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By A. Allaire

The Goldex operation of Agnico-Eagle Mines (AEM) commenced operations in the spring of 2008. Following some months of initial operation, the grinding circuit capacity was under-performing according to the original design throughput. BBA Inc. (BBA) was commissioned, in February 2009, to study the different options and recommend the quickest and most cost-effective solution to increase the grinding circuit throughput rate. The mandate was to increase the throughput of the grinding circuit to beyond the original design of 7,000 tpd to 8,000 tpd or greater, while retaining the existing SAG and ball mills. The circuit was modelled using JKSimMet software to evaluate the different options, each with a number of different operating parameters. The option of secondary crushing of the SAG mill feed was retained. Comparison of the different options and simulation outcomes, design of the secondary crushing circuit, operating conditions, and initial adjustments in the design and operating results of the new grinding circuit are discussed in this paper.

Jan 1, 2012

In 2009 Newmont Mining Corporation?s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By P. A. Crane, N. Shirley, Aung Moe, H. M. Nicholson, D. Kan

Kazakhstan’s first commercial copper-leach solvent extraction-electrowinning plant, Central Asia Metals’ Kounrad project, was commissioned in April 2012. Exploiting low grade waste stockpiles produced during Soviet era open pit mining, a 10,000 tpa copper cathode plant was designed, constructed and commissioned within 18 months. Overcoming initial challenges with a workforce unfamiliar with the technology and with extensive periods of sub-zero conditions during winter the project has consistently met targets and produced high quality copper cathodes at cash costs of less than US$1/lb. Challenges encountered during the first two years of operation are described and future plans briefly discussed.

Jan 1, 2014

By E. O. Lilge

THE USE of the Driessen cone as a heavy-media concentrator involves a mineral dressing process in which many variables inherent in the ore and in the process may have an effect on the efficiency of mineral separation and the operation of the cone. The magnitude of these effects and their possible interrelationships must be known before a full-scale plant can be designed and built. It appears that, among the most important variables, are the following: Ore Variables: The particle size of feed The difference in specific gravity between economic and non-economic minerals The intimacy of mineral association Cone Variables: Cone inlet area Ore to media ratio Cone ratio Size distribution in heavy media Specific gravity of media Viscosity of media Type of media

Jan 1, 1956

By P. Chollet, A Constant

THE RESULTS of a previous investigation ( 1) on the work-softening of some heat-treated steels have led to the conclusion that the occurrence and intensity of the phenomenon is possibly governed by the work-hardening capacity of the material, and the relative amount of retained austenite. The first assumption is compatible with Polakowski's theory (2) that the absence of work-softening, in steels quenched and tempered at relatively low temperatures, may be attributed to the high rate of work-hardening which compensates for, and even out-weighs, the loss of internal energy associated with the simultaneous rearrangement of the original system of internal stresses. Indeed, Polakowski first considered the work-softening as a manifestation of a partial release (by cold-working) of the latent strain energy stored in

Jan 1, 1962

By D. A. Riva

"The Line Creek Project is located in southeastern British Columbia, approximately 25 kilometres north of Sparwood. The design is to produce a total of2.7 million tonnes of coal annually. This is made up of1.4million tonnes of thermal coal and 1.3 million tonnes of metallurgical coal.Construction commenced in the spring of 1980 and mining operations began in July 1981. The thermal processing plant, maintenance and dry facilities, as well as extensive road and bridge construction, were completed in early 1982. A collective agreement was signed with the International Union of Operating Engineers, Local 115, in June 1981.The first unit train left Line Creek on February 18, 1982 with a load of thermal coal bound for the Ssangyong Corporation in Southern Korea. It was the start of a ten-year contract to supply 350,000 tonnes annually to fire their cement kilns. Additional contracts for 750,000 tonnes will fuel the boilers of Korea Electric Company's San Chon Po and Go-Jeong power stations. Metallurgical coal shipments are scheduled to leave the Roberts Bank port in Vancouver in April 1983.Tracking an introductory presentation given at the 1981 CIM Annual General Meeting in Calgary, this paper highlights the salient developments by which ""The Line Creek Project"" has progressed during the past year to the"" Line Creek Operation"". Line Creek has com e on stream as scheduled and will meet all contractual commitments pertaining to timing, volumes and quality for thermal coal. The first train load left the plant in mid-February, and the first boat load to Korea departed Roberts Bank in mid-April. Metallurgical coal deliveries will commence in April 1983."

