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By Robert Gannicott

??A mining company without the burden of operating a mine ??Management focused on marketing a high-quality, run-of-mine range of Canadian diamonds ??Robust revenue stream ??Specialist diamond knowledge ??Canadian exploration and development expertise ??BUT ??Single asset revenue base from depleting ore reserve ??Limited influence on production plans

Apr 1, 2005

By Brian A. Ferguson, Raynald O. Vezina, Marielle Gaudet, Raoul R. Boissonneault

"Kiena has been committed to developing a fresh management and employee relations approach since the commencement of production in 1981. The functional organizational structure encourages joint participation and commitment on the part of all employees to common goals in safety and production. The results over the last four years have been extraordinary. Kiena won the John T. Ryan Canada Trophy for 1983 for its safety record and has experienced a steadily increasing productivity through the application of new mining equipment and technology in the hands of a well-trained and motivated team of employees.This paper serves to highlight the fact that productivity, safetyand technical innovation are closely linked to employee participationand involvement which are likely to be the key to theCanadian mining industry's survival in the years ahead.This presentation follows up on an earlier unpublished paper, given at the 84th Annual Meeting of CIM in Quebec City in April, 1982, which discussed the philosophy and the planning which took place before implementation of the management and employee relations system at Kiena. This present paper reviews and expands on material given in the earlier work. IntroductionThe mining industry, which has always been considered as rather conservative in its approach, has experienced with some regularity, cyclical periods related to metal prices. These cycles, previously foreseeable to some extent have become less coherent over recent years during which time the industry has had to face fierce international competition. The issue to productivity is without doubt the major concern of the mining industry in Canada today and it represents the greatest challenge facing us during the present decade. Developments that have been made in mining technology over the precious two decades have failed to completely produce the significant advancements in higher over-all productivity that were expected."

Jan 1, 1987

By L. Nichols, H. Keele, K. Czajewski

"The oil sands industry in northern Alberta disposes of the by-products of bitumen extraction into tailings ponds. The mix of tailings sand and mature fines, with gypsum added as a flocculent, constitute a waste stream called consolidated tailings or composite tails (CT). The two main challenges of the tailings disposal process are a chronic shortage of economical containment and the potential mobility of CT deposits in the event of breaching by, for example, long-term erosion, which makes abandonment of tailings ponds more complicated. Thick deposits of CT do not consolidate in adequate time to provide reassurance for abandonment of the CT containment facilities and that is why the containment must be adequately robust or the properties of CT improved for long-term stability. This paper addresses potential solutions to these problems by applying the gravity drainage of CT and quasi-homogeneous construction for containment facilities.Gravity drainage is suggested as a mechanism to facilitate the consolidation of CT in critical areas of the ponds by inserting internal sand layers within the body of the deposit. Critical CT areas are defined as areas around the perimeter of containment. The advantages of this solution are longterm stability of the disposal area by creation of stiff deposits around its perimeter and facilitation of reclamation efforts on its surface.The present solution for containment of CT deposits is not favourable from a materials balance point of view. In general, sand has become a valuable resource as it both forms the primary component of the CT matrix and becomes the containment building material. If sand is required for CT, less is available for dyke construction. This puts additional pressure on the industry as a whole to maximize the use of overburden and interburden for construction of tailings containment structures. Typically, only 50 percent of dry mine waste (overburden + interburden) is incorporated into dyke construction. The remainder of dry waste is stored either in waste dumps or in tailings ponds, consuming valuable in-pond space originally allocated to CT material. Quasi-homogeneous dykes are proposed to contain CT deposits rather than traditional minimum cross-section dykes built of overburden and/or cell sand. The quasi-homogeneous dyke may change the unfavourable material balance and lessen the construction constraints that are presently imposed on the mine/waste disposal process."

