for individual precious metal or less.In mineralogical studies, micro-analytical techniques such as the electron microprobe were first applied to obtain analyses for major elements in about 1959-60, but as the instrumentation improved early attempts for PGE in potential carrier minerals indicated that reasonable levels of detection (LOD) were of the order of 300-400 ppm, depending on analytical conditions, X-ray spectral lines, and mineral matrix (e.g., Cabri and Laflamme, 1976). Eventually, the lowest detection levels by electron probe micro-analyses (EPMA) obtained for some PGE were of the order of 10s of ppm using high accelerating voltage and current for extended measuring time on peak and background (Gervilla, Cabri, Kojonen, Oberthür, Weiser, Johanson, Sie, Campbell, Teesdale and Laflamme, 2004)."

Jan 1, 2010

By R. G. S. Mussi

An inclined cooling plate is utilized as a modification in the compocasting process of magnesium alloy and the mechanical properties of the composites obtained are studied in this work. Based on crystal separation theory, molten AZ91D is poured onto an inclined plate in order to produce solidification nuclei inside the fluid metal, and is mechanically stirred while reinforcement is added. Particulate SiC was utilized as reinforcement in quantities varying from 0 to 15%vol. Dispersion of the reinforcement was observed by macro and microstructure analysis. SiC was properly mixed into matrix until 15%vol., and Vickers hardness tests were carried out for the composites produced. Results obtained for hardness were shown to increase with reinforcement addition and comparable to those of traditional compocasting. Utilization of Inclined Cooling Plate produced good inclusion and homogenization of SiC through an AZ91D matrix, at lower temperatures and shorter times than traditional compocasting.

Jan 1, 2006

Block caving is an underground mining method for the profitable extraction of massive, low-grade orebodies. Lately, it has become the mining method of choice, for many mining companies, because of depleted high-grade orebodies, and declining metal market prices. Block cave mining, however, still faces several challenges. Lack of access to the cave remains a major issue in understanding the rockmass response to mining for method optimisation. Improving our understanding of the rockmass response to caving will lead to safer and more productive operations. Combining large datasets from multiple sources with virtual reality scientific visualisation (VRSV) is a viable alternative to understanding complex cave behaviour without access to the cave. This is achieved using immersive environments with the ability to view complex multi-dimensional data (beyond 3D) graphically. VRSV offers a unique platform where it becomes possible to immerse the multi-disciplinary experts, and/or management team, in a virtual mine environment for quick decision making and fast resolution to conflicting conclusions. The underground mining system is complex due to multiple interrelating factors such as geology, excavation geometries, stress and time. Block caving is even more complex than most underground mining methods due to the network of tunnels required, and the use of induced stress, among others. As a consequence of the complexity in the block caving environment, it is vital that the mining system is analysed holistically, as a system, rather than optimizing individual factors one at a time. This paper presents a customised software module developed for use in the Advanced Visualisation Interactive Environment (AVIE) at The University of New South Wales (UNSW), Australia, to enable VRSV investigation into block cave mining systems (BCMS). This approach has the potential to provide a better understanding of the effect of time in in rock engineering, which has proven to be an important factor in hard rock mines (Ma & Daemen, 2006; Malan et al., 1997; Suorineni, 2010) but never validated. This work back analyses the early undercutting phase of a case study block caving operation with the view to understanding time/sequence effects. There is evidence that heterogeneous rockmass time-dependent behaviour governs the seismic response of the rockmass following undercut developments.

Jan 1, 2015

By Jacob Masliyah, Zhiang Zhou, Tshitende Kasongo, Jianjun Liu, Zhenghe Xu, Jeawon Choung

"Slime coating is a recognized challenge in fine particle flotation, not only in decreasing recovery, but also in reducing the selectivity and hence froth quality. In this presentation, a novel method based on electrophoretic mobility distribution measurement to study slime coatings is described. By measuring electrophoretic mobility distribution of individual minerals and their mixtures, the interactions between these minerals can be evaluated.For illustrative purposes, a model system of fine coals, or oil sands with two different types of fine clays was studied. Flotation tests showed a significant decrease in coal (bitumen) flotation recovery with montmorillonite but not with kaolinite clay addition. When electrophoretic mobility distribution of a fine coal/montmorillonite clay mixture was measured, a single modal zeta potential distribution was obtained, in contrast to a bimodal distribution for fine coalkaolinite clay mixture. This finding suggests a stronger adhesion of montmorillonite than kaolinite clays on fine coal surfaces. In the case of bitumen, the bimodal zeta potential distribution was measured for the mixture of bitumen emulsion and kaolinite or montmorillonite, indicating a weak attraction of the clays by bitumen. In the presence of calcium, however, a single modal zeta potential distribution was obtained in the mixture of bitumen emulsion with montmorillonite but not kaolinite clays. These findings are in excellent agreement with bitumen flotation results, demonstrating that the electrophoretic distribution measurement is a powerful tool to study slime coating phenomenon in a complex fine particle flotation system."

