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By U. Martin

Advanced copper materials for conducting applications require an optimal combination of high mechanical strength at ambient and moderately elevated temperatures together with superior electrical and thermal conductivity. Mechanical alloying under repeated cooling of the milling vials in liquid nitrogen has been applied to produce ultra-fine grained (UFG) oxide dispersion strengthened (ODS) copper with a high yield strength at ambient temperature. In the present study ODS copper was manufactured by mechanical alloying of copper powder and 3% by volume of incoherent oxide dispersoids. During the high-energy milling a homogeneous distribution of fine dispersoid particles (diameter nearly 100 nm) can be achieved in the powder. Samples with a density of more then 97% of theoretical value were produced by uniaxial hot pressing under 650 MPa at 600°C for 20 minutes. The high yield strength at ambient temperature can be described by a linear superposition of the Orowan stress for particle hardening and of ultra-fine grain strengthening according to the Hall-Petch mechanism. Simultaneously, a best value of 75% IACS could be obtained for the electrical conductivity. The creep behaviour of ODS copper in the temperature range from 500°C to 700°C is described within the frame of diffusional creep deformation.

Jan 1, 2007

By C. B. Webber

"Sherritt Gordon's experience with rubber mill liners began in 1964 at the Lynn Lake Farley Mine and continued at the Fox Mine in 1960, and the Ruttan Mine in 1973. This paper describes the history of the performance of rubber mill liners at the three mine operations.LYNN LAKE - FARLEY MINEThe Lynn Lake Farley Mine, which ceased production in 1976 due to exhausted ore reserves, was a 3500 T.P.D. copper-nickel operation; consisting of two parallel rod mills followed by three stages of ball mill grinding. A circuit modification in 1964 necessitated one of the tertiary ball mills to be used as a pyrrhotite regrind mill. This 8' x 5' Hardinge conical mill drawing 225 HP was initially installed with steel liners and lifters. After several months of operation a routine inspection revealed severe channeling and washing behind the liners which was threatening to erode the ball mill shell. It was thought that the highly acidic condition in the mill, due to grinding 100 º6 pyrrhotite, was accelerating the wear of the steel liners. At this time it was decided to reline the mill with rubber liners to see if the wear problem could be relieved, and in December 1964 a set of Skega rubber liners were installed."

Jan 1, 1981

By S. A. Willis

For over 150 years gypsum from Nova Scotia has been shipped via water to the United States east coast. The history of the movement has been one of continual improvements in quarrying, loading, and shipping. At the start, man-size rock quarried by hand auger and black powder was loaded into horse-drawn carts, hauled to the waterfront, and dumped into 100-ton sailing schooners. Last year the Canadian Gypsum Company completed the latest and most modern of these successive installations for the movement of this Nova Scotia product. The new system loads crushed gypsum into 11,600-ton vessels at Hantsport in two hours' time at high tide. At the head of the bay of Fundy are located vast deposits of gypsum. The tidal rise and fall of 45 feet twice a day, with its attendant swift currents, has always presented major navigation and shipping problems. When the tide is low, the Hantsport ship-loading pier is high and dry, with no water within 400 feet. Three hours later a large river has flooded in (running up hill) and large steamers can dock at the wharf. Before high water, the ship has been loaded and -there is a depth of 30 feet or more of water around the wharf. At high water, the ship sails away on the ebbing tide as the river runs in the other direction. Tides are caused by the gravitational attraction of the moon and sun on the ocean. When both celestial bodies are pulling together the 'spring tide' results, which means a 50-foot variation from high to low. This occurs at new and full moon. A week later, when the sun and moon work in opposition, the difference is only 32 feet between high and low water. The bay of Fundy, having a funnel shape (150 miles wide at mouth from Yarmouth to Portland, while the upper estuary at Hantsport is only one mile wide), builds up a tidal influence from 10 feet at the mouth to an average of 45 feet at Hantsport.

