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By R. Patrick

As a unique South African organisation, CSIR: Division of Mining Technology (Miningtek) strives to support the mining industry by improving health, safety and productivity through developing, adapting and transferring technology. Considerable effort is currently directed towards the development of potential non-explosive mining methods with the potential to allow continuous mining in narrow reef conditions. Besides improving productivity, continuous mining results in concentrated mining which has a significant impact on reducing infrastructural costs. Impact Ripping and Water Pulse Rock Breaking have been tried on gold mines, whereas Activation, Mini-Disc? cutting and the Plasma Holemaker are currently being tested on platinum mines. The organisation?s many years of experience in novel rockbreaking, together with its world-wide collaborator network, has placed it in a unique position to assist the mining industry and manufacturers in developing and/or adapting existing technologies for application underground. Currently a range of technologies are being investigated, which have reached different stages of maturity. The main technologies under investigation are; - Impact ripper system - Water pulse rock breaking - Activated undercutting rollers - Mini disc cutters - Electric rock breaking

Oct 1, 2001

By B. W. Williams

The crack propagation behaviour of Zr-2.5Nb pressure tube material was studied through comparison of the measured behaviour with the predicted response from finite element analysis. Three-dimensional finite element simulations of compact tension specimens were performed using the crack tip opening angle as a fracture criterion to allow for crack propagation. To obtain reasonable agreement with the measured behaviour, it was important to capture both the anisotropic plastic deformation behaviour of the Zr-2.5Nb material through use of the Hill-48 yield criterion and damage due to void growth, nucleation, and coalescence through the use of a Gurson-based constitutive model in the simulations.

Jan 1, 2010

By J-P. Rossetti, A. Guerin, M. Jaboyedoff, L. Baillet, A. Mariscal, J. D'Amato, D. Hantz

"The processes leading to the fall of rock compartments from rock walls are poorly known as well as their velocity. It ensues that quantitative prediction of the failure time for a rock compartment which is presently stable, is not possible by a purely geomechanical approach. However a quantitative probabilistic prediction of rockfalls at the scale of a rock wall is possible if the spatial-temporal rockfall frequency can be determined or estimated (Hantz, 2011). For a better knowledge of failure processes and frequency, rockfalls have been detected in several rock walls, using annual terrestrial laser scanning, allowing comparison of the frequencies in different geological conditions. For one of these rock walls, the spatial detection have been completed by a precise dating of the events, using a quasi-continuous photographic survey (one photo every 10 mn), allowing the study of the influence of meteorological factors.The precise dating of rockfalls has been carried out for the Saint-Eynard cliff which towers above a residential area of the town of Grenoble (French Alps). The South-East facing cliff consists in bedded limestone gently dipping North-West and located at an elevation between 850 m and 1100 m. The surveyed zone is about 750 m large and 250 m high. Between 01/02/2013 and 26/11/2013, 65 rockfalls ranging between 0.01 m3 and 20 m3, have been detected by diachronic comparison of laser scanner data and dated by comparison of photographic images. The temperature at the elevation of the cliff has been calculated from the temperature measured (every 5 mn) at a meteorological station located at an elevation of 245 m and 2.5 km away from the cliff, using a temperature gradient of 0.003°C/m (D’Amato et al., 2014). The precipitation were measured 900 m away from the cliff at an elevation of 469 m. Different meteorological conditions have been defined: (a) “freeze” qualifies days with negative mean temperature (but with a thaw period, except for two days); (b) “thaw” qualifies days with positive mean temperature, but following a freeze day; (c) “rain” qualifies days with precipitation.Table 1 shows the rockfall temporal frequency for the different meteorological conditions. It appears that the frequency is about 6 times higher the freeze days, 2.5 higher the thaw days and 3 times higher the rain days than days without freeze, thaw or rain."

