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By M. Leroux, J. A. Finch

"Sizing below 38 µm (400 mesh) is an increasing requirement in mill testing laboratories. The Cyclosizer is gaining wide acceptance in this role. A recent alternative is to use electro-formed sieves (micro-sieves), which are available with openings down to 5 µm. The advantage of micro-sieving is a cut size which is independent of mineral density, easier retention of the fi nest fraction and reduced purchase cost. A simple method of microsieving using an ultrasonic bath, which performs readily to 10 µm, is described.A systematic study of Cyclosizing and micro-sieving is reported for three samples; silica, copper oxide and a lead concentrate. Micro-sieving gave comparable results. Comparison with a standard sizing method, the Sedigraph 5000D, revealed misplaced material in each fraction by both methods. The range for micro-sieving was from 20% to 60% depending on the sieve and material; for the Cyclosizer it was a consistent 40-50% for all cones and all materials. The Cyclosizer can be sensitive to feed mass and particle size for dense materials. It is recommended that for minerals of specific gravity greater than 5, no more than 35 g of -38 µm be used.The disadvantage of micro-sieving is that it requires continuous operator attention and sieving time depends on sample mass. To fractionate 35 g-as used on the Cyclosizer and considered at reasonable mass for mill testing purposes-through 25-, 15- and 10-µm sieves requires about 80 minutes.IntroductionParticle size has a pronounced influence on mineral separation processes. Consequently, the measurement of particle size plays an important part in mill testing. By far the most common method is by screening. This, however, is usually limited to 38 µm (400 mesh) or occasionally 25 µm (500 mesh). Increasingly, mineral products are becoming finer than this limit and consequently finer sizing methods are required."

Jan 1, 1982

By Tony Lipiec, Greg Gosson

"When it comes to new mines being developed, there is a general industry consensus that most low-hanging fruit has been picked. Many projects currently in the mine development pipeline have been around for decades, but were held back because of technical challenges. Future development of these deposits will likely require access to the public capital markets, and in Canada that means providing scientific and technical disclosure on these deposits in compliance with NI 43-101. As many of these “challenged” projects have metallurgical issues, the companies that own the projects need to ensure their metallurgical Qualified Persons provide transparent disclosure regarding proposed solutions to those issues.This paper provides an overview of the disclosure requirements under NI 43-101 that are pertinent to metallurgists, and other Qualified Persons who prepare technical disclosure regarding the metallurgical characteristics of a mineral project. It lists the triggers for a technical report under NI 43-101 and Canadian stock exchange policies, and identifies the sections of the report that should involve input from a metallurgist or process engineer. It briefly outlines new civil liabilities under Canadian securities laws that increase the possible consequences for not complying with the technical disclosure standards.These materials are provided for general information purposes only and do not constitute legal advice. Readers are advised to seek specific legal advice from their own legal counsel in relation to any decision or course of action contemplated."

Jan 1, 2003

By N. C. Karmakar, Y. V. Rao, M. Aruna

No one can properly work without sufficient light and this is especially so in mines where conditions are difficult. Artificial lighting is very important for the night shift to provide a safe and efficient working environment, which must be evenly illuminated with no obvious dark spaces and a minimum amount of glare. During an illumination survey of a large mechanized surface mine, it was found that the illumination level varied and was not uniform throughout the length of the road; it was high at one side of the road instead of at the centre. There were also different combinations of lamps, with angles of light arm varying from 35º to 70º. In this respect, an experimental study was carried out with a fabricated telescopic light pole to uncover the optimum design parameters of lighting installations. The analysis was done by plotting isolux contours for fixed installations and drawing graphs for various combinations of luminaries, reflectors, light arm angles, and height of lanterns by plotting the horizontal angle of the light arm along the abscissa, and the contour area along the ordinate. The study revealed that the design parameters of the lantern are mainly dependent on the type of luminaires. It was revealed that the pot reflector with a combination of tubular bulbs produces a wide distribution of light, and contributes towards a reduction of luminaries when installed in longer roads.

