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By H. Chaouki

The aim of this work is to simulate the forming process of a green anode. For this purpose, a nonlinear compressible viscoelastic constitutive law is presented. The concept of natural reference configuration is considered. Within an isothermal thermodynamic framework, a Helmholtz free energy is proposed to take into account the nonlinear compressible deformation process occurring between natural reference configuration and current configuration. A dissipation potential is introduced in order to characterize the irreversible aspect of compaction process. Thus, the constitutive law is formulated through two equations: 1) an expression of Cauchy stress tensor and 2) a differential equation characterizing the evolution of the natural reference configuration. Material parameters are assumed to be a function of the bulk density. This allows capturing the micro-mechanical phenomena within the chosen macroscopic approach. An experimental study based on compaction tests is carried out in order to characterize the mechanical behaviour of the anode paste. A user's material VUMAT subroutine for finite element dynamic explicit analysis has been developed and implemented in the ABAQUS commercial software. To evaluate the model predictive capability, numerical simulations of the compaction forming process of anode paste were performed. Simulation results show that the constitutive law predicts the experimental trends and gives interesting physical responses. This constitutes a first step toward making a benchmark with experimental results on the forming process of anode paste.

Jan 1, 2011

By Y. W. Pan, Y. R. Liu

The disturbed natural rock mass tends to equilibrium state accompanying with non-equilibrium evolution process which has significant influence on the long-term stability of engineering structure. The deformation development in the non-equilibrium evolution is determined by two intrinsic processes, trend to equilibrium and damage development, which can be illustrated by evolution of excavated tunnel. Thus the creep and damage must be taken into account in study of non-equilibrium evolution process. Within Rice’s irreversible thermodynamics with internal state variable (ISV), the conjugate force function which equals to zero is a convex surface which divide the stress space into two parts, called equilibrium and nonequilibrium stress space respectively. The concept of effective stress of non-equilibrium has been proposed, in which the stress difference (d - d ) are the effective driving forces of non-equilibrium evolution process with hardening and damage effective. The formulations of inelastic strain rate and energy dissipation rate have been recast in the form of effective stresses. The inelastic complementary energy (ICE) is proposed to measure intensity of non-equilibrium evolution of material system. The specific equations of conjugated forces and kinetic equations of internal state variables are presented. The ICE and rate of energy dissipation are all calculated to be used to evaluate long-term stability of geo-engineering. The results show that rate of energy dissipation may be more convenience and flexible than ICE for internal state variable constitutive equation of rock mass.

Jan 1, 2015

By D. Ling, Santos. R. M., T. Van Gerven, M. Guo

The valorization of alkaline waste materials from thermal processes utilizing intensified mineral carbonation routes is investigated. The principal advantages of this approach are the chemical stability and storage safety of mineral carbonates, the opportunities for process integration presented by the technology, and the potential for conversion of low-value materials into useful products. Treatment and disposal of steel slags are a costly burden on steel plants. Sustainable solutions for Argon Oxygen Decarbonisation (AOD) and Continuous Casting (CC) stainless steel slags and Basic Oxygen Furnace (BOF) steel slag are desired. An integrated on-site mineral carbonation approach is envisaged as a favourable solution.

Jan 1, 2011

By D. J. Lucifora

Monitoring-While-Drilling (MWD) is a proven technique that records instantaneous on-drill parameters which can be used to supply contextual information for in-situ, down hole conditions, such as: changes in geology, the presence of pre-existing fractures and dynamic alterations, down hole conditions including bit bailing, bit blockages and bit wear, and improper drill operation. This technique has been widely used in the oil and gas industry and, eventually, it was transferred to the mining industry. A challenge when analyzing and interpreting MWD data is in utilizing proper filtering which enables one to properly eliminate any ?noise? from the signals of interest. Overall the importance of MWD data is that, through the collection of operational field-based data, a dataset can be acquired which allows experimentation and analysis to be carried out. Such a dataset is often impossible to replicate in a laboratory setting. If successful, and through iterative refinement, any promising method can eventually be implemented on-machine and using real-time monitoring techniques. This paper will provide a state of the art review of presently used MWD techniques and applications in industry. The paper?s primary focus will be on shallow, mining-style, blast hole drilling but will also take into account techniques and applications utilized in oil and gas drilling which have not been adopted in the mining industry. In the cases where MWD techniques and applications exist solely in oil and gas drilling the paper will examine and comment on the potential utility of technology transfer to mining applications.

