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By A. Noël, R. Lapierre, M. Provencher

"Modem aluminum smelters are facing significant operating cost pressure. Key methods used by smelters to manage this pressure are automation and production-information systems to optimize processes, manage quality, anticipate problems and reduce operating costs. In 2002, Aluminerie Alouette Inc. began its Phase II Expansion project, and retained the joint venture of SNC-Lavalin and Hatch (SLH) as its engineering, procurement and construction management (EPCM) team. Alouette had the distinction of being one of the most efficient aluminum smelters in the world. Alouette already understood the importance of systems integration in project delivery. For Phase II, key objectives were identified to ensure ""a state of the art"" integrated architecture that would support Alouette's production goals to integrate the existing facilities with the expansion, to form a single efficient facility and meet project schedule and budget targets. Achieving those objectives within the context of a large project often creates major challenges due to the nature of the traditional EPCM delivery model, which relies on several vendors and third-party-systems integrators. In this case, an integrated Alouette-SLH team was made responsible for all aspects of the systems integration, taking over the task from most suppliers. The integrated team was responsible for delivering an automation system and plant-wide-production IT system for the new facilities while accommodating migration for the existing systems. Through the use of rigorous methodology and advanced state of the art technology, the IT and automation strategy led to significant value creation and is recognized today as one of the key factors of the project's success. The primary results were: fast and efficient start-up of facilities, due to quality programming and implementation; a plant able to operate as a single entity; automation and IT systems delivered before time and under budget; standard programming methods implemented throughout the plant; and reduced and simplified maintenance."

Jan 1, 2006

By U. Caliskan, S. Miskovic

Gravity separation is a technique that depends on the difference in density of minerals for their separation. Although this method is one of the oldest separation techniques, it is still preferred in the industry because of its low capital and operating cost while it is environmental-friendly. In this paper, we present a new numerical methodology that can be used to investigate dynamics of dense slurry flows in gravity separation systems. A simple channel with a set of riffles is selected as a test platform in order to observe the effect of the riffle shape on segregation profile of particles with different densities. It is believed that the riffle shape would affect the slurry flow and possibly cause one class of particles to segregate within the riffle zone. The turbulence, as a disturbance effect within the riffle zone, causes heavy particles to displace the light, that is, the heavy particles will be trapped in riffles, while the lighter particles are carried by water to the end of the channel, which is an example to uninterrupted suspension. MP-PIC model in OpenFOAM is used to study the effect of riffle shape and slurry percentage of solids in this simple gravity separator on particle segregation profile of four discrete mineral density classes, which are Quartz/Clay (SG 2.6), Pyrite (SG 4.2), Chalcopyrite (SG 5.1), and Gold (SG 19.32). Gold particles are found to be readily captured and retained in the riffles because of their high density, while particles with the intermediate densities are more influenced by the flow. The developed model framework has been proven robust and capable of providing physical results even for the flows with a very high percentage of solids, characteristic for mineral processing operations. INTRODUCTION Gravity-based ore concentration techniques make use of differences in density of minerals within an ore to enable separation of valuables from the gangue. As some of the oldest techniques used for ore beneficiation, they are known to offer a range of benefits such as low specific energy consumption and low capital and operating costs (Burt, 1999; Falconer, 2003; Holland-Batt, 1998), however, they suffer from low selectivity, poor separation efficiency, and low capacity. Gravity separation techniques are common practices in the mining industry and are employed widely for the precious mineral concentration, iron ore recovery and coal preparation (Kroll-Rabotin, Bourgeois, & Climent, 2013; Laplante & Spiller, 2002; Williams, 1997). For example, gravity separation systems are highly applicable for precious metal enrichment operations by being included in primary grinding circuits, shaking table tailing separation, pre-concentration of leach feed and flotation concentrate enrichment for both flash and conventional flotation purposes (Burt, 1999; Falconer, 2003; Holland-Batt, 1998; Laplante & Spiller, 2002; McAlister, 1992). Gravity separation can be employed in the copper processing circuits by being integrated into the pre-flotation circuit to capture the gravity recoverable gold (GRG) and any free copper aiming to enhance the gold and copper recovery of the plant. When native copper and GRGs are present in the deposit, this integration not only facilitates plant overall performance via removal of the valuables early in the circuit, but it also reduces downstream operational expenditures due to less retention time of coarser copper particles in the system.