Jan 1, 2005

By Gabriel Voicu, Marc Bardoux, Ross Stevenson, Nuno Machado, Jean Lafrance

"Abstract - Paleoproterozoic gold is found in two different volcano-sedimentary sequences and intrusive bodies separated by 600 km within the Guiana Shield. The 2148 Ma St-Élie granite intruded volcanic-arc sequences of the Paramaca Group, whereas the 2096 Ma Omai stock penetrated backarc/ island-arc sequences of the Barama-Mazaruni Group. Positive ?Nd values suggest that both suites lack Archean crustal contaminants, which is consistent with an origin in an oceanic arc setting.The St-Élie deposit is characterized by quartz-dominant vein systems with minor metallic minerals, represented chiefly by pyrrhotite and pyrite. Biotite, calcite, and chlorite are the main gangue minerals. The alteration haloes at St-Élie feature a strong potassic zone, which is absent at Omai. The ore-controlling structures are ductile and the vein emplacement is related mainly to contemporaneous, high-angle ductile shear zones. The St-Élie deposit formed at temperatures >350°C. The stable isotopes values are compatible with a magmatic or metamorphic source.The Omai deposit is characterized by quartz-dominant vein systems with minor metallic minerals, represented mainly by pyrite. Ankerite, scheelite, albite, and chlorite are common gangue minerals. The vein emplacement is syn- to post-deformation and it is related mainly to brittle shear zones with low-angle, stockwork networks and breccia zones. The Omai deposit formed in a temperature range between 250°C and 170°C, much lower than the St-Élie deposit. The stable isotope values are compatible with mixing between deep-seated fluids of metamorphic or magmatic origin with surface- derived fluids.These differences between St-Élie and Omai are interpreted in terms of their depth of formation. Alteration patterns, structural elements, and paragenetic assemblages indicate that the gold at St-Élie was most probably emplaced at a mesozonal depth, whereas the Omai setting yields evidence for epizonal conditions."

Jan 1, 1999

By André Chagnon, Michel Malo, Benoît Dubé, Chantal Pelchat

"Abstract- In the southern Gaspé Appalachians, gold mineralization is spatially associated with the Acadian dextral strike-slip Grand Pabos-Restigouche fault system. Two different structurally-controlled gold prospects, the Lac Arsenault and the Saint-André-de-Ristigouche, are described to unravel the genesis of gold mineralization in this part of the Canadian Appalachians.At the Lac Arsenault gold prospect, gold mineralization consists of Au-As-Pb-Zn-Cu-(Ag) polymetallic fault-filled quartz veins with laminated textures emplaced in brittle-ductile sinistral X shear fractures. Mineralized veins are hosted by Middle Ordovician graywacke of the Arsenault Formation, belonging to the Dunnage Zone, the Early Paleozoic oceanic domain of the Appalachians. Terrigeneous rocks of the Arsenault are regionally metamorphosed at the lower greenshist facies and the mineralized veins are included in a zone of Fe-carbonate alteration.The Sb-Au-As mineralization of the Saint-André-de-Ristigouche gold prospect, in the southwestern Gaspé area, comprises extension veins in the extension direction emplaced in brittle conditions. Mineralized veins are hosted by calcilutite and laminated silty and argillaceous limestone of the Early Silurian part of the White Head Formation, which belongs to the Gaspé Belt, the Middle Paleozoic successor basin in the Gaspé Appalachians. Metamorphic grade of the White Head Formation in the southwestern Gaspé area is very low, but the gold mineralization is included in a zone of hydrothermal propylitic alteration which includes two Cu-skarn mineral occurrences. The Lac Arsenault gold prospect has many characteristics of "greenstone-hosted quartz-carbonate vein" deposits whereas the southwestern Gaspé area, which includes the Saint-André-de- Ristigouche gold prospect, shows affinities with the geological setting of sediment-hosted gold deposits (Carlin-like deposits). The two gold prospects are controlled by the Grand Pabos- Restigouche fault system but they were not emplaced at the same level in the crust. Acadian strikeslip fauting played a major role in their respective genesis in providing channelways for ore-bearing fluids. The recognition of the analogy of the geological setting of the southwestern Gaspé area with that of Carlin-like mineralization gives new ideas for exploration in the area and elsewhere in the Appalachians.Résumé - Dans le sud des Appalaches de la Gaspésie, on trouve des minéralisations aurifères spatialement associées au système de failles de coulissage dextre acadien de Grand Pabos-Restigouche. Deux indices très différents, Lac Arsenault et Saint-André-de-Ristigouche, sont décrits pour évaluer la genèse des minéralisations aurifères à contrôle structural de cette partie des Appalaches canadiennes. Au Lac Arsenault, la minéralisation aurifère comprend des veines polymétalliques à Au-As-Pb- Zn-Cu-(Ag) en remplissage de failles. Ces veines à texture laminaire se retrouvent dans des zones de cisaillement fragiles-ductiles senestres de type X. Les veines minéralisées sont encaissées dans les grauwackes d’âge Ordovicien moyen de la Formation d’Arsenault appartenant à la zone de Dunnage, le domaine océanique du Paléozoïque précoce des Appalaches canadiennes. Les roches terrigènes de l’Arsenault sont métamorphisées régionalement au faciès inférieur des schistes verts et les veines aurifères sont dans de larges zones d’altération dolomitique (Fe-carbonate).Dans le sud-ouest de la Gaspésie, la minéralisation à Sb-Au-As de Saint-André-de-Ristigouche est dans des veines d’extension comprises dans la direction d’extension et mises en place dans des conditions de déformation fragile. Les veines minéralisées sont encaissées dans les calcaires argileux et les calcilutites de la partie silurienne de la Formation de White Head qui appartient à la ceinture de Gaspé, le bassin successeur du Paléozoïque moyen des Appalaches de la Gaspésie. Le degré métamorphique des roches du White Head est très bas, mais"