Jan 1, 2002

By D. A. Livingstone

Abstract Golden Manitou Mines, Limited, nine miles east of the town of Val d'Or in northwestern Quebec, are presently milling, at the rate of 1,000 tons daily, a relatively complex 3.11-phide ore and producing, in decreasing order of value, zinc, silver, gold, lead, and copper. The products are a zinc concentrate, a silver-lead-copper concentrate, and a silver-gold precipitate from cyanidation. Although several independent pre-production metallurgical investigations into the treatment of the ore were carried out, current practice is different from any of the recommended methods and, while still leaving room for improvement, is considerably more effective than earlier performance. Flow-sheet developments from the commencement of operations in 1942 are dealt with briefly, showing the reasons for making numerous changes, the shortcomings of the various schemes tried, and, finally, covering data pertinent to present-day practice. From the recovery standpoint, silver has presented the greatest difficulty. The writer's association with the Company coincided with the start of production. Characteristics of the Ore The predominant metallic minerals present in the ore, in decreasing order of their abundance, are: pyrite, sphalerite, galena and chalcopyrite, with lesser amounts of argentiferous tennantite-tetrahedrite, arsenopyrite, covellite, bornite, and chalcocite. The sphalerite is mostly light in colour, sometimes colourless, and practically free from combined iron. Some of the sphalerite is very closely associated with minor amounts of pyrite, chalcopyrite, and galena. Pyrie is abundantly disseminated as medium to fine grains; more rarely it is massive and contains occasional grains of sphalerite, galena, and chalcopyrite.

Jan 1, 1952

By A. F. Banfield

"IntroductionELEMENTAL sulphur occurs in three types of deposits: in salt domes in the Gulf Coast region of the United States and Mexico, from which over 90 per cent of world native-sulphur production is obtained; in sedimentary deposits such as those in Sicily, which are thought by some authorities to contain the largest world reserves of elemental sulphur; and as surface deposits, associated now or in the past with some phase of vulcanism, the type which bas the greatest world-wide distribution.Deposits of the volcanic type are the subject of this paper.From antiquity until the successful development of the sulphur-bearing salt domes at the beginning of this century, important sulphur production for local needs was obtained from volcanic deposits in many parts of the world. Due to technical and economic factors, however, producers could not compete in price with sulphur from salt domes. •The result has been that, except in Japan and Chile, little sulphur was produced from volcanic deposits from about 1910 until the start of the Korean war in 1950. Shortly after the outbreak of the Korean war, an acute world sulphur shortage developed and prices skyrocketed in many countries up to several hundred dollars a ton. Interest in volcanic deposits was renewed and exploitation of many was undertaken. Few of these operations have been successful, mostly due to inability of management to solve technical problems.While important volcanic deposits of elemental sulphur have not been reported ( 1) in Canada, and it is doubtful that any will be found, data presented in this paper may be of interest to students of ore genesis.This paper is based on field examination of numerous deposits of the volcanic type in North and South America."

Jan 1, 1954

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 M. N. Brodie

"The ability to adjust the speed of a SAG mill offers benefits to the process and to equipment maintenance. It can be provided with some slight effect on availability ranging from somewhat enhanced to somewhat reduced, depending on the particular equipment that is used. Several techniques have been developed for monitoring the magnitude of the contained charge, and several algorithms have been used to control mill feed rate and mill speed. The various benefits and the means by which they can be realized are examined and compared. Reasons for Variable SpeedProcess RequirementsThe recovery of minerals from ore is dependent on particle size and residence time in process. Separation in a given plant is most efficient at a particular rate and a particular size (e.g., 80% minus 200 mesh). If the particle size increases, less mineral will be liberated. If the particle size is significantly reduced, the process of choice may not be able to effect separation, and power, media, and maintenance costs would be increased.If a SAG mill-ball mill combination delivers the desired throughput at the correct size for efficient separation when processing ore of the design hardness, some adjustment must be made to maintain this condition when the ore changes. The processing of ore softer than design will result in overgrinding, unless:• the throughput is increased inversely to the change in hardness which lowers recovery by overloading the separation facilities;• or the SAG mill feed rate remains constant, but the speed is reduced to feed coarser material to the ball mill for finish grinding to the desired size.There is also the effect of changing milldiameter to consider. A nominal 36 ft diameter SAG mill will have an effective diameter of 35 ft with new liners and 35 ft 6 in. with worn liners. A mill designed to operate at 0.76 p.u. (per unit) of critical speed with new liners (9.84 rpm) will be changed to 0.765 p.u. with worn liners. If 0.76 p.u. is the desired value, the mill speed should be reduced to 9.77 rpm."

