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By Niels Verbaan, Ron Molnar, David Dreisinger

"An acidic chloride leach solution was generated from the treatment of an ore containing the following value elements: silver, gold, indium, gallium, copper, zinc and lead. Iron was also co-extracted into solution as a ferric chloride species. Iron extraction was a significant component of the overall acid consumption of the leaching process. The recovery of iron by solvent extraction and water stripping was investigated. Tri-butyl-phosphate (TBP) was very effective at recovering iron from the leachate. The water strip solution could be decomposed to produce ferric oxide (hematite) and hydrochloric acid for recycle via hydrothermal hydrolysis or pyrohydrolysis.INTRODUCTION The Malku Khota deposit is situated in the eastern part of the Bolivian Altiplano at elevations between approximately 3,800 and 4,580 meters above sea level (Figure 1). The project is located 98 km east-southeast of Oruro, and 85 km south of Cochabamba in a relatively remote area."

Jan 1, 2016

The control of carbon concentration in a counter current carbon absorption circuit is critical to optimise gold recovery. MINTEK has developed a carbon movement controller to address this potentially problematic area in gold extraction. This controller reduces operator interaction by automating carbon movement. Elution schedules are entered into the control system, which then moves the carbon through the circuit into the first adsorption tank until enough carbon is available for elution. This is done while maintaining the specified carbon profile within the circuit. MINTEK has also developed an online-carbonconcentration- meter to measure carbon concentration in pulp. The meter uses an ultrasonic measurement technique. Long term testing has shown the measurement to be robust and require minimal maintenance. Results from a gold mine in South Africa’s well known Witwatersrand gold producing area has shown a decrease in soluble gold loss between 30 - 50% when the controller was used.

Jan 1, 2014

By S. M. Grillo, M. Fiori, R. Bornioli, C. Marini, S. Fadda

The Na-feldspar orebodies in Sardinia occur along structures belonging to a regional ENE-WSW system that developed during the late stages of the Hercynian orogeny, and that was reactived during the Alpine orogeny. The main petrographic facies include granitoids, albitized granitoids, albitites (more or less rich in quartz), and albitites containing Mg minerals. Field observations and petrological and geochemical data point toward a metasomatic origin for the albitite orebodies. Albitization involved depletion of K from K-feldspar and biotite, dissolution of free quartz, and a lowering of Sr/Na2O and CaO/Na2O ratios in the protolith, under conditions of a positive thermal gradient. The absence of later K-metasomatism implies that, during a subsequent decline in temperature, the composition of the albitizing fuids was modified by an influx of meteoric or other waters. Copyright © 1996 Canadian Institute of Mining, Metallurgy and Petroleum.

Jan 1, 1997

By W. Evans, T. Steis

"Sulphide ores under certain circumstances will react with explosives to generate an autocatalytic chemical reaction. This reaction is exothermic and results in the production of large volumes of poisonous gases and creates an unsafe, unstable condition with the possibility of a low energy deflagration or even a detonation of the loaded hole. This paper outlines the conditions that need to exist for such a reaction to take place and the precautions necessary to minimize or eliminate the problem in areas of reactive ore. A special case study involving a northern Ontario mine will be detailed.IntroductionOne of North America's leading underground gold producer's processes over 6500 tonnes of ore per day from an orebody containing high concentrations of sulphides. After six years of problem free operation, the mine experienced two serious reactions in two months between the sulphides and AMEX II, the ammonium nitrate and fuel oil explosive it uses."

Jan 1, 1995

By Raynald Vézina, Richard Leclerc, Jean Boissonnault, Louis P. Gignac, Gérald Veillette

Since mid-1989, Cambior has increased its producing gold mines from four to six, having acquired the Chima Mine and brought the Silidor Mine onstream. In June 1990, the company announced that the Mouska project would also be put into production. Gold production reached almost 190 000 ounces in 1989 and is expected to exceed 220 000 ounces this year. Cambior has also a non-gold operation with an interest of 50% in the Niobec Mine and has recently signed an option agreement in the development of the Lac Knife graphite deposit in northeastern Quebec. During the past year, the company has extended its exploration activities to the United States and Indonesia, and now has interests in nearly 80 properties. Last May, Cambior signed an option agreement with Golden Star for a gold deposit in Guyana, the OMAI Project, containing at least 2 000 000 ounces of gold in situ.

