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By Descarreaux. Jean

"The Abitibi volcanic belt was sampled along a cross section extending from Matagami to a point east of Rouyn. A few samples were also collected in Louvicourt township, Quebec. The major elements were determined for 344 samples, and rock names were defined using normative minerals. The analytical data were studied by means of variation diagrams. The Abitibi volcanic belt is characterized by rocks belonging to both the tholeiitic and calc-alkaline magmatic series, but they show some differences as compared to some typical reference series, particularly those from Japan. Basalt is the predominant rock type and accounts for 44 per cent of the sampled outcrops. The volcanic rocks are relatively poor in K2O and TiO2. Regionally, the volcanogenic copper-zinc mineralization is associated with the calc-alkaline volcanic sequences. Locally, within such sequences, some types of abnormal deviations from the averages are recognized only in association with the copper-zinc mineralization. The anomalies are ascribed to hydrothermal alteration consisting of the introduction of MgO and removal of N a20; enrichment in K20 is also observed where zinc mineralization predominates. Examples of such anomalous zones show that, in places, this alteration phenomenon can be quite extensive. Petrochemical characteristics can be used as geochemical ore guides in exploration programs."

Jan 1, 1973

By L. C. Lien

Tower crane layout (TCL) is a typical construction site layout (CSL) problem, which is suitable for a wide range of work assignments and site conditions. Tower crane is one of the key facilities for vertical and horizontal transportation of materials, especially for heavy prefabrication units such as steel beams, ready mixed concrete, prefabricated elements and large panel formwork such as machinery and equipment, and a wide variety of other building materials within a construction site. However, it is a difficult combinatorial optimization problem to determine the locations of tower cranes with materials quantity supply and demand for engineers. Swarm intelligence (SI) was very popular and widely used in many complex optimization problems which was collective behaviour of social systems such as honey bees (bee algorithm, BA) and birds (particle swarm optimization, PSO). This study applied a hybrid swarm algorithm namely particle bee algorithm (PBA) based on a particular intelligent behaviour of honey bee and bird swarms by integrates theirs advantages. This study compares the performance of PBA with BA and PSO for a proposed hypothetical construction engineering of TCL with materials quantity supply and demand problem. Results show that PBA performs better performance than the mentioned algorithms on a proposed hypothetical TCL problem.

Aug 1, 2013

By Michelia Alba, Ronaldo S. Sampaio, Davi S. Braga, Mathieu Dubé

Climate change is pressuring industries and governments for decarbonization commitments, research, testing, and use of best practices to achieve the target of global warming below 1.5/2 °C. As it accounts for as much as 7% of all global CO2 emissions and 7% of energy consumption, the steel sector needs to address this issue with extended efforts. This paper provides information on the key potential of renewable biochar as an alternative fuel for pellet production. It also summarizes the successful application of biochar in a pioneering case study as the main fuel for a Grate-kiln pellet plant in Brazil, as well as the study of its use to replace coke and anthracite as an additive for iron ore pellets and other possible applications in the steel industry in COREM's precompetitive research & innovation program. The final discussion reveals the large quantity of biochar required by the Brazilian and Quebec scenarios for reducing CO2 emissions of iron ore pelletizing plants.

Jan 1, 2023

By G. Chahal, L. C. So, S. Faucher, S. Mostaghel, S. -Y. Oh, S. K. Lee

Slag dumping and water granulation are the most commonly used slag treatment methods in the metallurgical industries. In both processes, water is present (by desire for cooling and dispersion or as a result of rain accumulation) and thus equipment and operations are designed to minimize and mitigate the risk of steam explosions resulting from the inappropriate contact of slag with water. Slag handling practices have, therefore, never been inherently safe; even good design, operation, and maintenance are not sufficient to prevent explosions or other related injuries from occurring. For slag handling to become inherently safe, our industry must eliminate the potential contact of water with molten slag. This is today feasible with the advent of dry granulation technologies, a review of which is presented, and it thus falls to us, in the metallurgical sector, to lead the way in their final stages of development and adoption. Furthermore, while slag dumping and water granulation offer some metallurgists the means of valorizing their slag as a by-product, for most, this is not the case. The energy in slag is lost through dumping and water granulation processes, and where slag is sold as a by-product, it is for its chemical content only. Here, dry granulation processes also offer advantages including the production of by-products which hold value in both their chemical content and physical properties and heat recovery. Dry granulation, therefore, augments the methods by which slag may be valorized over traditional processing methods.