Jan 1, 1948

By T. Melfi, M. James

Attaining required mechanical properties in welds made using the double submerged arc welding (DSAW) process is difficult, and it is becoming more difficult as the strength level of the base materials continues to increase. Producing weld metal with adequate mechanical properties involves factors that are often overlooked and not taken into consideration. Not least amongst these problems is simply finding information to use in selecting the appropriate flux/wire combination. Most of the available data on flux/wire combinations provided by consumables manufacturers is generated using the multiple pass welding procedures required for classification per specifications such as AWS A5.17 and A5.23. This data really gives no insight into the properties that can be expected in a DSAW application. Also, base plate composition plays a very significant role because of the fact that base plate dilution can be as high as 70% in DSAW welds. This means that if any elements are present in the base metal that are deleterious to mechanical properties, they will also be present in significant quantities in the weld deposit. Some of these elements can decrease toughness and increase hardness (increased hardness is a concern if the pipe is intended for sour service). Some of these problems can be mitigated by proper selection of welding consumables. Selection of proper welding consumables means selecting an electrode that provides the appropriate alloying elements to obtain the desired level of impact toughness while also keeping the hardness within any specified limits. In order to attain the necessary impact toughness, selection of a flux with an appropriate composition (in terms of its basicity and its ability to control the nitrogen content of the weld deposit) is required. As with all welding processes, the mechanical properties of DSAW welds are also highly dependent on the welding procedures. This work clarifies how to select appropriate consumables to meet a given set of requirements, and also how to achieve the optimum mechanical properties from those consumables.

Jan 1, 2005

By Lei Pan, Roe-Hoan Yoon

"Sea water flotation is becoming a reality due to shortages of fresh water. To better understand the mechanisms involved in sea water flotation, we have studied the effects of KCl and MgCl2 on the surface forces present in the wetting films of water formed on hydrophobic surfaces. The measurements have been conducted using the force apparatus for deformable surface (FADS), which is capable of measuring both the surface and hydrodynamic forces responsible for bubble-particle interactions. The results obtained with the gold surfaces hydrophobized with butanethiol (C4SH) show that the wetting films of Ultrapure water do not rupture despite the relatively high water contact angle (??= 80o) and the presence of a long-range hydrophobic force with a decay length (D) of 25 nm in the film. The film is metastable with its equilibrium thickness (he) at 140 nm, where the repulsive double-layer force is equal in magnitude to the capillary force as shown in Figure 1. The film loses its metastability and ruptures in a 10-2 M KCl solution, in which the double-layer force decreases substantially due to the decrease in Debye length (?-1) while the decay length of the hydrophobic force remains as large as 23 nm.The effects of MgCl2 has also been studied using a C4SH-coated gold surface with a water contact angle of 87o. It has been found that in a 10-4 M solution double-layer force decreases due to the decrease in the negative ?-potentials and Debye length, which should help destabilize the wetting film. However, the film remains stable due to the decrease in the decay length of the long-range hydrophobic force from 45 nm in Ultrapure water to 14 nm in the MgCl2 solution. Thus, the results obtained in the present investigation support the view that the difficulties in sea water flotation may be due to the presence of MgCl2 rather than the presence of NaCl in sea water (Ramos, et al., 2013)."

Jan 1, 2016

"These guidelines, implemented in 2003, were recommended by the Diamond Exploration Best Practices Committee established by the Canadian Institute of Mining, Metallurgy and Petroleum. The guidelines are applicable to public companies and their consultants reporting diamond exploration results.“The guidelines are referenced in the Companion Policy of NI 43-101 with a statement that disclosure regarding the reporting of diamond exploration sampling results should conform to them.”Reporting GuidelinesThe following guidelines have been recommended by the Diamond Exploration Best Practices Committee established by the Canadian Institute of Mining, Metallurgy and Petroleum. These guidelines are applicable to public companies and their consultants reporting diamond exploration results.In respect of these guidelines, Diamond Exploration Results are results derived from the initial activities undertaken to investigate a diamond bearing prospect or deposit, to generate tonnage, grade and value estimates that cannot be classified as a Mineral Resource or Mineral Reserve. They do not address the earlier stage reporting of geophysical, geochemical or kimberlite indicator mineral results.Public reports of Diamond Exploration Results relating to mineralization not classified as Mineral Resource or Mineral Reserve must address the confidence limits of the result and contain sufficient information to allow a considered and balanced judgement of the significance of the results.The objective of these guidelines is to assist public companies and consultants in making appropriate disclosure of diamond exploration results by reporting in a manner which is:Uniform within the diamond exploration industry; Consistent with reporting from other industry sectors .Comprehensive .Unambiguous .The guidelines are not prescriptive. Materiality is the overriding principle that determines the information that should be disclosed. However, where a company or consultant deviates from the guidelines, the disclosure or technical report should state the extent to which the guidelines have not been followed, and the reasons for the deviation.The guidelines do not in any way replace jurisdictional reporting requirements (For example, the requirement for Canadian reporting issuers to comply with Canadian Securities Administrators National Instrument 43-101 by having technical disclosure endorsed by a Qualified Person as defined in that legislation)."