Jan 1, 2008

By N. H. J. Freire, D. Majuste

In this paper, the effects of some organic compounds on the current efficiency, cell voltage and specific energy consumption during nickel electrowinning, and on the deposit features (morphology, crystallographic orientation and nanohardness) were described. The organics tested here (extractant, diluent, flocculant, lubricating oil and acid mist suppressant) are currently used in industrial plants. The results indicated that only the flocculant and acid mist suppressant exhibit relevant negative impacts on the current efficiency and energy consumption. The current efficiency dropped from 93.6 % (organic-free solutions) to 86.0 % and to 92.8% in electrolytes containing 100 mg.L-1 of acid mist suppressant and flocculant, respectively. At this concentration, their addition to the electrolyte led to increases of the specific energy consumption in the order of 18 % (acid mist supressant) and 2 % (flocculant). Cyclic voltammetry showed that Ni nucleation occurs at more negative potentials at 50 and 100 mg.L-1 of these organics in the electrolyte, thus indicating an inhibition of the deposition process. The deposit quality decreased at the higher concentration of all organics, when more hydrogen pitting was observed. The acid mist suppressant caused delamination of the Ni deposit at 50 and 100 mg.L-1. The addition of 100 mg.L-1 of flocculant and acid mist suppressant to the electrolyte increased the nanohardness of the deposit around 31 and 72%, respectively. The increase in Ni deposit hardness may lead to a decrease in the material ductility, thereby affecting the stripping and cutting of Ni sheets. Our findings may be helpful since strong adverse effect of some organics that may be present in the electrolyte were identified, thus the industry can control and optimize the organic´s dosage in the corresponding operations.

Jan 1, 2016

By W. G. Miller, J. D. Scott, D. C. Sego

ABSTRACT An overall study was conducted to evaluate the properties and processes influencing the rate and magnitude of consolidation for oil sands fine tailings produced using different extraction processes. As part of the overall study, a comprehensive description of physical and chemical characteristics of fine tailings generated by caustic and non-caustic processes was carried out. Ultimately, the influence of these fundamental properties on the compressibility, hydraulic conductivity and shear strength properties of the fine tailings was assessed. The characteristics of the fine tailings are presented in terms of index properties, mineralogy, specific surface area, water chemistry, liquid limits, particle size distribution and structure. A difference in water chemistry was concluded to be the cause of substantial differences in particle size distributions and degree of dispersion of the comparable caustic and non-caustic fine tailings. The degree of dispersion was consistent with predictions for dispersed clays established by the sodium adsorption ratio (SAR) values for these materials. A linear variation of increasing dispersion with increasing SAR up to a SAR value of about 40 has been suggested, above which fine tailings are completely dispersed. The observed dispersed or flocculated structures (viewed using a scanning electron microscope) supported the predictions based on SAR values.

Jan 1, 2010

By Christoph Broeckmann, Andrew Gardula

"The adoption of high-pressure grinding throughout the cement industry has yielded enormous savings in energy and wear material costs. There are also a number of installations, which are applied in iron ore and kimberlite processing operations. High pressure grinding offers the same potential for energy and media savings, as well as opportunities for improved, downstream metallurgical performance, in hard rock mineral processing. This paper focuses on developments in machine design and wear surface engineering for high-pressure grinding of the hard rock ores in the mineral processing industry.INTRODUCTIONIn the early eighties 3.4 % of the world electric energy was consumed for crushing and grinding operations of minerals and 0.6 % in the ore dressing industry. During that time using a laboratory press Prof. Schönert found that interparticle comminution at high pressure requires remarkably less energy as conventional grinding technologies. In grinding of cement clinker he expected energy savings between 33 and 50 % compared to ball mills [1]. Piston presses are limited in throughput. Thus, the principle of interparticle comminution was adapted by the use of high pressure grinding rolls (HPGR) to a continuous plant process. Figure 1 shows the main components of a roller press: The roller nip of width s is formed between the floating roller (1) and the fixed roller (2). The diameter of the rolls will be denoted with D, the width with B. The total press force F can be adjusted using a hydraulic system with two or four pistons (3). In order to compare machines with different roll geometries the specific pressing force p is introduced:"

