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By Michael S. Moats, Addin Pranowo, Gerardo R. F. Alvear F., Nigel Aslin

The toxicity of arsenic is well known and documented. However, the presence of arsenic in copper electrorefining anodes and electrolyte is critically necessary to produce high quality cathode. Arsenic as well as antimony and bismuth concentrations vary depending on their relative concentration in the anode copper received from the smelter. This paper will discuss the behaviour and benefits of arsenic in copper electrorefining and the detrimental effects of antimony and bismuth on cathode quality and tankhouse performance. This will include the minimization and mitigation of problems associated with arsenic, antimony and bismuth including cathode contamination, floating slimes, scaling and anode passivation.

Jan 1, 2014

By O. Garg

This paper summarizes the computer applications in open-pit mine planning at the Iron Ore Company of Canada (IOC). A brief history of the use of computers at IOC is given, and a description of the existing facilities is outlined. The following systems are discussed: storage and retrieval of geological data; geotechnical data analysis; long-term grade and tonnage forecasting; ore grading; and open-pit mine design. Justification for using computers in open-pit mine planning is given, and possible future areas of application are considered.

Jan 1, 1979

By Ken G. Stowe, Stephen L. Chryssoulis, Joe Y. Kim

"Lead ions originating from galena during processing of complex sulphide ores migrate to ""cover"" the surface of sphalerite and iron sulphide mineral rarticles, and cause poor selectivity in differential flotation. Generally in sulphide ore processing, the lead activated minerals float in the Cu/Pb circuit. Subsequently, surface lead complicates the zinc flotation circuit by lowering the concentrate grade due to the co-flotation of lead- activated iron sulphide minerals. The effect of lead in the differential flotation of sphalerite from Cu-Pb-Zn and Pb-Zn ores is discussed. Plant and laboratory test data are interpreted by determining the surface composition of individual grains of sphalerite and iron sulphide rarticles using two surface analytical techniques, Laser Ionization Mass Spectrometer (LIMS) and Time of Flight-Secondary Ion Mass Spectrometer (TOF-SIMS). Cationic and anionic species on the surface were analyzed to elucidate the phenomena.IntroductionSurface properties play a critical role in many aspects of mineral processing such as flotation, flocculation, etc. An understanding of interaction mechanisms of different reagents (inorganic cations and anions, collectors, regulators, etc.) with mineral surface in an aqueous solution is a very important pre-requisite in achieving the desired selective flotation. In the flotation of complex sulphide ores, the flotation collectors respond to the activation of minerals such as sphalerite, pyrite etc. by heavy metal ions of Cu, Pb or Ag, which is a strictly surface phenomenon."

Jan 1, 1995

By P. Erskine

"Hyperaccumulator plants can be utilized as ‘metal crops’ in agromining operations. This emerging technology produces ‘bio-ore’ by growing ‘metal crops’ on sub-economic ore materials, such as natural ultramafic soils. In a typical application plant material is periodically harvested, followed by air-drying and incineration to produce the bio-ore intermediate. The bio-ore is of very high grade (>15 wt. % nickel), and of high purity, and may be processed into a number of different products (including nickel metal, nickelbased catalysts and pure nickel salts). Current research efforts from our team focus on Mediterranean climate field trials (Albania, Spain) and tropical climate field trials (Malaysia, Indonesia). Field-scale demonstrations are required to provide evidence of real-life performance and of economic viability. If the trials are successful, agromining may in the near future support local livelihoods with income opportunities as an alternative type of agriculture: to farm nickel.INTRODUCTION AND BACKGROUNDHyperaccumulators, plants with the exceptional ability to uptake and concentrate trace elements in their shoots, can be utilized as ‘metal crops’ in agromining operations (Van der Ent et al., 2013a; Chaney et al., 1998; 2007; Baker et al., 2010). Agromining produces ‘bio-ore’ from harvested ‘metal crops’ grown on unconventional resources such as natural ultramafic soils (Van der Ent et al., 2015a). The bio-ore is a high purity and very high-grade (>15 wt. % nickel) product intermediate that may be turned into a range of different nickel products (nickel metal, nickel-based catalysts and pure nickel salts). The potential for agromining is greatest in tropical regions (Asia-Pacific Region: Indonesia, Malaysia, Philippines, Papua New Guinea and New Caledonia) where very large expanses of ultramafic soils exist (Van der Ent et al., 2013b). Agromine operations may replace existing marginal agriculture on poor ultramafic soils, for example oil palm plantations that require high fertilizer inputs to be profitable, or take place under a cocropping regime. The ability of ‘metal crops’ to achieve high nickel concentrations in biomass (and hence in harvested bio-ore) from soils with just <0.5 wt. % nickel, makes it possible to access non-conventional resources, not accessible by traditional mining techniques. For example, agromining could be implemented both on the large ‘halo’ around the mine leases, and as part of the progressive rehabilitation process after conventional resource extraction. As with all methods for resource extraction, agromining will be finite due to the diminishing concentrations of nickel in the zone accessible by plant roots (Chaney et al., 2014). Nevertheless, considering soil materials with 0.2 wt. % nickel and ‘metal crops’ with a yield of 100 kg nickel ha-1 the agromining venture may be sustainable for decades (Van der Ent et al., 2015a)."