Jan 1, 2003

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 Richard C. Williams, Herman Pieterse, Ken Thomas, K. S. Fraser, Ron H. Colquhoun

"The Banick Goldstrike Mines Inc. (Goldstrike) operation is located in Eureka County in north-central Nevada on the Carlin geological trend. Gold in the sulphide mill feed, occurs primarily as submicroscopic inclusions or possibly solid solution in a pyrite and marcasite matrix. Sulphide mill feed is pretreated in a pressure oxidation plant allowing gold recoveries of 90 per cent and greater to be achieved. Anticipated 1994 gold production for the sulphide gold facility is approximately 1,500,000 ounces.In January 1989 American Banick Resources Corporation (Banick) announced the US$365 million Betze Development Plan for the Goldstrike property. The Betze plan was based on a three (3) staged expansion of the original 4,500 STPD oxide gold plant. This expansion would involve addition of ore and gold processing capacity and the total conversion of all ore handling facilities to treating Betze sulphide ores.Phase 1 of the Betze Development Plan involved the construction of a pressure oxidation circuit, including a single autoclave and supporting ancillary services. The pressure oxidation circuit was commissioned in February 1990. Currently a throughput of 2,000 STPD is being achieved.Phase II of the Betze Development Plan, commissioned throughout April and May 1992, included the expansion of grinding, leaching, and gold recovery facilities enabling the treatment of combined oxide, and sulphide ore. Pressure oxidation capacity was increased by the addition of two (2) autoclave circuits each treating 2,600 STPD of sulphide ore and other required ancillary services. By June 1992, the Phase II gold facility had achieved a combined throughput of 15,000 STPD of oxide and sulphide ore.Phase Ill, the final stage of the Betze Development Plan, was successfully commissioned in February and March 1993. This final stage of development increased the design throughput of the pressure oxidation plant to 15,000 STPD by the addition of three (3) autoclave circuits with combined capacity of 7,800 STPD."

Jan 1, 1994

"At the May 15, 2006 and the May 1, 2007 Canadian Securities Administrators (CSA) Canadian Institute of Mining, Metallurgy and Petroleum (CIM) meetings in Vancouver and Montreal, CSA requested CIM consider certain issues arising out of the CSA review of Technical Reports and public disclosure, in general, regarding the practice of estimation and reporting of Mineral Resources and Mineral Reserves. The following is a summary of the issues raised by the CSA and the responses of the CIM.Preamble: At the May 15, 2006 and the May 1, 2007 Canadian Securities Administrators (CSA)-Canadian Institute of Mining, Metallurgy and Petroleum (CIM) meetings in Vancouver and Montreal, CSA requested CIM consider certain issues arising out of the CSA review of Technical Reports and public disclosure, in general, regarding the practice of estimation and reporting of Mineral Resources and Mineral Reserves. The following is a summary of the issues raised by the CSA and the responses of the CIM Reserve Definition and the CIM Estimation Best Practices Committees (the Committees). This information is intended to provide the Qualified Person (QP) with further guidance when estimating Mineral Resources and Mineral Reserves and in preparing a technical report written under National Instrument 43-101 (NI 43-101). Several members of the CIM Reserve Definition Committee, the CIM Estimation Best Practices Committee and some members of the Committee for Mineral Resources International Reporting Standards have reviewed these issues and provide the following commentary.Issue 1. - CSA requested CIM review and comment on the selection of an appropriate commodity price to be used in Mineral Resources and Mineral Reserves estimates.Commodity prices are used in the estimation of Mineral Resources and Mineral Reserves and in the economic analysis of a property. In times of rapidly changing commodity prices, or when prices are at the extreme ends of a commodity price cycle, the QP has a difficult job in selecting an appropriate commodity price.• The selection of appropriate technical variables, including commodity price, is clearly the responsibility of the Qualified Person (QP). The QP must describe the reasons for selecting these variables, including price, in the technical report.• The definition of a ""Mineral Resource"" contains the wording ""reasonable prospects for economic extraction,"" therefore, a QP must select economic parameters, including commodity price, that will result in an estimate of Mineral Resources and Mineral Reserves that have ""reasonable prospects for economic extraction""."