Jan 1, 1990

By A. Dave Mackintosh

The Current demand for potash has pushed world prices to record levels and allowed Saskatchewan producers to operate at maximum capacity. Several years of strong demand has resulted in a permitting rush not seen since the 1960?s. Even though Saskatchewan has a huge potash resource, mining and processing constraints will limit the areas of economic development. Introduction In 1969 M. E. Holter prepared a report ?The Middle Devonian Prairie Evaporite of Saskatchewan?, published by the then Dept. of Mineral Resources. Holter?s report has remained the bible of geologists working in potash ever since. It is astounding that a report written before there was really much potash mining history in the province, is as valid today as when it was first published. This paper re-iterates much of Holter?s report and adds a little mining experience to essentially confirm the importance of his work.

May 1, 2008

By A. I. Gorshkov, Y. A. Bogdanov, O. Y. Bogdanova

Abstract - Detailed crystal-chemical study of iron and manganese oxides and some other minerals from low-temperature hydrothermal deposits in a newly discovered inactive mound in the TAG hydrothermal field were used to determine the precipitation sequence of mineral phases during lowtemperature processes and their post-sedimentary transformations. Particles of primary sedimentary X-ray amorphous proto-ferrihydrite with high silica content were replaced in situ by nontronite, ferrihydrite, or goethite during alteration. Ferrihydrite is the only proto-hematite phase. The transformation of the iron minerals, related to change in the physicochemical environment, is an important characteristic of low-temperature hydrothermal processes. The occurrence of hydrogenetic Fe vernadite and Mn feroxyhyte in the uppermost part of low-temperature deposits and bottom sediments near the base of the mound is evidence for cessation of low-temperature hydrothermal processes. Among the investigated mineral phases, goethite, nontronite, and hematite are stable in reduced sediments only.

Jan 1, 1999

By B. M. Das, V. J. Hucka, J. H. Tu

Subsidence can cause serious damage to surface installations such as railroads, highways, pipelines, buildings and other facilities over a period of many years. Although total elimination of the effects of subsidence is difficult, the damage can be minimized through a systematic analysis. An example of such a study for reducing the effects of subsidence on pipelines is presented in this paper. Subsidence-induced stresses on a pipeline over some coal mining properties in Utah have been analyzed using a computer with graphics capabilities. The results are useful in predicting the extent of damages due to mining subsidence. In view of the gradual replacement of room-and-pillar mining by longwall with caving, this sort of analysis will become more and more important. In the next phase of this study the predicted results will be compared with the permissible stress levels on pipelines over actual subsided areas in an actual case.

Jan 1, 1989

By D. Lessard, S. Nantel

"Surface crown pillars are important Canadian,mining structures. Mines operating in the Canadian Shield usually have several, forming a first line of protection from surface elements.Detailed technical information from twenty-four Canadian hard rock mines show that the deposits dip steeply and are generally either single or multiple veins. Considerable overburden usually cap the deposits. The rock mass is often altered and intersected by important discontinuities.The designs for these types of pillars lack basic data and are based on experience rather than a scientific approach. Regardless of the competence of the rock mass, the surface crown-pillar thickness to width ratios (an unscientific design tool used by the industry) are usually less than five. Rock bolting is, in almost every case, used as a support measure. However, there are many openings neither backfilled nor monitored.The characteristics of openings with surface crown pillars are also examined."

Jan 1, 1988

By M. Isac, R. I. L. Guthrie, S. Ge

The Al-Mg-Sc-Zr alloys have shown exceptional potential as structural materials for transportation applications. These alloys have proved to be good candidates to be processed as thin strips via the Horizontal Single Belt Casting (HSBC) process. The HSBC process is a near-net-shape casting technology, which involves casting molten metal directly into thin strips, close to the final product thickness, at high cooling rates. It offers an efficient, economical and environmentally-friendly approach to the production of metal strips. Fluid mechanics and associated heat transfer are important aspects of any casting process, and the novel HSBC process is no exception. Three dimensional Computational Fluid Dynamics (CFD) simulations using ANSYS FLUENT 14.5 were performed, in order to assess the importance and effects of the various operational conditions of the HSBC process. This enabled process parameter optimization. Numerical predictions were validated against experimental casting results.