Jan 1, 2015

By B. K. Gorain

"As mining has evolved over a century, so are the challenges associated with mining. Mining of complex ore bodies at greater depths is a major challenge requiring high capital and operating costs due to remote locations, high energy costs, water quality and complex environmental issues. In addition, the stakeholder expectations are growing along with challenges associated with highly complex mine permitting processes and changing demographics of mining jurisdictions. The dynamic metals market adds to these challenges impacting the long term development and sustainability of mining projects.These challenges are compelling mining companies to look at various innovations with an integrated approach focusing on meeting the needs of various stakeholders. Mining companies are slowly tapping into some successful concepts that have transformed other industries such as manufacturing, chemical, pharmaceuticals along with oil and gas.This paper provides an overview of various innovations and technology developments in mineral processing that have shaped the current mining industry. A glimpse of the present and future challenges in mining is also presented. An integrated approach to problem solving involving various stakeholders is gaining momentum and this has been reflected in this paper. Various developments that are being pursed in mineral processing focusing on a change in the existing mining paradigm are also presented in this paper.INTRODUCTIONAs mining is evolving, so are the challenges associated with mining. Some of the key challenges are complex ore bodies at greater depths, high capital and operating costs, water scarcity and quality issues, high energy costs, complex environmental issues including tailings management, worldwide constraints on resource availability, more and more elaborated regulations in emerging economies impacting the permitting processes, increasing stakeholder expectations, changing demographics of mining operations with ever-changing cultural or community expectations and the urgent need for a better assessment of project viability, this in very dynamic metals markets impacting the dynamics of mining projects development and sustainability."

Jan 1, 2016

By G. Graves, J. A. Walker

"Abstract - The Mount Fronsac North volcanogenic massive sulfide deposit is the most recently discovered massive sulfide body in the Bathurst Mining Camp. The deposit occurs within a sequence of intercalated fine-grained felsic tuff and sedimentary rocks (Little Falls member), at the top of the Nepisiguit Falls Formation. Aphyric to sparsely feldspar-phyric rhyolite and related volcanic rocks of the Flat Landing Brook Formation overlie the host sequence. The massive and semimassive parts of the deposit have a north-south strike length of 525 m and a dip of ~45°E; the deposit is continuous downdip for 600 m, and thickness varies from 2 to 20 m. The deposit contains an estimated geologic resource of 14 Mt of low-grade, semimassive (>60%) to locally massive sulfides, and includes a high-grade zone of 1.26 Mt grading 7.65% Zn, 2.18% Pb, 0.14% Cu, 40.3 g/t Ag, and 0.40 g/t Au. The semimassive to massive sulfide intersections occur in an envelope of quartz-sericite±chlorite schist, which is interpreted to be intensely deformed felsic tuff. This sequence has a maximum thickness of 140 m and contains significant (up to 50%) fine- to coarse-grained disseminated pyrite. The pyritic envelope has a strike length of 900 m and extends over 1000 m downdip. Massive sulfides are found throughout this alteration envelope, but more commonly occur at or near the upper contact. The significance of the discovery of this deposit is that it represents a near surface discovery of a large tonnage sulfide body in a mature mining camp, one in which the possibility of discovery of a new shallow deposit had been all but discounted. This opens the possibility for future discoveries in this part of the Bathurst Mining Camp. Sommaire - Le gîte de sulfures massifs volcanogènes du Mont Fronsac Nord est la découverte de sulfures massifs la plus récente dans le Camp Minier de Bathurst. Le gisement est situé dans une séquence de tufs felsiques à grains fins interlités de roches sédimentaires (membre de Little Falls, au sommet de la Formation de Nepisiguit Falls. La partie massive et la semimassive s’étendent du nord au sud sur 525 m et ont un pendage de ~45°E; le gisement est continu sur 600 m en angle de chute et son épaisseur varie de 2 à 20 m. Le gisement contient une ressource géologique évaluée à 14 Mt de sulfures semimassifs (>60%) localement massifs à basse teneur, incluant une zone à haute teneur de 1.26 Mt titrant 7.65% Zn, 2.18% Pb, 0.14% Cu, 40.3 g/t Ag, et 0.40 g/t Au. Les intersections de sulfures semimassifs à massifs se situent dans une enveloppe de schiste à quartz-sericite ± chlorite interprétée comme un tuf felsique intensément déformé. Cette séquence contient une quantité importante (jusqu’à 50%) de pyrite disséminée dont le grain varie de fin à grossier et son épaisseur maximale est de 140 m. L’enveloppe pyriteuse s’étend latéralement sur 900 m et a été tracée jusqu’à 1000 m en angle de chute. Des sulfures massifs sont trouvés partout à l’intérieur de cette enveloppe d’altération, mais ils sont plus fréquents près du contact supérieur. L’importance de cette découverte tient à ce qu’elle est un exemple d’un gisement à fort tonnage nouvellement découvert à une faible profondeur dans un camp minier mature, i.e., un camp ou l’on ne croyait plus qu’il était possible de trouver un gisement près de la surface. Ceci ouvre la porte à la possibilité d’autres découvertes dans cette partie du Camp Minier de Bathurst."