Jan 1, 2016

Overview of Presentation ?About MiHR ?Human Resources Challenges in the Minerals and Metals Industry ?Getting the Facts -Sector Study Project ?Key Findings ?Recommendations ?Conclusions ?MiHR?srole

May 1, 2006

By Masafumi Maeda

Metal recycling and waste treatment have become common issues in various metal industries, notably, the iron and steelmaking industry and the nonferrous industry. The former tends to treat mass wastes such as municipal wastes or plastics. However, volatile compounds are condensed in dusts of their incineration processes and they should also be treated, likely by the nonferrous industry. Those "end-of-life" products contain heavy metals that might be harmful to mankind and should be handled by the non-ferrous industry. Not only revenue derived from regeneration of metals from the secondary materials but also the revenue generated from the treatment charges is a strong attraction for nonferrous industry to process secondary materials. The present study presents some statistical data of the Japanese corporations in the iron and steelmaking industry as well as the nonferrous industry on their revenues generated from processing of secondary materials. Some of the companies are now concentrating their business resources on new areas of the market. Although the quantity of waste or recyclable material is still small at present, the quantity will increase in the near future, and it is anticipated that international collaboration is required to handle the greater variety and the larger quantity of secondary materials.

Jan 1, 2004

By T. Moyo

Ammoniacal solutions are attractive and effective lixiviants for the dissolution of chalcopyrite, allowing for the formation of stable ammine complexes with copper while rejecting iron. Chalcopyrite dissolution in ammoniacal solutions is reviewed from literature, and results from a recently completed study evaluating it through electrochemical and controlled leach studies are discussed. Ammoniacal leaching of copper ores dates back to 1916 in the leaching of low grade copper ores in the Kennecott leaching plant and in the Calumet and Hecla mines, followed by the commercialisation of the Sherrit Gordon process for the ammoniacal leaching of sulphide copper ores in 1948. Since then ammoniacal leaching has received intermittent focus from researchers with the development of the Anaconda’s Arbiter process and the unsuccessful Escondida process. In these leaching processes, the formation of surface deposits has historically been reported to result in the passivation of the chalcopyrite surfaces, whereas oxygen mass transfer in solutions has been the focus of process design improvements. Results of studies on high grade chalcopyrite material is presented in this paper which show that although a surface deposit was formed, it did not result in the passivation of chalcopyrite in ammoniacal solutions, and that while oxygen transfer is critical, it is not the direct oxidant in the reaction. INTRODUCTION Ammonia and its salts have been used in the hydrometallurgical treatment of non-ferrous metals such as copper, cobalt and nickel from oxide ores. Its chemistry allows for the selective dissolution of desired metals, leaving behind gangue including iron. Chalcopyrite is a copper sulphide ore known to be very stable and hence recalcitrant to many hydrometallurgical processing methods. Thus, the dissolution of chalcopyrite continues to be an attractive area of research. The dissolution of chalcopyrite in ammoniacal solutions is possible due to the stabilisation of copper(I) and copper (II) ions by ammonia in alkaline media. Ammonia has become more attractive as a lixiviant during the present socio-economic climate due to its low toxicity, relatively low cost and ease of regeneration by evaporation (Meng & Han, 1996). Ammonia processes are ideal when the gangue minerals are acid consuming e.g. with calcareous or dolomitic gangue (Paynter, 1973).