Aug 1, 2013

By C. Groccia

As the search for new ore bodies drives mines to be developed at greater depths, the associated high stress environments present challenges for rock support design. Excavations in highly stressed brittle rock are often subject to large volume increases due to rock failure, a phenomenon known as rock mass bulking, which can result in significant wall convergence. Support systems need to be designed to minimize the amount of bulking and to accommodate large wall convergences. In order to design such a support system, empirical guidelines are often used to predict the amount of bulking. However, the empirical guidelines that are currently available are based on a limited number of case studies and consider few input parameters, which may result in an inaccurate bulking assessment. This paper describes methods of collecting quantitative field data at Creighton mine in Canada to better understand rock mass bulking and to further develop the empirical guidelines for bulking assessment for tunnels in highly stressed grounds. Measuring

Aug 1, 2013

By G. Shore

Radiation grafted structures my be fabricated to contain ion exchange groups selective to an ion complex. Proper choice of substrate and monomer will provide selective ion exchange with differing physico and chemical properties. Grafting a selected monomer to the proper polymer will provide selective ion exchange with assured chemical protection of the substrate. Ion exchange systems utilizing radiation grafted structures have been fabricated to ''capture'' gold, silver and palladium from dilute solutions. Other ion exchange systems can feasibly be produced to remove other precious metals. Rotating Cathode Technology is used to recover the metals from their regenerating solutions are pure metal foil.

Jan 1, 1985

By M. Kozlowski, I. Candy, S. Kashani-Nejad

The production of ferronickel and matte from nickel laterite ores is dominated by the Rotary Kiln, Electric Furnace (RKEF) process. Over time, major improvements have been made to kiln operation. In particular, kilns are now required to perform substantial amounts of reduction of the metallic oxides, thereby reducing the load on the electric furnace and substituting less expensive fossil fuel for electrical energy. To the basic refractory lined cylinder have been added: internal features such as dams and lifters, aimed at changing residence times in different sections of the kiln and enhancing gas/solids interaction, on-board fans to introduce tertiary air and on-board scoop mechanisms to allow reductant coal additions to be made at advantageous locations along the kiln. Many of these advances in design have been made on a trial and error basis and by 'borrowing' technology from related kiln processes, supplemented by proprietary modeling to various levels of sophistication. This paper presents a conceptual review of modeling components for the development of a computational model for granular material flow, combustion and heat and mass transfer in a nickel laterite kiln. These components include: granular material flow and segregation models for the simulation of bed motion, heat transfer models that simulate heat transfer by turbulent diffusion and radiation and the distribution of this thermal energy within the bed, and fluid flow models for the prediction of combustion aerodynamics.

Jan 1, 2005

By A. Paulin, J. Roth, S. Spaic

This experiment was carried out to see whether copper-iron ingots from Late Bronze Age hoards could have been produced by smelting ferruginous copper ores. Since ferruginous copper-ores are chalcopyritic, chalcopyritic concentrate from a present day copper mine was dead roasted in our experiment in lieu of a rich chalcopyritic ore. Charcoal was used as a reducing agent in the reduction of calcine (i.e., a product of dead-roasting), and quartz sand was used as a flux. Two separate metallic solutions, a copper-base and an iron-base alloy, were obtained as a result of two factors: the presence of carbon and the miscibility gap in the Cu-Fe-C system. The metallic melts appeared in a form of bigger or smaller droplets, enclosed by a molten slag which, during the cooling, solidified into metallic beads. The presence of both metals was noticed in the majority of the examined beads. It was therefore concluded that calcine consisted of an intimate mixture of oxides of both metals which were simultaneously reduced during the reduction process. Due to the miscibility gap in the Cu-Fe-C system, separate iron and copper regions were formed in the beads. In both regions, sulphide inclusions were found. The formed molten copper and molten iron solution were found to be saturated solutions. The metallographic analysis revealed the precipitation of iron out of copper and that of copper out of iron during the cooling and solidification of melts. The formed slag contained little iron and no copper oxide.