Jan 1, 2014

By O. A. Ojo, D. L. Chen, N. Zhou, J. Q. Zhang, A. K. Khan

Dual phase (DP) steels are designed to consist of hard martensite dispersed in a relatively soft ferrite matrix, which offers a favorable combination of high strength with good deformability. Fiber laser welding (FLW) is becoming increasingly important for joining advanced materials due to its flexibility and deep penetration. In this study, the microstructure of a dual phase steel, DP980, welded by FLW technique was carefully analysed. Gleeble thermo-mechanical simulation coupled with analytical transmission electron microscopy (TEM) revealed that the FLW process produced significant microstructural changes in a narrow heat affected zone (HAZ) and fusion zone (FZ), which can result in dramatic changes in mechanical properties. This is reflected in the micro-hardness profile obtained across the welded material. The salient phase transitions induced by the FLW, including the formation of new martensite grains in the upper-critical HAZ and FZ, are discussed.

Jan 1, 2014

By C. F. Harris

Following the initial development of the zinc-lead blast furnace, efforts have been directed both at increasing the scope of the process and increasing the cash return. The paper reviews the process developments which enable the process to smelt efficiently a range of material which encompasses high-grade zinc sulphide concentrates. mixed concentrates, Waelz oxide, zinc ashes and other materials blended to give a furnace feed ranging from 25 to 65% zinc and from 1 to 25% lead, with a copper-lead ratio exceeding 1 to 8. The paper also reviews the process developments which have enabled the capacity of a furnace and condenser system of standard size to be boosted from 30,000 to 80,000 tonnes/annum. The benefits achieved are used as a justification for continuation of the development of the zinc-lead blast furnace. Predictions are made of the benefits expected from further developments.

Jan 1, 1979

By B. M. Das, F. Claridge, V. K. Garga

Coal, as well as a large part of other minerals in Canada, is produced by surface mining methods. This has resulted in short and long-term accumulation of waste rock in dumps. Two main problems arise from the flow of water through these dumps: stability of dumps and the impact on stream flows. In recent years, a number of mines have started placing waste rock in valleys for general disposal or far constructing mine access road ways. All these have created challenges in the following areas: effective design of dumps and flow-through dams; stability monitoring of the structures; environmental impacts downstream by way of increased amount of fines in suspension, sedimentation, and toxic substances; and long-term status of flow and flood. Similar situations also exist in many civil engineering structures. This paper discusses the status of rock drains and the immediate and future research needs.

Jan 1, 1990

By G. Deschenes

"This literature survey discusses the recovery of gold from thiourea solutions. An overview of techniques used and general comments on the basic cyanidation methods are presented. The chemistry and mechanisms of cementation, activated carbon, resins, electrowinning, solvent extraction and pressure reduction are examined. Conclusions and recommendations give orientation for future research and development activities in this field.RésuméCette revue littéraire traite de la récupération de I ‘or des solutions de thiourée. Elle fait un survol de I ‘ensemble des techniques utilisées tout en introduisant des commentaires généraux sur la méthode classique qu'est la cyanuration. La cémentation, Ie charbon active, les résines, l'électroextraction, I ‘extraction par solvant et la réduction sous pression sont les méthodes analysées tout en considérant leur caractère chimique respectif ainsi que les mécanismes qui y sont rattaches. Des conclusions sont tirées et différentes recommandations sont suggérées pour orienter la recherche dans ce domaine."

Jan 1, 1986

By K. Meyer, M. E. Goddfellow

"At Teck-Corona Operating Corporation's David Bell Mine, a water quality management strategy is employed to produce both a chemically and biologically clean effluent prior to discharge to the environment.The strategy includes operating methods to minimize contaminants leaving the concentrator and an effluent treatment plant for cyanide, antimony, and heavy metal removal of concentrator, mine and site waste streams.Concentrator practices, the effluent treatment plant, process chemistry and the present day performance of the water quality management strategy are reviewed.INTRODUCTIONThe David Bell Mine is located in the Hernia gold camp 35 km east of Marathon, Ontario. The concentrator has a design throughput of 1,000 tonnes per day. ROM ore (-6"") is ground in a semi-autogenous mill followed by a ball mill, thickener, leaching, and carbon-in-pulp gold recovery unit operations. The concentrator flow sheet is shown in Figure 1."

Jan 1, 1991

By F. Lindroos

A cornerstone in the LKAB Green Pellet concept is to produce pellets with a small footprint in terms of energy con-sumption, CO2 emission and emission of other elements harmful to the environment, like dust, sulphur dioxides, nitrogen oxides, chloride and fluorine. The concept also encompasses our determination to make pellet products that contribute to low environmental impact and low energy consumption in our customer?s processes. The presentation will focus on the pelletizing process. It will describe both how we have attempted to decrease the generation of unwanted components in the process gas, and how we have tested or evaluated equipment for external gas cleaning. We will discuss and give examples from recent and on-going efforts and outline some of the future challenges we see, to meet our own environmental standards and also the tough demands imposed by EU and national legislation, while striving to boost production.