Jan 1, 2019

By Phillip Mackey, Elmira Moosavi-Khoonsari

L'industrie du cuivre traverse une période passionnante, marquée par une forte demande, de bons prix et l'ouverture de nouvelles grandes installations. L'année 2022 a battu des records de production de cuivre, ce qui laisse entrevoir un potentiel de croissance supplémentaire. De grands projets sont en cours, comme la technologie Double Flash à Manyar, en Indonésie, qui peut produire plus de 500 000 tonnes de cuivre par an. À Munda, en Inde, on a construit la plus grande usine de cuivre du monde, qui produit plus de 1 000 000 tonnes de cuivre par an en combinant deux phases. De plus, l’installation de cellules de flottation de dernière génération au Mexique, au Chili et dans d'autres pays témoignent de la volonté de l'entreprise d'utiliser les technologies les plus récentes [1]. L'importance du cuivre dans la transition énergétique est évidente, l'accent étant mis à la fois sur la croissance et sur la protection de l'environnement. Cela se traduit par le développement d'usines de premier ordre dédiées aux pratiques durables.

May 2, 2024

By C. Acuña

The case is presented that the key role of frother is control of bubble size in the pulp zone. Compared to water alone, the addition of frother produces a narrower distribution and finer bubble size. An empirical model is presented for bubble size as a function of frother type using a normalized concentration. The model provides a benchmark for assessing operations. There is no agreed upon mechanism of how frothers act to reduce bubble size. Prevention of coalescence is a common explanation and this action is illustrated. The case against the 'coalescence' model alone is presented and a breakup mechanism is introduced based on pilot cell and single bubble studies. Phenomena associated with bubble shape, velocity and surface flows are used to illustrate the force associated with surface tension gradients. Breakup mechanisms resulting from this force are proposed. The concept can be extended to high salt concentrations which also promote small bubbles.

Jan 1, 2007

By Hong-wei Ma

With social development and technological advancement, mine rescue robots used in complex environments have developed as a research hotspot. This paper reviews the progress of research on coal mine rescue robots, and key technologies of rescue robot design are put forward, such as mechanical structure, self-navigation and self-orientation, multi-sensor information fusion, multi-robot cooperation, and wireless communication technology.

Aug 1, 2013

By Unknown

With the present-day trend of rising labour costs and a lowering of production efficiency of workmen, it has become imperative that every effort be made to use manpower to the greatest advantage and to mechanize mining as much as possible. During the past few years this trend has gained much prominence in the Porcupine camp. In view of this, the executive of the Porcupine Branch considered that the Mechanical Movement of Muck would be a very timely subject for a Symposium. Accordingly a Committee was formed, with A. K. Douglass, Mine Superintendent for Delnite Mines, Ltd., as Chairman, and the Symposium was held in the Auditorium of the McIntyre Community Building, Schumacher, on March 25th last. Papers dealing with shovel loader and mechanical scraper operation at six of the larger mines of the camp were presented and discussed, and a tabulation was prepared giving data on the machines in operation at a total of eleven mines. The papers and tabulation, reproduced below, will doubtless be of considerable interest to operators of mines in all parts of Canada.

Jan 1, 1948

By J. S. Fox

It is generally recognized that the interpretation of bedrock geochemical data in volcanic terrains can be improved by adjusting for rock-type. Various chemical attributes of volcanic rocks have been put forward in the literature as rapid indicators of rock-type, but there is some question as to which of these is the most reliable . Only one such attribute, total iron, seems to have seen systematic use in geochemical mapping in the Flin Flon region. Discriminant analysis of 500 basalts, andesites, dacites and rhyolites suggests that SiO2 is the most important rock-discriminating variable and that MgO, CaO, TiD2, AI2O3 and FeOtot, are successively poorer discriminators. Lithological normalization in the subalkaline volcanic environment should therefore be made over ranges of this variable. Trace-metal data from drill core through the sulphide orebody at Hanson Lake, Saskatchewan are used to demonstrate various approaches to lithological correction, including silica normalization, factor analysis and trend analysis. All of these extract economically important information from the core that is not apparent in the raw data logs. However, silica normalization does not seem to be subject to as many serious limitations as factor and trend analysis in this case, and therefore seems to provide the most reliable basis for the interpretation of subsurface exploration geochemical data.