Jan 1, 2001

By D. Virely, M. Gasc-Barbier, J. Guittard

"The valleys of the Dordogne and the Vézère (France) have been inhabited since prehistoric times, as evidenced by the famous site of Lascaux. A few miles away, the village of La Roque-Gageac is also a very popular tourist destination (about 1.5 million tourists per year): The village is sandwiched between a massive limestone cliff and the Dordogne river. The collapse of a cave roof high above the village in January 2010 led us to characterize instability together for the cave and the whole cliff and propose a adapted instrumentation to monitor the fracture openings in the rock mass that are linked to climatic variations. Measurements have been going on and been recorded for nearly 4 years. They point out the role of thermal stress fatigue in the breakdown of the rock mass. In this paper we describe the site under study, the instrumentation and its main results. INTRODUCTIONThe phenomenon of thermal fatigue has been very little studied as far as rocks are concerned, whereas it is rather well characterized for other types of materials: Elsevier published a journal dedicated to fatigue (International Journal of fatigue). In the case of rocks, thermal phenomena and their impacts on mechanical behavior have been analyzed from a micro-structural point of view, and it is now well-known that an increase in temperature causes a dilatation of crystals (Arnould et al., 2004; Berest & Weber, 1998). This dilatation may lead to the development of inter-granular traction and compression stresses, and if those stresses are greater than fracture strength, inter-granular and intra-granular cracks may take place. On the other hand, the fatigue phenomenon (cyclic repetition of a temperature variation which is less extreme than the one that may lead to this inter-granular or intra-granular fracture) is a phenomenon which has not been much studied.The principal studies on thermal fatigue on rocks come mainly from the field of geomorphology, particularly in connection with the analysis of the evolutions of past climate that can explain the present shapes of those landforms: those studies remained essentially qualitative and not quantitative. Le Ber & Oter Duthoit (1987) proposed a thermal and thermodynamic approach to analyse the disaggregation of rock masses. This analysis is dedicated to the study of paleoclimates and was implemented to better understand the formation of slope deposits in order to propose transfer models permitting the reconstruction of the climactic conditions contemporary to their appearance. Since deterioration in the cliff only appears after several cycles, it means that it is a gradual and irreversible deterioration which leads to an increase of the « disorder ». Seen from a macroscopic system point of view, this irreversible evolution is quantified by the internal creation of entropy."

Jan 1, 2015

By B. Surender Mohan

Mother Earth being a treasure of minerals, it is prime duty of the mankind to preserve this natural source to ensure steady growth of the nation. Utmost care is to be taken to see that these natural resources are explored and exploited scientifically in a sustained manner to ensure that the resource base improves and last longer. In this backdrop, the topic of ?Lignite - its resource and technology options to exploit deep seated deposits? is an apt subject to be deliberated upon in the present context, where the shallow deposits may slowly get dwindled. I shall deliberate upon the resource base of lignite, production profiles of the last five decades, consumption pattern, demand / supply projections, future available technology options to exploit the deep seated deposits, growth trends of the sector etc. in my paper. With the available resource base and future technology options, I can confidentially make a statement that ?lignite will remain as cocontributor along with coal to India?s energy generation and may well maintain its same status in the 21st century too, as it has been in the later part of the twentieth century?.