Jan 1, 2003

By K. Horikawa, S. Kitahata, H. Kobayashi

"It has been clarified that the Al-5%Mg alloys containing 200 mass ppm of sodium showed grain boundary (GB) fracture, even when tested at room temperature, as well as at high temperatures (~500°C). SEM/EDX study revealed that the GB fracture was associated with the segregation of sodium on grain boundaries of the Al-Mg base alloys. Differential scanning calorimetry (DSC) revealed that the GB fracture at room temperature of Al-Mg alloys was caused by sodium segregation in the solid state. It was also shown that the tendency of the GB fracture strongly depended on the heat treatment; the alloys after the solution heat treatment showed severe GB fracture compared with the alloys after the homogenizing treatment. Moreover, it was shown that the GB fracture at room temperature by sodium segregation was suppressed by the addition of bismuth or indium. The suppression of the GB fracture by the additional elements was believed to be the scavenging effects by forming the sodium bearing compounds in grains.INTRODUCTIONIt is widely known that Al-Mg base alloys containing high amount of magnesium(~5 mass%)show better workability at room temperature, while that the alloys show grain boundary (GB) embrittlement at higher temperatures ranging from 200 to 500°C, depending on grain size(Otsuka, 1984), sodium impurity level(Ransley, 1959, Okada, 1997, Horikawa, 2001)and testing strain rate(Yamada, 2012). In the case of coarse-grained Al-5%Mg alloys (~300 ?m), 2 mass ppm of sodium causes severe GB fracture around 300°C, however, the Al-5%Mg-2ppm alloy does not show GB fracture at room temperature. It has also been shown that the GB embrittlement caused by 2ppm of sodium was suppressed by the additional elements, such as bismuth (Talbot, 1995), antimony (Ueda, 1997) and indium (Horikawa, 2012). Basedon these facts, we have concluded that the GB embrittlement at higher temperatures of Al-Mg alloys is attributed to the synergy effects of GB segregation of atomic sodium and GB sliding. For the GB embrittlement mechanism of Al-Mg alloys, involvement of low melting point metallic phases has been pointed out (Lynch, 2002),since the GB embrittlement appeared only at high temperatures. Up to date, the effects of high amount of sodium addition more than 2 ppm on GB fracture were not fully investigated in Al-Mg alloys. In the present study, the effect of 100 ppm ordered sodium impurity on GB fracture of Al-5%Mg alloys was examined, together with the effect of another additional elements."

Jan 1, 2017

By P. A. Witt

"Highland Valley Copper is a conventional truck-shovel mining and flotation concentrator operation located 75 km southwest of Kamloops, British Columbia (Fig. 1).The ore is situated within a porphyry copper deposit and is mined at a rate of 135,000 mt/day from two separate open pits. The nearby mill produces concentrates containing 375 million pounds of copper and 5 million pounds of molybdenum metal yearly. In the Valley pit, head grades are roughly 0.40% Cu at a 0.23% Cu equivalent cut-off. The Valley pit strip ratio currently sits at 0.55:1 with waste quantities made up of separate rock and unconsolidated overburden units. From the mill, concentrates are trucked to nearby Ashcroft and then hauled by rail to ocean port facilities in Vancouver. The mine employs 950 people and is planned to operate until 2009. The operation is a partnership between Teck Cominco (63.9%), BHP Billiton (33.6%), and others (2.5%). Management is shared by the two principal owners and directed by a management committee."

