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By Robin E. Goad

?Located 160 Km northwest of Yellowknife, NWT, Canada Current winter road access ?New all-weather road planned ?Power within 22 km ?Hwy to Edmonton 80 km south Close to existing infrastructure

May 1, 2006

By K. Sinding, R. Poulin

"Recent land-use decisions in British Colwnbia, and the publication of a report on compensation for expropriations of resource interests, have highlighted the nature of land use policies. Landuse decisions, such as the creation of large new parks, raise three principal issues which have implications for how land-use policy is conducted and how it impacts on the mining industry. The first is the identity of the parties advocating different land-use policies and their motives for doing so, the second is the changing nature of benefits derived from land, and the third is the change of property-rights regime which is devised to accommodate the (changing) benefits from using land and natural resources, as well as the interests of the different parties involved.Involved Parties and BenefitsThe process of establishing or modifying property rights depends on the interest groups involved. Three distinct categories, each with distinct incentives which can influence the process, must be distinguished: private claimants, politicians and bureaucrats (Libecap, 1989).The first groups claim rents and management powers through asset ownership. They may be incumbent owners seeking enforcement of the status quo, new claimants seeking redistribution of assets, or third parties who depend on the distribution of assets (e.g. lenders, labour suppliers and contractors). Some infonnal property arrangements can be negotiated within the group whereas others requires action in the political arena through lobbying politicians for (re)allocation of property rights and influencing bureaucrats for favourable administrative decisions. The second category is politicians, who direct the powers of the state to change or enforce property rights. Both incwnbents and office-seekers fall in this category and their actions and opinions are shaped by their constituencies and financial backers. However, not all causes can be championed and trade-offs have to be made, resulting in decisions that maximize political benefits. The third category of parties in the process is the bureaucrats. The power to manage has been delegated by politicians but bureaucrats also have opportunities and incentives to further their own interests. These can include maintaining or expanding jurisdictional turf or increasing operating budgets (Libecap, 1989)"

Jan 1, 1994

By Qing-hua Tian, Xue-yi Guo, Fei Li

A novel process for the preparation of a-Al2O3 from secondary aluminum dross was studied. Factors including alkali dross ratio, salt dross ratio, smelting temperature, smelting time, leaching temperature, leaching time, and the solid-liquid ratio, which possibly influence the transfer of Al into water were studied, and the feasibility of using seed precipitation as a treatment technology of the leachate was discussed. The optimum condition of the process was determined as: alkali dross ratio 1.3, salt dross ratio 0.7, smelting temperature 500°C, smelting time 60min, leaching temperature 60°C, leaching time 30min, solid-liquid ratio 1:4. The results show that using the seed precipitation method, the leaching of aluminum reaches 92.71%, demonstrating the technique as a feasible and effective treatment technology of the leachate.

Jan 1, 2011

By Mitchell Gordon

"In almost all thickener applications the highest possible solid/liquid separation efficiency is what is desired by the user. There is a trend in the industry due to monetary restraints and environmental pressures to look at ways to extract this maximum performance by either retrofitting existing thickeners or installing the most cost effective new thickener. This paper looks at some of the common problem areas and presents a range of solutions developed by Outokumpu Mintec in North America and outokumpu's subsidiary Supaflo Technologies Pty. Ltd.The Emerging PictureAfter many hours of discussions with a large number of plant personnel over the last two years a picture began to emerge regarding current thickening operations in the industry. Initially, it seemed that everybody had their own unique process problems and therefore needed a correspondingly unique solution. Looking more closely at all the cases and the ideas that we had either implemented or suggested, it gradually became apparent that the majority of operators all had one and the same process need ....""Better Separation Efficiency""The range of operational problems that were uncovered in the survey were much more varied than expected and often were not even considered initially to be thickener problems. Often, it was only after the rejection of many solutions to the problem, generally due to capital cost, that the actual cause of the problem was looked at and found to be a thick-ener.A summary of the problems that have so far been identified is presented in Table 1. They are subdivided under three major categories of environmental, process and paste fill to highlight the wide range of mining activities that can be affected by poor thickener performance. These seem to be the major areas where the need for better separation efficiency is rooted."