Jan 1, 1982

By K. Purazrang, P. Sh. Naseri, P. Abachi

In present work, the comparative measurement of aluminum alloys' resistance to the unstable fracture was provided. Besides, the rupture mechanisms of high strength 7075 and 7050 aluminum alloys were investigated. The specimens were used as solution treated, quenched and aged condition. The elastic-plastic behavior of specimens was determined by carrying out tensile test on cylindrical specimens. The small sized specimen with 6.35 mm thickness and V-notched radius less than 60 µm was used for evaluation of damage properties, in accordance with ASTM B871-96 standard test method. All tear specimens were machined in L-T orientation. The mechanical tests were conducted at RT on an universal Instron machine under cross head speed of 0.1 mm/min. The results of mechanical tests made the evaluation of tear strength to 0.2 % tensile yield strength ratio, as a measure of notch toughness, available. The comparison of specimens' resistance to crack propagation and unstable fracture due to the presence of crack-like strain concentrator was provided using tear test data. The microstructure of specimens was studied under optical microscopy. The rupture micro-mechanisms were analyzed by examination of specimens fracture surfaces using SEM. The microstructure examination indicated almost equiaxed grains on the transverse directions and elongated grains on rolling direction. Moreover, intermetallic particles were evident at microstructure. Considering the SEM fractographs, it seems that the intermetallic particles act as void nucleation and damage initiation sites. However, the damage mechanism of tensile specimens and severely notched specimens, especially near the notched root differs due to stress and strain states.

Jan 1, 2006

By G. B. Harris

In recent years, increasing attention has been focused on the hydrometallurgical treatment of base metals feeds, especially nickel laterites and polymetallic sulphides. One approach that has received some attention is the use of high?concentration chloride solutions (brines), which are now showing some promise after initial setbacks. Iron is usually the major component in the base metal feed to such processes, and if physical means cannot be used to remove it, then the iron concentration in the pregnant leach solution is always significant. This paper presents some of the background theory on the hydrolysis of iron in high-strength (>3M) chloride brines, and discusses the roles of temperature, solution concentration and free acidity. It is shown that the system is complex, but that crystalline and readily-filterable hematite can be generated, and that the system has a low energy requirement.

Jan 1, 2006

By O. E. Humeniuk, A. I. A. Salama, M. W. Mikhail

"The Western Research Centre (WRC) of CANMET operate a unique pilot plant facility where ongoing R&D on coal preparation and mineral processing is conducted. The pilot plant carries out two functions: coal preparation processing using state-of-the art technology and coal-liquid mixture preparation with intensive cleaning circuits that can also be used for mineral processing. In total, the pilot plant includes more than 30 different flowsheet options. The facility is dedicated to small and fine coal, and designed to be flexible and versatile.This paper describes the use of a pilot-scale facility as a research tool for process control development, fine coal beneficiation, development of coal-liquid fuels technologies, development of process models and testing and evaluation of new developments. The pilot plant is used to assist in resource development by evaluating and optimizing flowsheet selection, and producing sufficient samples for utilization tests. The facility is also an important tool for evaluating and testing samples from troublesome circuits of operating plants to find means to optimize and improve recovery, particularly of fines circuits.Detailed examples are given to demonstrate the role of a pilot scale facility in coal preparation R&D, coal industry development and optimization of coal processing operations. These examples include the development of heavy-medium cyclone computer control system, detailed evaluation of beneficiation of a coal deposit with high clay content, development of column flotation, and its role in fine cleaning circuits and treatment of ultra-fines in relation to intensive cleaning, the importance of testing coals in different processes, and cleaning processes influence on coking quality and other utilization applications. The potential of the facility for helping the mineral industry is also described."

Jan 1, 1992

"Pilot plants for pressure hydrometallurgy represent special design and project execution challenges. Over the past twenty years, Zeton has designed and fabricated a variety of world-class pressure hydrometallurgical pilot-plant facilities for the nickel industry, and this paper discusses design considerations and strategies related to such projects. Project execution methods are also discussed, and guidance is given for the selection of materials of construction and for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical pilot equipment. The paper concludes with a discussion of the need for process similarity with future commercial operations and the realities of pilot-scale equipment.INTRODUCTION The process technology developer or owner and the designer/fabricator of a new pilot-plant facility are faced with some difficult technical choices even after the decision to build a dedicated plant has been taken. A pilot-plant project is usually on the critical path of a large commercial project involving investments many multiples greater than the capital cost of the pilot plant. Schedule savings in the design, manufacture, and commissioning of the pilot plant or in a rapid completion of the experimental program can be disproportionately beneficial to the overall development project. However, inappropriate shortcuts resulting in major oversights can be disproportionately problematic. A number of considerations and suggestions for both the project execution approach and the process engineering design of pressure hydrometallurgical pilot-plant facilities are presented as a guide for potential owners and operators of new pilot-plant equipment and facilities. These suggestions are particularly applicable to the nickel industry, where the majority of our firm’s prior hydrometallurgical experience was obtained. This paper is an update to an earlier publication (Martin, 2004), offering an opportunity for a new generation of metallurgists and engineers to learn the specialist requirements of pilot- and demonstration-scale plant design, which are key functions in the development and commercialization of new processes."