Jan 1, 2015

By M. A. Roche

The property of the Hudson Bay Mining & Smelting Company, Limited is located at Flin Flon lake, 85 miles northwest of The Pas, Manitoba, on the Manitoba-Saskatchewan boundary. The area is at latitude North 54°, and is approximately 1,000 feet above sea level. The ore-body occurs in amygdaloidal greenstones, which are to be referred to the earliest basic volcanic flows in the district. It was discovered in an outcrop on a point of land jutting into Flin Flon lake, and subsequent diamond drilling proved that it extends under the lake both to the north and south of the point of discovery. After the taking of soundings from the ice during the winter months, it was estimated that l,000,000 tons of overburden, mainly mud and clay, would have to be removed to expose the underlying ore. Flat diamond-drill holes indicated that the ore-body was separated into more or less independent lenses by horses of unmineralized greenstone, and that in places the overall width, including horses of waste, reached 450 feet. These several] conditions were the main factors influencing the management in their decision to adopt an open-cut method for the mining of the upper portion of the ore-body. Before it was possible to commence stripping operations, it was necessary to dam-off the eastern portion of Flin Flon lake, instal pumps, and de-water the dammed-off area. Dams for this purpose were constructed of mine waste rock and clay filler from nearby hillsides. Material for the bottoms of the dams was taken across Flin Flon lake in hopper-bottom barges. Trestles were then built on the dam bottoms and dams were complete by the time trackage was available. De-watering commenced in April, 1930, and was completed by the latter part of May of the same year. Estimated pump output for the period was roughly four billion gallons. Two Morris 10-inch dredging pumps were used, direct-connected to 250 h.p. electric motors. Individual pump capacity was rated at 3,000 g.p.m. against a 150-foot head. Average head for the operation was 50 feet, which increased the total output considerably. The pumps were mounted on floating barges in cribbings of piling driven at the lowest points in the lake bottom.

Jan 1, 1933

By T. Johnson, D. Kelley, J. Graham

"Hydrometallurgical processes can be exceptionally corrosive. Conditions associated with metal extraction and refining require materials of construction that can withstand process acids and acid chlorides at temperatures up to 90°C (194°F). Process vessels, piping, scrubbers and ducting can be rapidly compromised in these aggressive environments if not designed with care. Design engineers are challenged to find materials that can stand up to hydrometallurgical processes especially for copper, zinc, nickel, cobalt and uranium. This paper will evaluate material solutions to determine which provides attractive economics for initial procurement as well as high durability for reasonable life cycle costs.INTRODUCTIONMining activity in a number of metal ores has been running quite high over the last few years. In particular, those metals that employ acid functional extraction processes such as copper, nickel cobalt and uranium have been particularly active.The world’s largest nickel mine – the massive $4.76 billion Ambatovy nickel mine on the African island nation of Madagascar is nearing completion. When it reaches its full production capacity in 2013, the mine will produce 60,000 MT/yr of nickel and 5600 MT/yr of cobalt. Coming on the heels of the Ambatovy project is the Long Harbour Processing Plant in Newfoundland, Canada which will process the ore from Vale’s Voisey Bay mine in Labrador. Voisey’s Bay is expected to generate more than 50,000 MT/yr of nickel ore when it starts up in 2013. Next up will be the Boleo project in Mexico on the Baja peninsula. When commissioned in 2013, the $858 Million Boleo project is expected to produce 60,000 MT/yr copper, 3100 MT/yr cobalt, 36,000 MT/yr zinc and 100,000 – 250,000 MT/yr manganese carbonate.High nickel alloys and rubber lined steel have been used for decades to design corrosion resistant equipment for mineral processing environments. These materials demonstrate reasonable resistance to corrosion for most environments. Unfortunately, higher nickel alloys are quite expensive. Rubber lined steel is a bit more affordable but requires continuing service over time which ultimately drives up its cost as well. FRP (Fiberglass Reinforced Plastic) has also been used extensively in mineral processing for tanks, piping and ducting employed in aggressive environments. Today, more and more design engineers and material specifiers are calling for FRP composites for both new and replacement equipment used in the refining and processing of a variety of metal ores."