Aug 1, 2013

By A. J. Monhemius

"The paper reviews the history of modern iron control processes in hydrometallurgy. Particular attention is paid to the processes developed in the 1960s by the electrolytic zinc industry for the removal of iron from zinc sulphate leach liquors - namely the Jarosite, Goethite and Hematite processes. Problems faced by the industry in the safe disposal of the iron residues produced by these processes are discussed. The lessons learnt over the past half century by the zinc industry are projected on to the current efforts to develop hydrometallurgical processes for the treatment of copper sulphide concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” is doomed to ultimate failure, unless and until methods are developed that can recover iron from solution in a form that can be directly utilised by the steel or pigment industries.INTRODUCTIONYou suddenly realise that age is catching up with you and that technology is moving on apace when you are asked to talk about the history of a process or a technology that you’ve grown up with. Such was my reaction when, out of the blue, I received an email last year from the chairman of the CIM’s Historical Metallurgy Committee, asking me if I would give a talk on the early developments of iron control in hydrometallurgy. Once I’d got over the initial shock of realising that I had now become living history, I was of course flattered that the invitation was to give a talk at the prestigious IMPC, a conference series that has been going for as long as I have been in the business. That this particular IMPC was to include the 4th Symposium on Iron Control in Hydrometallurgy, made the invitation even more appealing and appropriate, because I was the co-chairman of the First Symposium on Iron Control, together with my old friend, John Dutrizac (known by many as Dr Jarosite), which was held 30 years ago in Toronto.first became involved with iron at the very start of my career in hydrometallurgy – the research topic for my Masters degree thesis at UBC, back in the mid 1960s, was “Reductive leaching of Goethite with SO2”. My thesis supervisor was the late Professor Ian Warren, who himself was a protégé of Professor Frank Forward, one of the founding fathers of modern hydrometallurgy. Little did I realise at that time, now 50 years ago, that the problem of iron and how to deal with it in hydrometallurgical processes would be a theme that followed me throughout much of my 40-year career in academia."

Jan 1, 2016

By J. Paturaud, A. G. Villemiane, J. Y. Buffiere, D. Fabregue, M. Perrier

In this work, a detailed characterization of the cyclic damage mechanisms on duty in car heat exchangers has been carried out in order to improve their reliability. The material which consists in very thin (<0.3 mm thick) sheets formed of 3 co-rolled aluminum alloys (4045 /3916/ 4045) has been brazed in order to obtain metallurgical and surface conditions representative of those of the real components. Fatigue tests at constant stress amplitude have been performed at room temperature and 120°C in order i) to characterize the cyclic resistance of the studied materials and ii) to study the effect of temperature on the fatigue damage mechanism. The mechanisms leading to failure have been identified from post mortem fractographic analysis. The Wohler curves obtained show that, contrary to common structural Al alloys, this type of thin sheet brazed multi material can be cycled for several hundred thousand cycles at very high stress level (> ~ 80 % of the tensile strength). This behaviour is analysed with respect to the microstructure resulting from the brazing process and the low number of grains present in the sample thickness (around 5 grains).

Jan 1, 2015

By Yoshitaka Mitsuda, Masao Miyake, Masafumi Maeda

A leaching treatment was investigated to recover metals including rare earths from the mixtures of hydrogen storage alloys and nickel hydroxide. A potential-pH diagram of the La-Ni-H20 system including the domain of stability of LaNi5 was drawn to find appropriate leaching conditions. Alkaline solutions containing ligands that form complexes with nickel ions were supposed to be available to separate hydrogen storage alloys from the mixture. When the mixture was leached with ammoniacal alkaline aqueous solutions, the nickel hydroxide was dissolved and the hydrogen storage alloy was recovered as its original alloy.