Jan 1, 1995

By Donald Leroux, Robert Grant

"Flotation is a complex and highly multivariate process. Using the conventional OFf (one-factor-at-a-time) technique, the optimization of flotation circuits through laboratory or plant testwork is difficult, time-consuming and therefore, expensive and often results in marginal improvements. The optimal operating conditions can be more efficiently estimated when a systematic approach like SDE (Statistical Design of Experiments) is taken.The concentrator of Noranda's Brunswick Mining Division (near Bathurst, New-Brunswick) is well known for the complexity of its differential copper-lead-zinc flotation circuits. One of them, the chalcopyrite-galena separation (or CuSep) circuit, is impacted by more than 20 variables.Statistical Design of Experiments (SDE) techniques were applied at the laboratory scale to improve the performance of Brunswick's CuSep circuit. Screening tests were conducted using Fractional Factorial designs while optimization tests were carried out based on Response Surface Modelling techniques like the Central Composite design. Every series of tests, without exception, revealed new information and process insights which led to significant circuit performance improvements in the plant So far, the metallurgical gain may be as high as four percentage points of copper recovery (in the CuSep circuit). Potential cost savings of expensive consumables (steam, activated carbon) have also been identified but will require additional circuit modifications before being realized.IntroductionIn spite of its apparent simplicity, flotation is a complex three-phase (solid, liquid and gas) separation process. Fundamentally, it is a highly multivariate process. Industrial flotation circuits are commonly affected by 10 or more process variables."

Jan 1, 1997

By Yuhua Wang, Wei Sun, Dongfang Lu, Yuehua Hu, Tao Jiang

"With the continuous depletion of high-grade tungsten ores, the low-grade refractory wolframite has become an important source for the tungsten industry. However, the large-scale utilization of low-grade refractory wolframite is disappointedly scarce, it is due to leanness of valuable minerals, complex mineral characterization and use of toxic collectors.The aim of this study was to develop an environment-friendly processing flowsheet, which was used for beneficiation of low-grade tungsten ore containing 0.45% WO3 from New Brunswick in Canada, and the content of arsenic is 0.68% in this materials. The objective of beneficiation studied was to obtain a concentration containing 60% WO3 with less than 0.5% of arsenic under the condition without any flotation reagents. In this environment-friendly processing flowsheet, magnetic separation technology, classification and gravity separation technology were combined and employed. Firstly, magnetic separation was employed for the first pre-concentration process, over 95% of the feed was rejected as the final tailings, meanwhile, over 85% of arsenic minerals were removed with tailings. Secondly, gravity separation tests were employed on the classified magnetic pre-concentrate in the second pre-concentration process, a second pre-concentrate with WO3 grade of 54.32% and As grade of 5.41% was obtained. Finally, two stage magnetic cleaning were conducted on the second pre-concentrate for upgrading the second pre-concentrate, the mostly arsenic and gangues were removed from the second pre-concentrate. Finally, this novel processing achieved an effective recovery of fine wolframite from low grade tungsten ore with high arsenic. A concentrate with WO3 grade of 64.81% were obtained in new opened processing flowsheet, and As grade was less than of 0.5% in this concentrate. Furthermore, remarkable feature of this processing flowsheet is environment-friendly due to avoid using the toxic flotation reagents during the whole mineral processing.INTRODUCTIONTungsten is an essential metal and is the most widely used in industrial production such as national defense, electro-mechanical products, textile and leather sectors (Srivastava et al., 2000). Wolframite and scheelite are the main mineral sources of tungsten metal. With the continuous depletion of high-grade tungsten ores and the increasing demand for tungsten alloy, the low-grade refractory wolframite has become an important source for the tungsten industry. However, the large-scale utilization of low-grade refractory wolframite is disappointedly scarce, it is due to leanness of valuable minerals, complex mineral characterization and heavy use of toxic collectors."