Jan 1, 2005

By A. Vien, B. C. Flintoff, R. P. Edwards

"This paper provides a critical review of the development and application of advanced controls in mineral processing at the industrial level. These algorithms can be sub-divided into four broad categories: Kalman filter, self-tuning, extended horizon, and knowledge based or expert systems. Applications from each category are described outlining the benefits derived, the relative advantages of that particular controller, and potential limitations of the controller which may inhibit their more widespread application. The paper will conclude with a description of control algorithms which are currently in the rudimentary design stage, but may hold tremendous potential for mineral processing control systems in the next decade. INTRODUCTIONThe Canadian mining industry has a large installed milling base and many plants are run with manual or low level automatic process control. The competitive pressures imposed by the market will not allow these operations to ignore the significant increase in efficiency that can be achieved through the effective application of advanced process control. These improvements will come in the form of better quality, higher productivity and reduced costs.There have been quite a number of reports of successful applications of advanced control in mineral processing applications. As this trend continues, and more of the work is documented, the technology will be more effectively transferred to process and control engineers. It is the authors' opinion that the most difficult problems facing process control are not really technical in nature. Rather, they lie more in process control education. This extends from management, through engineering to the operators.The purpose of this paper is to provide a tutorial type overview of some of the more frequently encountered advanced control algorithms. The assumption is that the reader has a superficial knowledge of this technology. In the discussions which follow, several techniques are explored within the framework of simple process examples. Industrial examples are cited for each and an evaluation of the expected longer term potential is given."

Jan 1, 1992

By K. G. Thorne, D. R. Lentz, A. F. Park

"The Main zone of the Clarence Stream gold deposit is hosted by a shear zone adjacent to the Saint George batholith in southwestern New Brunswick. The mineralization history relates to progressive deformation in the shear zone and the intrusion of the Magaguadavic granodiorite.Of three phases of deformation that have affected the area (D1-D3), D1 is not observed in the Clarence Stream shear zone. Two suites of igneous rocks intrude the shear zone: post-D2, pre-D3 gabbro; and granitic dikes, which crosscut the gabbros. Granitic dikes show a diverse range of relationships to D3 features, from pre-syn-D3 mylonitic fabrics in transposed and highly deformed enclaves, to nondeformed and entirely discordant dikes (post-D3).A variety of veins occur within this shear zone. Zoisite-bearing and later, crosscutting epidote-bearing veins are preserved as relics in quartz-mylonites, and predate quartz veins that host gold mineralization. The epidote-bearing veins are associated with pseudotachylitic cataclasite dikes, consistent with transient brittle failure during ductile deformation.Deformation relates to right-lateral strike-slip motion across the shear zone, and subhorizontal and near-vertical stretching lineations imply transpression. A late (late- or post-D3) dip-slip phase of motion is also apparent, and cooling followed a metamorphic peak early in D2-D3 history. Deformation of the shear zone, and more localized transient brittle failure, provided the permeability for fluid movement and vein emplacement. This scenario is similar to the findings of other studies, in which geochemical, tracer isotopic, and age-dating (U/Pb, 40Ar/39Ar) results suggest that the adjacent Magaguadavic granodiorite provided heat and metals. La zone principale (Main zone) du gisement d’or de Clarence Stream est encaissée par une zone de cisaillement qui longe le batholite de Saint George dans le sud-ouest du Nouveau Brunswick. L’historique de la mise en place de la minéralisation accorde un rôle important à la déformation progressive dans la zone de cisaillement et à la mise en place de la granodiorite de Magaguadavic.Des trois phases de déformation à avoir affecté la région (D1-D3), les effets de D1 ne sont pas observés dans la zone de cisaillement de Clarence Stream. Deux suites de roches ignées se sont mises en place dans cette zone de cisaillement : un gabbro post D2, pré-D3 et des dykes granitiques qui recoupent le gabbro. Les dykes granitiques montrent une grande diversité de relations avec les structures D3, allant de précoces à synchrones aux fabriques mylonitiques D3 dans des enclaves transportées et fortement déformées à des dykes complètement discordants et non déformés (post-D3).On note diverses veines dans cette zone de cisaillement. Des veines contenant de la zoisite ainsi que des veines d’épidote sécantes plus tardives, lesquelles sont préservées comme reliquats dans les mylonites à quartz et sont plus vieilles que les veines de quartz contenant la minéralisation aurifère. Les veines d’épidote sont associées à des dykes de catacalasite à texture de pseudotachylite, compatibles avec une rupture cassante épisodique durant la déformation ductile.La déformation résulte d’un mouvement décrochant dextre le long de la zone de cisaillement et les linéations d’étirement subhorizontales et quasi-verticales impliquent de la transpression. Une phase tardive (tardi- ou post-D3) de mouvement selon le pendage est aussi apparente, et le refroidissement succède à un pic métamorphique tôt dans l’histoire D2-D3. La déformation de la zone de cisaillement et la rupture cassante épisodique ont fourni la perméabilité nécessaire au mouvement des fluides et à la mise en place des veines. Ce scénario est similaire à celui proposé par d’autres études, dans lesquelles les résultats de géochimie, de traceurs isotopiques et de géochronologie (U/Pb, 40Ar/39Ar) suggèrent que la granodiorite de Magaguadavic avoisinante a fourni la chaleur et les métaux."