Jan 1, 1998

By P. Kostuik

"Recent interest in the pipeline transport of solid mate-als has been sparked by the idea that, in an inflationary onomy, pipeline costs are more stable than the costs of any other transport systems. Pipelines have proved over 1e years to be dependable, records indicate that main-•nance and operating costs are comparatively low, and 1eir amenability to automation is of considerable im->rtance.The concept of hydraulic hoisting of solids from under-round, or cross-country hydraulic transportation of con-~ntrates and ores, is currently of prime interest to the ining industry. In general, this paper deals with a preliminary investi-ation of energy losses incurred while transporting a rela-vely heavy, crushed mine product, namely magnetite, oth vertically and horizontally. The basis and validity of everal equations derived by other experimenters to com-ute these losses is discussed. A theoretical analysis of ydraulic hoi:,,ting is made, and, based upon test results, calculation of horsepower requirements for hoisting an re under a given set of conditions is presented. Results indicate that:n vertical transport, the friction head losses are identical to those of clear water, and the total energy requirement for hydraulic hoisting then becomes a function of height of lift, concentration and specific gravity of the solids being hoisted. .-In horizontal transport, friction head losses can be calculated with reasonable accuracy using Bonning-ton's correlation curve. Losses computed utilizing Durand's correlation (K = 85) result in estimates which are too low by 10 to 30 per cent, an<l those calculated using Newitt's correlation (K = 1,100, K = 66) give friction loss values which are too high by 10 to 30 per cent . . -The theoretical horsepower (RMS-hp.) required for hoisting hydraulically is approximately half of that required for conventional double-drum skip hoisting."

Jan 1, 1966

By G. W. Brooks

This short article is quite different to the general run of papers that are presented to the Institute, but no apology is offered because I consider that first-aid and mine-rescue work are of equal importance to many other subjects that are dealt with in our Transactions. Members of the Institute should be as much interested in the safety of persons engaged in the mining industry as they are in the practical methods of modern mining. We must not only do our best to conserve life and property by adopting every known device to that end, but we must also prepare ourselves so that we may take prompt and effective action when life is in danger, or when property is subject to loss. The need for such preparation in Alberta is perhaps greater than in most places where mining is carried on, and we must spare no effort to assemble at every mine men who are well trained in first-aid and mine-rescue work. The large area over which the mines are distributed renders central training stations out of the question, hence the need for local rescue-teams. Hospitals with skilled staffs, close enough to the mines to be convenient, also seem to be out of the question; therefore the greater need of a high standard of first-aid training for the people in our mining camps. The Government mine-rescue cars are supplied with the equipment necessary for training persons in this essential work and also for dealing with disasters should they occur. The question then arises: are there a sufficient number of men who are trained ? If so we can rest assured that what is possible to be done will be done. But if a sufficient number of trained men are not available much loss of life and damage to property is likely to result.

