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By M. B. Kime

"Discrete-element method (DEM) modelling is a powerful tool for studying particulate systems within the mineral processing industry. DEM simulations were conducted to investigate the power draw, load behaviour, and impact energy profile of an experimental ball mill under different milling conditions. The variables considered were mill rotational speed (percent critical speed), ball size, and lifter face angle. The simulation results indicated that the grinding efficiency would be enhanced by using 80% critical speed, 30 mm ball diameter, and 45° lifter face angle. These findings can be useful in guiding actual ball milling tests involving an ore sample.RÉSUMÉ La modélisation par méthode des éléments distincts (MED) est un outil puissant qui permet d’étudier les systèmes particulaires au sein de l’industrie de traitement des minerais. Des simulations par MED ont été menées de façon à étudier le profil de la consommation énergétique, du comportement de la charge et de l’énergie de rupture d’un broyeur à boulets expérimental dans diverses conditions de broyage. Parmi les variables prises en compte figuraient la vitesse de rotation du broyeur (vitesse critique en pourcentage), la taille des boulets et l’angle de coupe de la cornière élévatrice. D’après les résultats de la simulation, on pourrait améliorer l’efficacité de broyage en utilisant une vitesse critique de 80 %, un diamètre de boulet de 30 mm et un angle de coupe de 45 ° de la cornière élévatrice. Ces résultats peuvent se révéler utiles pour les essais concrets de broyage à boulets impliquant un échantillon de minerai.INTRODUCTIONComminution is a very energy intensive process. It consumes approximately 5% of the electricity produced worldwide and more than 50% of the total energy used in mineral processing plants (Pokrajcic, 2010). Among all the comminution stages, ball milling is one of the most energy intensive processes. In ball mills, rotational movement provides the rise of the load and the media that are projected and impact on the mill shell at lower angular displacement, resulting in particle breakage. Ball mills are able to reduce particle size over a relatively wide range of particle sizes. This explains their wide applicability in research laboratories and the mineral processing industry."

Jan 1, 2017

By N. J. Bunce, B. Vollick, A. F. Souza, D. Bejan, P. Maharaj, C. Shamshoom

"Copper electrodeposition from synthetic and authentic acid mine drainage (AMD) is inhibited by ferric iron (Fe(III)), through re-oxidation of copper. Polarization to –2.5 V versus standard hydrogen electrode prevents the dissolution of predeposited copper from the cathode. Above pH 1, copper deposition is independent of Fe(III) concentration to approximately 25 g/L. Fe(III) is reduced to ferrous iron (Fe(II)), with a high combined current efficiency for iron and copper reduction. In a divided cell, the conversion of Fe(III) to Fe(II) is almost quantitative, with efficient transfer of acidity from catholyte to anolyte. Prospects for developing electrochemical technology for complete remediation of AMD are discussed.RÉSUMÉ En raison de la réoxydation du cuivre, le fer ferrique (Fe(III)) nuit à l’électrodéposition du cuivre à partir de drainage minier acide (DMA) véritable et synthétique. Une polarisation à -2,5 V par rapport à l’électrode standard d’hydrogène empêche la dissolution du cuivre déjà déposé de la cathode. À un pH supérieur à 1, la déposition du cuivre est indépendante de la concentration en Fe(III) jusqu’à environ 25 g/L. Le fer ferrique est réduit en fer ferreux (Fe(II)) avec une efficacité combinée élevée pour la réduction du fer et du cuivre. Dans une cellule divisée, la conversion de Fe(III) en Fe(II) est près de la quantité théorique, avec un transfert efficient de l’acidité de catholyte à anolyte. Les perspectives de développement d’une technologie électrochimique pour la remédiation complète du DMA sont discutées."