Jan 1, 2004

By D. B. Felsher

"Lakeshore Gold’s Bell Creek Mill is located in Timmins, Ontario. The mill has been in operation since 2009 and has undergone several small expansions since then. In 2012 - 2013 the first major mill expansion was commissioned raising the mill capacity from 2,000tpd to 3,150tpd. This was done through the installation of a new ROM ore truck dumping facility, jaw crusher, ore storage dome, SAG mill, leach tank, CIL tank, and electrowinning cell. This paper will cover the equipment installed to raise the tonnage as well as the commissioning of the new equipment including problems encountered and how these problems were solved.IntroductionLake Shore Gold acquired the Bell Creek Mill, along with the Bell Creek Mine, from the Porcupine Gold Mines Joint Venture, a joint venture between Goldcorp Canada Ltd. and Kinross Gold Corporation, in December 2007.The Bell Creek mill, which processed ore from the Bell Creek Mine has consistently achieved recoveries of over 95%, is a conventional gold mill circuit, involving crushing and two stage ball mill grinding, gravity and leaching, followed by Carbon-In-Pulp (CIP) process for gold recovery. The facility had been placed on care and maintenance in 2002. At the beginning of 2009, the mill had been refurbished with an initial capacity of 800 tonnes per day and was subsequently refurbished to a capacity of 1,500 tonnes per day near the end of the third quarter of that year. The Mill was then expanded in 2010 to a capacity of 2,000 tonnes per day.In late 2011, the Company commenced a 50% expansion of its milling facility, from a processing capacity of 2,000 tonnes per day to 3,150 tonnes per day. Phase 1 of the expansion, which mainly involved enhancements to the solution circuit (“back end”) and increased the mill’s capacity to 2,500 tonnes per day, was completed at the end of 2012. Commissioning of Phase 2 of the expansion, to a capacity of 3,150 tonnes per day, commenced at the end of July 2013."

Jan 1, 2015

By Jiachen Wang

Longwall top-coal caving mining is one of the major mining methods for extracting thick coal seams in China. The top-coal caving longwall mining was began to use in the 1980s in China, and got the rapid development. The development of the top-coal caving mining technology in China, the achievements and the theoretical aspects progress of this method are described in detail in this paper. And the main technical model of China&apos;s top-coal caving mining is introduced in this paper. This paper also introduces the application of large-cutting-height mining in China and the technical level it has reached.

Aug 1, 2013

By Su-Ping Peng

Three dimensional (3D) seismic exploration has been carried out since the 1980s in the mining district of China, where it has been playing an indispensable role in the high yield and efficiency of coal mining. Unlike oil exploration, this technique uses high density seismic acquisition technology. In recent years, it has focused on wide azimuth 3D seismic acquisition. Evaluation of geometry moved away from depending on folds, azimuth and offset, toward being based upon a focus-ray beam. Conventionally, coalfield 3D seismic interpretation focused on time domain and was based on kinematics information, which is only suitable for less complex geological conditions. To achieve high-resolution processing for the complex topography and structure in coalfields, data processing shifted from poststack to prestack. The means to improve the accuracy of interpretation for complex geological conditions are 1) integration of multiple attributes and multiple disciplines, 2) combination of seismic and geological data, and 3) comprehensive combination of time domain and depth domain data. With the demand for lithological exploration, high-resolution data processing must also take into account the requirements of preserving amplitude in seismic data. Seismic attributes technology, seismic inversion technology, and dynamic tracking interpretation are key techniques in 3D seismic exploration. They greatly improve interpretation accuracy, produce better results in the goaf space description of the coal-bearing strata and coal seam structure, and effectively reduce exploration costs under complicated geological conditions. Therefore, these techniques will be the primary means employed in the future to deal with coalfield complex structure and lithological exploration.

Aug 1, 2013

By L. Lariviere, M. Grenier, R. Khalili, D. Shook

A mineral processing facility near Montreal, CEZinc, Noranda Inc., has recently implemented a leading-edge intranet solution for monitoring the performance of plant operations, and providing condition-based maintenance. This innovative multi-faceted software implementation incorporates: web-delivered plant information systems; area-wide control loop performance assessment (using sophisticated algorithms to evaluate poorly performing controllers); and integrated alarm management functions.The system has enabled a project to improve plant operations through better process control. Maintenance technicians, engineers, supervisors and managers all can see the performance of the controllers, and the performance of the plant itself, through webdelivered graphics and reports. Information is combined from many sources, real-time, historical, relational and analytical, to provide a complete picture of plant operation.The web-based solution centralizes the administration of user access, and simplifies the deployment of several different kinds of information to many desktops. It is an extensible system that allows users to create and share their own web pages and data views.The paper will discuss the solution architecture and the improvements the IT, operations, maintenance, and engineering groups have experienced, and overall benefits to the facility.