Jan 1, 1978

By J. Chretien

The ability to continuously monitor the air quality within a mine has become instrumental in becoming a low cost producer. The many considerations involved in monitoring air quality include sensor type, hardware placement, as well as data storage medium. BESTECH has had the opportunity to gain insight into these air quality monitoring considerations through deployments of NRG1-ECOTM, a minewide energy consumption optimization system. This paper explores the particular challenges overcome through these installations, and provides a set of guidelines for mines that want to maximize data capture while minimizing costs. It provides a view of additional benefits of air quality monitoring, such as ventilation control, reporting and trending.

Aug 1, 2013

By M. N. Pons, F. Ferrari, V. Houzelot, B. Laubie, A. Bani, Université de Lorraine-CNRS LRGP

"More than 400 plants in the world are able to accumulate nickel in their aerial parts at concentrations higher than 10 g per kg of dry biomass. Then, nickel (Ni) can be recovered from the biomass of these hyperaccumulator plants. Agromining is a chain consisting in growing such plants and recovering metal and has been developed thanks to the combined know-how of agronomy and hydrometallurgy. Plants can be grown on serpentine soils, containing rather high concentrations of Ni, on sterile heaps or on contaminated soils. This crop enables us to extract Ni from secondary resources, and to improve soil quality by lowering its metal content. For example, Alyssum murale can be grown at the field scale in the Balkans, at yields corresponding to 110 kg Ni per hectare.Hydrometallurgical processes have been designed from the lab scale to the pilot scale to produce nickel salts: ANSH (ammonium and nickel sulphate hexahydrate), nickel sulphate, acetate, etc. and so on. These salts are used for surface treatment and in the paint and chemical industry. Ni salts are prepared from ashes, after plant calcination. Processes are based on the conventional methods of hydrometallurgy: acid leaching followed by different precipitation steps. These processes will be presented, as well as the pilot scale design. A life cycle assessment has been performed and clearly shows the environmental interest of this approach as a potential part of an anti-erosion strategy. An economic assessment has proved process feasibility and the final step is the launching of a start-up. At the moment, the approach is widened to other metals (cadmium, cobalt) and rare earth elements (REEs)."

Jan 1, 2016

By M. Clotilde Apua, A. F. Mulaba-Bafubiandi

"The efficiency of hydrochloric acid (HCl) leaching of gold from low grade gold-bearing material has been investigated in the presence of sodium hypochlorite (NaOCl) to produce in situ chlorine gas which is an oxidizing agent able to oxidize gold metal to its soluble forms. The effect of concentrations of HCl, NaOCl, and mixtures of HCl + NaOCl was sought. Iron and potassium present in the feed were leached and consumed all the HCl. Gold found as inclusion in pyrite was not exposed to the lixiviant. Therefore, leaching of gold from low grade gold-bearing material in aqueous chlorine solution is not an effective process for now.INTRODUCTIONHydrometallurgy of gold is commonly based on cyanide leaching solution. Due to the environmental concerns related to cyanidation and mercury processes, and inefficiency of cyanide gold leaching to dissolve refractory ores, sustainable alternative lixiviant systems, capable of generating gold (I) and gold (III) complexes must be studied. Amongst non-cyanide gold lixiviants there is the chloride/chlorine system (Hilson and Monhemius, 2006; Senanayake, 2004; Pilsniak and Trochimczuck, 2007; Wang et al., 2007; Reeves et al., 1999; Khodadad et al., 2008).In practice, the most oxidizing agents utilized for the leaching of gold as chloride, are chlorine (Cl2) or hypochlorite (HOCl) which are either generated in situ by suitable reaction or added in solution (Adamson, 1972). The dissolution of gold concentrate using hydrochloric acid, sodium chloride and sodium hypochlorite (Cl-/HOCl system) were studied (Puvada and Murthy, 2006). The effect of NaOCl and NaCl concentrations were also investigated. The leaching was performed under the following conditions; time: 4h, solid–liquid ratio = 1:4, at room temperature. It was found that the increase of the NaOCl concentration from 25 to 75 g/L did not have any meaningful effect on the recovery of gold which was about 30% (experimental conditions; S/L ratio = 1:4, NaCl concentration: 25 g/L, HCl concentration: 0.35 M). It was also found that from 25 g/L to 200 g/L NaCl, the recovery of gold rose from 30% to 40% (experimental conditions; S/L ratio: 1:4, NaOCl concentration: 25 g/L, HCl concentration: 0.35 M)."