Jan 1, 2012

By H. A. Wilson

Introduction Salt (sodium chloride) occurs naturally either in the solid state as rock salt or in solution as a component of natural brines. It is the major saline constituent of sea water, which contains about 4 percent salt-roughly 164 million tons, or enough to meet world salt demands for five years, per cubic mile. The great rock salt deposits of the world are generally regarded as having been formed by the evaporation of sea water over long periods of rime in wholly, partially, or periodically cut-off bays of ancient oceans. History and Occurrence of Salt in Canada We can speak today of the vastness of Canada's salt resources, but it was not always so. Settlement of our Atlantic seaboard and the Sr. Lawrence valley began in earnest in the early 1600's. The first small commercial salt works in Canada did not come into operation until 1866. Thus, for some two and a half centuries, the inhabitants of this growing country were entirely dependent on foreign sources for every pound of salt they consumed. The record shows that from at !east 1800 onward, the need for a domestic salt industry was clearly recognized by the governments of the day. It was during the Western Ontario oil-boom of 1866 that the initial discovery of rock salt in Canada was made, not far from Goderich, at a depth of 1,000 feet. A salt company was promptly organized, and with their operations there began the gradual and still uncompleted conquest of the Canadian salt market by the Canadian salt industry. Over the next thirty years many holes were drilled into the Salina formation both in Ontario and Michigan, and encountered rock salt. A vast salt-basin was disclosed, approximately outlined, and given the name Ontario-Michigan Salt Basin. The Ontario portion of the basin extends over at least 3,500 square miles, is met with at a depth varying between 800 and 1,600 feet, and has a thickness of 50 to 250 feet. No attempt has ever been made, so far as we know, to calculate the total salt reserves of this basin, but the minimum indicated in the Ontario portion by the figures just cited is just under thirty-five cubic miles. The specific gravity of rock salt is 2.2. From these data, those so inclined may calculate the tonnage.

Jan 1, 1947

By W. F. Baker

Location and History God's lake is in the northeastern part of Manitoba, about 400 miles northeast of Winnipeg, or about 250 miles due north of Red lake, Ontario. The lake is quite large, having an overall length of 54 miles and a maximum width of 18 miles. There are numerous islands in the lake, the largest of these, known as Elk island, being about 15 miles long and 3 miles wide in the widest part. The accompanying map (Figure 1) shows the location of God's lake and of the mine. The God's Lake area has long been regarded as promising country for the prospector, but, due to its inaccessibility, practically no prospecting was done prior to 1927. In the years 1927-1931, inclusive, a few prospectors visited the area, but no discoveries were made. In 1932, Bob Jowsey and Archie McDonald entered the area from Island lake. They first prospected in the vicinity of Knife lake, which is immediately south of the main part of God's lake, and then moved on to the latter lake, heading for the north shore of Elk island. The first afternoon on God's Lake, when looking for a place to camp on the north shore of what is now known as Jowsey island, Jowsey discovered a quartz porphyry dyke which was cut by a number of gold-bearing bluish quartz stringers. On the strength of this discovery, he and McDonald began at once to stake the Reno group of claims. Rumours of the discovery brought in other prospectors, and other groups of claims were staked to the east, along the north shore of Elk island. A second discovery was soon made by Dan McCrea on his Gold Standard claims, three and a half miles to the east of the original discovery. Staking still continued to the east, along the north shore of Elk island, and Bob Brown and Harvey McKenzie staked the Akers group on a discovery approximately two miles east of McCrea's discovery. Through the efforts of Jowsey, the Reno, Rand, Elk, and Cona groups, belonging to the original syndicate for which Jowsey and McDonald staked, were combined with the Gold Standard, Greenstone, and Akers groups, and the Company known as God's Lake Gold Mines, Limited, was formed. Several additional groups of claims were later taken over by the Company and a considerable area of adjoining ground was staked to round-out the property.