May 1, 2011

By Marc Ruest

A new instrumented cable bolt has been developed by the National Institute for Occupational Safety and Health at the Spokane Research Laboratory in Spokane, WA. Although various instruments are available to measure load distribution and magnitude along a grouted cable, this instrument is innovative in that it uses strain gauges internal to the cable as load-measuring sensors. The instrument has been successfully tested in the field at FMC?s Granger Mine, Meikle Mine, and Getchell Mine. A ?split-pipe? laboratory pull test was performed on each of three cable bolts instrumented with the new device. Each test consisted of grouting a 1.83-m-long cable in two 0.91-m-long sections of schedule 80 pipe. A numerical analysis was then performed in which laboratory boundary conditions were simulated and model properties derived from textbook guidelines. The loads calculated by the model were then compared to the measured loads.

May 1, 2002

Overview ?G-9 Discovery Hole 420 drilled May 2005 ?14.16% Zn, 1.76% Cu ?Greenfield discovery built into the G-9 Mine in under 4 years. ?Utilized a unique ?Parallel Track? approach to fast-track mine development. ?Raised over $200million in financing without a Feasibility Study. ?Mine built for $149.7 million, only 20% over PEA. ?Commercial Production declared April 1, 2009. ?G-9 Mine has now completed the first year of commercial production on April 1, 2010. ?Initial cash costs per pound of zinc US$0.39/lb -US$0.45/lb range. ?Mill operating at over1,900 tpd in March 2010, well above design capacity (1,500tpd) only one year after starting commercial production. ?Balance Sheet -$167 million assets, $24 million long-term debt, $22 million cash. ?Restarted Exploration ?excellent initial results. ?Strategically positioning Farallon to grow to a mid-tier mining company.

May 1, 2010

By Carlos Palacios M., Brian K. Townley

"Abstract - The mainland Aysén region of Chilean Patagonia (44°15' - 47°30'S) is a representative segment of the South American active continental margin, distinct with respect to northern and central Chile. Mineralization consists mainly of polymetallic deposits, with important Zn-Pb mines and more recently discovered Au-Ag deposits, unlike the central Andes, which are dominated by Cu mineralization. On a regional scale, rocks may be grouped in four main map units: 1) the Paleozoic metamorphic basement; 2) upper Jurassic-Cretaceous calc-alkaline volcanic and marine sedimentary rocks; 3) the Patagonian batholith, and 4) upper Cretaceous to Miocene basalts and marine and continental sedimentary rocks. The upper Jurassic-Cretaceous rocks and the Patagonian batholith formed in a volcanic arc and back-arc setting superimposed on the Paleozoic metamorphic basement.Based on geographic location and geologic and tectonic setting, ore deposits in this region are assigned to three groups, from south to north: El Faldeo, Fachinal, and El Toqui. The El Faldeo group (south of 47°05'S) includes upper Jurassic Zn-Pb skarn and associated polymetallic massive sulfide vein deposits locally overprinted by Au-rich epithermal mineralization, hosted by volcanic and sedimentary rocks and/or by rocks of the metamorphic basement. The Fachinal group (46°05' - 47°05'S) consists of volcanic-hosted lower Cretaceous Au-Ag epithermal deposits, except for the Mina Silva and Manto Rosillo deposits, which are metamorphic basement-hosted Zn-Pb skarns. The El Toqui group (44°30' - 46°05'S) comprises lower Cretaceous Au-rich Zn-Pb skarns and associated polymetallic veins, as well as Au-Ag-rich epithermal deposits, hosted by volcanic, intrusive, and marine sedimentary rocks. Galena lead isotopic signatures for each deposit group indicate a decreasingly radiogenic trend from south to north, suggesting different lead sources or differences among underlying crust. Three metallogenic provinces and two metallogenic epochs are proposed for the Aysén region: the El Faldeo metallogenic province of Late Jurassic age; and the Fachinal and El Toqui provinces of Early Cretaceous age. Résumé - La partie continentale de la région d’Aysen (Patagonie chilienne, 44°15' - 47°30'S), est unsegment représentatif de la marge continentale active d’Amérique du sud, différent des segments du nordet du centre du Chili. La minéralisation, qui consiste essentiellement en des dépôts polymétalliques, avec d’importantes mines de Pb-Zn, et des dépôts d’Au-Ag récemment découverts, différe de celle des Andes centrales où domine la minéralisation cuprifère. A l’échelle régionale, les roches peuvent être regroupées en quatre unités cartographiques principales : 1) le socle métamorphique paléozoïque, 2) les roches volcaniques calco-alcalines et les sédiments marins du Jurassique supérieur-Crétacé, 3) le batholite patagonien, et 4) les sédiments marins et continentaux ainsi que les basaltes du Crétacé supérieur-Miocène. Les roches du Jurassique supérieur-Crétacé et le batholite patagonien, formés dans un contexte d’arc volcanique et d’arrière-arc se superposent au socle métamorphique paléozoïque.Fondé sur la localisation géographique ainsi que sur le cadre tectonique et géologique, les dépôts de minerais de cette région se répartissent en trois groupes, du sud au nord, El Faldeo, Fachinal et El Toqui. Le Groupe El Faldeo (sud de 47°05'S) contient des skarns à Pb-Zn du Jurassique supérieur associés à des veines de sulfures massifs polymétalliques, localement recoupées par des minéralisations épithermales, riches en Au, et contenus dans des roches sédimentaires et volcaniques et/ou dans des roches du socle métamorphique. Le Groupe Fachinal (46°05' - 47°05'S) consiste en des dépôts épithermaux Au-Ag, se trouvant dans des roches volcaniques du Crétacé inférieur, excepté pour les dépôts de la Mine Silva et Manto Rosillo, où des skarns à Pb-Zn, se trouvent dans le socle métamorphique. Le Groupe El"