Jan 1, 2003

By M. Carvalho

The primary motivation underlying the proposal of polygeneration systems for mine sites is to increase the efficient use of natural resources by combining different technologies and energy resources while satisfying energy service demands. For many mineral producers, particularly in Canada?s mining extremes of climate and depth, energy in support of mineral production can be the second largest cost centre after labour. A generic methodology is proposed for the design of energy supply systems in mine sites, based on a search for the minimum discounted cost of energy supplied for all feasible different plant configurations. These configurations can be represented within a connectivity matrix which corresponds to a network representation. A Mixed Integer Programming formulation is set out for the multiperiod synthesis and operational planning problem. This is characterized by i) binary variables for the selection of technologies, ii) integer variables for the determination of the number of units installed, and iii) by continuous variables for the representation of energy and economic flows. Through the integration of particular energy supply strategies matching specific mine circumstances (on-grid, remote, degree days, etc) and consideration of technologies that improve energy efficiency, hitherto not considered new technologies and demand management systems or new perspectives on optimal mine site energy supply can be investigated. Some of these investigations identify the economic conditions through which biomass energy feedstocks should be used, for direct heat production, for gasification and providing for Fischer-Tropsch syndiesel manufacture. As well as integrating demand from mobile diesel-fuelled plant into an optimization procedure that hitherto has only been considered for static energy production and consumption plant, this analysis shows how the techniques can be used to explore economic conditions of threshold prices for biomass (purpose-grown biomass and peat are considered herein) and trucked-in diesel. The methodology also allows for electricity and syngas storage and diesel and biomass bunkering. Within the paper the energy demands for a remote, open pit mining operation located in Northern Ontario are considered as a case study to illustrate the technique and investigations. As expected, for mines close to electricity, natural gas, and diesel distribution infrastructures, the optimal choice is to connect. When a constraint is applied specifying that connection is not possible, as would be for the case exemplified, the optimal choice includes some of the more exotic options for mine site energy supply.

Aug 1, 2013

By K. Soucek, J. Ptácek, A. Hastíková, R. Kukutsch, P. Konícek, P. Waclawik

"Cable bolts are used frequently as a secondary support system (with steel arch support) in difficult stress-strain conditions of deep coal mines. The load transfer mechanism of cable bolts depends on several factors, such as the strength, deformation and geometric properties of the bolts, resin and the surrounding rock mass so-called cable-resin-rock system (CRR system). The bonding length and bolt/borehole diameter ratio strongly influence the final bearing capacity of the CRR system.The study presents the behaviour of CRR system during a pull-out test which is usually used in the carboniferous rock mass in the Czech part of the Upper Silesian Coal Basin. A series of 28 pull out tests were performed on 3-m-long cable bolts, with various combinations of borehole diameters and bonding lengths, to understand this behaviour. Boreholes were drilled into a solid rock mass consisting of fine-grained sandstone to guarantee similar conditions during the pull-out tests. Video inspection and measurement of borehole diameters were performed to determine their quality and real diameters. Three characteristics were observed from pull-out test results: ultimate pull-out load; displacement of the end of bolt and system stiffness. Numerical modelling by FEM (Finite Element Method) was used to determine the stiffness of the CRR system for variable bolt/borehole ratios and bonding lengths each under constant load. A linear elasto-plastic model and a mohr-coulomb model were used for cable and resin-rock respectively. The results of the experiment may contribute significantly to improving of the methodology of cable bolts installation as well as the design of used cable bolts."

Jan 1, 2015

By D. W. McDonald

Coal mining and railway transportation are so closely en-twined and so dependent one upon the other that the failure of one would mean the total collapse of the other. With this indisputable fact in mind, there is no doubt that the operator of each is deeply interested in the other's success. Railway transportation began at the mouth of a coal mine. The first railway car was the English coal-wagon, a crude box on four wooden trowlets, running on wooden rails and holding 1,600 pounds. This was operated by gravity or horse-power in England to convey coal from the mines to the rivers. The first coal-cars used on Nova Scotia railways were of 4 tons capacity with side doors and "V" shaped centres. Then followed flat-bottom, 4-ton cars that operated on tipples, the car bei.ng held in tipple by a chain passing over the top and fastened on either side. Next came the 6-ton car with drop-bottoms, then the 10, 15, 30-ton cars, and now the modern 50 and 100-ton steel cars, equipped with automatic couplers, brakes, and rachet dumping device. Contrast the first coal-car with a modern luxurious pull-man or a I 00-ton coal and ore car, and you have a record of progress in railway transportation. The development of the steam locomotive was no doubt the greatest factor in this progress, but let us not forget that the foundation of all industrial development was and is coal. and that development in mining and railway transportation should keep abreast.