Jan 1, 2016

By M. F. Goudge

THE present century has witnessed an amazing transformation in the uses of limestone. From being mainly a structural material, a role it has played since the beginning of civilization, it has become one of the in-dispensable raw materials for use in the great chemical and metallurgical industries that play such a vital part in the economic life of the nations today. Its uses have become so diversified and numerous that it enters, directly or indirectly, into nearly every phase of modern life. In this introductory paper it is proposed merely to outline the general usefulness of limestone and to point out some of its salient features, and to leave any detailed discussion of uses to the papers that follow. The term limestone as herein used embraces all kinds from the variety known as high-calcium limestone, which is composed almost entirely of calcite, to the dolomitic variety, composed largely or entirely of the mineral dolomite. Lime is simply calcined limestone and, in considering the uses of limestone, the uses of lime should also be included, particularly in view of the fact that, in many processes, it is possible to use limestone in either the raw or the calcined state.

Jan 1, 1939

By R. Lowery

TODAY, man uses, at will, the land, the water, and the air to transport himself and his goods everywhere across the face of the world. He no longer thinks with wonder of the magic of conquering these elements - he takes his mastery of them for granted. He is, however, constantly striving to squeeze more and more efficiency from each mode of transport. Man's first method of transporting himself and his goods was, obviously, himself; then he acquired his first beast of burden - woman. Most other two-legged female animals carried their young around clinging to their fur. Human mothers were, generally speaking, furless and their offspring less 'Prehensile, and so slings and other trappings were invented to carry young children. Man's inventive genius soon adopted these devices for carrying other burdens, and for countless centuries woman carried all in order that man could walk unencumbered except by his weapons. Later other ?beasts of burden were trained and used, including dogs, horses, oxen, camels, etc. Man also discovered quite early that he could drag along the ground more than he could carry on his back.

Jan 1, 1956

By S. Nafisi

Permanent mould casting may be regarded as a near net shape manufacturing process where simple to very complex shaped engineering components are fabricated with high degree of precision in a metallic mould, In this group, High Pressure Die Casting (HPDC), have attracted more attention because of its production rate, where both liquid and semisolid metals (SSM) can be cast with high degree of precision and versatility. The SEED process, Swirled Enthalpy Equilibration Device, the new process for semi solid metals slurry production route, consists of two steps: The initial step involves extracting specified amount of heat from the molten metal to generate liquid-solid slurry, i.e, mushy structure, followed by drainage of remaining liquid to produce a compact free standing feedstock for rheocasting operation. In this paper, microstructural evolution during the process and some initial casting results of automotive components an also reported.

Jan 1, 2005

By Jan Butra

In copper ore mines located in the Pre-Sudeten Monocline the deposit mining using room and pillar systems has been carried out for more than forty years. When implementing mining systems in deep copper ore mines it appeared to be necessary to adapt them to variable geological conditions and natural hazards. In the initial period of exploitation there were mainly caving and rockburst hazards. The adaptation of room and pillar system was connected with a state of knowledge in the scope of identifying, forecasting and controlling rock mass hazards. The new solutions allowed the safe and efficient exploitation of a blanket deposit of variable thickness from about 2 to 15m, seated on progressively increasing depth. They included exploitation in constrained conditions, such as in protective pillars. In the exploitation period, technical and organisational activities aimed at rockburst hazard control were introduced including active methods for controlling rockburst hazard and procedures for conducting mining works in the rockburst hazard conditions. When mining at a depth exceeding 1,200 m, the exploitation method and technique are additionally affected by thermal hazard and by gas and rock breakout hazard. New solutions of the room and pillar system and a longwall system with mechanical mining have been developed for exploitation in the associated hazard conditions. The require application of many innovative solutions in the scope of mining process and ore haulage mechanisation, excavation support and forecasting and control of existing hazards. The main purpose of these solutions is to conduct the safe and economically effective exploitation of the deposit.

Aug 1, 2013

By N. Campbell, W. T. Orvine

The metalliferous deposits of British Columbia are largely confined to that portion of the Cordilleran province lying west of the Rocky Mountain trench. Massive sulphides in the coastal area carry important copper •values together with lead and zinc and are composed mainly of pyrite which replaces schists or shear zones. The massive sulphide ore of the interior, on the other hand, contains lead and zinc with little copper. Pyrrhotite rather than pyrite is... the dominant metallic and deposition took place through selective replacement of sedimentary beds.