Jan 1, 1925

By L. C. So, S. Faucher, S. Mostaghel, A. Triwahyuono, D. Sauter, S. -Y. Oh, S. K. Lee, K. Aswin

"Molten hauling and water granulation are the commonly used slag treatment methods in the production of nickel. Water is present in these processes either to accelerate cooling of the dumped slag or in the granulation itself which creates an inherent safety risk of explosions. Even good design and operation are not sufficient to prevent explosions or injuries from occurring. Several dry methods to treat slags have been intensely studied. However, most of these technologies have never been commercialized due to numerous challenges including scalability, cost, low heat recovery efficiencies, and difficulties in heat utilization. Ecomaister-Hatch has recently developed and commercialized a reliable and simple Dry Atomization process, which eliminates water and allows for heat recovery. As part of the development towards other sectors, laboratory-scale and pilot-scale trials have been completed in a number of base metals and PGM facilities. Recently, Dry Atomization of a nickel laterite slag was successfully demonstrated at the laboratory-scale. The current paper introduces the technology and reports the test results obtained from atomization of the nickel slag.INTRODUCTION The processing of nickel laterites produces vast amounts of slag with over 90% of the feed to the furnace reporting as slag. Slag handing is therefore of critical importance to a laterite smelter. Traditionally there are two ways in which the slag is handled (1) Molten hauling, dumping, cooling and quarrying (2) Water granulation, dewatering, stockpiling. There are inherent disadvantages of both methods that will be outlined in this paper. An alternate route of Dry Atomization provides distinct advantages over the two conventional routes that are of particular interest to the nickel producer such as elimination of molten hauling, dumping and quarrying, elimination of water and improved safety. There is also the potential to convert the slag, which is typically regarded as a waste product, into a value added product and the continuous nature of slag tapping makes it amenable to heat recovery. Hatch has recently conducted laboratory-scale test work on laterite slag to demonstrate its viability for Dry Atomization. Results of this work are presented."

Jan 1, 2017

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."

Jan 1, 2017

By V. L. Gravitis

Radioisotope X -ray techniques of analysis for nickel have been tested in laboratory and plant trials. In the laboratory tests. a comparison was made of radioisotope and conventional analyses for nickel in solid s samples taken from streams of a nickel concentrator. Coefficients of variation of 1.7% for feed and concentrate samples , and equal to 10% for final tailing samples, were obtained. Continuous determination of nickel in final tailing slurries was demonstrated in a trial lasting 20 days at a nickel concentrator (Western Mining Corporation), nickel being determined with a standard error of 0.036% Ni in the slurry solids within the range of 0.24 to 0.68% Ni. This error, obtained by comparison of on-stream probe analyses with assays of samples taken from the stream, includes errors in sampling and assay by conventional techniques.

Jan 1, 1977

By Joël Kapusta

La pyrométallurgie du cuivre est essentiellement une chaîne de trois étapes successives d’oxydation préférentielle du fer et du soufre et des impuretés moins nobles que le cuivre qui sont contenues dans le concentré de cuivre issu de l’usine de concentration du minerai, aussi appelée concentrateur. La Figure 1 illustre la chaîne complète d’élaboration du cuivre depuis la mine jusqu’au cuivre pur. La voie hydrométallurgique traite le concentré par lixiviation, c.à.d. par dissolution en phase aqueuse à température typiquement inférieure à 100 ou 150⁰C, alors que la voie pyrométallurgique traite le concentré par fusion à température de l’ordre de 1200 à 1300⁰C.

May 2, 2024

By A Walker

The presence of high noise levels in many industries, together with the fact that countries are becoming increasingly concerned with the health of its citizens, has contributed to the importance of the problem of hearing loss. This problem has become the focus of scientific research, law and medicine, and the object of this thesis is to present the means whereby noise may be detected, with its resulting effects and possible means of control, in mining operations. 0BJECTIONABLE noise is a particularly prevalent by-product of the mining industry, and, al-though a dangerous noise level has been recognized, it is believed that at no time now, or in the future, will it be possible to enumerate a single over-all decibel figure at which hearing impairment will oc-cur. Individual susceptibility must be recognized in any study of occupational loss of hearing aimed at the setting of standards and criteria for industrial noise control.