Jan 1, 1935

By Colin Hardie, Simon Pelletier, Rakan Rhabani, Guy Comeau

"In order to improve the nickel concentrate thickener operation at Raglan Mine, two pulp deaeration cyclones were installed. These units obtained from Outotec Pty Ltd, also called the FrothBuster®, have been in continuous operation since mid-October 2006. The primary objective of the de-aeration cyclones is to lower the solids content in the thickener overflow by de-aerating the concentrate pulp before it enters the concentrate thickener. This dearated slurry should help decrease the nickel particle losses that report to the thickener overflow because of the flotation effect within the thickener.Optimizing the de-aeration cyclones has been a slow and ongoing process, however, initial testing is encouraging. The latest test results indicate a 50 % reduction (0.070 to 0.035 % solids) in nickel losses to the concentrate thickener overflow resulting in an additional $350,000 in annual revenues.This paper will present an overview of installing the de-aeration cyclones within a limited space, as well as the preliminary commissioning and testing challenges. This paper will also discuss the most recent concentrate thickener operating results since the de-aeration units were installed.INTRODUCTIONThe Xstrata Nickel Raglan Concentrator, located at the northern limit of Quebec’s Nunavik Region has been in production since 1997. In early 2002, the concentrator implemented the Zero Process Water Discharge (ZPWD) project to recycle the process water to decrease fresh water consumption and reduce discharges to the environment. Due to this initiative, the chemistry of the process water changed significantly resulting in flotation concentrate streams, which were very frothy and difficult to manage. This phenomenon has resulted in operational challenges in many areas of the concentrator including slurry pumping, flow measurement and concentrate thickening.In October 2005, the Raglan Mine underwent a conversion from an AG mill to a SAG mill operation in order to increase throughput and to optimize key process areas. As part of this project, the first two North American pulp de-aeration (FrothBuster®) units from Outotec were installed to improve the operation of the concentrate thickener. The primary objective of the deaeration technology was to lower the solids content in the thickener overflow by de-aerating the concentrate thickener feed pulp. This in turn was to reduce the froth, which accumulates on the thickener surface, and more importantly reduce valuable nickel losses to the thickener overflow because of the flotation effect within the thickener."

Jan 1, 2008

By A. Esterhuizen, S. Essack, H. Joubert, N. Fowler

Tenova Pyromet has developed innovative technologies for copper smelting and electric slag cleaning furnaces. Based on client feedback and requirements, innovative designs have been developed to address key design areas and improve furnace reliability, operability and hygiene. These developments include the NovaLance™ lance system to prevent lance bending on top submerged lance furnaces, the SlagFlo™ slag tapping flow control device to better control bath levels and tapping rate for granulation, and an electrode seal for improved sealing directly onto the electrode casing to allow water-cooled electrode components to be located above the furnace roof. The potential application and benefits of these innovative designs are discussed. INTRODUCTION Tenova Pyromet has a long history in the engineering and supply of innovative electric furnace and related equipment for the base metals and platinum industries. Recently Tenova Pyromet has used its furnace equipment design experience to engineer innovative solutions for top submerged lance (TSL) furnaces, and potentially other furnace technologies. These equipment design solutions are developed to address specific operating challenges and operator requirements. Three of these innovative equipment developments are discussed in this paper. First the NovaLance™ lance technology to prevent lance bending during operation in TSL furnaces, such as used for primary copper smelting, is described. Lance bending has been identified as a significant problem for TSL furnace operators as it causes down time and affects furnace availability. The SlagFlo™ device to control the slag flow rate during tapping has been developed based on specific requirements in the mineral wool industry. The SlagFlo™ device can be used to control slag bath levels in primary smelting, converting and slag cleaning furnaces for base metals including copper. In addition, it can be remotely activated for the safe closing of slag tapholes located upstream from a water granulation system. Finally, Tenova Pyromet developed an electrode seal that seals directly onto an electrode surface. This is a special requirement related to base metals and platinum electric smelting and slag cleaning furnaces where furnace operators prefer to keep the water-cooled electrode equipment above the furnace roof. The seal can be used to seal directly onto the potentially hot and uneven surface of Söderberg, pre-baked and graphite electrodes.