Jan 1, 2019

By W. Haibei, Lei. Z., Z. Bangsheng, W. Yufang, J. Kaixi

In 2007 output of zinc was more than 3.71 million tons in China. Some new projects have finished FS and several new zinc plants are building now. In recent ten years it happened great changes in zinc industry. For zinc concentrates one pressure leaching plant was built with capacity 10,000t/a and at least four companies are carrying out FS or engineering design now. Direct atmospheric leaching will put into used in China in 2008 with capacity 100,000t/a. It is estimated that until 2010 the output of direct leaching will be 400,000t/a.

Jan 1, 2008

By J. A. Dubinski

One of the greatest threats of mining in hard coal mines are underground fires, which in the past often resulted in the mining disasters. Implementation of scientific principles of fire fighting into practice contributed to a significant reduction of fire hazard in coal mines. However, despite numerous achievements of science in the fight against the underground fires, they still occur creating a potential hazard for the miners and contributing to generate significant costs of fire-fighting operations, the temporary suspension of production or loss of longwalls. This concerns both spontaneous fires and exogenous ones. A significant decrease in the number of spontaneous fires was the result of cooperation between Polish scientists with experts in the field of new methods of fire hazard prediction and selection of new fire prevention and fire hazard monitoring methods. A significant part played here researchers from the Central Mining Institute. The original method of endogenous fire risk assessment based on calorimetric tests of coal and developed mathematical model of the process of coal self-heating allow to predict the risk of spontaneous fires and select proper fire prevention measures adequate to the involved risk. The frequency of exogenous fires is in the last few years is low, but their share in the total number of fires is relatively high and constitutes about 30%. This results from the prevention activities, carried out regularly in mines which are aimed at reducing the fire hazard connected with the use of fire-resistant conveyor belts and other non-metallic materials. Further directions to reduce the hazards connected with underground fires should focus on improving the methods for monitoring hazards together with automation of fire fighting operations.

Aug 1, 2013

By R. Pérez, James A. Finch, F. Tavera, Cesar O. Gomez

"Gas holdup is a variable which affects the operation of flotation columns. On one hand, gas holdup is a function of bubble size (a function of sparger type, frother characteristics and concentration, and air flowrate), tailings flowrate, solids content, and mixing patterns in the collection zone. On the other, gas holdup defines flotation kinetics and carrying capacity. Therefore, gas holdup is a useful variable to control and diagnose the operation of a flotation column, but the lack of a reliable sensor for on-line gas holdup monitoring has prevented its use in industry.This work describes the principle and the practical difficulties associated with the development of a gas holdup sensor based on the measurement of the electrical conductivity of dispersions. Two different approaches have been devised. These approaches will be described and test results presented of prototypes in laboratory and industrial columns.Background.Several years ago, a research program was initiated at McGill to use electrical conductivity as the basis for developing sensors for process measurements in mineral processing. Electrical conductivity is an intensive property which is a function of the concentration of the different phases present in a dispersion. The initial focus was on the detection of the interface between two dispersions with different characteristics (i.e., that between the collection and froth zones in flotation columns or that between clear water and sedimented solids in thickeners). The technique works in this case by searching for the location at which a sudden change in specific conductivity occurs, as a consequence of different gas holdup or solids content, and absolute values of the specific conductivity of the dispersions involved are not necessary1,2."