Jan 1, 2016

By J. Xie

In underground coal mining, the potential for an outburst of coal and gas is considered to be one of the major hazards. As such, considerable emphasis is given to understanding and preventing such events. A number of indices are used in the prediction of the outburst in a coal mine. The main indices include initial gas desorption rate, gas pressure, gas content, coal strength, gas flowrate from a borehole drilled in a coal seam, and combinations of the above. Some of these indices are considered to be inadequate, inappropriate or impractical for some coal seam conditions, such as those with soft and friable coal. The Huainan Mining Group (Huainan) in China and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia have been jointly developing gas content based technologies to predict the risk of the outbursts. One of the major progressive achievements is a new method for determination of outburst gas content threshold values. The method utilizes empirical analyses, numerical modeling, and seam-specific knowledge . This paper describes the method and its application for the #11 Seam at Guqiao mine, Huainan.

Aug 1, 2013

By Silvio E. Kruger

Real time measurement of wear and corrosion provides crucial information needed to determine an optimal schedule for corrective maintenance and is a powerful tool to maximise equipment availability and reliability. It also leads to savings from optimized spare parts handling and helps to avoid costs of accidents and their negative impact on safety and the environment. This paper presents the technology of ?painted-on? ultrasonic transducers that can be integrated to structures and accurately measure the remaining thickness and therefore determine wear or corrosion losses. These transducers have a small footprint, a performance comparable to other commercially available ultrasonic transducers and can sustain temperatures as high as 400ºC. The application of this technology to mining equipments and its potential benefits are discussed.

Aug 1, 2013

By H. A. Kishawy, S. Kannan, M. Balazinski

Metal Matrix Composites (MMCs) are new generation engineering materials that possess superior physical and mechanical properties compared to nonreinforced alloys. However, the presence of abrasive ceramic reinforcements in the ductile matrix causes severe tool wear and premature tool failure. Flank wear was found to be the dominant wear mode while the main wear mechanism was abrasion. Analysis of the cutting tools using scanning electron microscopy has shown that both two body and three body abrasion are operational during machining MMCs. A methodology for predicting the tool flank wear progression during bar turning ofMMCs was presented in an earlier paper [1]. In the proposed model, the wear volume due to two body and three body abrasion mechanisms was formulated. Then, the flank wear rate was quantified by considering the tool geometry in 3D turning. The main objective of this paper is to investigate the contribution of two body and three body abrasion towards the tool wear volume during cutting MMCs.

Jan 1, 2006

By C. -S. Xie, J. -H. Kong

The microstructure and mechanical properties of X80 hot-rolled thick steel strips with a thickness of 17.5mm produced in Wuhan Iron & Steel Company (WISCO) are introduced in the paper. The steel strips as fabricated through proper thermomechanical processing (TMP)/ on-line accelerated cooling (OLAC) processing have shown high strength and toughness, low brittle transition temperature, good weldability, and high Shear Area (SA) percentage in Drop Weight Tear Test (DWTT). The microstructure of the steel strips is characterized with mainly acicular ferrite, and fine dispersed Martensitc-Austenite (M-A) phases. It is determined that the mechanical properties are improved due to the presence of the fine M-A phases and precipitates, which could be formed by reducing the finish rolling and coiling temperatures.

Jan 1, 2005

By Nural Kuyucak, Bohumil Volesky

"Extensive screening revealed a seaweed (alga) biomass type which in its non-living state possesses a very high cobalt sequestering capacity comparable to that of activated carbon and the ion-exchange resin currently used in the cobalt production process. Performance of the new bio-sorbent material was studied by examining its equilibrium metal uptake isotherms generated under different solution conditions such as initial cobalt concentration pH, temperature, and the presence of selected cations and anions. The rate of cobalt uptake was determined, which is a crucial parameter for recovery process design. Almost all cobalt sorbed can also be desorbed with a solution of CaCI2. The bio-sorbent material can be used repeatedly in the sorption-desorption cobalt concentration process. IntroductionIt has been well documented that certain types of microbial biomass, living or non-living, possess a high potential to sequester and accumulate inorganic ions present in aqueous solutions. Metal concentration by microbial biomass from a solution is termed bio-sorption. This phenomenon is quite complex and includes adsorption of metals onto the surface of a microorganism and/or into the cellular structure in combination with ion-exchange, complexation, and/or micro-precipitation. Bio-sorption is generally considered to be a rapid physical/chemical process. The cell wall structure is porous and allows metal ions, as well as large organic nutrient molecules, to pass freely through. Polysaccharides of the cell wall could provide binding amino, carboxyl, phosphate and sulphate groups. In addition to these functional binding groups, polysaccharides often have ion-exchange properties. Sometimes, bivalent cations, such as Ca2+ or Mg2+, help the formation of ionic bond bridges between the negatively charged cell surfaces and positively charged cations in the solution, Proteins in the cell wall could offer functional groups and also offer peptide bonds to bind ions. Interactions between metal and the cell wall components are responsible for the sequestering of metals by way of bio-sorption. Many metals feature a complex solution chemistry and it is not always possible to determine what ionic species are actually present in the solution. The equilibria involved are dependent on pH, concentration, the anions present and other factors. The transport system for the ions are sometimes dependent on both temperature and energy. Biosorbent material could also be regenerated for multiple reuse."