Jan 1, 2019

By K. Nasrallah

"The Dumont deposit is a large (1,179 Mt proven and probable reserve) low grade (0.27% nickel), nickel sulphide project located in the Abitibi region 25km west of Amos, Quebec. Royal Nickel Corporation acquired the project in 2007 and has since taken the project from a scoping study in 2010 through to completing the feasibility study in July 2013.The Dumont deposit in a nickel deposit with the recoverable nickel contained in three minerals; pentlandite, haezlewoodite and awaruite. The minerals are recovered by a combination of flotation and magnetic separation. Over the course of the studies many flowsheet design decisions and changes were made. This paper outlines an overview of the project, flowsheet design including the comminution circuit, desliming and awaruite recovery. The overall resulting flowsheet that was used for the feasibility study is then presented along with the confirmatory locked cycle testing that showed the feasibility design basis was able to produce the predicted concentrate grade and recovery.IntroductionRoyal Nickel Corporation (RNC) is a mineral resource company headquartered in Toronto, Canada, primarily focused on the exploration, evaluation, development and acquisition of base metal and platinum group metal properties. RNC's principal asset is the Dumont Nickel project (Dumont project) located in the established Abitibi mining camp, 25 km northwest of Amos, Quebec. RNC acquired a 100% interest in the Dumont property in 2007. The mineral claims covering the Dumont deposit are currently held 98% by RNC and 2% by Ressources Québec.The Dumont project is located in the province of Quebec in the municipalities of Launay and Trécesson approximately 25 km by road northwest of the city of Amos, 60 km northeast of the industrial and mining city of Rouyn-Noranda and 70 km northwest of the city of Val d’Or."

Jan 1, 2016

By A. M. Martinez, L. Melis, R. C. Peláez, L. G. Garcia

Orovalle Minerals S. L. operates a copper/gold mine in the Asturias region of northern Spain, with the operation dating back to December 1997. The feed to the El Valle mill, consisting of oxide/sulphide (skarn) mineralization, is highly variable, even on a shift by shift basis and presents challenges to the mill operating staff on a daily basis. The mineralogical characteristics of the ore are quite complex with copper present as native copper and sulphides as well as copper minerals with deleterious elements. Gold is present as native gold and electrum. The mill circuit includes SAG/ball mill grinding, gravity recovery of native copper and gold, flotation of copper concentrate, carbon-in-leach gold recovery and SO2/air cyanide destruction. The paper will provide a description of the different unit operations and present operating data of the mill operation.

Jan 1, 2019

By K. Meyer

"The largest cost centres of the David Bell Mine concentrator are grinding, leaching and effluent treatment. Optimizing results during the 6th year of operation are listed below: o SAG mill slurry density control and operating strategies improved liner life and media consumption by 10 and 25%, respectively.o Poly-met liners clad the SAG mill except for the feed end. Lower noise levels and reduced mill downtime have resulted in an improved and more efficient workplace (time required for liner changes is 2 to 3%).o A comparative grinding media study using seven different marked media at the same time showed media wear rates range 120 to 198 mg/kWh and ball mill charge replacement frequencies of 8.3 to 13.1 per year, and that a meaningful wear test must include all media to be tested at the same time in the same mill. High quality carbon steel cylinders had the best economics.o Pre-aeration, using pure gaseous oxygen is accomplished in pipe reactors. Small bubble generators provide oxygen in the first three leach tanks. 1500 to 3000 kg of oxygen is consumed per day. Leach kinetics have improved and trends indicate increases in gold recovery of three to seven ounces per day at reduced costs. Effects of reduced cyanidation of accessory metals on the effluent treatment plant will be discussed in a separate paper."

Jan 1, 1991

By Malcolm Scoble

Process Technologies Suitable for Application Underground Design Criteria - coarse particle technologies - compact, robust, flexible - waste products suitable for use as backfill Process technologies identified: - Optical/conductivity sorting - Dense media separation - Coarse-particle flotation Process technologies supported by compact & efficient comminution stages Mineralogical evaluation to select process & estimate Performance Further Work U/G Plant Layout & Excavation Modelling Evaluate scenario at increasing depth Establish properties of waste as backfill Model impact of improved backfill quality Evaluate further case studies Evaluate further Environmental Health and Safety Issues Model impact of system development on inventory of national mineral reserves Conclusions Technologies exist for integrated underground mining and processing systems These technologies to be successfully integrated into underground mining system Positive economic and environmental benefits Technical issues to be resolved at depth System Development path identified