Jan 1, 1963

By L. Furtenbach, T. Möller

"Grinding mills are the heart of the mineral processing plant, and are production-critical machines which are required to achieve high availability. Liner wear life and a liner design that promotes ease of installation are important variables to achieve a high level of mill availability. Increased mill size results in more mill internal surface to protect, and more liner components to install and remove. This drives designers toward an increase in liner size to minimize the number of components to be installed by the liner handler. The liner attachment method can also have a large impact on mill availability as well as safety during installation.This paper outlines the experience from the development, installation and follow-up of liners installed in two 38&apos; x 45&apos; AG Mills at Boliden Aitik in Sweden. A new Poly-Met shell liner concept has been developed to minimize the number of liner components. The new Poly-Met shell liner components are made much larger than conventional Poly-Met or steel liners. This reduces the number of components to be installed/removed by the liner handler and helps to minimize installation time and consequently down- time. A new attachment system has also been developed to eliminate the need for the installation crew to be in the “drop-zone” of the shell liners while installing the liner bolts.One interesting aspect of this project was the requirement to predict liner life for these new large format AG mills. The existing 22&apos; diameter mills at Aitik provided a base-line reference for this purpose, and DEM studies were used in the project development stage to predict the wear life of shell liners for the new 38&apos; diameter AG mills. The results from this study are included."

Jan 1, 2012

By Helen Shang, Jianjun He

In nickel and copper production, sulfur dioxide (SO2) is generated during mineral smelting. Emission of sulfur dioxide into the atmosphere causes serious health and environment issues. Sulfuric acid plants, which convert the harmful SO2 gas to commercially useful sulfuric acid product, ensures safe and environmentally sound smelter operations. The sulfuric acid plant is mainly composed of a SO2 to SO3 converter, a series of heat exchangers and SO3 absorption towers. The SO2 converter is crucial for minimizing SO2 emission in a smelter. In this paper, steady state and dynamic modelling are carried out for the converter using mole and energy conservations. Simulations are performed to investigate the effect of feed conditions on SO2 conversion. The developed model represents an important component for modelling the acid plant in a smelter and is expected to provide a fundamental tool for the future optimization and control development.

Jan 1, 2014

By I. Kirman, B. Waters

World wide applications for nickel use will be summarized and examples of those uses given. Nickel products are critical to many important aspects of modern society. These products are just as important for modern China as they are in other parts of the world. It is argued that future pattern of nickel use in China should be expected to be very similar to that in the rest of the developed world. Total use of nickel in products in China is already very large. In 2004, it was the largest market for stainless steel (nickel containing) in the world. A survey of Chinese stainless steel applications will be presented. Current high nickel prices have revived speculation about substitution, particularly for nickel containing stainless steels. The presentation will discuss some of the complicating factors that need to be taken into account when considering substitution. These factors are as valid in modern China as they are in other developed economies. Recent substitution efforts and the reaction to them will be examined. The Nickel Institute position regarding appropriate application of the various grades of stainless steel will be discussed. Price-motivated substitution in China, and elsewhere, will occur but it is argued that the extent will probably be limited.

Jan 1, 2005

By K. L. Ford, D. R. Lentz, J. H. Rickard, R. P. Taylor

Abstract - Coupled gamma-ray spectrometric and lithogeochemical studies throughout the Heath Steele Mines area, Bathurst Camp, New Brunswick, indicate that primary and secondary geochemical differences exist between the stratigraphic footwall and hangingwall crystal tuff units which host the massive sulfide deposits. Of particular interest is Th, and to a lesser extent, Zr and Y, which are more concentrated in the hangingwall than the footwall crystal tuffs, whereas the opposite is true for TiO2. This expands on earlier lithogeochemical-chemostratigraphic results concentrated in the eastern part of the Heath Steele belt that led to revision of the local stratigraphy, and necessitated a structural re-interpretation of the area with implications for exploration. Although K depletion (decreased K and K/Th) is typical of chloritized footwall zones of chloritization, these features were not fully apparent here due to the recessive nature of these altered zones. In situ radiometric analysis using a portable gamma-ray spectrometer is a rapid, inexpensive analytical technique for chemostratigraphic characterization of rock units within volcanogenic massive sulfide deposit settings, provided there is a contrast in the distribution of natural radioelements, particularly Th and K.