Jan 1, 1960

By S. Kelebek, B. Nanthakumar

ABSTRACT The sensitivity of sulphide minerals towards oxidation depends on the mineralogical makeup and nature of sulphide ores. This paper focuses on chalcopyrite behaviour in a nickel-copper sulphide- ore matrix that was aged in the mine-site stockpiles. Results of collectorless, collector-induced flotation and recovery by size are presented following a discussion of XPS analysis that was used to gain insight into oxidative alteration of chalcopyrite’s surface chemistry. Chalcopyrite maintains its high flotation activity despite exposure to weeks of oxidative conditions. It is concluded that chalcopyrite is quite tolerant to stockpile oxidation due to various factors related to alteration of its surface chemistry.

Jan 1, 2012

By D. J. Reddish

The paper describes a case study where numerical modelling has been applied to predict potential risks associated with inflows of water in active mine workings from an overlying sandstone aquifer. The objective of the modelling was to predict the development of strata fractures and strains as the longwall panels were extracted and investigate their relationship to an sandstone aquifer. The numerical modelling study also included the investigation of the effect of mining on a fault that existed close to the start position of one of the panels. The potential effects of mining on the fault were undertaken by parametric studies adjusting properties for the fault and the relative position of extractions, which allowed the mine planner to position the panel layout accordingly.

May 1, 2003

By DONALD E. BARNETT

Since the days of early settlement ew Brunswick has produced a variety of industrial minerals but it is perhaps only the recent discoveries of significant reserves of potash that have elevated the meaning of industrial minerals in their contribution to the provincial economy. With potash production commencing in July 1983, the role of industrial minerals will increase significantly to the value of mineral production in the province.

Jan 1, 1984

By Georgy A. Cherkashov, Andrey V. Efimov, Yury S. Borodaev, Nadezhda N. Mozgova, Sergey G. Krasnov, Tamara V. Stepanova, Alexander M. Ashadze

"Abstract - A horizontal mineralogical-geochemical ore zonation with a southeast to northwest trending succession of Cu and Fe (Zn) main zones has been discovered in the Logatchev hydrothermal field (14°45??N Mid-Atlantic Ridge). The major minerals are pyrite, chalcopyrite, bornite, isocubanite, digenite and chalcocite. Zn-sulfide, marcasite and covellite are less abundant. Rare minerals are native copper, zincian copper and cobalt pentlandite (first found in oceanic massive sulfides), Cu and Cu-Co-bearing Fe-disulfides. Two groups of the main sulfide assemblages with different copper contents are recognized: Group I comprises assemblages with primary sulfides (isocubanite, chalcopyrite, pyrite and Zn-sulfide; Cu up to 35 wt% in Cu-bearing minerals); Group II contains assemblages with secondary Cu-rich sulfides (bornite, digenite, chalcocite; Cu ~60 wt%) as well as rare minerals (cobalt pentlandite, native copper and zincian copper). The assemblages of Group I formed at a temperature of about 300°C; the sulfur fugacity (log fs2 atm) at 300°C is probably 9.9. Relations between minerals of this group are contradictory, attributed to non-equilibrium environments, and no unified sequence of crystallization of minerals has been determined. Minerals of Group II replace, rim or cross the assemblages of Group I. Group II minerals crystallized in a distinct sequence (cobalt pentlandite-bornite-digenite- chalcocite-native copper), with increasing copper content from the start to the end of the depositional sequence. This may correspond to pH from 7 to 8 near Eh = -0.2 at 250°C. Minerals of this group were generally formed under hypergene alteration processes. Compositions of ore minerals were studied by means of electron microprobe analysis (EMPA) (150 analyses). Narrow composition fields were revealed in all main sulfides, which comprised known experimental data. ZnS contains 6.0 to 28.0 mol.% FeS, which is close to data known for other hydrothermal massive sulfides from the Mid-Atlantic Ridge (MAR). A common admixture in ZnS is Cu (0.16 to 1.32 wt%). Rare grains of unusual anisotropic Fe-disulfides, (Fe0.95Cu0.05)S2 and Cu(Fe,Co)9S20, were found among the ore minerals."

