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By S. Esfahani, M. Barati, K. Danaei

"Substituting Portland cement with slag cement is one of the most economically attractive uses of slags. For this application, high cooling rates are required to form an amorphous structure. However, this is counteracted by the need to use small coolant flowrate to allow recovery of slag thermal energy as high quality heat to the coolant fluid. Therefore, a relationship between cooling rate of slag and its structure is essential to recover the heat effectively while making an amorphous slag.A modified Single Hot Thermocouple Technique (SHTT) was employed to investigate the crystallization behavior of slags by plotting their TTT (Time-Temperature, Transformation) diagrams. Seven different slag compositions containing CaO, SiO2, Al2O3, MgO were prepared at varying basicity (CaO/SiO2 =0.5-1.4).The results indicate that with increasing basicity, the TTT curves of glassy to crystalline transformation shift to the left which means higher crystallization tendency. This agrees with the fact that with the increase of basicity, the Si-O bonds are weakened, which in turn facilitates the re-ordering and crystallization of the silicate structure."

Jan 1, 2014

By M. Hozayen, E. S. Radwan, P. A. Nawrocki, A. Jebbouri

"A major geomechanical study was conducted for one of the UAE onshore oil fields with the purpose of studying reservoir rock properties and stress distribution, based on which a 3D coupled reservoir geomechanical model was built. This model was later used for wellbore stability analysis and for analyzing the effect of fractures on future reservoir production performance, including fracture deformation and permeability evolution occurring due to reservoir depletion and resulting changes in local stress field. The subject of this study was a complex fractured Upper Cretaceous carbonate reservoir characterized by high degree of heterogeneity, both vertically and laterally. Wellbore instability related drilling problems were encountered while drilling the wells in this field. The problems were mainly in drilling the horizontal wells, including breakouts and mud losses. Experimental results of laboratory tests are summarized in this paper whereas wellbore stability analysis and formulation of a 3D geomechanical model that was built for that purpose is summarized in a sister paper (Part II).A suite of tests reported includes tensile strength, uniaxial and triaxial compression and permeability under stress at simulated reservoir conditions. All tested rocks have been grouped into twelve test units and reservoir geology, rock types and challenges related to designing a viable sampling and testing program for a big reservoir are discussed first followed by sample selection criteria and details of the testing program. All test units showed brittle behavior at zero confinement and some samples showed similar behavior at low confining stresses. With confining stress increase, the behavior gradually turned to plastic but some samples showed features of ductile behavior even at low confinement.Obtained experimental data have been summarized in the form of strength criteria and correlations. The Mohr-Coulomb strength equations were obtained for each test unit and also for the averaged values. It was noticed that triaxial compressive strength (TCS) increases with decreasing porosity or increasing density but their influence on TCS is getting smaller with confining pressure increase. Good correlation of porosity and density with Young’s modulus, Poisson’s ratio, unconfined compressive strength (UCS), friction angle, cohesion and tensile strength has been noticed and there was an increasing trend between the confining pressure and TCS. Rock type (mud or grain supported) was not influencing the TCS as much as porosity and density and the two lithologies encountered affected TCS approximately in the same way. These results and correlations are summarized and explained in this paper. They were further used in the numerical modelling part (Part II) of this paper, Hozayen et al. (2015). It is also concluded that rock lithology is not a decisive factor and mechanical properties of tested rocks should be rather considered dependent on porosity and permeability. This helped greatly in reducing the number of tests that had to be performed."