Jan 1, 2006

By B. Simonian

"The Mount Milligan mine, located in central British Columbia, began operation in September 2013 with a design nameplate capacity of 62,500 dry metric tonnes per day, using a conventional SABC grinding circuit followed by bulk sulphide flotation. Over the last few years, many changes have been implemented in order to debottleneck and optimize the comminution circuit to meet and exceed the nameplate design capacity as well as improve the metal recovery of the flotation circuit. This paper discusses changes, grouped into mechanical modifications, projects, and operational changes. The implementation of these changes as well as ongoing challenges and potential solutions will also be discussed.INTRODUCTION The Mount Milligan mine began production in the fall of 2013. It is a conventional truck-shovel open pit gold and copper mine and concentrator with a 62,500 tpd design capacity copper-gold flotation processing plant. The average head grades for the life of mine are 0.18% Cu and 0.39 g/t Au. At full capacity, the mine produces an average 400 dry tonnes per day of copper-gold concentrate containing approximately 21.5% Cu and 50-60 g/t Au. Current mine life is 21 years. This paper will discuss a selection of the operational, engineering, and administrative changes that have been made at the site since the publication of An Update on Reaching Nameplate Throughput and Continuous Improvement at Mount Milligan (Yue, 2017). PLANT FLOWSHEET CONFIGURATION Run-of-mine ore is crushed through a 60-110 gyratory crusher to a top size of seven inches. Up to 100% of the gyratory crusher product is diverted to the secondary crushing circuit by a moveable gate. The material diverted to the secondary crushing circuit is fed to a vibrating double-deck screen. The screen oversize is placed on a surge pile and reclaimed by four vibrating feeders to feed two 1250 kW standard head cone crushers in open circuit. The screen undersize is combined with the crusher discharge and returns to the conveyor feeding the coarse ore stockpile along with primary crusher product that by-passes the diverter gate."