Jan 1, 2017

"Line Creek Resources Ltd. produces three million clean tonnes per year of metallurgical and thermal coals for the international market. The mining operation, which is located in the mountains of southeastern British Columbia, produces coal from four pits by conventional truck and shovel methods.The South Pit, which has been in operation since J982, has a benched highwall 490 m in height. Shallow dipping coal seams at the base of the syncline formation will be exposed in the highwall over the next four years of pit life. The first of these seams, which will measure 500 m in final highwall length, was exposed in J994. An auger, powered by a 1250 hp engine capable of cutting 2.2 m diameter holes, was brought on site in J994 and has proven to be a successful means of recovering coal from the J3 m thick seam.This paper covers the background to the selection of an auger mining method to recover highwall reserves together with the geotechnical and methane considerations for this approach.IntroductionLine Creek Resources Ltd., a wholly owned subsidiary of Manalta Coal Ltd., owns and operates the Line Creek mine. The operation which consists of four active pits, a processing plant, and rail loadout is located in the southeastern coal fields of British Columbia. Figure 1 shows the general area.The coal bearing sequence at the mine is preserved on the east and west limbs of a major syncline. Up to twelve mineable coal seams, ranging in thickness from 2 m to 15 m are contained in the formation. Within the pits the seams are stratigraphically consistent and structurally undisturbed, except for small-scale thrust faults that create multiple repeats of the seams."

Jan 1, 1995

By Gang Mei, Nengxiong Xu, Yanlin Zhang

After open-pit mining finishes, an iron mine with steeply inclined ore-bodies will generally transform to underground mining. Non-pillar sublevel caving method, with horizontal slice mining from up to down, is commonly used for mining deep ore-bodies under the open-pit bottom. As horizontal slice mining proceeds, a gradually enlarging goaf will be formed under the open-pit bottom, the rocks surrounding the handing and heading sides of the goaf will collapse continuously, and then these results in rock-mass failure with large deformation and displacement in the open-pit slope. Based on FLAC3D, a modeling approach to predict pit slope deformation and failure induced by transitioning open-pit to underground mining is proposed in this paper. This method mainly consists of three procedures of modeling, i.e., mining modeling, landslide modeling, and filling modeling, of which landslide modeling is the core of the proposed approach. In the procedures of modeling with FLAC3D, iteration non-convergence is taken as a local failure criterion of pit slope. When iteration calculation cannot converge, the sliding modeling will start by deleting some elements with large displacements, and finish until convergence. Before modeling landslide, several displacement contours of rock-masses in the pit slope are searched out, and each contour is an approximate possible sliding surface of the open-pit slope. From these contours, the most proper one is selected as the slope sliding surface by using the iteration calculation convergence and minimum element deletion as the judgment condition. Landslide modeling is then realized by removing the elements outside the slope sliding surface. Finally, to demonstrate the effectiveness, the proposed approach is used to simulate the process of open-pit to underground mining at Yanqianshan Iron Mine, and to predict the deformation and failure characteristics of open-pit slope during underground mining. The case study results show that: the prediction of the slope stability determined by using our method is consistent with that calculated by using the limit equilibrium methods.

Jan 1, 2015

By J. H. D. Hargrove, A. F. Snowball

Atmospheric pollution control has become increasingly important in re-cent years with laws and public opinion having required the reduction of contaminants from industrial gas effluents. Treatment methods have advanced to make possible, with proper plant design and operation, a satisfactory removal of these contaminants. Gases from Cominco's metallurgical operations at Trail, approximating 900,000 c.f.m., are treated by baghouses, electrostatic precipitators, cyclones, or wet scrubbers. The tabulated data include gas and dust conditions, plant performance, and some details of plant equipment. Discussion emphasizes the special features, scope of application, and basic design principles of the treatment methods, all based on Cominco experience. Recovery of over 99 per cent of the fume and dust is achieved by the major installations from which effluent gases go to atmosphere. Cooling of gases for baghouse recovery and conditioning for electrostatic precipitation are mentioned. Co3ts are tabulated for some of the installations on the basis of a unit of 1,000 cubic feet of gas. Suggestions are made on the procedure for assessing a smoke treatment problem and for selection of suitable equipment.