Jan 1, 2015

By Eiichi Sato, Koichi Kitazono, Hiroshi Masuda, Kenta Higane

"The present study investigated the low-temperature creep mechanisms in ultrafine-grained (UFG) aluminum manufactured by accumulative roll bonding. UFG aluminum with grain size 0.39 µm showed steady state creep even at room temperature under low stresses as confirmed by the creep curves in the strain rate–strain plot. The low-temperature behavior was divided into four regions by three distinctive stresses, sI, sII and sIII: sI (=45 MPa) is denoted as the micro-yielding stress with which dislocations start movement, sII (=85 MPa) the dislocation-multiplication stress above which dislocations multiply with creep deformation, and sIII (=171 MPa) the conventional yield stress above which macroscopic plastic strain is generated. During low-temperature creep, below sI, negligible plastic strain is generated. Between sI and sII, creep deformation with stress exponent 2.5 occurred, which is accommodated by dislocation absorption into grain boundary and grain boundary sliding, similarly to the low-temperature creep of HCP metals. Between sII and sIII, creep deformation with stress exponent 7.0 occurred, whose mechanism is similar to the low-temperature creep of coarse-grained aluminum. Above sIII, power-law breakdown occurred.INTRODUCTIONIt is well understood that the creep deformation brings about at high homologous temperatures (T/Tm) of >0.4, where Tmis the melting point, with diffusion processes. Recently, the importance of aluminum is increasing for cryogenic temperature parts such as a metallic liner or a cap in high pressure-hydrogen vessels, and the presence of creep behavior in aluminum at room temperature has become recognized (Matsunaga, 2013;Kassner, 2015).In HCP metals and alloys, especially intitanium, steady-state creep behavior appears at room temperature with apparent activation energy of1/10 of that for self-diffusion(Neeraj, 2000; Matsunaga, 2009).On the other hand, Kassner (2015) claims that aluminum shows creep behavior at room temperature with apparent activation energy of 4/5of that forself-diffusion, but never reaches the steady state. We should note that it is derived from the data obtained from short-term creep tests of few hour, and Matsunaga (2013) already claimed the presence of steady state in room temperature creep in aluminum with activation energy of 1/5of that for self-diffusion.The mechanisms for low temperature creep are considered different between HCP and FCC metals: in HCP metals, grain boundary sliding is observed and is thought to accommodate piled-up dislocations at grain boundaries through absorbing them. The so-called slip-induced grain boundary sliding occurs with low number of activated slip systems(Matsunaga,2009).On the other hand, in FCC metals, many activated slip systems bring about work hardening with dislocation cell structure formation. In the initial stage of creep, it results in primary creep (Kassner, 2015), but Matsunaga (2013) claimed that once the annihilating of a cross-slipped dislocation to another reaches balance, steady state is established. It has been, however, strongly required to show more convincing experimental verification for the presence of steady state in FCC metals at low temperature."

Jan 1, 2018

By Patrick Andrieux

Cet article décrit une nouvelle méthodologie qui quantifie les chances de succès d’un sautage confiné à grande échelle de relaxation des contraintes dans un pilier de mine souterraine, pour un massif rocheux et un régime de contraintes donnés. La méthode est basée sur un nouveau paramètre nommé « Indice de relâchement », qui considère huit paramètres géomécaniques et de forage-sautage qui contrôlent ultimement le procédé. La rétro-analyse d’études de cas bien documentées a démontré que l’approche peut indiquer de manière fiable si une situation donnée de hautes contraintes de terrain est susceptible d’être améliorée par un tir de relâchement confiné à grande échelle et si le design proposé est adéquat pour atteindre ce but.

Jan 1, 2009

? The Mining Association of British Columbia (MABC) was established through an Act of Parliament in 1901 ? The MABC represents the interests of B.C.?s ? Coal and mineral mining companies ? Smelting companies ? Advanced stage development projects ? Key areas of work: ? Environment, Health and Safety ? Policy & Government Relations ? Knowledge and Information Services

May 1, 2008

By Paul Johnston

or is it? Mining Automated Loader Technology Application ? Intelligent software mounted in hardware on a remotely controlled scoop. ? Led by INCO, Sudbury, with ? C-CORE, St. John?s ? Automated Mining Systems, Aurora ? Bell Canada, Sudbury ? Laurentian University, Sudbury ? University of Western Ontario, London Completed: March 2000