Jan 1, 2019

By M. Abouhamad

According to the Canadian Urban Transit Association (CUTA), 140 Billion CAD is required to maintain, rehabilitate, and replace subway infrastructure between 2010 and 2014. The current practice adopted by transit authorities for prioritizing subway stations for rehabilitation is based on the station structural needs. While this classification is reflective of station condition, other factors, such as station size, location and passenger capacity, play an important role. The criticality of a station is an index that represents the functional importance of a station depending upon a set of identified factors. The system criticality is based on several attributes, such as station location, size, and nature of use. This paper presents a novel method of clustering subway stations for rehabilitation priority based on their criticality level. The different stations in a subway network are rated according to their relative importance against predefined attributes. The weights and scores of the attributes are computed with the help of experts and current subway network data. The analysis is done using the Fuzzy Analytic Network Process (FANP) to accommodate the subjectivity of human judgment as being expressed in natural language which entails ?fuzziness? in real-life problems and account for the interdependency between the selected attributes. The output of the model is a criticality based clustering of subway stations. The proposed framework helps authorities prioritize stations for rehabilitation and highlight stations with more criticality for a more robust asset analysis.

Aug 1, 2013

By Mansoor Barati, Xue Yin, Yanhui Sun, Alex McLean, Yindong Yang

The formation and evolution of inclusions in Ti-Stabilized, 17Cr Austenitic Stainless Steel produced by the ingot casting process were investigated through systematic sampling of liquid steel and rolled products. Analysis methods included total oxygen and nitrogen contents, optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The results indicate that the composition of inclusions was strongly dependent on the types of added alloying agents. During the AOD refining process, after the addition of ferrosilicon alloy and electrolytic manganese, followed by aluminum, the composition of inclusions changed from manganese silicate-rich inclusions to Al2O3-rich inclusions. After tapping and titanium wire feeding, pure TiN particles and complex inclusions with Al2O3-MgO-TiOx cores coated with TiN were found to be the dominant inclusions when [%Ti] was 0.307 in the molten steel. These findings were confirmed by thermodynamic calculations which indicated that TiN inclusions could be formed in the liquid phase due to the high contents of [Ti] and [N] in the molten steel. From the start of casting to the rolled bar, there was no obvious change in the composition of inclusions compared to the titanium addition stage. Stringer-shaped TiN inclusions elongated along the rolling direction with lengths varying from 17 to 84µm were observed in the rolled bar, which could detrimentally impact the mechanical properties of the stainless steels.

Jan 1, 2015

By G. N. A. Senhorinho, J. A. Scott, C. A. Laamanen

"Closed mine sites are widely regarded as a negative asset due to their legacy of environmental impacts. These sites are often characterized by waterbodies with elevated metal concentrations and low pH that are traditionally considered to have little or no value. These sites are potential sources of beneficial biocompounds produced by microalgae in response to environmental stresses. A bio¬prospecting program found that certain microalgae from waterbodies near historical mine sites exhibited higher antibacterial activity than any microalgae previously reported in the literature. There is potential for the mining industry to be involved in examining features such as tailings ponds at mine sites for high-value compounds, including ones that might help mitigate rapidly growing microbial resistance to current antibiotics. ¦ KEYWORDS Antibacterial, Closed mining sites, Metabolites, Microalgae, Stressed environments RÉSUMÉ Les sites miniers clôturés sont généralement considérés comme des actifs négatifs en raison de leurs répercussions sur l’environnement. On trouve souvent sur ces sites des étendues d’eau affichant de fortes concentrations en métaux et un pH faible, généralement considérées comme ayant peu, voire pas de valeur. Ces sites sont des sources potentielles de biocomposants bénéfiques produits par des microalgues en réponse aux perturbations environnementales. Un programme de bioprospection a permis de déterminer que certaines microalgues trouvées dans ces étendues d’eau à proximité de sites miniers historiques présentaient une activité antibactérienne supérieure à celle mentionnée dans toute la docu¬mentation existante. L’industrie minière pourrait bien participer à l’examen de particularités telles que la recherche de composants à haute valeur dans des bassins de décantation des résidus sur des sites miniers, notamment des composants qui pourraient aider à atténuer l’augmentation rapide de la résistance micro¬bienne aux antibiotiques actuels. ¦ MOTS CLÉS antibactérien, environnements perturbés, métabolites, microalgues, sites miniers clôturésINTRODUCTION The mining industry is one of the largest economic drivers in the world. Within Canada, for example, it contributed 2.8% (C$57.6 billion) of the 2016 gross domestic product (Marshall, 2016). Canada also has the highest non-ferrous exploration budget worldwide (Marshall, 2016); therefore, it is likely that mining operations, mine waste disposal, and the number of closed sites will continue to grow in Canada. The environmental impact of mining operations stems from the volume of tailings produced, which can be up to 97–99% of the total volume of ore processed at a mine (Adiansyah, Rosano, Vink, & Keir, 2015). In 2010, mining was the world’s largest industrial producer of waste at a total of 65 billion tonnes: 51 billion tonnes of waste rock (mine overburden) and 14 billion tonnes of tail¬ings (Jones & Boger, 2012)."