May 1, 2004

By Mario E. Rossi

The full economic evaluation of a mining project requires a block model that provides an estimate of the tons and grades of available resources. The model must be representative of the mineralization to be found at the time of mining for specified extraction periods and within acceptable error margins. In an operating mine, there may be a reasonable understanding and estimates of actual dilution and ore loss. This paper discusses the issue from the perspective of a project at a feasibility or preproduction level of development. Three types of dilution are discussed. Internal dilution (or change of support) is function of the spatial distribution of the mineralization and its relation to the operation?s selectivity. Geologic contact dilution is the unavoidable mixture at contacts or boundaries of material with different geologic characteristics, grades, or metallurgical performance. Operational planned and unplanned dilution should also be considered, sometimes incorporated by factoring the resource model, but more accurately by mimicking the grade control process. The resource estimation process always carries uncertainty, which is sometimes significant, and usually caused by several factors. These include quantity and quality of drill hole information; quantity and quality of geologic data; grade estimation methodology; dilution and mining recovery factors applied; etc. A key decision is to whether estimate as accurately as possible the in-situ geologic resource or to estimate the tons and grade of the material to be fed to the processing plant. The geologic modeling and grade estimation methods used are conditioned by this decision.

May 1, 2009

By Peter A. Eshun

This paper studies two methods that account for risks associated with gold mining projects such as mineral risks and country risks. The first method is sensitivity analysis, which investigates the effects of a change in any economic parameter such as operating cost, capital investment, gold price or taxes on the viability of the project. The second method is Monte Carlo Simulation technique, which takes into consideration the simultaneous random variation of the economic parameters on the project's viability. An automated simulation cash flow model has been developed as part of this paper. Sensitivity analysis and the simulation model have been used to investigate the economic viability of the Dokrupe Gold Project (DGP) serving as a test case. It is concluded that, the Monte Carlo Simulation technique gives a more realistic judgement of the economic viability of gold mining projects.

May 1, 2004

By James F. Archibald

In historic mining practice, typical thin liner support systems have been considered to comprise non-reinforced or mesh-reinforced shocrete linings. In the early 1990?s, development of alternate forms of liner systems was initiated in Canada which is now undergoing significant international growth in countries which sustain major mining activity. Now internationally designated as thin, spray-on liner systems, a wide spectrum of liner materials, ranging from liquid/liquid to liquid/solid component combinations, has become commercially available. This innovative family of products is characteristically identified as being rapidly deployable, capable of creating ultra-fast setting coverage over rock surfaces, and able to develop tenacious adhesion and pull strength capacities for resisting rock falls and movements. This paper presents a summary of current liner developments and use in principal mining districts world wide. Additionally, a database of material properties for principal product types used in mining and a review of common quality control testing procedures under development are provided. Such information is based upon recent Canadian and international efforts being taken to assess and develop user standards for the implementation of thin, spray-on liners as rock support in mines. This work is intended to continue for a period of years, with the eventual goal being to establish support and installation guidelines for mines based on quantifiable laboratory and field research.

May 1, 2002

By E. Wolmarans

The selection of the main mineralised zone (MMZ) concentrator milling circuit has followed a comprehensive route over the preceding 10 years. Many knowledgeable parties have contributed and assisted in developing the milling circuit according to the best available information. The final selection of the flow sheet was completed after DRA conducted a techno-economic study on four possible comminution circuits ranging from conventional crushing and ball milling to fully autogenous (AG) milling. The results from all the above mentioned work indicated that it is possible to treat the MMZ ore at the desired throughputs to the desired grind sizes in a fully autogenous grinding circuit. The flow sheet was designed to treat the main mineralised zone (MMZ) arising?s from both underground and open cast operations and incorporates a fully autogenous grinding (AG) circuit. Commissioning of the 375ktpm concentrator at Nkomati Nickel began in August 2009 with the first ore reporting to the mill on the 15th of September 2009.