Jan 1, 1959

By G. A. Moruzi

Two sulphide dust secondacy explosions have occurred in the mines of the SUdbury operations of Falconbridge Ltd. during the past 18 months. 'Ihe main similarity between the occurrences is that they both happened in vertical crater retreat blasthole stopes. A relatively high p:,v.tier factor was noted in both instances. other details are enumerated and examined, as well as some results of tests done by Noranda Research on company ore samples.

May 11, 1988

"The QEMSCAN system is the third generation of automated mineral analysis systems that began with the QEM*SEM at CSIRO 30 years ago (Butcher et al. 2000). It is now a successful commercial instrument with 39 instruments in operation around the world. Back Scattered Electrons (BSE) and Energy Dispersive (EDS) X-Ray spectra are used to create digital mineral images with mineral identification occurring online. Low-count EDS spectra are used preferentially to BSE brightness, allowing minerals to be accurately identified by chemical composition. Individual minerals or groups of similar compositions are identified by comparison to a comprehensive mineral database incorporated into the QEMSCAN software. Optical mineralogy and Scanning Electron Microscopy is a metallurgists’ tool for determining the ore process mineralogy and delivering a better flowsheet. These techniques have limitations, provide limited information and sometimes fail to provide representative information. In contrast, QEMSCAN provides information on the nature and occurrence of all mineral species present plus the liberation characteristics, looking at thousands of particles in the sample presented. Some of the data presented includes:• Particle and grain sizes• Dominant mineral species• Particle shape• Calculated metal content• Density• Deportment of elements of interest between the mineral phases• Quantitative mineralogy• Mineral associations, locking and liberation• Textural relationships (particle images)It can also be used on concentrates, polished sections or drill core. This is a significant improvement in ore characterisation providing lithology, mineralogy, liberation, ore grade and porosity from a sample. Theoretical grade-recovery curves can be created to be mineralogically limited from QEMSCAN analysis which, when compared with metallurgical results, are valuable in evaluating whether liberation or chemical selectivity is driving flotation performance. A number of case study examples are given where the QEMSCAN had a significant bearing on future project development at an early stage of exploration and mine development."

Jan 1, 2012

By Louis Frost

MINE ventilation has for many years been the subject of intensive study by numerous investigators who have presented their findings in forms that are understandable to the average mining man, and all this writer hopes to do is to review those findings in relation to the 'manager's' problem in mine ventilation. It would not, perhaps, be wholly correct to acclaim practical mine ventilation as an exact science, because of the many variables entering into the problem. Each mine has its own particular problem and ventilation characteristics. Fan design, in contra distinction to mine ventilation, is an exact science, but the designer cannot always take into proper consideration the practical variations to which each mine is subject. Fan designers, accordingly, are forced to base their design on such data as the mine manager or engineer is able to supply, and, when it is borne in mind that the mine characteristic is constantly changing, it is not at all surprising that fans do not always show efficiencies hoped for. In many instances, fans work far beyond the de-signer's limitations, and, in consequence, are an economic disability in the colliery cost-sheet, and it is of paramount importance that the colliery manager evaluate all the factors involved in relation to fan performance for the colliery to receive full benefit from its investment.

Jan 1, 1941

By H. Nejati

Experimentally, the Semi-Circular Bending Moment (SCB) fracture toughness test results of Basalt Specimens Under Illumination (BSUI) have shown reduction in fracture toughness and failure force as a result of micro-cracking. The fractographic investigation of BSUI confirms initiation and extension of micro-cracks. Determination of a relation between strength reduction (herein fracture toughness reduction) and density, location and orientation of thermo-mechanical induced cracks due to microwave radiation is critically important. Numerical modeling can bridge strength reduction and the density of thermal microcracks generated due to microwave radiation. Discrete Element Modeling (DEM) is a power tool for simulation of micro-crack initiation, coalescence into macroscopic fractures and failure mechanisms in brittle rock specimens under different stress regimes (herein combination of pure tensile stress due to SCB testing, and thermal stress due to microwave radiation). For this purpose, a DEM modeling of SCB testing of basalt using EDEM (i.e., a DEM based software). DEM models are calibrated according to results of experimental SCB testing as reported in previous papers. This paper first reviews some background data on SCB fracture toughness, and experimental results of fracture toughness of microwave treated SCBs. Then it proposes a new methodology for simulation and validation of rock samples exposed to microwave illumination with regard to experimental results, and discusses the correlation between fracture toughness of BSUIs and density of micro-cracks, which is attributed to applied microwave power and duration of illumination.