Jan 1, 2005

By K. M. Mayhew, G. D. Barr, T. M. McCoy, C. T. Knilans

"Teck Resources Limited (“Teck”) has developed and extensively tested on a continuous basis the CESL Technology hydrometallurgical process for treating copper and nickel sulphide concentrates, including bulk copper-nickel concentrates. Copper, nickel and cobalt are leached efficiently into solution, utilizing CESL process conditions. Total precious metals including gold, silver, platinum and palladium are recovered from the residue stream via sulphur flotation. This paper describes the CESL Technology testwork on a bulk copper-nickel concentrate derived from Twin Metals Minnesota?s (TMM) deposits within the Duluth complex and evaluates the economic benefits (increased cash flow, increased revenue certainty) and investment criteria (capital cost, payback and cash flow) of incorporating CESL Technology into the staged development of TMM?s deposits.INTRODUCTION Mineral Processing and the Role of Hydromet in the Duluth Complex The Duluth Complex in northern Minnesota, United States (US), represents one of the largest undeveloped accumulations of copper, nickel, gold, and platinum group metals (PGMs) in the world, ranking second in copper and PMs and third in accumulation of nickel. The figure below identifies some of the larger known deposits within the Complex (see Figure 1). Copper, nickel, PM and PGM mineralization within the Duluth Complex is hosted by mafic to ultramafic intrusive rocks that are part of the overall intrusive complex.One of the mineral processing challenges of Cu-Ni-PM-PGM deposits in this Complex is the complicated, polymetallic nature of the mineralization1: copper occurs primarily as chalcopyrite and cubanite with minor occurrence of talnakhite; nickel occurs as pentlandite and refractory nickel oxide/silicates; iron sulphides are present as both pyrrhotite and troilite; and PMs/PGMs occur in both the sulphide matrix as well as discrete minerals. An additional challenge for the Duluth Complex is the ratio between copper and nickel; in most of the identified deposits, copper grade is three to four times greater than the nickel grade, which precludes the production of a simple bulk concentrate due to the lack of a traditional smelting market for a bulk concentrate of this character."

Jan 1, 2017

By D. Naden, D. J. King

"The high capital and operating cost of liquid-solid separation circuits in hydrometallurgical plants has led to an increased focus on the use of in-pulp systems for metals recovery in order to eliminate the need for solids washing and to reduce the need for liquid-solid separation.Carbon-in-pulp (CIP) has now been accepted in Canada and around the world as the leading process for recovery of gold and silver, replacing the Merrill-Crowe process and thus removing the need for CCD thickeners or belt and drum filters. The overall design of conventional CIP adsorption circuits was established in the late 1970s and it has remained substantially unchanged until now. Most of the development work since 'hen has been concentrated on improving methods of separating pulp and carbon and on reducing carbon losses during transportation and agitation.Resin-in-pulp (RIP) has been used for many years in uranium mills in the USA. However, most of the plants were built in the 1960°s and RIP was only chosen when liquid-solid separation of leach pulps proved very difficult. The plants are far from ideal as they have high resin losses and high maintenance costs. Consequently, there is room for improvement.Davy McKee has taken a fresh look at the engineering development of in-pulp contactors leading to a fundamental redesign of the adsorption units. The improved in-pulp technology uses a modification of the proven air-swept screen techno1ogy together with a new technique of process operation. The new contactor operates at high pulp throughput rates with high concentrations of carbon or resin in the recovery stages, resulting in a significant reduction in the contactor size over conventional design. As a result of this reduction in the size of the contactor by up to 80%, significant savings can be made in equipment and building costs. In addition, the plant 1s easier to operate than a conventional CIP plant."

Jan 1, 1987

By William B. Coker, Vladimir J. Sopuck, J. S. Fox

"Preliminary investigations indicate that organic lake sediments offer some potential for gold exploration within the Canadian Shield of northwestern Saskatchewan. It is also apparent that certain precautions must be taken.Gold is primarily related to the organic fraction of the lake sediments, which, although giving consistant Au contents to those sediments, may restrict the dispersion of Au within the lake itself. It may be necessary to carry out selective extractions on the lake sediments to differentiate between Au related to organic sequestration, indicative of hydromorphic and/ or chemical dispersion, and Au related to inorganics, indicative of mechanical dispersion.Lake sediments are probably only of use for very detailed exploration (i.e. every lake). One to three samples per lake should be appropriate, although a single centre-lake organic-rich sediment sample may be adequate in very small lakes. Each lake sediment sample should be analyzed at least twice and the analytical data carefully monitored and evaluated.The use of As in lake sediments as a pathfinder element for gold is applicable in the search for certain types of gold occurrences.Following detailed lake sediment sampling, basal till sampling can possibly be used to localize areas of potential gold with or without base metal mineralization."

Jan 1, 1982