Jan 1, 1999

By W. P. Clement, M. C. Bell

"PT International Nickel Indonesia, a subsidiary of Inco Limited, mines and processes nickel laterite ores for the supply of nickel matte, primarily to the Japanese market. It has large ore reserves and a substantial portion of its energy requirement is supplied from its own hydro-electric plant. Since the early 1980s, the company has increased its production level and has dramatically reduced its unit costs. Projects are in progress to further decrease costs and recently a major expansion - 31% increase in nominal capacity - has been undertaken, consistent with marketing opportunity in Japan. The expansion project, which has a low capital cost per unit of production, is outlined in this paper.IntroductionPT Inco is a fully integrated mining and smelting facility located in Indonesia on the island of Sulawesi, and is based on a very large, world class nickel laterite orebody located 60 km inland from the Gulf of Bone. Construction of a single furnace line plant started in 1973. Complete supporting infrastructure of townsite, hospital, schools, shopping centres, road systems, and an airport, all had to be built. Prior to completing the first phase, the decision to expand the plant to a three kiln-furnace line was made. A major factor in the decision was the ability to develop the hydroelectric potential of the nearby Larona River. This involved construction of a 30 m high dam, and a 7 km surface canal to the generating station. The penstocks drop 150m to three 55 Mw turbines. The power generated is sufficient to supply the entire electrical load for the complete smelting complex and town site. The unique capability to supply the high smelting energy requirements for a lateritic nickel ore by fully captive hydro power, has, over the past decade insulated PT Inco from the large upward swings in oil prices suffered by other lateritic nickel producers.Wet ore is first partially dried to 20% moisture in two co-currently fired rotary driers, screened on an internal trommel, and delivered to two dry ore storage buildings. The partially dried ore is calcined at 750°C and partially reduced in three large 100 m by 5.5 m kilns. Reduction is accomplished by lancing bunker C oil onto the ore bed at the discharge end of the kiln. The kilns are equipped with five air pipes with onboard blowers to gradually bum the combustible gases generated by the lance oil. The kilns were also originally equipped with two side burners to supply additional heat close to the feed end of the kiln. Calcined ore is transferred by 20 ton refractory lined containers to the furnace feed bins at the top of the smelter. Smelting is carried out in three 18 m diameter furnaces powered by 45 Mw transformers. Slag is skimmed at 1550°C through water cooled breast plates and removed to the slag dump by Haulmaster Carriers. Matte of 25% Ni, 1O% S, 65% Fe is tapped at 1350°C into the converter aisle. The iron is slagged in converters to produce a nickel sulphide matte at 80% Ni. Three rotary Kaldo converters were initially installed. The product matte is granulated, dried, and shipped in returnable rubber bags to Japan. Most of the matte is fluid-bed roasted to nickel oxide and then directly reduced in a second reducing fluid bed reactor at our facilities in Japan.The smelting complex was designed to smelt two million tonnes of dry ore per year, equivalent to 34 000 tonne nickel production at an ore grade of 2% Ni. The cost of the entire project including working capital was $900 million."

Jan 1, 1990