Jan 1, 2008

By G. Azimi, K. K. Varanasi1, A. T. Paxson, R. Dhiman, H. -M. Kwon

Hydrophobic materials that are robust to harsh environments are needed in a broad range of applications. Although durable materials such as metals and ceramics, which are generally hydrophilic, can be rendered hydrophobic by polymeric modifiers, these materials deteriorate in harsh environments. Here it is shown that a class of ceramics comprising the entire lanthanide oxide series, ranging from ceria to lutecia, is intrinsically hydrophobic. Their hydrophobicity is attributed to their unique electronic structure, which inhibits hydrogen bonding with interfacial water molecules. In addition, this work demonstrates that these ceramics sustain hydrophobicity even after exposure to high-temperature environment (1000 °C for 2 h in air). It is envisioned that this class of robust hydrophobic materials will have far-reaching technological potential in various industrial applications, where water repellency and dropwise condensation are desirable.

Jan 1, 2014

By R. L. J. Phillips

"The environmental impact of the Rabbit Lake project is presented. Baseline data for fish, water, air and radon collected in 1973, 1975, 1980and 1986, are compared with post-development environmental monitoring data. Predicted environmental impacts for the developed Rabbit Lake and B-zone deposits are compared to the actual impacts. INTRODUCTIONThe environmental impact of the Rabbit Lake project has been documented through the years in several submissions to the government agencies. In 1972, the environmental baseline study for the Rabbit Lake area was completed prior to any mining activity at the Rabbit Lake pit (Fig. 1).Sampling concentrated on Hidden Bay and Pow Bay, which received the treated effluent and the waters drained from Rabbit Lake respectively.A second baseline study was done on the Collins Bay area in 1980(Fig. I) in preparation for the mining of the B-zone pit. The detail in this study was considerably greater than the detail in the previous study. Collins Bay and Harrison Peninsula were the areas sampled. The B-zone deposit is being mined at present.With the discovery of the A-zone, D-zone and Eagle Point deposits, it was decided in 1986 to begin proceedings to obtain approval from Saskatchewan's Department of the Environment, and from the Atomic Energy Control Board to develop these deposits.In preparation, a third baseline study of both the Rabbit Lake and Collins Bay areas was done in 1986 and 1987. The emphasis was to establish the baseline at the three new deposits, to quantify the actual impacts of the existing Rabbit Lake operations and to confirm the Collins Bay B-zone (1980) impact predictions. The new deposits will allow us to continue to produce uranium into the future. In January 1988, Saskatchewan approval was received.Since 1975 in the Rabbit Lake area and 1980 in the Collins Bay area, routine environmental monitoring has been done. This has resulted in one of the largest and most comprehensive environmental data bases in North America in mining. By the time the Eagle Point deposit is mined to completion, there will have been data collected for approximately 40 years.Further discussions follow which describe the impacts of the past (1972 to 1984), the present (1985 to 1987) and the future. In addition, the past and present performances and the future plans of the .waste management systems will be discussed."