Jan 1, 2012

By Fidelis T. Suorineni

Rapid drifting enables quicker access to orebodies, higher productivity rates and a resultant reduction in activity costs. Increased advance rates, by examination of the key components (face preparation and drilling, hole loading and blasting, scaling, mucking and support installation) in the development cycle, and optimizing these processes is a high priority for research in the Canadian mining industry. Support installation time alone is typically 36 to 46% of the total development cycle time. A reduction in support installation time or techniques and alternative scaling strategies could result in significant gains in drift development advance rates. Support Staging and hydroscaling within the drift cycle could offer alternative drift development sequences that could reduce the overall cycle time. MIRARCO?s research into the support and hydroscaling processes for rapid drift development also suggests that there are many other factors (e.g. mine ventilation services) that have a significant impact on the rate of advance. These factors should be considered to promote and manage safe and rapid drift development. Constraints to the rapid drift development processes can only be overcome by sound construction management practices. In other words, the goals of rapid drifting can be achieved by the implementation of contractor-type construction management. This paper examines various constraints and processes affecting rapid drift development and draws attention to other factors affecting safe rapid drift development.

Apr 1, 2005

By Liang Zhen, Jian-Tang Jiang, Guo-Ai Li, Xiao-Ya Wang

"Deformation behavior of 2A97 aluminum alloy containing coarse secondary phases was studied using uniaxial hot compression (HC, 340–490°C, 0.4001–1 s-1). The flow stress could be described by a Zener-Hollomon parameter in hyperbolic sine function with the hot deformation activation energy of 237 kJ/mol. Based on the experimental data and dynamic materials model, processing maps were generated to demonstrate the hot workability of the alloy. The coarse secondary phases experienced dissolution by varying degree under different deformation temperature, which producing different effects on the microstructure evolution. When deformed at relatively low temperatures, a mass of fine grains shaped up in the original grains and grain boundaries, and the dominating deformation mechanism was believed to be dynamic recrystallization. As the deformation temperature rising to 490°C, most secondary phases disappeared and few recrystallized grains were observed, indicating that the secondary phases dissolved sufficiently along with dynamic recovery occurred during the hot deformation. Particle stimulated nucleation related to the coarse secondary phases was believed to promote the recrystallization and the recrystallization behavior was sensitive to deformation temperature.INTRODUCTION Al-Li alloys has received much attention as new promising structural materials in the aircraft and aerospace industries, due to their lower density, higher elastic modulus and improved fatigue crack growth resistance in comparison with the conventional commercial aluminum alloys (Ou Ling, 2015). 2A97 alloy is one of the 3rd generation Al-Li alloys targeting at comprehensive improvement of aviation aluminum alloy and applications for wing spars and ribs to other internal structures for transport aircraft. Al-Li alloys are usually formed by hot deformation, either by rolling or extruding. The deformation behavior and resulted microstructure evolution during the forming process mainly dominates the formability of the alloy and the serving performances as well. Therefore, the deformation behavior and microstructure evolution at elevated temperature need be made clear for optimizing the hot processing parameters and controlling microstructure evolution."

Jan 1, 2018

By J. Keith Haddock

"The Luscar Mine is a metallurgical coal mine located in the foothills of the Canadian Rockies, 41 km southeast of Hinton, Alberta. The mine is operated by Cardinal River Coals Ltd., a 50/50 joint venture between Luscar Ltd. and Consolidation Coal Company of Canada. The mine produces a high quality medium volatile metallurgical coal which is sold on the export market principally to Japan and South Korea. Operations consist of a surface mine with capacity to produce 3.0 million tonnes per year and an underground mine which is currently mothballed due to market conditions.GeologyBedrock units within the Luscar minesite are of Devonian to Upper Cretaceous age. The commercial coal measures in the area are, however, confined within the Lower Luscar Formation. The Luscar Formation consists of a 460-metre thick sequence of interbedded sandstones, shales and coal seams. The sequence is primarily deltaic in origin, and is bounded to the north and south at the Luscar mine by tectonically induced thrust faulting.The only mineable coal seam at Luscar is referred to locally as the Jewel seam. Average thickness of this coal measure is usually 10.5 m to 14 m, although in some areas folding and faulting has produced ""pods"" of coal from 15 m to over 40 m thick while in others the structural deformation has thinned the coal to 3.0 m to 4.6 m. Waste within the Jewel seam seldom exceeds a metre of shale, carbonaceous shale or infrequent sandstone stringers.Reserves and Coal QualityProven surface mineable reserves, based on pit scheduling through 1996, are 50.8 million raw tonnes. An additional 19.2 million raw tonnes are contained in possible extensions to the present planned operations. These surface mineable reserves are considered to be those reserves within 155 m of the surface. Underground reserves, located within 770 m of the surface show that 25.7 million raw tonnes have been proven to date in additon to 27 .5 million indicated and 260 miIJion inferred.Coal specification at Luscar Mine is as follows:"