Jan 1, 1988

By Suzie Poulin, N. Geoffroy, G. P. Demopoulos

Most metallurgical industries generate toxic waste that must be treated prior to being released to the environment. However, in a lot of cases, the waste materials are poorly characterized or the analytical results are not well interpreted. These shortcomings often result in the development of inefficient industrial procedures, thus causing economic waste and difficulty meeting environmental regulations. Fortunately, a wide range of analytical techniques are available to guide researchers and engineers into making sound process development decisions. In this work, an industrial selenium and mercury removal process is used as an example to illustrate the application of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (PXRD) on solid waste. Furthermore, samples of analytical results are presented and interpreted and the modifications to the industrial process that resulted are explained. Finally, a brief description of the advantages and limitations of the aforementioned analytical techniques is given with an emphasis on industrial solid waste material.

Jan 1, 2011

By W. Blum

Progress made in improving the creep resistance of Mg alloys is reviewed with the emphasis on microstructural interpretation. Experimental results on the increase of creep strain with time at constant stress a measured for limited times and strains are displayed in a transparent form as creep rate-strain diagrams from which the minimum creep rate stress is safely derived. In addition, data on the thermal stress component a derived from high-precision a-reduction tests are reported. Within a simple statistical dislocation model these data allow one to quantify the relation between dislocation velocity v and a . In combination with structure evolution laws this relation serves as a basis for modeling the creep rate. New alloys have distinctly higher creep resistance than AZ91 where precipitation hardening plays a minor role. This is due to hardening by intermetallic phases which may form a continuous skeleton along the grain boundaries (e.g. Ca-alloyed AZ91) and/or submicron-sized precipitates within the grains (MRI230D, Mg-Zn-Ca alloys).

Jan 1, 2006

By K. Nikkhah, N. Dhadli, G. Freeman

Ammoniacal pressure leaching operations have been in commercial use at the Fort Saskatchewan refinery of Sherritt International Corporation since 1954. Recent improvements have significantly increased the capacity of this circuit. The computer modeling of this process has proved to be a valuable tool in facilitating the evaluation of different operating scenarios in an effective manner. Reagent response in the ammonia leach of nickel and cobalt sulphides is examined using the dynamic process simulation capabilities of IDEAS(TM) software. The dynamic simulation enables accurate measurement of the sensitivity of the process to variables such as temperature, feed rate and ammonia concentration as well as compartmental analysis of metals concentration, pulp density, vent gas composition, and the formation of specific complexes. The complexity of the ammonia leach process makes it a logical choice for evaluation by computational analysis. The methodology for dynamic modeling of a pressure leach process is presented.

Jan 1, 2005

By Derek Harvey

"The paper briefly describes the development of the Eickhoff ESA60 roadcutter which is based on the old and well used principles of the shearer loader. It is intended to show that the machine offers a viable alternative to the normal methods used for driving roadways and also for coal production . References are made to installations currently operating in Europe with applications ranging from roadway drivage to pillar recovery. The paper also looks at possible applications in Canada.IntroductionThis paper is an attempt to show how the principles used in mechanical cutting, conveying and roof support are being applied to a development system capable of catering to a variety of situations and conditions. It is also intended to illustrate how the same system can be used as a total mining system for the mining of many minerals.In order to give some sort of time perspective to the age of the principles, reference can be made to an article in Coal Mining & Processing which states:- During World War II the Germans developed the "" panzer"" or armoured face conveyor.- After the war the English developed power cutters or trepanners that were mounted on the face conveyor, this then developed into the shearer.- The first shearer was produced by the Anderson Company in England in 1950 and shortly after that the Eickhoff Company started manufacturing shearers in German y.- The first hydraulic roof support was produced in 1954 by Gullick.This is a potted history of the three major components of the new system, i.e.:- Mechanical cutting element based on the shearer.- Transport element based on the panzer.- Optional roof support based on the hydraulic face supports.It can therefore be said that since the "" youngest"" of the elements was produced in 1954 the principles of the system in respect of the rapid change in mining equipment are in fact old.Of the three major components the most important is the cutting element since the major benefits of the system are to be obtained from this."