Jan 1, 1998

"In the present study, the reduction behavior of composite pellets comprising of iron oxide, synthetic graphite and slags were investigated in a laboratory-scale horizontal tube furnace. Two different types of slags indicating silicate base and aluminate base slags were chosen to examine the effect of slag chemistry on the reduction behavior of pellets. Slag composition of binding materials has influences on the reactions occurring in composite pellets during direct reduction. In-situ high temperature visualization approach was used to observe the slag / iron / carbon interactions at 1773K (1500°C). The off-gases were measured by means of infrared analyzer to determine the reaction rates of the pellets. Different physical appearances during the in situ reaction inferred a strong correlation between the slag composition and internal reactions. In addition, compression tests were conducted to examine physical strength of the pellets. This investigation was carried out to establish feasibility of physical property control of pellets by selecting optimum slag compositions of binding materials INTRODUCTIONCurrently, most of the iron ore mines have facilities that make an ore more usable for the blast furnace operation by improving its physical properties (e.g. pelletizing and sintering). However, during the process, a large amount of fuel is supplied to indurate materials which consequently deteriorate energy efficiency and produce more CO2 emission. Along with increased interests, direct reduced iron (DRI) making process; simply without coke oven or sintering process, has opened the era of clean and environmental friendly iron making process. While some of the established DRI technologies such as Midrex and HYL were restricted to certain locations where natural gas is abundant, coal based technologies using Rotary Hearth Furnace (RHF) such as FASMET and ITmk3 have been developed with regardless of expensive fuel deposit. In addition to the direct use of pulverized non coking coal and fine iron ore, RHF process also has advantages of utilizing waste materials such as EAF dust, biomass and recycled plastics. Nevertheless, there are still many challenges in the coal utilizing technologies as the unprocessed coal and the waste materials contain huge volatiles and ashes. Although recent investigations on volatiles in a RHF process (Sohn and Fruehan, 2005, 2006) have indicated the benefits of coal in terms of iron oxide reduction and have shown feasibility of multi-layer process, carbon composite pellets still have disadvantages because of its weak mechanical bonding strength. As the mixed system with carbon and oxides generates intermediate gases (e.g. CO and CO2) between solid particles, it is difficult to keep its physical state without the help of binding materials. In this reason, industries have been tried to use various binding materials such as bentonite, kaolinite and Portland cement. However, they are still struggling to find out new materials that provide not only sufficient mechanical strength but also metallurgical properties, such as porosity, reducibility and swelling throughout the reduction reaction. Recently, Canadian researchers (Aota et al, 2006) observed enhanced mechanical strength of pellets by using high alumina cement as a binder and concluded that the method could be used to recycle EAF dust as well, but in depth mechanism of reinforced strength has not been concerned. Most of the ashes coming from binders formulate certain type of slag during the reduction process due to its incombustibility. Thus, observation and regulation of slag property is an essential for the control of carbon composite pellet. Yet, only a little thermodynamic consideration from the perspective of slag chemistry has been adapted in the iron and steel making industries as ash has been easily ignored for its tiny proportion. In this study, effect of CaO-SiO2- Al2O3 slag system on the reduction of iron oxide was investigated in terms of"

Jan 1, 2012

By A. Roy, T. LeBel, P. Coursol, P. Lind

At the early stage of a mining project, small amounts of concentrates are available for testwork. For gold concentrate or ores containing significant arsenic levels, batch bench scale roasting is often unreliable, leading to highly variable gold recoveries to be used in the project’s financial justifications. With an appropriate bench scale unit using continuous feeding and residence time control for solid and gas phases, reliable numbers can be obtained at small scale with only a few hundred grams per test condition. This paper describes the development of a pilot fluid bed roasting unit by Kingston Process Metallurgy Inc. (KPM) to perform representative trials on gold concentrates containing arsenopyrite, arsenian pyrite and carbonaceous components. Calcines produced under different conditions were characterised by chemical analysis and electron microprobe; the calcine microstructure obtained is described. The most important parameter affecting gold recovery is oxygen content in the roasting atmosphere, with the lowest controlled oxygen level giving the highest gold recoveries. Higher local temperatures in the bed may cause the formation of molten glassy phases which can also reduce the gold recoveries significantly. The impact of roasting conditions in the two inch fluid bed is compared with commercial results obtained in full scale operation.