May 1, 2008

By G. J. Desroches, E. Ozberk, M. J. Collins, B. D. Krysa, I. M. Masters

The zinc refinery of Hudson Bay Mining and Smelting Co., Ltd. went through a major modernization in 1993, when the roaster and the calcine and fume leach circuits were replaced by a new Sherritt zinc pressure leach plant. The HBMS plant, in Flin Ron, Manitoba, represents the first commercial application of the Sherritt two-stage zinc pressure leach process, with /00% of the zinc concentrate feed processed in autoclaves. The process design of the new plant required definition of the deportments of elements such as antimony, arsenic, chlorine, cobalt, fluorine, germanium, magnesium, manganese, selenium, tellurium and thallium. This paper describes the deportment of these elements in the commercial zinc plant during the first nine months of pressure leach operation, and compares these results with operations prior to the introduction of pressure leaching, and with the results of tests carried out in the She"itt laboratory during the process development phase.

Jan 1, 1995

By A. A. Burgoyne

"The McDame chrysotile asbestos deposit located near Cassiar in northern British Columbia isfound at depth and on trend to the southeast of the currently mined open-pit Cassiar asbestos deposit. The ultramafic rock hosting the McDame is serpentinized peridotite of the Upper Paleozoic Sylvester Group contained in an ophiolitic sequence preserved within a lower thrust sheet of the Sylvester Allochthon. The Sylvester stratigraphic package is a series of thrust slices composed of argillite, tuff and volcanic flows, diorite and serpentinite. Contacts between units are often fault-controlled.The McDame asbestos-bearing ultramafite is considered to represent a separate interleaved fault-bounded slice of rock distinct from the Cassiar asbestos deposit.Asbestos mineralization of the McDame deposit was discovered in /978. Exploration during /980 and /98/ focused on extensive underground drilling of the deposit and in /983 on geological mapping, airborne and ground magnetic surveys. In /984 a 622.5 m borehole was drilled with a 242 m intersection of McDame ultramafite of which the lower 15/ metres contain potentially economic chrysotile asbestos. The McDame deposit averages 90 m thick, trends north-south, dips easterly and plunges southeasterly. The deposit is estimated to contain geological reserves in the order of 62 million tonnes containing asbestos fibre similar in value to the Cassiar deposit.The McDame is considered a major world-class asbestos deposit. A decision to develop and mine the deposit will require further substantial underground exploration and evaluation. A + 1200 m exploration adit driven to the hanging wall of the deposit was undertaken in 1985 in anticipation of bulk sampling and diamond drilling in 1986."

Jan 1, 1986

By J. Oliveira, A. R. Barnes, R. Pandher

Sub-stoichiometric roasting of arsenic-bearing copper ores is a well established practice. However, ores containing calcium commonly prove challenging where very low arsenic levels are desired, but the reasons for this phenomenon have largely been speculative. In the course of treating arsenicbearing copper ores by partial roasting in fluid bed reactors, XPS encountered one of these Ca-bearing ores which proved a challenge to roast to acceptably low levels of arsenic. Mineralogical examination of the calcines using a combination of XRD (X-ray diffraction), QEMSCAN (Quantitative Evaluation of Materials by Scanning Electron Microscope) and EPMA (Electron Probe Micro-Analysis) helped to identify the arsenic bearing species and assisted in developing a workable theory on the sequence of reactions occurring during the roast. With the assistance of thermo-chemical modelling, this allowed adjustment of the roasting conditions to minimise the amount of arsenic retention in the calcine in spite of the presence of calcium in the ore and advance the roasting program to a commercially acceptable solution.