Jan 1, 2012

By T. Bhambhani, D. R. Nagaraj

"Ultramafic Ni ores present significant challenges in processing in that both recoveries and grades are not satisfactory, due to the presence of Mg silicates in large amounts. Significant quantities of xanthates and CMCs are generally used for their recovery by flotation. Additionally, given that some of these ores are processed under acidic conditions, CS2 generation due to xanthate decomposition presents some safety hazards. Technology to replace xanthate has been developed for which the safety and health issues are absent. Collector S-10294 shows significant improvements in Ni and overall S recovery at a dosing rate of one half that of xanthate. New polymeric modifiers have also been developed that help reduce the Mg content of the concentrates at very low dosages. The reagents are custom designed for use in normal or hypersaline water, and acid or alkaline conditions.INTRODUCTION The use of xanthates in sulfide mineral flotation is reported to have started as early as 1925 (Nagaraj 2005). The reagent is now ubiquitous in the mining industry, accounting for 40-50% of total collector consumption. In recent years, the development of more selective reagents has rendered xanthates largely obsolete in Cu flotation. However, xanthates continue to be sold in large amounts in the Au, PGM and Ni flotation industry, where bulk sulfide flotation is required. The low cost and easy availability is the largest driver for the use of xanthates in the minerals industry. Of particular interest to this study is the use of xanthates in the flotation of Ni sulfide ores. About 60% of the world’s annual nickel output is obtained from sulfide Ni ores (Hoatson, 2006). A strategically important category of these ores is the ultramafic hosted sulfides, such as those of Western Australia and Canada. These ores are characterized by low Ni grades (<1%), with the Ni minerals being pentlandite, violarite, millerite and mackinawite, and gangue minerals comprising an array of altered Mg silicates, mostly serpentines. The challenges associated with treating these ores are well documented (Eltham et al. 1973; Claridge et al. 1975). One challenge is that Ni recoveries from these ores are lower. This has been attributed to the increased pulp viscosity, as discussed in detail by Vasudevan et al., 2010. Additionally, Mg silicates tend to report to the concentrate in large quantities, which is problematic for two reasons: a) concentrate dilution, and b) the high melting point of Mg silicates tends accelerate wear on the refractory lining of smelters. This has been attributed to network transport to the froth phase via bubble flux and entrainment (Patra et al, 2010)."

Jan 1, 2012

By J. Lee, M. Peart, T. Bhambhani, D. R. Nagaraj, P. Riccio

"Over the past decade or so, our efforts have focused on developing the rationale and concepts for new technology in reagent development and optimization in the processing of base and precious metals. A major outcome of these efforts have been the development of a novel family of collectors, principally driven by the MAXGOLD® and Aero XD-5002® chemistries, for precious metals recovery from primary Au ores and Cu-Au ores. These chemistries was developed to be robust to address the complex mineralogy and gold deportment in these ores. Plant trial data for a variety of ores have confirmed that the both Aero® XD-5002 and MAXGOLD® chemistry are indeed versatile in recovering gold values occurring as gold alloys and/or associated with many types of sulfides, and in altering the deportment of certain sulfides (such as those bearing As, Bi etc). An overview will be given in this paper using plant data to highlight the application of these reagents.INTRODUCTIONThe subject matter of this paper is the flotation of Au containing minerals from their ores. The motivation from this manuscript comes from the several challenges faced with the processing of Au ores, as was articulated in detail by Nagaraj (2008). The biggest challenge is the complex mineralogy; most easy-to-treat free-milling ores bodies are largely depleted. The Au values are distributed in multiple host minerals such as pyrite, pyrrhotite, arsenopyrite and Cu minerals such as chalcopyrite. Au values also happen to be finely disseminated within the various minerals and are sometimes invisible in optical microscopy. Additionally, on any given day, some mines treat multiple ore types, and the mineralogy is different for each ore type.Xanthates continue to be the collectors of choice at most Au and PGM operations around the world. Most primary Au operations tend to consume very large amounts of collectors; the dosage ranges anywhere between 40-400 g/t and this has been attributed to both mineralogical and non-mineralogical factors (non-mineralogical factors include the low cost of xanthates and the mindset that “more is always better”, which is not necessarily the case). In addition, several studies now show that xanthates alone are never sufficient where multiple value minerals are present, and that supplementary collectors are required. The large doses present a substantial cost to the minerals industry, and many mining companies have expressed the need for more efficient reagents that can improve metallurgical performance at low dosages."

Jan 1, 2013

By Transfert Environment and Society

Transfert?s added value ? Building bridges between project promoters and communities ? Unique expertise in working toward Social License to Operate through meaningful community engagement ? 25 years of recognized innovation and a systematic approach ? Key mining clients: ? Royal Nickel Corporation ? IAMGOLD - Niobec ? Richmont Mines - Wasamac ? Mine Arnaud ? Managem

Aug 1, 2013