Jan 1, 1995

By Charlie Jefferson

Main Goal: Resource Assessment 1. Incorporate existing data & results, old process. 2. NEW Quantitative Analysis (Chung and Chen) 3. Try mass balance of U and geochemical tracers 4. Use holistic process approach ?with key foci ?Targeted basin / belt assessments ?Is there as much in the Athabascaas they say? ?Athabasca reference for other basins (Thelon, etc) ?Compare sandstone & volcanic with USA, Kazakhstan etc: do their models apply here? ?Which IOCG systems are prospective for uranium? 5.Consider Groundwater, Environment; 6.Communicate

May 1, 2006

By G. A. Barclay

"I - INTRODUCTIONSteel castings still comprise the largest volume of wear materials used in crushing and grinding in the Canadian mining industry. The range of impact and wear properties possible with steel castings enables them to be used successfully in both high impact crushing as well as milling where abrasion resistance is the main criterion. Approximately 15,000 tons per year of steel mill liners and crusher castings are used by Canadian mines.The properties of the main steel casting alloys used - manganese, pearlitic chrome-moly and martensitic medium carbon steels will be discussed with reference to their applications. Field data on a new application in primary gyratory crushers for martensitic medium carbon steels is presented. Liner wear life and mill efficiency can be improved through proper liner design.The liner wear pattern can be used as an indication for liner profile changes to improve wear life. Changes in liner configuration can improve through put and use of larger castings can reduce downtime. Casting performance can be improved and foundry production costs reduced by adopting certain design improvements.II - ALLOYS USEDTable I list the most common ferrous liner materials used in relation to their hardness and wear resistance (1). The most wear resistant materials are the irons at the top. In many applications the service impact exceeds the impact strength of the irons and tougher less wear resistant steels must be used. The impact resistance improves from top to bottom with manganese steel the toughest. The hardness of the martensitic steels approaches that of the Ni-Hards however the wear life, because of the absence of carbides, is less."

Jan 1, 1983

By S. F. LEAMING

Jade occurs with alpine-1ype serpe111iniIes in a be// of middle Paleozoic to Triassic rocks extending from southern British Columbia in10 Yukon Territory. Most known deposiIs are in BriIish Columbia and are associa1ed wi1h the Cache Creek Group. Jade deposits are generally small len1icular masses 1ha1 lie along con1acIs beIween serpenIinites and various countIy rocks; some are 1ec1onic inclusions wi1hin se1pen1ini1es. Qualify and quan1i1y of 1he jade varies widely. Deposi1s occasionally, but rarely, reach 3,000 /Onnes. The ma1erial may be rendered non-commercial by .frac1ures, impuriIies, inferior colour and poor IexIure. Because unit value of jade can approach $80.00 per kg, greaI incen1ive exisIs 10 exploi1 1his resource. Successful commercial operations, however, depend on large- *A more detailed version of 1hi paper occur in Leaming (1978). PHOTO I . Sawn blocks of nephrite ready for shipping. 270 volume sales, for which $6.00 to $15.00 per kg is more realistic. Many undiscovered jade deposits undoubtedly remain in the Canadian Cordillera.

Jan 1, 1984

By J. P. Mogan, E. D. Dainty

Polynuclear aromatic hydrocarbon (PAH) levels were measured in underground mines in the vicinity of diesel vehicles equipped with several types of emission control hardware. In general, the emission control devices appeared to reduce PAH levels, but the companion mutagen study suggested that the reduction might not always be beneficial. All underground PAH concentrations were below the threshold at which a significant impact on health might be expected, but recent animal exposure studies have indicated that PAHs may not be the primary hazard from chronic diesel fume exposure.

Jan 1, 1994

By L. G. Morrell

Introduction A Self-Dumping cage which combines the features of a small skip and a cage has been used in a vertical winze between the 2,000 and 2,500 levels at the Coniaurum mine for the past three years, during which time its success has been demonstrated by uninterrupted service and low maintenance charges. lt was designed by John Reddington, mine manager, and was built under his supervision in the Coniaurum mine shops. Being new in many of its operating features, a small-scale model was made and tried before the final construction was undertaken. The mechanical performance of the model suggested a few minor changes that were incorporated in the final drawings. During its three years of use, the automatic dumping device has saved the expense of deck-handling of the cars. This actually represents a gross economy of something over four times the cost of construction and installation, which totalled $1,325. The cage, empty, weighs 2,200 pounds, of which 500 pounds represents the weight of the dumping accessory and necessarily heavier construction. Besides a considerable financial saving, the time saved in unloading increases the daily hoisting capacity of the winze. In raising ore from the 2,500 level, five minutes are required for a complete trip. Allowing one minute for the alternative of decking, we believe that the automatic dumping has increased the capacity of the winze hoist nearly 20 percent.