Jan 1, 1989

By S. J. Haynes

"This paper documents the characteristics of the different quartz veins, and their relation to gold, in the turbiditic Meguma domain of eastern Nova Scotia. Eleven different types have been distinguished in the greenschist facies on the basis of form, internal structure, mineralogy, wallrock alteration and crosscutting relationships to each other and to regional structures. Gold is present as rare visible disseminations in host rock slates and in ore-grade, early-formed veins, that pre-date the formation of upright Acadian folds and intrusions of Devonian granitoids. Four vein types pre-date Acadian folding. Five gold-deficient vein types are associated with Acadian folding (syndeformation); whereas two gold-deficient vein types clearly post-date this deformational event: Previously unreported, wall rock alteration is associated with early crosscutting and semiconcordant auriferous veins. In contrast, early stratiform veins are devoid of wallrock alteration. It is suggested that the auriferous vein arrays formed as submarine exhalitive systems over synsedimentary tensional faults and that the Meguma domain may represent the opening of a basin similar to the modernGuaymas rift .IntroductionThe term ""turbidite-hosted gold deposits"" is introduced to distinguish gold deposits contained within a turbiditic sequence of wackes and shales (or their metamorphosed equivalents) from gold deposits in other types of sediments. Usage and justification for the term is similar to ""carbonate-hosted lead-zinc deposits"" or ""volcanogenic massive sulphides"". A range of different characteristics can be present in individual deposits, some of which may be indicative of specific deposit types in the same manner that volcanogenic massive sulphides can be subdivided into ""Cyprus type"", ""Kuroko type"", ""Besshi type"", etc. Historically, gold deposits hosted by turbiditic flysch were an important class of quartz-vein gold mines in the 19th century. They included the goldfields of Victoria, Australia, Otago, New Zealand and Nova Scotia, Canada. Production from most of these fields had ceased by World War II and interest in this type of deposit waned. However, the recent exploration interest in gold has resulted in both re-assessment of the classical mining camps and the discovery that ""turbidite-hosted"" gold deposits are present in many parts of the world.Mapping of the regional geology and gold deposits of the Megumadomain of Nova Scotia was carried out by E.R. Faribault of the Geological Survey of Canada between 1886 and 1939. Faribault produced a comprehensive series of maps and reports for each gold district, a compendium of which was published by Malcolm (1929)."

Jan 1, 1987

By R. H. Seraphim

"Western Mines Limited produces gold, silver, copper, lead and zinc from a number of Paleozoic volcanogenic deposits near Buttle Lake on Vancouver Island. The deposits were emplaced along a series of submarine linear volcanic ridges that extended for at least 6,000 metres in a northwesterly direction.Rock types mapped include: andesitic, dacitic and rhyolitic flow s and volcanic breccias; detrital breccias, tuffs and hematitic silts; black and green cherts; and a variety of dykes and sills, including quartz porphyry and diorite. Orebodies are associated invariably, and in places intimately, with quartzsericite schist and rhyolitic rocks. The ore is complex, varying in mineralogy and tenor both within each deposit and from one deposit to another.Recent studies have increased our knowledge of the structure and left no doubt that the orebodies were deposited both within the throats of the linear vents and on paleoslopes adjacent to these vents.IntroductionWestern Mines Limited operates an 850-tonne-per-day mine, located 85 km south of Campbell River, B.C. The mine is at approximately 400 metres elevation, near the south end of Buttle Lake on Vancouver Island (Fig . I). It has operated since early 1967 and produced 3,650,000 tonnes with an average grade of 1.9 g (0.06 oz) gold, 93 g (3.0 oz) silver, 1.6 per cent copper, 1.0 per cent lead and 7.5 per cent zinc per tonne by the end of 1978. Current reserves are 1,157,000 tonnes of 2.7 g (0.09 oz) gold, 117 g (3 .8 oz) silver , 1.2 per cent copper, 1.2 per cent lead and 8.0 percent zinc per tonne (December 31, 1978).Ore from one zone, known as Myra High-Grade, is mined and milled separately because of its grade. Ore milled prior to December 31,1978, plus reserves, 180,715 tonnes of6.6 g (0.21 oz) gold, 554.5 g (17 .7 oz) silver, 0 .8 per cent copper, 3.2 per cent lead and 10.6 per cent zinc are included in the figures listed in the preceding paragraphs."