Jan 1, 2014

By Denni Nikols

"Planning for coal beneficiation in the electric utility industry is relatively complex, involving the coordination of experts and specialists in a broad range of fields, as well as compliance with a wide variety of government regulations.This paper examines the role of the planner, reviews possible benefits of coal beneficiation, identifies potential problems and illustrates a typical planning schedule.The steps involved in the planning process are:Step I-Bench- and pilot- washability studyStep 2- Wash plant designStep 3- Power plant and boiler designStep 4-Mine designStep 5-Major environmental and technical problems to address.IntroductionElectrical utilities and coal have a long and intimate relationship . Cleaned coal is becoming an increasingly popular fuel with the utilities for a variety of reasons. Generally, the greatest impetus to burn a cleaned or prepared coal fuel comes from the need to control airborne pollutants.Long-range planning is a standard practice for electric utilities, forecasts of demand must be made well into the future. Since the lead time required to provide new facilities is often as long as 10 years and the cost very high , planning becomes an important task.For a utility that owns and directs the operation of its coal mines, the mine planning or fuel acquisition planning takes on the magnitude of other corporate planning functions. It is from this perspective that a utility would view coal preparation. Except for the interaction of a coal-fi red plant on the actual mine design the planning considerations o f a beneficiating facility for a captive mine or a contract raw coal supply are about the same. Because TransAlta Utilities is currently supplied from captive mines, this discussion will tend to focus in that direction.It is the role of a planner to plan. This is easy to say but it is not always easy to do. Often we are working within a context that resembles the geological time scale. Frequently the objectives are not clearly defined when we begin and ultimately our plans are tested in the waters of government regulations and cost benefit analyses .Planning for beneficiation of Plains coal, or any coal, provides just such a test. The planner's role in this endeavour requires a wide vision. While parts of the process may be amenable to classical methods of project scheduling, the broad range of subjects and interaction of seemingly unrelated tasks is sure to obscure some of the considerations that must be made. Therefore, the planner's chief role is coordinating the work of many experts and specialists toward the final objective.Among the specialists are combustion , geo technical, mining, civil , and mineral processing engineers , geologists, hydrogeologists, soil, and reclamation experts to list a few.When one considers coal beneficiation, the planning part o f that consideration is probably more complex than any other single engineering function. Due to the company's location in the Alberta Plains and the proximity o f the mine to the thermal generating station, this paper will tend to emphasize that situation.Beneficiation may offer some advantages over run-of-mine coal to the power plant opeator. Some of these advantages are: removal of a contaminant, power plant efficiency gains , lower plant capital costs (for new plants), possible lower mining costs."

Jan 1, 1984

By J. Smit, F. Parada, R. Parra, E. Balladares, M. P. Merino

"In this study, a two-step process was developed for recovering copper, molybdenum, zinc and iron (hematite). In the first step, grinded slags (-65 mesh) were sulphated with SO3 at 350-500ºC to form iron, copper and zinc sulphates. In the next step, the formed sulphates were decomposed to hematite, copper and zinc sulphates and oxysulphates at 700-750ºC. The generated SO3 was recirculated back to the sulphation step. The generated calcine in the decomposition step is leached with 25 gpl acid at 50ºC to dissolve the copper, zinc and molybdenum for further conventional separation and recovery. The hematite residue, of intense red color, can be used as pigment, in the ceramic industry or as pellet feed. The fine crystalline silica remains in the hematite residue."

Jan 1, 2014

By Yihan Liu, Jintao Zhang, Chen Xiao, Xiaomeng Zhao, Guanglei Song

To estimate the performance of the inert anode materials based on NiFe2O4 spinel ceramic during it used for aluminum electrolysis, we investigated the wetting process of cryolite molten salt which is in composition of industrial aluminum electrolysis with carbon anode and NiFe2O4 based cermet materials, by means of determination the interface wetting angle between the molten cryolite electrolyte and the solid anodes interface. The results show that the wetting angle between the electrolyte and carbon anode is larger than 90 angulation, this means that they basically can not wetting; however the nickel ferrate spinel ceramics behaves much better. In regard to the NiFe2O4 matrix materials, their initial wetting angles is 76.9. The initial wetting angles for 1.0wt%MnO2, 2.5wt%TiO2 and 0.5wt%V2O5-doped samples are respectively 56.86°, 52.98° and 51.93°. However, after 50s later, all the wetting angles came down below 15°.