Jan 1, 1933

By Jennifer L. Durocher

The speciation of Uranium in silica-rich depositional layers in the proximity to uranium ore deposits was investigated using micro X-ray fluorescence (VESPERS beamline), X-ray Photoelectron Spectroscopy, Laser-Ablation ICP-MS, Scanning Electron Microscopy, X-ray diffraction and micro-Raman Spectroscopy. The heterogeneous Si-rich laminations contain micrometer-size inclusions of secondary uranyl-minerals. The U concentration in these layers range from several ppm to lower weight percent and the U 4f spectra indicate variable U6+ : U4+ ratios. Correlation between the concentrations of U and other metals (M) suggests the presence of M-U-bearing nanoparticles or species within the amorphous silica matrix.

Aug 1, 2010

By A. Gakwaya, K. Ba, M. Guillot, J. Levesque

"In the aerospace industry, parts requiring tight dimensional tolerances and high mechanical properties are often produced by forging. This forming process allows for an optimal use of the material and can produce high quality parts at a reasonable cost. Thanks to CAD techniques, it is now easier to predict flow profiles and in-process defects occurrence as well as wear of the forging dies. However, in order to determine the properties of the forged part with computer simulation methods, a good material constitutive law is a prerequisite. This paper presents a virtual manufacturing process modeling for the closed die forging of a workpiece performed with Abaqus. The hot closed die forging is a regular process applied to manufacture metallic components used in aerospace industry. In this forming process, the material flow and final properties depend on the microstructure evolution during the process that is why it is important to include the microstructure effects in the material model. Based on the stress-strain data measured experimentally, the material parameters of the standard (classical) Johnson-Cook constitutive model and of a modified Johnson-Cook constitutive law including the microstructure effects have been determined. The obtained simulation results are compared with the experimental results for validation.INTRODUCTIONDue to their good physical and mechanical properties such as ductility, fatigue strength, corrosion resistance and rupture, aluminium alloys are often used in the aeronautic and the automobile industries. In this work, we present the forging of an Al-Zn-Mg-Cu alloy, a high strength aerospace alloy recognized for his good combination of physical and mechanical properties. The forging process is simulated in Abaqus Explicit using both the standard Johnson-Cook law (Johnson & Cook, 1983; Hor, 2011; Lin et al., 2012), and its modified version as proposed by Andrade et al., (1994). The Johnson-Cook law offers the advantage of considering the coupled effect of the plastic strain, the plastic strain rate, the temperature of forging and the hardening effect. However, it is a phenomenological model which does not account for the effect of the microstructure evolution. In this work, a modified Johnson-Cook model implemented in a user subroutine is used. It includes the effect of the dynamic recrystallization phenomenon during the hot deformation. The dynamic recrystallization has a noticeable influence on the microstructure and on the properties of the material. The term dynamic means that the process starts and acts during the deformation and this is different from the static mechanism of recrystallization which occurs during an annealing and after cold or hot deformation. Since properties of the alloy used in this work are not readily available in the literature then characterization tests have been done at various temperatures and strain rates, in order to determine the thermomechanical properties and the material behavior during the process of hot forming, more precisely during the hot forging process."