Jan 1, 1999

By A. Rodriguez-Prado

"Magnetic fields affect the growth of cultured cells and plants; however, limited information exists about their effects on vegetation performing environmental remediation. Constructed wetland mesocosms treating hexavalent chromium (Cr(VI)) wastewater exposed to low-intensity magnetic fields (60 Hz, 56.5 × 10-6 Tesla) produced 100% more biomass than the unexposed control. Nonetheless, they removed only 43 ± 27% of Cr(VI), compared to 60 ± 21% for the control. A Cr(VI) reduction expression was developed as a function of the magnetic field. The design and operation of constructed wetlands to treat mining wastewater can be corrected for magnetic field effects.RÉSUMÉ Les champs magnétiques affectent la croissance des cellules et des plantes cultivées; toutefois, il existe peu d’information quant à leurs effets sur la végétation utilisée à des fins d’assainissement environnementale. Les mésocosmes des marais artificiels traitant des eaux usées, contenant du chrome hexavalent (Cr(VI)), exposés à des champs magnétiques de faible intensité (60 Hz, 56,5 × 10-6 Tesla) ont produit 100 % plus de biomasse que le contrôle non exposé. Néanmoins, ils n’ont enlevé que 43 ± 27 % du Cr(VI), comparativement à 60 ± 21 % pour le contrôle. Une expression de réduction du Cr(VI) a été développée en tant que fonction du champ magnétique. La conception et l’exploitation de marais artificiels pour traiter les eaux usées des mines peuvent être adaptées pour tenir compte des effets des champs magnétiques."

Jan 1, 2015

By C. A. Lavery

A DISCUSSION is presented of natural gas production and field processing equipment as now utilized in the gas producing areas of the United States, with reference to use of such equipment in Canadian gas areas. The scope of the paper is confined to a general description of various types and methods of using surface production equipment. The discussion is divided under two general groups: well-head production equipment, and field processing. The first will be concerned primarily with indirect heaters, separators, knockouts, and special versions of this equipment. The second major group includes the field processing equipment for handling natural gas. A delineation should be made here as to the meaning of field processing as used in this discussion. We will limit our term to mean such processing equipment as may be used in producing fields to process gas or its by products in a manner that does not require conventional plant practices either in operation or supervision. This covers such equipment as is necessary to complete preparation of gas for sale to pipeline and/ or is necessary to recover valuable components. Under this heading we will discuss glycol dehydration, solid desiccant dehydration, low-temperature separation, mechanical refrigeration, and desorbtion-stabilization. These are all processes involved in preparing gas for final sale or disposal. They do not include the more conventional and large-scale plant process systems.

Jan 1, 1956

By Earle J. Klohn

"The design, construction and operation of tailings dams is rapidly becoming a major consideration for most new mining developments, as well as for many existing operations. In North America, under pressure from public opinion, various government agencies have in recent years enacted legislation covering the design, construction and operation of tailings dams. In British Columbia, comprehensive legislation has been passed during the past year (1971). All of these new regulations may be placed into two broad categories: regulations concerning the safety of the dam and appurtenant structures, and regulations concerning the prevention of pollution. Both types of regulation affect the design of the tailings dam facilities. Consequently, they must be considered jointly by the designer. A good tailings dam design must satisfy the basic requirements of safety, pollution control, storage capacity and economy. To achieve this, 'the design must be based on a thorough understanding of both the geotechnical problems involved and the requirements of the mining development. Obviously, this requires close cooperation between the designing geotechnical engineers and the mining operators. This paper outlines the major engineering factors that should be considered in the investigation, design, construct ion and operation of tailings dams. Basic methods of tailings dam construction are reviewed and the advantages and disadvantages of each briefly discussed. Comparisons are made between the design and construction of conventional water supply dams and tailings dams. Examples are presented of some of the problems that may arise during construction and operation of a tailings dam. The paper also explains the need for basic instrumentation of tailings dams and for carrying out simple field tests and measurements during construction and operation. Of prime importance is the downstream monitoring of surface and subsurface seepage flows. These observations are invaluable where contamination of surface and/or subsurface water may become a contentious issue at some future date. Each tailings dam design must be based on a study of the particular requirements of that project. To make a proper evaluation, adequate data must be available concerning a large number of items•, including such things as: topography, hydrology, geology, subsoil properties, seismicity, government regulations, fineness of mill grind, mill water balance, availability of suitable construction materials, volume of water to be stored behind starter dam, downstream development or liability, and many others. The large number of variables involved in such an evaluation often result in the designer considering two or more alternative designs. Selection of the final design, which is usually based on detailed cost analyses of the alternatives, must be made in close consultation with the owner."