Jan 1, 2003

By Maureen Jensen

For mining companies looking to establish a strong North American presence, raise their profile or finance and position themselves for future growth, there is no other destination in the world that can offer a mining company the same opportunities as Canada whether you are an established blue chip or promising junior. Despite historically poor world commodity markets and shaky investor sentiment towards junior explorers caused in part by fallout from the high profile Bre-X fraud, Canada continues to shine as the undisputed mining finance capital of the world. Our natural riches and mining history go a long way to explain Canada's international prominence in mining finance. Canada has actively created and maintained one of the most integrated national frameworks to support mining ventures of all kinds. Our diverse industry, from one-person grass-roots explorers to mining industry giants, is one of our main strengths whether your company is Canada-focused or internationally active. The mining industry continues to be a vital contributor to the Canadian economy, contributing $26.2 billion in 1997 or 3.8% of national GDP, and is the second largest earner of foreign exchange. Industrial mineral companies are a very important part of this strength. These companies require a continuing access to capital to ensure that they can continue to compete and the globalisation of the Canadian mining industry has affected this industry just as much as it has affected every other industry in Canada.

Jan 1, 2001

By Karl J. C. Harries

"The following is an outline or check sheet of some things that might be looked at when considering the concept of a royalty or royalty provisions. It is not intended as a guide to what is right or wrong (that is for the parties to decide). It does not replace the discussions in this work and is not intended to be a complete or exhaustive compilation of matters to be considered. It presumes that you are familiar with the basic concepts of royalties and has been included as an aide memoire only. Use it as such, with caution and common sense, and amend it to suit your needs. Remember also that brevity can result in inaccuracy or imprecision. This is a danger in many points below.The section references are for the sections where the matter is the main subject of the section – see the index for other sections.Royalty TypesNet Proceeds [§§ 5.8.; 11.4.]• No accepted or understood meaning within industry.• Literal meaning, if not defined, would imply “net operating profit”.• Often defined as net profit with revenue base of proceeds from sale of product.• Should not be used without detailed and clear definition. Net Operating Profit [§§ 5.8.; 11.4. – referred to only]• Net profit without recoupment of pre-production expenditures.• Revenue base: usually proceeds from sale of product.• Operating costs deductible.• Some reserves may be permitted.• Recoupment of some post-production capital expenditures may be permitted.• Not often seen as basis for royalties in Canada."

Jan 1, 2003

By SangHyeok Han

Selecting the best possible cranes and identifying spatial conflict-free locations on sites can result in productivity and safety improvements for large-scale industrial construction projects. In the current practice, experienced lift engineers select cranes based on the heaviest lift and/or the largest lifting radius of the identified crane. This practice is relatively time-consuming, and optimization of the crane?s use and location is also difficult. There are many factors which need to be considered during the crane selection process, a reality which further complicates the process. This paper presents a framework which aims at developing a decision support system to enhance the crane selection process and collision-free path planning for large-scale construction projects. This paper utilizes an innovative crane selection matrix in order to establish a process for optimized crane selection for construction projects. The study considers more than 40 different factors in order to reduce time and improve safety for crane operations. Following finalization of crane type (mobile crane versus tower crane), a visualization model to simulate crane operation and identify collision-free crane operation paths is proposed. This process can assist project managers to plan the lifting process more effectively and efficiently. A case study-based approach was utilized to demonstrate the proposed methodology. The methodology was tested in the planning and construction process for boiler house structures in Mannheim, Germany. The project entailed numerous challenges: one of the major tasks was to lift a 102-ton load on the top of the boiler structure through crane collaboration; space limitations on site also presented several challenges related to crane selection, location, and operation processes. Based on the project constraints, the proposed crane selection framework, and the visualization models, two tower cranes were selected and successfully implemented in the case study.

Aug 1, 2013