Jan 1, 2015

By A. E. M. Warner, A. Vahed, P. J. Mackey

In the decade 2002 to 2012 some 6.7 million tonnes of new copper concentrate production capacity was brought on line, corresponding to 2 million tonnes of contained copper. This increase in concentrate supply necessitated the commissioning of a number of new copper smelters as well as the modernization and/or expansion of existing plants to meet the demand. This paper gives an overview of the copper extractive industry, reviews recent copper production trends and changes in the copper industry, including an examination of pyrometallurgical and hydrometallurgical technology developments. WorleyParsons has supported a number of the projects involved in these developments and this role is briefly discussed. The paper introduces a number of ideas related to possible future directions of the copper industry.

Jan 1, 2014

"The Pierre Beauchemin Mine attained commercial production in January 1989, and went on to produce 23 968 ounces of gold for the year, 3% higher than forecast. Underground development was accelerated to prepare the way for the production of an estimated 40 000 ounces in 1989.IntroductionThe Pierre Beauchemin Mine is located nine miles west of the city of Rouyn-Noranda (Fig. I).As a result of the amalgamation with Sullivan Mines in October 1987, the mine is now entirely owned by Cambior Inc.The Eldrich deposit was discovered in 1953and began production in 1955, closing in 1962 following the decrease in gold prices and the simultaneous decrease in silica content in the ore, which was sold to the Noranda smelter for flux. A total of 717 000 tons grading 0.14 oz Au/t were produced during this period.From July 1984 to October 1987, an underground exploration program was carried out by Sullivan on the Eldrich mining concession and the nearby Flavel property. The first phase of the program included reinstallation of surface facilities and dewatering of the Eldrich Mine. Following the completion of the first phase, extensive exploration was carried out, including a major program of diamond drilling. It was then decided to deepen the shaft to a depth of 1800 ft to access a new zone called the No.5 Zone .Following the amalgamation with Sullivan in October 1987, Cambior assumed the role of operator for the project, and continued the shaft deepening work that had already been started. A feasibility study was completed in April 1988 and the Cambior board of directors approved a production decision for the Eldrich-Flavel project.The preproduction program extended from May to December 1988 and was aimed at preparing the stopes in the upper part of the mine and at developing the mine infrastructure at the bottom of the mine.The mine was officially opened in August 1988. Cambior renamed the project the Pierre Beauchemin Mine in recognition of Pierre Beauchemin's pioneer-work."

Jan 1, 1990

By Seong-Ho Ha, Shae K. Kim, Young-Ok Yoon

In the this study, surface segregation of Mg and Ca with Mg addition range from 5 to 10wt% in Al-Mg alloys with Mg+Al2Ca master alloy and its effect on the oxidation resistance were investigated. The addition of Mg+Al2Ca master alloy as the Mg alloying element led to the surface enrichment of Mg and Ca during high temperature oxidation. As a result of the oxidation test by TGA, the oxidation resistance of all the examined alloys was significantly improved with increasing Al2Ca content. The weight change of Al2Ca added Al-5Mg and Al-7.5Mg alloys indicated the complete oxidation resistance during the whole oxidation test time, while a slight weight increase was shown in the case of Al-Mg alloys even with Al2Ca addition. The improvement of the oxidation resistance in Al2Ca added alloys may be attributed to the formation of the protective oxide layer mixed with CaO and MgO on the surface.

Jan 1, 2015

By Martin Wacker

Cameco Corporation, on behalf of a joint venture, is preparing surface and underground facilities at their northern Saskatchewan property in preparation for the future operation of a high-grade uranium mine. The Cigar Lake orebody is situated about 430 metres below surface at the unconformity between metamorphic basement rocks and flat lying sandstone. Major technical factors influencing the mining method selection include ground stability, control of ground water, radiation exposure and ore handling and storage. A decade-long test mine program resulted in the selection and validation of ?jet boring? a non-entry mining method. Cigar Lake?s jet boring mining method involves several major steps; artificial ground freezing of the orebody and surrounding rock, TBM (tunnel boring) type development of access crosscuts below the orebody, installation of cased pilot holes upwards through the ore, and ore extraction using a rotating high pressure water jet within the pilot holes. The resulting cavities are surveyed and backfilled with concrete. The ore slurry will be processed underground and pumped to surface. This paper discusses the jet boring mining method in general terms and includes highlights of the Cigar Lake test mine program completed in 2000.