Jan 1, 2019

By M. Tiedtke, T. Crary, P. MacPhail, M. Ounpuu

"The SGS carbon-in-pulp (CIP) / carbon-in-leach (CIL) model was used to evaluate and optimize the carbon circuit at Alamos Gold’s Young-Davidson Mine. Plants samples (pulp and carbon) were tested in a series of small scale batch experiments to determine rates of gold leaching and adsorption on carbon from a combined flotation concentrate/tailing product. The testwork data, along with existing plant data were then used to model the performance of the existing CIL plant and optimize the circuit to improve performance and overall recovery. The primary purpose of the modelling exercise was to determine the most cost effective way to lower solution losses at the plant. The modelling was also used to learn how the various parameters in the CIL circuit affect solution losses and the gold inventory tied up on the carbon. This resulted in recommendations for minor changes in the CIL flowsheet, which were successfully implemented in the plant. The approach, results and plant changes are presented.INTRODUCTION This paper presents the details from testwork conducted on samples from Alamos Gold’s Young- Davidson gold mine which is located near the town of Matachewan, approximately 60 km west of Kirkland Lake in Northern Ontario, within the southwestern part of the Abitibi Greenstone Belt. The objective of the test program (completed by SGS Canada in 2013) was to investigate and model the combined flotation concentrate / tailing carbon-in-leach (CIL) circuit and suggest ways to improve gold recovery. The metallurgical test program included mineralogy, rheology, and carbon modelling testwork. Plant information was provided during the test program and used in the optimization process. Upon completion of the testwork, plant changes were recommended and implemented at site (October 2014). Plant results from 2014 to 2017 confirmed the modelling results."

Jan 1, 2018

By S. Oppenheimer, P. Au, R. M. Kearsey, J. Tsang, E. McDevitt

A new superalloy, ATI 718Plus® Alloy (718Plus), has been developed to have a 55oC higher temperature capability over the traditionally used Alloy 718, while maintaining favourable processing characteristics and intrinsic raw material costs. The fatigue and dwell-fatigue behaviour of four microstructural variations of 718Plus are evaluated and compared to Waspaloy: 1) standard heat treated condition (HT1), 2) standard heat treated condition with thermal exposure at 732ºC (1350ºF) for 1000 hours (HT2), 3) fine grain condition with a modified d phase (HT3), and 4) fine grain overaged through modified heat treatment (HT4). The results show that the steady-state fatigue crack growth rates of each microstructural variation and both alloys are identical, with all of the 718Plus variations showing a clear advantage over Waspaloy in the fatigue crack threshold regime. Dwell-fatigue results show that Waspaloy has better resistance to crack propagation under dwell conditions; however, optimization of the precipitate phase shows vast improvement in the dwell-fatigue resistance of 718Plus.

Jan 1, 2010

By G. B. Harris

In recent years, increasing attention has been focused on the hydrometallurgical treatment of base metals feeds, especially nickel laterites and polymetallic sulphides. One approach that has received some attention is the use of high?concentration chloride solutions (brines), which are now showing some promise after initial setbacks. Iron is usually the major component in the base metal feed to such processes, and if physical means cannot be used to remove it, then the iron concentration in the pregnant leach solution is always significant. This paper presents some of the background theory on the hydrolysis of iron in high-strength (>3M) chloride brines, and discusses the roles of temperature, solution concentration and free acidity. It is shown that the system is complex, but that crystalline and readily-filterable hematite can be generated, and that the system has a low energy requirement.