Jan 1, 2016

By Hongpu Kang

The fully mechanized top coal caving mining method has been the main mining approach for thick coal seams with high output and efficiency in Chinese coal mines. The gateroads for the top coal caving mining faces should be driven along the floor of the thick coal seam with a part of the seam as roof. The support of the gateroads is commonly difficult because of the low strength and broken structures of the coal seams, and the increasingly large section of gateroads meeting the need of greater and greater face coal output. Based on the analyses on the geomechanics properties and production conditions of the top coal caving mining, the influences of the top coal caving mining parameters on the stability of gateroads, including mining thickness and face length, are studied. The deformation and damage features of the rock mass surrounding the gateroads with the top coal seam as roof are investigated, the interaction of the support with the surrounding rock mass, the support theory are studied. The bolting design method and criteria, bolting forms and parameters for the gateroads with the top coal as roof are put forward. The rock bolting components, including bolt bars, face plates, cable tendons, meshes, and steel straps, are introduced. Finally, the gateroad bolting effects are evaluated through a typical case study on the basis of field monitoring data, such as the displacement of surrounding rock mass and the forces along bolts and cables.

Aug 1, 2013

By G. R. Yourt

"Generally speaking the usual approach for controlling dust is three-fold:1. Suppress the formation of dust at the source.2. Confine dust that cannot be suppressed.3. Dilute and remove dust that cannot be confined.This discussion will be concentrated on the second approach, namely, confining and disposing of dusty air.Dust BehaviourBefore delving into actual design principles a brief discussion on behaviour of dust should be helpful. For prevention of silicosis only respirable dust, ranging in size from < 0.5 to 5u needs to be controlled. As particles of this size have insignificant mass and momentum they follow air movements very closely. Consequently if contaminated air around dust sources is confined within enclosures and leakages maintained, strongly indraft dust is automatically controlled and capture velocities are of no concern.Dust SourcesAt metal mining operations ore is prepared for wet concentration by crushing it to mostly <3"" in size. This usually involves a jaw crusher, one or two cone crushers, one or more screens and several conveyors. Dust is actually produced only by the crushing action but it is liberated also when numerous fine particles contained in the ore stream are dispersed by surges and vibration at the discharge of the crushers, screens and headpulleys of conveyors. Furthermore, dust is dis¬persed when the slime adhering to the underside of the return portion of belts becomes dry and is rendered airborne by vibration and by cleaning floors especially where the slime has dropped."

Jan 1, 1971

By E. Talebi, P. Roghanchi

"This study aims to discuss personal and behavioral parameters contributing to heat-related accidents. To study the prevention approaches, it is essential to look at the various factors at the individual, management, and industrial levels. Qualitative risk analysis methods are used based on the public data in the USA to find the impact of the environmental and behavioral parameters on the heat stress and heat strain of mine workers. The effects of individual factors such as worker experience, age, fitness, lifestyle, acclimation, and more are illustrated. The significance of factors such as the roles of the mine management and regulatory agencies are addressed.INTRODUCTIONOccupational hazards in mining industry endanger the health and safety of the workers and productivity loss for mining companies. Among those hazards is the exposure to excessive heat that has adverse effects on the health of mine workers. The intensity of heat load is a significant factor in fatal and non-fatal heat-related accidents. Severe environmental conditions combined with a high level of activity in the mining industry increases the vulnerability of individuals to health and safety hazards (Ngwenya, Oosthuizen, Cross, Frimpong, & Chaibva, 2018). Lack of regulations and legislation addressing the heat issue in the mining industry (i.e., underground and open pit mines, processing plants) also raises widespread concerns.Along the climate change, various sources contribute to the overall heat load at a mine site (Hanna, Kjellstrom, Bennett, & Dear, 2011; Kjellstrom, Lemke, Hyatt, & Otto, 2014). In underground mines, the majority of heat comes from different sources such as geothermal gradient, equipment, auto compression, groundwater, and blasting (Maurya, Karena, Vardhan, Aruna, & Raj, 2015). On the surface, however, the majority of heat load can be sourced to solar energy. The exposure to excessive heat might result in heat-related illnesses, fatigue and fainting, loss of concentration, performance reduction, and production loss (Kocsis & Sunkpal, 2017; Roghanchi, 2017). The severity of the effects depends on duration and level of exposure and the response of an individual to heat stress. The response of an individual is influenced by different factors including age, gender, fitness, lifestyle, experiences, and past medical history."

Jan 1, 2019