Jan 1, 1985

By Linruo Zhao, Qi Yang, Akihiro Sato

TiN coating has a wide range of tribological applications from wear reduction of cutting tools to erosion protection of gas turbine engine compressor components. The performance of TiN coating depends on its microstructure, mechanical properties and adhesion strength which are influenced by the coating deposition process. In this study the effects of cathodic arc deposition conditions on the microstructure, hardness, adhesion and erosion resistance of TiN coating were investigated experimentally. It was found that varying deposition temperature, substrate bias and N2 pressure could derive a processing window in which TiN coating with superior erosion performance can be fabricated.

Jan 1, 2010

By CIM Mineral Resource, Mineral Reserve Committee

Industrial minerals are generally considered to include non-metallic minerals, mineral products, or materials that provide raw material inputs for the construction, chemical, and manufacturing industries. They are often relatively low-value and bulky materials that are generally used close to where they are produced; however, some raw materials may be transported hundreds of kilometres to manufacturers and customers (ENDM, 2021). They do not include the metallic minerals, mineral fuels, or gemstones, and are used in industries based on their physical and/or chemical properties (Wikipedia, 2021). In contrast to most metallic minerals, a general distinguishing characteristic of the industrial minerals sector is their general low degree of market elasticity in relation to the market prices and product specifications. The estimation of either a Mineral Resource or a Mineral Reserve (MRMR) for an industrial minerals deposit can be affected to a significant degree by a number of factors that are not typically applicable to metallic mineral deposits. These factors can include such considerations as the particular physical and chemical characteristics of the final product, product quality issues, market size and market access. In some cases, such information may be confidential and proprietary. One of the key challenges of the industrial minerals sector is to define a commonly accepted listing of which types of minerals, materials, or mineral deposits can be considered as industrial minerals (Mining Standards Task Force, 1999). Although definitions for what constitutes an industrial mineral can vary in detail, general descriptions can be found in American Geosciences Institute (2021), Fastmarkets IM (2021), Snowden (2019), SME (2021) and Wikipedia (2021). A brief listing of some of the materials and minerals that are generally considered to be industrial minerals is provided in Table 1. For the purposes of this document, all references to industrial minerals include not only the minerals, materials, and mineral deposits themselves, but also the various commercial products that are derived from these sources.

Nov 19, 2023

By G. W. Harris, P. Mousset-Jones, J. Daemen

"To minimize ore dilution induced by blast movement in surface mines, it is necessary to quantify such movement. This will enable more accurate location of the grade boundaries beneath the surface of a blasted rock pile before excavation. A method has been developed and tested to accurately measure the direction and magnitude of subsurface blast movement. This technique uses a cesium vapour gradiometer and a real-time, differentially corrected GPS system to locate pre- and post-blast position of magnetically enhanced target objects placed within blastholes inside a bench. The procedure developed does not require the blasted rock to be disturbed, and the movement information is available within a sufficient time to allow for modification of the selective mining boundaries for each surveyed blast. It was found that the maximum depth of target detection was 18 m, with the overall accuracy being measured as ±1 m (horizontally) and ± 1.2 m (vertically). IntroductionOre dilution is a critical concern for many mining operations. In some instances, it may be the cause of considerable mineral loss. Where the mineralization is finely grained, sedimentary and disseminated in nature, and exhibits no clearly defined visual ore/waste boundary, there is a heightened possibility for ore grade dilution. In most modern open pit gold mines, it is economically desirable to minimize dilution in the production process through the practice of selective mining by defining pre-blast ore digging boundaries, called digging polygons, on the preblast bench area. The polygons’ positions are defined by sampling the production drill holes, with the resultant assay and survey data being used to estimate the areas of specified grade content within the bench. Once the ore is blasted in the bench, the pre-blast locations of these digging polygons are flagged as designated areas on the broken ore pile. The purpose is for the loader operator to be able to recognize which areas of blasted rock are to be sent to the appropriate processing facility or to the waste dump."