Jan 1, 1985

By Yusuke Yamamoto, Mineo Asano

"The present study investigated the texture transition during secondary recrystallization in the AA5182 sheet. During the initial stage of annealing, the texture showed a weak Cube orientation as the primary recrystallization texture. During the secondary recrystallization with abnormal grain growth, the area ratio of the {hkl} <011> orientations increased by consuming the other orientations. The texture transition was calculated by the 2-D Monte Carlo simulation with the misorientation dependency. When the higher grain boundary mobility was set in the specific range of the high angle misorientation, the orientation preferential growth of the RW {100} <011> orientation was reproduced. However, other {hkl} <110> orientations could not be well reproduced by the misorientation dependency.INTRODUCTION Crystal orientation and texture are important factors for aluminum sheet products from the standpoint of mechanical property, formability and isotropy. The recrystallization texture results from the orientation preferential growth from the rolling deformation microstructure and the texture (Alvi, Cheong, Suni, Weiland, & Rollett, 2008). Texture development has been a topic of intense research for decades with advances in analysis methods, e.g., orientation mapping (OIM) and computer simulations (Fjeldberg & Marthinsen, 2010; Ivasishin, Shevchenko, Vasiliev, & Semiatin, 2006). The grain boundary characteristic is considered to be a key for the orientation preferential growth. In the case of the recrystallization from the deformed microstructure, not only the grain boundary characteristic, but also the dislocation density and the subgrain size affect the nucleation and the grain growth (Engler, Löchte, & Hirsch, 2007). On the other hand, in the case of secondary recrystallization, the dislocation density and the subgrain size can be ignored and the effect of the grain boundary characteristic can play a significant role in the grain growth. There is intense research about the texture development during secondary recrystallization in aluminum alloys and it was reported that coarse {hkl} <011> grains were formed during the secondary recrystallization (Suk, Shin, & Huh, 2006; Rios, & Gottstein, 2001). However, the mechanism of forming the {hkl} <011> grains has not been fully clarified. In the present study, the effect of the grain boundary characteristic on the orientation preferential growth was investigated by EBSD analysis and Monte-Carlo (MC) simulation."

Jan 1, 2018

By Jaana Romppanen, Satu Jyrkönen, Tiina Ranki, Peter Björklund, Markku Lahtinen, Kaj Eklund, Päivi Suikkanen

Outotec is continuously developing our existing process equipment and new equipment solutions to enhance the Flash Smelting process. Thanks to the long operating history of the Outotec Flash Smelting process feedback from the numerous operating references are available and is utilized. The general goals for development work are to improve equipment performance, thus realizing savings in Smelter plant operation costs by increasing the process efficiency and online availability. Digitalization also opens new possibilities for the feeding equipment and furnace operation monitoring. These solutions will improve the safety and performance of the smelter, and provide process and equipment related information which has not been available earlier. INTRODUCTION The year 2019 marks the 70th anniversary of Flash Smelting. The technology was operated on industrial scale for the first time at the Outokumpu Harjavalta copper smelter in Finland in 1949. The Flash Smelting technology, is now owned and developed by Outotec Oyj and the first plant, is now owned by Boliden Harjavalta Oy. The two companies have been evolving throughout history by optimizing the process for various feeds and raw-materials, as well as through developing the equipment and operating practices. Even though sustainability was not a hot theme/topic during the first days of Flash Smelting, it has nevertheless been the key principle in guiding the development. This is well proven by the wide adoption of Flash Smelting for the processing of copper and nickel concentrates, mostly due to its ability to fulfil the economic and resource efficiency criteria demanded by its operators. Along with the process technology development, also development of the equipment has taken place over time. Outotec is continuously working on developing our equipment to better suit the changing need of our customers in the continuously changing operational environment. Orebodies are getting more challenging with lower ore grades and more impurities. Achieving high recoveries for all valuable elements becomes more difficult with high slag quantities and with the need to tackle the high impurity concentrations. There is a need for higher capacities in greenfield and brownfield smelters. The role of the Loss-in-Weight Feeder, the Air Slide and Concentrate Burner is to ensure even feed into the reaction shaft of the Flash Smelting Furnace, and to enable controlling the process well, thereby enabling the best performance for the customers smelter. The design of the Flash Smelting Furnace aims for high availability, long campaign and safe operation.