Jan 1, 1980

By Tom Gabardi, Peter Clarke

"MillMapperTM is a new 3D laser scanning technology that has only recently been introduced into the North American mining industry. It enables mill operators to gain a much more complete understanding of the condition of their mill internals and to more accurately predict how liners will perform in the future. This paper describes the technology and techniques used to obtain data on internal mill conditions, how this data is processed into meaningful information which enables better prediction of liner life and gives examples of the reports provided by the software. Examples are given, using client sites data, on how this information is being used to reduce the costs and improve the revenue from SAG and ball mills.INTRODUCTION Scanalyse Pty Ltd developed the MillMapperTM technology in Australia over a number of years and has recently introduced it into North America with a significant take-up in Canada. The technology was commercially released in Australia in late 2006 and there has been significant technical development in the features provided since that time. MillMapperTM has been accepted as a useful technology in the Australasian region and more recently has been introduced to sites in Chile, Peru, Brazil, USA, Canada, Laos and South Africa. Over 100 different mills have been scanned and the technology has been thoroughly tested and validated. It has become an integral tool in condition monitoring and improvement programs for SAG and Ball mills across many sites and is now providing significant and measurable benefits to the mining industry. Some of these benefits will be described in this paper using actual examples."

Jan 1, 2012

By S. Zekovic

"The paper gives an overview of the economics condition and strategic business challanges of the mining&metallurgy sector and their possible impact on the future development of the Bor basin of copper in Serbian part of Danube Region. Economics and strategic challanges in the mining& metallurgy complex are emphasized by world economic and financial crisis. An analysis of strategic challanges is undertaken by application of a comprehensive development framework approach. Paper indicates that an economics and evaluation of possible impacts of constraints and challenges for the development of Bor basin shows that it must be included in corporative decision, local and regional plans.INTRODUCTIONRisks are characteristic of every strategic development and business decision-making, so their successful management should be a part of the development strategy of the corporation, especially longterm. Due to the growing uncertainty in the general socio-economic environment, “risk management”, risk insurance, risk control, risk culture, risk optimization are frequently talked about. Among the key risks at a corporate level are the financial risks and risks of the regulative framework, especially in the field of environment and land use. In both cases, it is a question of external risks, which the companies need to relativize and successfully manage. Some companies pay more attention to production risks and search for better solutions in that domain which is not enough (Ernst&Young, 2008). Strategic business risks appear mostly on the macro-economic level, from where they should be” transferred” onto the level of sector economics and action level in corporations. Risk management include transferring the risk to other parts, avoiding the risk, preventing hazard, reducing the negative effect or probability of the risk, accepting some or all of the consequences of a particular risk.The research has included perspective and the general market trend and market positioning of the production and copper processing complex in the world; the impact of the requirements and strategic goals of the EU Directive and Kyoto Protocol on the institutional and other adjustments important for business in this sector; the impact assessment of the regulations important for business in the mining and metals sector, and case study of economics and challenges for the development of mining and metallurgy sector in the Bor basin of copper in Serbian part of Danube region. The analysis has included the identification and assessment of the global challenges on the future development of the copper complex in the miningsmelting basin Bor. Presented results in the paper are part of the research project “Sustainable spatial development of the Danube area in Serbia"" (No. 036036), financed by Ministry of Education and science of Republic Serbia."