Jan 1, 2001

"Virtual reality, a 3D computer-generated environment, has become a recognized delivery system for many forms of education. This paper describes the application of virtual reality to mineral processing education. An interactive mineral processing visualization module developed at the University of New South Wales, Australia, provides users with an overview of a base-metal concentrator and details about how the mined ore progresses through stages in processing. The module also involves developing instructional based plant layouts and flowsheets in the virtual environment. These assist the user in understanding the essential components of the base-metal concentrator.RÉSUMÉ La réalité virtuelle (RV), un environnement en 3D généré par ordinateur, est devenue un système de prestation reconnu pour diverses formes d’éducation. Cet article décrit l’application de la réalité virtuelle à l’éducation dans le domaine de la minéralurgie. Un module interactif de visualisation du traitement des minerais développé par l’université de Nouvelle-Galles du Sud, en Australie, offre aux utilisateurs une vision d’ensemble d’un concentrateur de métaux communs ainsi que des détails concernant la progression du minerai extrait à travers les différentes étapes de traitement. Ce module implique également le développement de schémas de réalisation et de traitement didactiques dans l’environnement virtuel, lesquels schémas aident les utilisateurs à appréhender les composantes essentielles d’un concentrateur de métaux communsINTRODUCTIONVirtual reality (VR) is the creation of an artificial environment that is experienced through sights and sounds provided by a computer (Squelch, 2001). The simulated environment is achieved through technologies such as 3D graphics, audio feedback, and special peripheral devices to produce interactive environments.Virtual reality has been used in diverse fields including medicine (Riener & Harder, 2012), entertainment (Hsu, 2011), military (Manojlovich, Prasithsangaree, Hughes, Chen, & Lewis, 2003), manufacturing (Zimmermann, 2008; Jiang, 2011), and chemical processing (Squires, Andersen, Reklaitis, Jayakumar, & Carmichael, 1992; Schofield, Lester, & Wilson, 2005). Virtual reality is also becoming the recognized delivery system for education in many fields, including engineering (Bell & Fogler, 1996, 1998; Shin, 2002). For example, VR laboratories have been designed and developed to teach users fundamental features of heterogeneous catalytic mechanisms and absorption columns (Bell & Fogler, 1995), the multi-phase and multi-component blast furnace iron-making process (Babich & Senk, 2009), and to guide users to identify various safety measures while working in a real laboratory (Bell & Fogler, 1996)."

Jan 1, 2017

By N. Saeidi

"For a mine section comprising 100 different stoping activities, there are ~10158 different possible stoping sequences to explore in the mine schedule optimization search and this figure is indicative of the challenge posed in maximising profitability through mine schedule optimization. Any viable excavation timetable must satisfy all conditions that will constrain feasible sequences. In general, consideration of additional constraint will tend to reduce profitability. Geomechanical constraints on mine schedules, introduced with the aim of avoiding excavation instabilities, can be established for underground mine schedule optimization processes but, currently, this is done only rather crudely; precedence relations between excavation activities (stoping or development) are encoded to produce particular stope sequence patterns (e.g. ‘chevron’ or pyramidal sequences).The work reported aimed to investigate automated processes for formulation of such geomechanical constraints. The timetable optimization approach to the problem precipitated a fresh look at time dependent, and excavation sequence dependent, deformation. Abundant evidence emerged that supported the notion that any methodology developed that failed to account for such time and sequence dependencies was itself bound to failure. Yet, it was also recognised that any deviation at all from an assumption of linear elasticity for geomechanical numerical modeling, adopted to inform geomechanical constraint formulation, would rapidly lead to impractical levels of computational effort.Thus the approach presented here represents a compromise: the elastic stress fields induced by individual mining activities are computed for each activity, independently considered within a computational domain identical to that of all other activities. These are stored in a database. Instability risk for a specific sequence of mine activities can be assessed through superimposition of stress fields drawn from the pre-computed database. Time stamps allocated to events corresponding to the excavation processes permit the conversion of the sequence of elastic stress fields into a time table of stress fields. For specific locations within the computational domain, the aggregate effect of the sequence of mine activities leads to stress-time histories having a castellated appearance, a result of the near instantaneous response of an elastic medium to the excavation perturbations. Time dependent deformation responses are crudely allowed for through the re-profiling these castellated histories through graphical construction of curved responses, where the curve gradients are related to a viscous parameter. Such curves form the basis for a geomechanical constraint formulation to be adopted for mine schedule optimization."