Jan 1, 1924

By William M. Luff

"The Bathurst area has recorded mining production as early as 1837, although the bulk of the production has come in recent years. Production has been mainly from the well-known massive sulphide deposits, but vein, gossan, and a variety of other deposits have also been mined. This paper summarizes the history of the mined deposits, along with tonnages and grades produced. A number of ""firsts"" have been noted in the Bathurst area. The A Zone deposit, located in the Heath Steele area, was the first in the world discovered using airborne electromagnetic methods. Heap leaching of gold from the gossan zone at Caribou was the first operation of its kind in Canada. The Keymet mine was the first base metal (lead-zinc) mine in New Brunswick. For the past few years, the Brunswick No. 12 mine has been one of the largest zinc mines in the world.IntroductionThe Bathurst area (Fig. 1) first had mining production in 1837 when copper was mined from a deposit on the Nepisiquit river (MacKenzie, 1958). The majority of the production, however, has been in recent years from massive sulphide deposits, but there are also other significant operations. . Table 1 is a summary of Bathurst area mineral production, showing concentrator feed tonnages and mill feed grades. The table does not include peat deposits, sand and gravel, dimension stone or rock quarries. Figure I is a general geology map of the Bathurst area, indicating deposit locations. The deposits are divided into four categories: massive sulphide, vein, gossan and other. The deposits in each category are described in chronological order of exploitation."

Jan 1, 1995

The following guidelines have been recommended by the Diamond Exploration Best Practices Committee established by the Canadian Institute of Mining, Metallurgy and Petroleum. These guidelines are applicable to public companies and their consultants reporting diamond exploration results. In respect of these guidelines, Diamond Exploration Results are results derived from the initial activities undertaken to investigate a diamond bearing prospect or deposit, to generate tonnage, grade and value estimates that cannot be classified as a Mineral Resource or Mineral Reserve. They do not address the earlier stage reporting of geophysical, geochemical or kimberlite indicator mineral results. Public reports of Diamond Exploration Results relating to mineralization not classified as Mineral Resource or Mineral Reserve must address the confidence limits of the result and contain sufficient information to allow a considered and balanced judgement of the significance of the results. The objective of these guidelines is to assist public companies and consultants in making appropriate disclosure of diamond exploration results by reporting in a manner which is: ??Uniform within the diamond exploration industry; ??Consistent with reporting from other industry sectors; ??Comprehensive; ??Unambiguous. The guidelines are not prescriptive. Materiality is the overriding principle that determines the information that should be disclosed. However, where a company or consultant deviates from the guidelines, the disclosure or technical report should state the extent to which the guidelines have not been followed, and the reasons for the deviation. The guidelines do not in any way replace jurisdictional reporting requirements (For example, the requirement for Canadian reporting issuers to comply with Canadian Securities Administrators National Instrument 43-101 by having technical disclosure endorsed by a Qualified Person as defined in that legislation).

May 1, 2003

By M. Knot

Fans delivered to the Russian Federation, and eventually to countries of the former U.S.S.R., for mine ventilation must meet the legislative requirements of local jurisdictions. This paper presents a discussion of these legislative requirements and presents examples of fan equipment designed to meet the requirements. The legislative obligations discussed include four (4) separate requirements, including: ?Technical design requirements ? The Federal Agency for Technical Regulation and Metrology is responsible to issue a GOST R certification declaring conformance to the requirements ?Operational requirements ? A ?License for Application? must be obtained prior to operation ?Explosion risk requirements ? If the area of operation includes potential for explosion a special certificate must be obtained ?Technical condition requirements ? Market segments within the mining industry require special conditions that must be satisfied Examples of fans designed specifically for use in the Russian Federation are also discussed and examples provided. Designs for fan volume flow control will be highlighted.