Jan 1, 2012

By Takahiro Kubo, Katsunori Yamaguchi, Hidehiro Sekimoto

Equilibrium relation between B2O3 slag, RExOy-B2O3 (RE = rare earths) slag and Fe-C alloy formed by melting treatment of neodymium magnet and B2O3 was investigated. When neodymium magnet was melted together with B2O3 and Fe-C alloy in carbon crucible, 3 liquid phases of B2O3 slag, RExOy-B2O3 slag and molten Fe-C alloy formed and clearly separated by the difference of the specific gravities. In the case that excess amount of Cu was also introduced in that system, molten Cu phase additionally formed. Almost all amount of RE were concentrated in RExOy-B2O3 slag. The concentration of RE in RExOy-B2O3 slag increased with the decrease of the melting temperature. While chromium, phosphorous, nickel, cobalt, and copper were concentrated in molten Fe-C alloy, silicon and aluminum were distributed in B2O3 slag and RE2O3-B2O3 slag.

Jan 1, 2014

By K. Parameswaran, A. Veek, A. Fernandez, P. Safe

ASARCO LLC (Asarco) Hayden Copper smelter, in Hayden, Arizona, has operated continuously (except for minor labor and economic curtailments) since 1912. The current plant configuration comprises INCO flash smelting, Peirce Smith (P-S) converting and fire refining/anode casting. In order to comply with the U.S. Environmental Protection Agency (EPA) 1-hour National Ambient Air Quality Standards (NAAQS) for sulfur dioxide promulgated in June 2010, the Hayden smelter had to increase overall sulfur fixation from approximately 95 % to 99+ %, requiring a retrofit of the existing converter department and upgrade of associated emissions controls systems. The Converter Retrofit Project (CRP) involved replacing the five existing 13’ diameter Peirce-Smith converters (2 blowing, 2 hot standby) with three new 15’ diameter Peirce- Smith converters (1 blowing, 1 hot standby) to allow for more effective process gas capture using the existing acid plant contact section. Significant upgrades were made to the acid plant wet gas cleaning section and converter primary gas handling system to improve capture performance, reliability, and sludge handling. In addition, a new tertiary gas capture system was installed to further minimize fugitive emissions from the converter aisle. The existing furnace tapping ventilation ESP was replaced with a new baghouse to enable at least 50% SO2 removal using high-surface-area dry lime injection, which was also implemented on the existing converter secondary gas baghouse system. The first two converters and all gas handling system improvements were started up in April 2018, and the third converter was brought online in November 2018. This paper presents the regulatory context; genesis and rationale for CRP; detailed description of the project; challenges during commissioning; system improvements implemented, and design considerations made, and systems performance and process optimization achieved since startup.

Jan 1, 2019

Many mines in Canada, the US and S. Africa are reaching the hoisting limit. Very little payload will be possible without compromising safety due the excessive weight. It has been suggested (DeLorme, 2000), that one of the most attractive concepts to enable deeper hoisting is to reduce the allowable factor of safety in the wire rope. Researchers at the Spokane Research Lab are developing new technology to improve hoisting safety and productivity by providing new monitoring and analytical tools. A Shaft Conveyance Monitoring System (SCMS) has been developed which determines hoist rope end load, true conveyance position and acceleration, and rope safety factor, as well as other hoist operating parameters. This information is transmitted to the hoist operator display 20 times per second. Recent field measurements on 45 mm(1 ¾ in.) diameter hoist rope indicate that dynamic forces during loading of a 9000 kg(10 ton) skip may exceed the safety factor of the rope. To improve on the current understanding of the mechanical behavior of hoist ropes, and to help interpret the results from field-testing of the SCMS, a new approach to computer modeling of stranded wire rope is also being developed. Particle Flow Code, PFC3D (Itasca 1995b) is used to simulate the structural behavior of wire rope and the interaction between individual strands when the rope is subjected to static and dynamic end loading. Details of the SCMS, field results from the measured rope loads, and the results of numerical modeling on the wire rope will be discussed.