Jan 1, 1972

By McNeely DuBose

INTRODUCTORY PROSPECTING for aluminum has always been, and still is, a peculiar combination of the technical with the physical approach, and 1 want to explain my conception of the term 'prospecting' when applied to aluminum, which differs in some respects from the ordinarily accepted idea of prospecting. In the early days of gold mining, prospecting was a search in the hills and the river beds for the metal, not for its chemical combinations. And so it was in the early days of aluminum, with the difference that the search for the metal was carried on, not in the hills and dales, but in chemical laboratories. Aluminum is never found in the elemental state and at that time the metal bad never been seen, but scientists of that day bad forecast that such a metal must exist and in 1807 Sir Humphrey Davy went so far as to give this unseen metal a name, aluminum, from the Greek word alumen. This word applies to our alum, and it was from alum that Davy sought to produce the metal. It is strange to think that, in laboratories throughout England and on the continent, prospecting for aluminum was busily under way by men who had never seen the metal they were searching for. Their situation was something like that of the fisherman and the 'big one' that got away. They could describe the metal, give its exact weight, and even name it, but they could not produce visual evidence of its existence. Eventually, however, the efforts of the scientist 'prospectors' were rewarded and in 1826 the metal was actually produced, possibly first by Wohler, though Oerstedt, a Danish chemist, is usually credited with the achievement.

Jan 1, 1951

The theory and practice of sampling of particulate material have been the focus of a continued attention on the part of the mining industry worldwide for almost a century now, because of its critical importance at all phases of a mining project, from exploration (bulk sampling, assaying) to production (grade control) and marketing (quality control). A powerful, complete theory was put together by P. Oy (1968 to i982), but its applications to gold ores have met with limited success to date, due to the inadequacy of its sampling variance and minimum sample mass determination formulae to the challenging case of gold ores. This paper presents a research project completed at Inco Exploration and Technical Services Inc., using a geostatistical approach, to shed light on the results of P.Gy's theory, and adapt them to the case of particulate gold ores. After a reminder of Gy's formulae and a simplified demonstration of the generic form of Gy's and more traditional formulae, an empirical approach, based on sampling experiments from four gold deposits, shows how Gy's formulae must be corrected to adjust to the case of gold ores. The generality of the results formula is then substantiated with a geostatistical analysis of the problem. A parameterized formula results, and indications are given on how to fit its parameters to experimental data. Application guidelines and charts to fit any case and budget are presented, along with a detailed practical example.

Jan 1, 1991

By D. G. F. Hedley, F. Grant

"In 1958, the Ontario Department of Mines appointed a committee to study the accident situation and mining methods used in the uranium mines in the E1liot Lake district. This committee reviewed the existing knowledge on mine design, pillar support and roof spans and came to the conclusion that scientific knowledge had not yet reached the stage of producing rational design procedures which would reduce the dependence on trial-and-error methods. Since that time, the Mining Research Centre has made numerous stress measurements in two mines to define the pre-mining and pillar stresses. A comprehensive series of tests has been done in the laboratory to measure the compressive strength of the rock; a geological survey of the region has been made to evaluate tectonic stresses; and a survey was done on mining conditions with regard to stable and unstable pillar configurations. This information has been used to evaluate pillar design as effected by pillar width and height, depth below surface, extraction and pre-mining stress fields. The resultant design of pillar widths and corresponding extraction as the depth increased is in line with past and present experience in these mines. The information available on roof stability is still insufficient to design stable stope spans with the same degree of confidence; experience and trial-and-error methods are still required."