Apr 1, 2005

By Ben Cottrell

In this paper technical drilling is referred to as the process of collecting engineering and metallurgical parameters for subsequent mine design considerations. Throughout the development of a mineral exploration property there are various opportunities to ?piggy-back? technical drilling onto the routine exploration drilling process, helping to reduce future costs and delays associated with re-drilling and missing information. This article is written from the engineers and metallurgists point of view, to outline some best practices for exploration borehole planning and technical data collection requirements.

Aug 1, 2013

By F. Ford, J. Dong

"Laboratory and miniplant testwork was carried out to reject uranium from an Iron Oxide Copper Gold (IOCG) deposit that contains an average of 60-70 ppm uranium with high variability. The dominate copper bearing mineral is chalcopyrite with minor bornite and trace covellite. The main gangue minerals are iron-rich chlorite, quartz and magnetite. The main uranium-containing mineral is uraninite (UO2). Downstream processes require the maximum uranium level of no more than 80 ppm in final copper concentrate.Mineralogical examination reveals that uraninite particles are finely disseminated with grain size of less than a few microns in the deposit requiring fine regrind in order to liberate uraninite from chalcopyrite particles. A lab flowsheet was developed to include ultrafine regrind of the rougher concentrate to the particle size of 80% passing 11-13 µm with up to four stages of recleaning in flotation columns. Finer regrind to 80% passing 5-6 µm may continue to improve liberation but does not decrease uranium level in the final concentrate. In each of the successive recleaning stages by flotation column after fine regrind, uraninite is rejected into the column tailings, with the final copper gold concentrate containing less than 70 ppm uranium from a feed containing 83 ppm uranium. The conceptual flowsheet was further tested in an integrated, continuous miniplant showing average 94% copper recovery with average 74 ppm uranium. The uraninite particles that report to the final concentrate are either locked with chalcopyrite or entrained as liberated particles of less than 5 µm in size."

Jan 1, 2016

By A. S. H. Kabir, I-H. Jung, J. Su, S. Yue, M. Sanjari

The final mechanical properties of wrought magnesium alloys are mostly controlled by microstructure and crystallographic orientation or texture. In common magnesium alloys, grain coarsening occurs during annealing process and formation of undesirable basal texture cannot be changed markedly. The aim of this work is to investigate the effect of static precipitation on microstructure and texture evolution during annealing at 250 °C after warm rolling of Mg-Al-Sn alloy. Mg-3Al-3Sn (wt. %) alloy has been designed using thermodynamic modeling software, FactSageTM, based on forming target stable and incoherent Mg2Sn precipitate within the industrial deformation temperature range. Microstructures and precipitation were investigated by optical and scanning electron microscopes and macro-texture was measured by X-ray diffraction (XRD) techniques. It was found that static precipitates form in a large scale at the recrystallized grain boundaries and retards the grain growth during annealing. Slight weakening in basal texture was also observed during annealing.

Jan 1, 2014

By E. Barsky

"Theoretical notions of mass transfer processes in cascade separation of bulk materials have not been adequately developed as yet (Barsky M.D. 1980). In this paper we have derived linear difference equation of the second order for a cascade with initial feeding top any stage proceeding from mass exchange regularities. The solution of these equations has allowed us to determine quantitative dependences of the material distribution over the cascade stages, which serve the basis of the method of predictive estimate of the process results. We have also examined the model of the material distribution coefficient formation at individual cascade stages.We have checked the adequacy of this model to experimental data. It is noteworthy that the obtained theoretical results are phenomenological, i.e. they can be applied to the processes of separation of different physical nature, e.g. of isotopes, liquid media, gases, etc.INTRODUCTIONRecently, the processes of cascade separation of bulk materials have found broad application in various industries. They ensure a high separation efficiency and high-quality composition of final products. Although specialized literature gives serious attention to cascade processes [1], their theory is not sufficiently developed yet. To achieve optimal organization of this process, we examine mass transfer in a cascade gravitational classifier with stages of identical design."

Jan 1, 2016