Jan 1, 2015

By W. E. Newton

THE following notes are offered primarily to show that industrial minerals or their products have a much more important place in the metallurgical industry than is perhaps generally realized, and with the hope also that some statement by the metallurgical consumer of the relative merits of various materials for particular requirements or services will l;>e of value to the industrial mineral producer. These notes are not in any way presented as complete. Also, some of the statements made may be debatable. The grouping adopted is as follows: (1) Refractories; (2) Fluxes; (3) Construction materials; and ( 4) Miscellaneous applications. Fuels are not dealt with in the present paper. REFRACTORIES GENERAL: Refractories are materials which will withstand high temperatures with-out melting or becoming markedly soft or pasty. While their primary function is to withstand heat, they are usually called upon to resist one or more of the following destructive influences: abrasion, pressure, corrosion by slags or fluxes, and rapid changes in temperature. Refractory materials may be conveniently divided into three classes: (1) Acid refractories-consisting of silica, or containing silica as their chief constituent. They combine more or less readily with metallic oxides, forming silicates, and are hence termed 'acid'. The most important of these are quartz, quartzite, siliceous sand, tripoli, Dinas rock, and ganister. Most fire-clays, although generally considered neutral sub-stances, contain relatively small amounts of free silica and are, to that extent, acid. (2) Neutral refractories-the term is merely relative in most cases, since, at high temperature, many of the refractories that are classed as neutral will react chemically with a strong base, functioning as a weak acid; or, conversely, with a strong acid, functioning as a weak base. Chrome and graphite are the most nearly neutral of all the commonly used refractory materials.

Jan 1, 1936

By Adriana Ramirez, Bradford C. Wesstrom, Blanca Olave

The Freeport McMoRan El Paso Copper Refinery optimizes electrolyte quality using a number of systems. The facility controls copper, arsenic, antimony and bismuth using electro-winning cells within the Tank House and Nickel Carbonate Plant Liberator Circuit (NCP). The NCP manages sulfuric acid content utilizing recycled electrolyte in the slimes autoclave as well as operation of the Acid Purification Unit, APU. The El Paso Refinery removes common sulfates using metal hydrolysis with sodium carbonate. Finally, a Mechanical Vapor Recompression, (MVR), at the water recovery plant removes sodium sulfate generated by the NCP. This paper will provide a summary of these operations. INTRODUCTION In the mid 1920’s Nichols Copper Company, in Laurel Hill, New York, recognized the need for a modern copper refining facility in the southwest. Because of the many railroad heads, affordable power and abundant labor supply, and the close proximity to regional copper smelters in Mexico, Arizona, and New Mexico, El Paso became the ideal location. In December 1928, ground was broken for the joint venture refinery between the Nichols Copper Company, Phelps Dodge, and the Calumet and Arizona Mining Company. In September 1930, Nichols Copper Company became a part of Phelps Dodge Corporation after a stock exchange. In July 1938, Nichols Division officially became Phelps Dodge Refining Corporation. In March 2007, Freeport McMoRan Copper & Gold acquired Phelps Dodge. Water is a precious commodity in the desert southwest, making conservation of this natural resource an important goal for the El Paso Operations. In the 1980’s, work on the treatment of slimes was improved through the use of pressure leaching of the refinery slimes using an autoclave. Due to the high tellurium content in the leached slimes solution, it was crucial to implement a method for its removal before the solution returns to the tank house electrolyte. A copper telluride cementation operation was installed for tellurium recovery and the ability for the recycle of the leachate and wash water to the refinery electrolyte. In October of 1997, ground was broken for the construction of the water recovery plant using an MVR to reuse process water, reducing water consumption by 25%. In 2002, electrolyte purification was further improved with the installation of an Acid Purification Unit, (APU) (Sheedy, Pajunen, & Wesstrom, 2007). The APU recycles 90% of the acids (both sulfuric and arsenic acids) back to the tank house electrolyte. The solution that passes through the APU is treated with soda ash to precipitate metals out of solution as carbonates and generates a sodium sulfate solution. This sodium sulfate solution is easily processed in the new water recovery plant, where the majority of the water recycles back into the plant as pure condensate. In 2012, the power plant at the refinery upgraded its Reverse Osmosis System to provide RO water to the tankhouse. This insured that the refinery would not have to bleed electrolyte for metals contained in well water such as: calcium, magnesium, iron and sodium chloride.

Jan 1, 2019