Aug 1, 2013

By Robert B. Parsons

"The February 18, 1987, Federal Budget contains a proposed amendment which would simplify somewhat the ""successor corporation"" rules in the Income Tax Act. Despite this amendment, though, the important successor rules will continue to be relatively complex.IntroductionThe February 18, 1987, Federal Budget papers propose an income tax amendment whereby the so-called ""successor corporation"" rules would be revised by removing the present provision which limits the application of these rules to a maximum of two ""successions"". The successor corporation rules represent one of the most complicated sets of rules in the Income Tax Act. This month, Tax Notes seeks to explain these rules and the proposed amendment in simplified terms.Basically, the successor rules provide a mechanism for transferring unused exploration and development expenses from one taxpayer to another , in specified circumstances. The aforementioned limitation of two successions refers to the rule which allows a maximum of two such transfers with respect to any particular pool of deductions."

Jan 1, 1987

By Dina Aloi

The need to be seen as responsible neighbours and good corporate citizens is a critical success criteria for mining companies. To be seen as responsible requires both achieving responsible performance, and making that good performance visible to the community, legislators, investors, and other stakeholders. This has broadened the skills required for the successful operation of a mining company to include social sciences, public affairs, communications, and environmental sciences. Mining companies still look to technical specialists to achieve the core of that good performance - broadly characterized as a sustainable operation. However, the degree of understanding that those specialists have of the requirements for sustainability and overall Corporate Social Responsibility has a tremendous impact on the overall performance of the project and company. In her keynote address to the Sustainability for Profit session, Dina will outline some of the key areas in which technical employees and consultants can contribute to achieving successful sustainable mining operations.

Jan 1, 2010

By A. Tohn, K. Adham, R. Lu, D. Lemieux

"To remove sulphur, carbon and arsenic from the gold concentrates of Dundee Sustainable Technologies (DST), Hatch has designed a demonstration plant roaster using the fluid bed technology. The fluid bed was selected for its ability to maintain stable temperatures and uniform reaction conditions. Data points from a small pilot plant (operated by DST) were used for setting the parameters of the demo plant roaster.The DST demonstration plant is being built to further prove their patented gold extraction process at an industrial scale. Their gold extraction process is based on halogenation at atmospheric pressure and relatively low temperatures. Before the halogen leaching, most of the sulphur, carbon and arsenic should be roasted out of the feed concentrate.The Hatch fluid bed roaster design includes a moist feed introduction system, simple bed cooling for temperature control, and cyclone fines recirculation. The demonstration plant roaster is planned for construction in 2014, and the performance results will be presented in a future paper."

Jan 1, 2014

The primary arsenic minerals in the uranium ore processed at the McClean Lake Operation are rammelsbergite, niccolite and gersdorffite. During processing, a large fraction (80 - 95%) of these reduced minerals is oxidized and dissolves primarily as As5+ in the leachate solution. In the tailings preparation circuit the dissolved As5+ is precipitated as a poorly crystalline form of the mineral scorodite. Following subaqueous deposition in the tailings management facility, a temporal rise and fall in arsenic pore water concentrations has been observed. This is due to the oxidation of the residual quantities of reduced arsenic minerals initially present in the tailings sediment. The XANES (x-ray absorption near edge spectrometry) technique has shown that the As1- is gradually oxidized to As3+ and then finally As5+ in the tailings sediment. This oxidation process results in a temporary accumulation of As3+ in solution and is the source of the rise and fall in arsenic concentration observed.

Aug 1, 2010

By A. Siegmund, F. Mucciardi, Z. Yuan, B. Bulnes

With conventional heat pipe science as the starting point, a new heat transfer technology --- termed Thermopump technology, has been developed at McGill University and is now being tested at a number of industrial operations. This technology is of particular importance for transferring energy in high temperature / high heat flux environments where solutions based on current techniques are not available. One important application for this technology is in the metals recycling area wherein this technology has been used to make a waterless, non-consumable, high efficiency Thermopump oxygen lance. The viability and efficiency of this oxygen lance have been demonstrated by preliminary plant trials in a reverb furnace for the recycling of lead-acid batteries at the RSR Corporation. Full-scale commercial trials of the Thermopump (TP) oxygen lance have been carried out at the RSR Corporation. The results from these tests will be presented. In addition, some applications of the Thermopump technology for other metal recycling processes will also be discussed in this paper.

Jan 1, 2004