Jan 1, 2019

By M. Fujikawa

The Kamioka Zinc Smelter was converted from the jarosite process to the goethite process in the year 2000. The reasons for the conversion of the process were that the silica content of the raw material increased and the iron content decreased. The silica easily turns to a gel in sulfuric acid solutions and this causes the solid-liquid separation characteristics to deteriorate. The basic behavior of silica in sulfuric acid solution was investigated and it was found that the goethite process is the most suitable to effectively separate and remove silica from solution. Furthermore, Fe has the capability to remove elements such as Ge that have an adverse effect on zinc electrolysis. This means that, when the Fe content of the raw material decreased, the impurity removal capability also decreased and there was a risk of a build-up of impurities in the process. Iron precipitates in many forms in sulfuric acid solutions. The capability to remove elements such as Ge differs depending on the compound precipitated. Goethite has a higher capability than jarosite to remove elements such as Ge. In this report, the results of applying the process established by investigations of the basic behavior of Fe, silica and Ge in the zinc refining plant are presented.

Jan 1, 2006

By David G. Dixon, Ahmad Ghahremaninezhad, Edouard Asselin

"Atmospheric leaching of chalcopyrite in sulfuric acid solutions is a slow process due to the mineral’s passivation. We have investigated the nature of the passive film in this work. Electrochemical reduction and oxidation of chalcopyrite over the potential range of -0.5 to 1.2 VSHE were investigated in 0.5 M sulfuric acid solution (pH 0.3) at 25 ºC by multicyclic voltammetry and open circuit potential measurement. The influence of scan limits on the evolution of current peaks was studied with both stationary and rotating electrodes. It was observed that the anodic oxidation of chalcopyrite begins at potentials above 0.6 VSHE, most likely by preferential dissolution of iron atoms over copper atoms. The selective electro-dissolution process results in formation of a metal-deficient sulfide passive film (i.e. Cu1- xFe1-yS2, y > x). The passive film dissolves at 0.9 VSHE. Elemental sulfur is one of the products of chalcopyrite dissolution above 1.0 VSHE. Cathodic reactions within the potential region of 0.1 to 0.6 VSHE and anodic reactions at potentials lower that 0.5 VSHE are associated with at least one soluble species from solution. The soluble species involved in the cathodic reactions are likely ferric and cupric, while the soluble species involved in the anodic reactions is likely H2Saq."

Jan 1, 2014

By Th. Hassel

The application of magnesium as an absorbable biomaterial demanded the consideration of the alloy composition, the mechanical properties and the corrosion a special adapted material development in terms of the human biological system. Magnesium for technical applications mostly comprised alloying elements up to 10 wt%. Thereby often metals (e.g. rare earth and aluminum) with high toxic potentials are used to optimize the mechanical properties. To minimize toxic reactions during the degradation of a absorbable magnesium alloy, the Mg-Ca system is being selected and investigated because both elements belong to the mineral nutrients. Rods and small tubes are produced by extrusion of gravity die casting billets (Ca-content 0.4 to 4.0wt%). The positive grain fining influence of calcium and its improvement of the corrosion behavior are additional advantages. The microstructure, the mechanical properties and the corrosion attitude are investigated. The results show that an optimal composition of micro alloyed Mg-Ca and ideally processing parameters lead to 16% strain and a tensile strength up to 185MPa. Electrochemical investigations and measurements of the hydrogen production demonstrate the influence of the Ca-content to the corrosion behavior of the investigated alloys.

Jan 1, 2006