Jan 1, 2006

Sherwood?s Minto Project ? High grade copper copper-gold deposit ? Yukon Territory, Canada ? Development underway ? Permitted ? Production by mid mid-2007 ? 40 40-50m lbs Cu plus Au/Ag by by-products ? Parallel exploration program underway ?Discover more high grade resources ?But what kind of deposit is it?

May 1, 2006

By Stanley G. Butcher

"Introduction Many operators in western Canada, with a background in the minerals industry, talk of ""coal beneficiation"", whereas the coal industry generally uses the term ""coal preparation"" . The sophisticated cleaning circuits and thermal drying units found in western Canada makes the term beneficiation particularly appropriate. This chapter uses standard coal preparation terminology(l,2J and assumes general knowledge of coal preparation unit processes and equipment(3,4,5). The geologic setting and mining methods of western Canada, described elsewhere in this volume, present for preparation run-of-mine coals which have particular problems. As a result the cost of preparation is a higher proportion of the total minesite production costs than in other coal fields . Preparation requirements are determined by the types of coals being produced and the markets in which they are sold. Western Canadian coals have a low sulphur content and do not require cleaning on this account. Prepared coal from western Canada has to be shipped vast distances -to the Pacific Rim countries and Ontario in particular -and the savings in transport costs justify the high costs of preparation. Factors which dictate selection and operation of the preparation processes are: i) Market specifications and coal rank. ii) Size distribution of particles and particularly the liability of coal and refuse particles to degrade during handling and processing. iii) Quantity and characteristics of the associated refuse. iv) Washability characteristics (the distribution of particles by specific gravity within each size fraction). v) Surface characteristics of the fines. vi) Variability of the raw coal. Where the product (coal or discard) has a high fines content special consideration must be given to dewatering, the removal of surface moisture, to give acceptable handle ability characteristics. In the severe winter climate of the western foothills and mountains thermal drying is necessary to prevent freezing of washed coal in stockpiles and railcars."

Jan 1, 1985

As part of the Australian Mineral Industries Research Association (AMIRA) P9 project, methods of characterising both the ore and the machines in flotation circuits have matured considerably over the past 15 years. Machine characteristics include gas dispersion measurements, such as bubble size, gas hold-up and superficial gas velocity. Ores can be characterised in terms of floatability parameters on a size and mineral basis. Measurements have been performed on various copper plants in many countries around the world over the last 5 years. This paper outlines the cell and ore floatability characteristics of each copper plant and provides a discussion on the differences between these plants. In general, most porphyry copper ore bodies are processed at high tonnage through several parallel banks of cells at each stage of flotation. The floatability parameters of these copper ores are very similar in terms of rate of flotation and proportion of fast, slow and non-floating material. The cell characteristics are also similar, with superficial gas velocity, bubble sizes, and gas hold-up values being of similar magnitude. Investigation of the similarities and differences of the modem copper flotation circuits has allowed an increase in understanding of the particularities of copper flotation. Comparison against other copper circuits provides a benchmark and opportunities for future optimisation.

Jan 1, 2007

By Y. Okita

The Goro Nickel Process, developed over a ten-year period, uses a number of novel processing steps and treats two ore types, limonite and saprolite, together. Nickel and cobalt are solubilized using a 270°C pressure acid leach in sulphuric acid, which rejects the bulk of the Fe into the leach residue as hematite particles. The leach liquor, after CCD, is aerated to oxidize any ferrous iron to the ferric form and is neutralized with limestone to precipitate iron as hydroxides together with gypsum from the neutralization of the free acid. Further neutralization with lime, together with steps to remove suspended solids, reduces the iron to trace concentrations. Nickel and cobalt are directly recovered from the low-iron leach solution by primary solvent extraction using Cyanex 301® (SXl) in a high-strength hydrochloric acid solution. Nickel is subsequently separated from cobalt in a secondary solvent extraction circuit using tri-isooctylamine. A granular nickel oxide is made by pyrohydrolysis, and this allows the recycling of hydrochloric acid to SXl. The process is currently being commercialized to produce approximately 60,000 t/y of nickel as nickel oxide granules and approximately 5,400 t/y of cobalt as cobalt carbonate. This paper describes the process development to control the Fe concentration in the SX1 feed solution.