Jan 1, 2014

By P. E. Cavanagh

Introduction A comprehensive study of the economics of processes for smelting iron ores has been made by the Ontario Research Foundation on behalf of the Ontario Research Commission. This survey has included investigations of all processes in commercial use, and proposed processes which are still in the experimental stage. The two main objects of this work were to discover (l) whether any known processes would be particularly suited to present and future Canadian conditions, and (2) whether any new process would be of assistance in solving the present scrap shortage in Canada. The future prospects of the Canadian iron smelting industry have changed radically in the past ten years. For nearly twenty years before 1939 no iron ore was mined in Canada. The ore used was imported, mainly from the United States and Newfoundland. The economics of iron blast-furnace smelting always force the location of blast furnaces near the source of coal for making high-grade metallurgical coke, and near the market for iron and steel, rather than near the iron ore. Blast-furnace installations in Canada are confined to the north shores of the Great Lakes with ready access to United States coal and ore and the major Canadian markets, and to Nova Scotia near the coalfields of that Province. This distribution of primary smelting capacity naturally results in relatively high prices for iron and steel in the West, the North, and in Quebec.

Jan 1, 1948

By D. Shishin

Continuous integrated experimental and thermodynamic modelling work is conducted in Pyrometallurgy Innovation Center (PYROSEARCH). The target is to develop a tool, which is capable to predict the compositions of phases, phase equilibria and enthalpy balance for pyrometallugical processes with higher accuracy. All these can be achieved by thermodynamic calculations based on Gibbs energy minimization algorithm. Recent developments made it possible to predict important factors, such as the chemical solubility of Cu in slag as a function of matte grade, temperature, P(SO2), Fe/SiO2 ratio in slag, wt% Al2O3, CaO and MgO in slag. In industrial practice, it is not only chemical solubility, but the overall amount of slag, which affects the recovery of copper and other valuable metals. It will also impact the energy balance. The presence of solids in the slag matrix influences the physical entrainment of matte in slag. Oxygen enrichment which is sometimes used to control the temperature of the furnace, may also affect the volatilization of minor elements into the gas phase. Same is true if additional fuel is used to compensate for heat balance. In other words, all key process parameters mentioned above are interrelated. Present study demonstrates the ways thermodynamic modelling can be used to link those process parameters on the example of copper smelting. INTRODUCTION Research methodology involving integrated thermodynamic modelling and experimental approach has been recently reported by the authors (Shishin, Hayes, & Jak, 2018 Shishin, Hidayat, Jak, Decterov, & Belov, 2016). Present paper reviews the updates and discusses challenges in the development of a large self- consistent thermodynamic database. The database covers the Al-Ca-Cu-Fe-Mg-O-Pb-S-Si-Zn-(Ag, As, Au, Bi, Ni, Sb, Sn) chemical system. The database works in the environment of FactSage software Bale et al., 2016 and related family of products: ChemApp (Petersen & Hack, 2007), ChemSheet and SimuSage. A list of phases, and thermodynamic models is shown in Table 1. For the copper industry, most important phases are Gas, Slag, Spinel and Liquid matte/metal/speiss. Black-colored elements represent the base system, elements in green can be considered as slag modifiers (slagging elements), and elements in red are minor. Ni is highlighted because it was included recently, in 2019, and currently under development. In addition to copper, the database covers the conditions typical for lead and zinc pyrometallurgical extraction. It is developed in consistency with the experimental results for high concentrations of Pb and Zn. Examples of applications in the present study include the thermodynamic analysis of fluxing for an agitated copper reactor to show the effect of Fe/SiO2, and calculations of copper slag cleaning using reductant.

Jan 1, 2019