Aug 1, 2013

By Lorant B. Geller

Sixteen miners died tragically at the Paymaster gold mine at Timmins, Ontario in February, 1945, when a badly corroded hoist rope broke. The investigation of the Royal Commission that followed arrived at a number of recommendations (Investigations, 1947) aimed at avoiding future disasters of this kind. One consequence was the development, and legislated use in Canada, several decades ago, of powerful electromagnetic (EM) instruments for the nondestructive testing of mine shaft wire ropes. The authors have been involved for many years in the design, production, and testing of EM instruments (Geller and Udd, 1990 and 1992, Geller and Kitzinger, 1991, Geller et al., 1993). Since the mid-1990s particular attention was paid to the design and operational results obtained from the computer- controlled portable MagnographJ II wire rope tester (Geller et al., 1995 and 1998). In the present article the authors summarize further hardware- and software-related developments of this instrument. Further, an account is given of the results obtained from the most recent design known as the PermaScanJ testing system. This is also a computerized dual-function system. In it, however, the sensor head is designed primarily, if not solely, for permanent installation and for remotely controlled operation. This represents a basic departure from traditional designs, which were intended for ad hoc temporary installations. The remotecontrolled instrument described in this paper has now been in operational use for more than 4 years.

May 1, 2003

By M. Sutherland

"Increased efforts to improve mine safety have led to various successful forms of ground control in Canadian underground mines. At Inca Limited's T-3 Mine in Thompson, Manitoba, a perimeter blasting method has been implemented in jumbo drilled development headings.The technique utilizes an increased number of perimeter blast holes in the drill pattern while decreasing the linear charge density of explosives in any individual perimeter hole. The decrease in perimeter charge density means less blast damage to the surrounding structure.The benefits realized include increased safety through less loose ground and substantially less scaling time, less overbreak and improved long-term drift stability. This paper highlights the development and implementation of the perimeter blasting program.IntroductionThompson Mine Thompson Mine is a 6000 ton per day underground nickel mine located just outside the city of Thompson, 400 miles north of Winnipeg. The mine is serviced by the T-I shaft and by the T-3 shaft. The shafts are 10 000 ft apart and are connected on several levels with the deepest operating levels at T-1 and T-3 being 4000 ft and 2400 ft respectively.The T-3 Mine presently produces 52% of the total Thompson Mine production and 65070 of the 3000 ft of mine development each month. Current development of the 5 million ton 1, C orebody below 2400 level at T-3 will maintain these production and development ratios.Depending on equipment requirements, development headings at T-3 Mine vary in size. The 1, C ramp, at 17 1/2 ft wide by 10 1/2 ft high, is presently the largest development heading at T-3. Fifty- two per cent of the development footage is done with four Gardner Denver two boom electric /hydraulic jumbos and one Gardner Denver one boom electric /hydraulic jumbo. The remaining 48% is driven with hand-held jack-leg drills."

Jan 1, 1990

By R. D. Brown

The first step in achieving a rationalization of Canada's crazy patch-work quilt of mining taxes and policies was achieved with the release last November of a major federal-provincial report on the taxation of the Canadian mining industry. The Report, prepared by a group of federal and provincial civil servants, sets out a concise and informative discussion of the major taxation and incentive issues facing the mining industry, and puts forward major recommendations for more rational and moderate taxation policies. It will be considered by federal and provincial Finance and Resource Ministers for possible action by the respective governments. The Report was prepared in response to a directive from the federal and provincial First Ministers in February 1978 to review the federal and provincial taxation of the resource areas. Although the Report is more successful in identifying problems rather than concrete solutions, and reflects some continuing differences of opinion between the governments involved, it does represent an important first step in a comprehensive review of our resource tax policies. This article summarizes the Report, which is some sixty pages in length. Although a detailed discussion of it is beyond the scope of this article, the report itself is recommended reading for those concerned about the current state of the Canadian mining industry.

Jan 1, 1979