Jan 1, 2006

By S. W. Marcuson

In the late 1960's concerns about the natural environment reached high levels within North America and provided activists with suitable platforms for exerting influence over the general public and politicians. In response a host of regulatory mechanisms were developed, statutes, voluntary measures, land grants, codes of practices etc. Emerging environmental awareness from the era provided impetus for rapid technological change that encompassed all industries, especially the base metal business. The resulting clean up impacted all aspects of copper production, dealing with issues such as waste disposal, water and air quality with specific impact on emissions of sulfur dioxide and particulate. This paper provides a perspective of these changes reviewing the macro-economic impact of environmental movement in mining with its specific implications to the copper smelting industry. The fundamental challenges that were faced by the old, but capital-intensive North American plants and the approaches taken to deal with the changing times are reviewed with special emphasis on the conceptual approach to smelter S02 abatement and different paths taken in the USA and Canada. The role of economics, sustainable R&D and presence of technical infrastructure that facilitated the change process is elucidated, and speculations are made about the future state of pyrometallurgy and the natural environment. Cu2007 -

Jan 1, 2007

By A. L. Mular

"IntroductionThe mining industry has made slow but steady progress toward the automation of mineral processing plants over the last 35 years. The stimulus to automate is associated with important economic and hidden benefits, so that today, the latest in instrumentation and technology is being employed.This chapter assesses the status of instrumentation justified economically, defines levels of control and certain fundamentals of feedback control loops, describes typical sensors employed in concentrator circuits, summarizes control strategies employed therein, and briefly highlights trends in integrated plant control.Current Status of AutomationAs early as 1948, the mining industry began to show interest in automation, probably because of its close association with the petroleum industry. By 1958, some regulatory control had been achieved in various sections of a concentrator, particularly in crushing circuits. Successes were attributed primarily to the reliability of sensors employed in the corresponding control scheme. By 1961, computers had appeared on the scene, initially, for data logging purposes.From 1958 to 1965, very few new control strategies had been implemented. Guidelines in vogue at this time appeared to be:- Install proven automation, unless a good instrumentation department exists at the concentrator.- Do not bite off too much instrumentation at one time.- Do not purchase on price alone; instrumentation must function in the concentrator environment.- Do not purchase automatic control equipment to be fashionable.Such guidelines were employed1 because of a lack of: (a) quantitative process knowledge, (b) reliable primary sensors, (c) initiative to try something new, (d) trained personnel, and (e) understanding that older concentrators could justify automation in many situations."

Jan 1, 1989

By D. Roy Eccles

A multi-element geochemical response, with contrasts of up to 29 times background, was obtained in soil above the Mountain Lake Diatreme, northwestern Alberta. The overall geochemical signature is indicative of an ultramafic source; geochemical responses contain elevated concentrations of Co, Cr,O, Cu and Ni with the presence of high Ba, Ga, HI, PO,, Rb, Ta, Ti and light rare earth elements suggestive ofa kimberlite or lamproite body. The shape, or morphology, of the enzyme leach-based geochemical signature over the Mountain Lake Diatreme combines moderately strong to strong oxidation halos, or a rabbit's- ear geochemical profile, with a sharply-defined apical geochemical profile. Because some Alberta diatremes discovered to date form positive topographic highs, the resultant geochemical signature may express the soil development profile that forms directly on top of kimberlitic and lamproitic bodies. The enzyme leach technique, which has proven to be a useful tool in base metal, precious metal and petroleum exploration, may have a significant impact on exploration for kimberlite, lamproite and related rocks in Alberta by providing industry with a useful and cost effective tool to probe blind and/or buried anomalies identified by airborne and ground magnetic surveys in areas of glacial overburden.

Jan 1, 2001