Jan 1, 1972

By K. M. Murphy, M. B. Wittrup

ABSTRACT The Saskatchewan Ministry of Environment recognizes the importance of environmental protection as an important contributor to Saskatchewan’s economy, with the environmental performance of industry closely monitored. Unfortunately, environmental regulation is often accompanied by significant process that does not always add value to environmental protection activities. The Saskatchewan Ministry of Environment has embarked on a visionary restructuring of its regulatory framework from conventional command and control regulation to a results-based regulatory framework. This new regulatory framework will provide for establishing clear environmental protection and resource management objectives; streamlining the environmental acts and regulations; developing an environmental code of practice; relying on qualified persons; enhancing compliance and enforcement tools; eliminating of many permits; and developing greater certainty in environmental assessment decisions. Results-based regulation promises to deliver enhanced environmental protection with less process. The uranium industry in Saskatchewan will be used as an example of the potential effects of results-based regulation.

Jan 1, 2012

By Roger V. Pierce

"WITHOUT mineral wealth, modern man would not exist. True, man could survive on a stone-age basis with an average life expectancy of, say, 25 to 30 years -once he got past infancy.However, no metal would tip his arrow in a hunt for protein; no steel plough would break the soil for the organized planting of seed; and no coal, nor oil, nor natural gas nor uranium fuels would pro-vide him with light or beat or safety from either beasts, or other men, or an unkind nature that threatened him and his family.Modern agriculture, fishing and forestry represent the other three wealth-producing industries. With-out metals, non-metallics and energy minerals, however, it would be impossible to fit any of these to man's modern needs."

Jan 1, 1967

By K. Hawboldt, J. E. Halfyard, C. Bottaro, I. A. Harrison

"The removal of elemental sulfur from leach residues derived from massive sulfide concentrates via hydrometallurgical routes has been demonstrated in a laboratory setting by converting water-insoluble sulfur to water-soluble polysulfides. The approach was applied to leach residue from Vale's nickel hydromet demonstration plant in Argentia, Newfoundland, which contained significant amounts of elemental sulfur. This technique offers an alternative treatment protocol for residues with a sulfur component not amenable to standard flotation/hot filtration processes. The practical considerations of a proposed flow sheet will be discussed including the impact of other sulfur species (e.g. thiosulfate and sulfides) and key process variables. INTRODUCTIONPresently, large scale elemental sulfur extraction from hydrometallurgical leach residue is performed by Teck Resources using a process of sulfur flotation followed by hot filtration (Chalkley et al., 1993). As mentioned, the technique proves viable for residues derived from specific concentrations - in this case zinc - whose residues constituency is primarily elemental sulfur itself. However, problems arise when this constituency is altered as happens when, for example, a mine containing one particular concentrate is mixed or replaced with a differing concentrate from a second mine. Such cases can often strain the effectiveness of current sulfur removal processes (D'Odorico, 2004). If hydrometallurgical residue containing elemental sulfur cannot be effectively treatment by flotation, the residue is stored subaqueously as is the case in some 'grass roots' hydrometallurgical plants (those not coupled with smelting operations). Hydrometallurgical processing of concentrates involving pressure leaching is becoming increasingly common throughout the mining world, the genesis of which can be found in research performed by Sherritt in Fort Saskatchewan since the 1950’s (Ozberk et al., 1995).The investigation of elemental sulfur removal by means other than flotation includes the uses of sulfide salts (NH3S or Na2S) effecting the conversion of hydrophobic elemental sulfur to hydrophilic polysulfides. The work of Kunda et al. (1974) and Olper et al. (2007) shows that elemental sulfur can be quantitatively removed from hydrometallurgical leach residue via the formation of a mixture of polysulfides."

Jan 1, 2012