May 1, 2002

By N. Bahrani

Photogrammetry surveys were used to document a footwall slab failure that occurred at a surface coal mine located on the eastern slope of the Rocky Mountains. Photographs taken before and after the failure provided the pre- and post-failure geometry of the slope and the failed slab. A 2D finite element model was constructed using slope profiles. The model contained joint elements that represented the bedding surface upon which the slab slid and the model was used to analyze the footwall slope. The in situ stresses, rock properties and the bedding surface shear strength and stiffness properties are discussed. The process of mining out a valley and exposing a highwall was modelled. As expected, elastic valley rebound occurred in the model, but shear stress and shear displacement reversals along the slip surface were also observed. The modelling results provided new insight into shear strength degradation that occurs when the pit floor approaches and then passes a specific point in the highwall.

Jan 1, 2009

By T. A. Grammatikopoulos, B. Vasily, A. H. Clark

"The St. Lawrence deposit is a large wollastonite skarn (ca. 9 Mt @ 41.3% wollastonite) adjoining the gabbroic-to-syenitic Leo Lake pluton in the granulite facies Frontenac Terrane of the Grenvillian Central Metasedimentary Belt. It occurs within a horseshoeshaped horizon of quartzite, open to the east. The skarn extends over 1.2 km2, and comprises wollastonite-dominant, wollastonite-clinopyroxene, and diverse quartz-feldspar-sulphide (-titanite) layers, interbanded with, and strongly folded within, the quartzite. As in the world-class wollastonite deposits of the Willsboro district, New York, no carbonate protolith is preserved, and calcite is a negligible constituent of the mineralized zones. Wollastonite development is nonetheless ascribed to metasomatism of a metacarbonate unit by magmatogene, silica-rich, CO2-poor (XCO2 < 0.05) fluids, at P = 350 MPa and ca. 560°C, or, alternatively, 550 MPa and ca. 630°C.Several high-grade zones, averaging >40% but locally exceeding 80%, of translucent, white, tabular wollastonite grains, with lengths of 0.2 cm to 5 cm, have been delimited by drilling. Preliminary beneficiation studies yield high aspect-ratio and high-purity (low Fe and Mn) concentrates.St. Lawrence compares favourably to other known prospects and operating wollastonite deposits: having good chemical and physical properties, low iron content, and high aspect ratios (>20:1). In addition, the deposit has a favourable size and location, and will benefit from a low Canadian dollar. Canada currently has no wollastonite production."

Jan 1, 2003

By Tano Balbin, Valery Astakhov, Juha Timperi, Lauri Koresaar

"Online elemental analysis is the basis of optimal flotation control in mineral concentrator plants. Traditionally XRF analyzers have been used as the online analysis method. However, online XRF analyzers struggle to measure elements below calcium in atomic number (Z=20). For many processes lighter element assays would be beneficial to improve control of grade and recovery. Processes where elements below Ca are required include P, Mg and Si in phosphate concentrators, Si, Mg and Al in iron concentrators, and S and C in gold concentrators. Laser-Induced Breakdown Spectroscopy (LIBS) based elemental analysis can readily be applied to these processes. LIBS is based on generating plasma in the slurry sample by a high energy laser and analysis of the plasma by optical emission spectroscopy. Capabilities of a new Courier® 8 analyzer based in LIBS technology are demonstrated for elemental analysis starting from lithium (Z=3). Results of a plant installation in a sulfide gold concentrator provide a good agreement with the analyzer and laboratory assays.IntroductionEffective process control can be regarded as one of the fastest paying investments for a mineral processing plant. Process optimization in flotation circuits requires constant feedback of the process state. If only manual laboratory samples are available, this optimization becomes difficult due to the long delay between taking the sample and acquiring the laboratory result. If the element grades are available in online basis, the operator or automatic process control system can make corrective actions in real time.Online X-Ray Fluorescence (XRF) analyzers have been in use at concentrators for decades. The XRF analyzers can provide a fast, accurate and precise analysis from slurry streams. However, the drawback of XRF analyzers is their lack of capability to measure elements below Ca (Z=20) in atomic number. The low energy X-rays of the low atomic number elements get absorbed by water in the sample, protective window of the analyzer, or air between the sample and spectrometer."

Jan 1, 2017