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By V. Murugaiyan

The Geotechnical Engineer is faced to view problems emerging from the task of protecting the environment and also the problems related to prevention of natural hazarders. Geo-Environmental Engineering, based on the development of geotechnical engineering, addresses the problems for the industrial world and the impact on health and welfare in relation to pollution of the ground. In the recent years, acute land pollution due to indiscriminate discharge of industrial effluents especially Organic acid based effluents has become one of the major concern due to erosion in the privatization of sustainable development under Indian Scenario. To study the effect of chemical changes on soil properties due to amino acid effluent contamination on soil and erosion behavoiur. The changes in the soil properties of effluent contaminated clay and silty soil were experimentally observed to be due to the interaction of organic and inorganic constituents of effluent on index properties of soil. The surface reactivity of soil mass is experimentally reported to be varying proportionately with respect to clay (%) in the soil. Also higher surface reactivity of clay increases the Solid Retension Time (SRT) with increase in rate of chemical transformation of organic and inorganic solids within soil. Hence soil S1 (high clay content 54.5%) showed increased SRT and soil S3 (low clay content, high silt and clay content 94.9%) showed decreased SRT and long transformation stage.

May 1, 2004

By Nick D. Rose

The importance of structural geology in open pit slope stability is overlooked in many mining operations due to pressures to cut costs and minimize mine personnel. As a result, mine geology staff are often unable to keep up with geological mapping of the pit slopes due to other day to day production oriented tasks. In some instances, key structural controls that contribute to slope instability may not be identified until after a slope instability has initiated, at which time it may be difficult or impossible to delineate these features in the field. Even for small slopes, understanding the engineering and structural geology of the rock mass, as well as the effects of groundwater and blasting practices, are of key importance to slope stability. Two case histories are presented as examples of mining operations that experienced slope instability with little more than anecdotal information about the structural and groundwater conditions encountered during mining. By conducting field reconnaissance, simple slope stability analyses and ongoing slope monitoring, practical remedial measures were implemented, allowing continued safe mining operation.

May 1, 2002

By Roe-Hoan Yoon

"Industrial flotation columns often suffer from low recoveries and high maintenance requirements because of poorly-designed air spargers. The MicrocelTM bubble generators were developed at Virginia Tech to overcome these problems. In this system, small air bubbles are generated by circulating a portion of the flotation pulp through a set of static in-line mixers. The small bubbles improve flotation kinetics and allow a higher recovery (or capacity) to be achieved. Other advantages of the system include reduced air consumption, plug-free operation and on-line maintenance. This article discusses the advantages of the MicrocelTM bubble generators and presents examples of successful in-plant demonstrations.IntroductionColumn cells are widely accepted in industry for cleaner operations because they are more selective than mechanically-agitated conventional cells. The improved selectivity can be attributed to the use of wash water which minimizes the entrainment of fine gangue particles into the froth product. Columns may also produce higher recoveries if the air sparging system is properly designed and steps are taken to minimize back-mixing. Furthermore, the quiescent conditions afforded by column cells may be beneficial for recovering coarse particles that are readily detached from bubbles under more turbulent conditions. Also, properly-designed columns offer advantages in terms of savings in floor space, reduced operating and capital costs, and simplified circuitry.It is unfortunate, however, that some of the advantages of columns are not fully realized in industrial practice. Some column circuits are unable to achieve their design capacity, while others require extensive maintenance programs. These shortcomings can usually be attributed to deficiencies associated with the design, scale-up and operation of the air-sparging system. In this article, some of the basic problems associated with commercial air sparging systems are discussed and alternatives are suggested."

Jan 1, 1994

By Serge Ouellet

Identification and quantification of cementitious phases in cemented paste backfill (CPB) is difficult due to the fineness of tailings and the low binder content used in the mixture. Techniques such as X-ray diffraction and thermogravimetry were ineffective (mainly due to tailing mineral interference) to identify and quantify hydration products in most works reported in the literature. On the other hand, scanning electron microscopy (SEM) was used in many cases but mainly for qualitative purposes. This paper presents the development of a new approach based on a computer program (SEM-XMAP) that combines X-ray dot mapping images acquired by SEM and generates a coloured image representing the mineralogy and the microstructure of a given CPB specimen. The technique is applied to one CPB sample mixed with blast furnace slag (BFS) and acidic sulphated mixing water sampled in a mine dewatering system. The technique allowed identifying calcic matrix, unhydrated and partially hydrated BFS particles, and sulphated phases.

May 1, 2007

By Don A. Toth

Until recently, the fire protection systems used to protect mining equipment were based on generically designed, off the- shelf concepts. These systems were reliant on single agent approaches and were generally comprised of a series of small twenty or thirty pound chemical canisters that would discharge their contents when triggered by thermal detection means. As the equipment grew in capacity, the logic used to increase the protection was to add more chemical canisters to the system. Hydraulic excavators and large-scale mining trucks grew dramatically in size into the 1990?s and beyond; with this growth came the increase in major losses due to fire. This was evidenced throughout this period, and continues to be of great concern today. During this presentation you will learn of the significant changes that have come about as a result of this history. Today, dual-agent products, infrared detection and unit-specific, engineered systems are the primary phrases used when discussing how to best protect this equipment from fire loss. This session is a must for anybody looking to optimally protect their equipment assets and for those looking to renew and/or secure new insurance for high value equipment in the future.

Apr 1, 2005

By Godfrey MacDonald

"The East West Caribou deposit with an underground mine, concentrator and ancillaries is located 30 km west of Bathurst, New Brunswick. The Restigouche deposit, an open pit mine is 30 km west of East West Caribou. The ore will be trucked from the Restigouche site to the East West Caribou minesite.History:The East West Caribou ore body was discovered in 1955 and the subsequent metallurgical programme focused on producing a bulk sulphide concentrate. However, in 1966 a Mr. P.G. Kihlstadt of Anaconda did float a Copper-Lead concentrate and a Zinc concentrate. He also reported that as the grind became finer the recoveries improved. In 1968 the Mines Branch in Ottawa produced a Lead concentrate of 30 percent at a 60.5 percent recovery and a 52 percent Zinc concentrate at an 83.4 percent recovery.Laboratory testwork proceed the 1988 start up of our current concentrator and underground mine facilities. The concentrator was designed to produce a Lead ""rich"" concentrate and a Zinc ""rich"" concentrate which were combined to make a marketable Bulk concentrate. In 1990 the operation was suspended because of declining base metal prices, increasing smelter treatment charges, increasing operating costs and operating difficulties.The 1997 operating plan is to produce a Lead concentrate and a Zinc concentrate.The Restigouche ore body was discovered in 1989. The subsequent testwork done at Lakefield Research recommended the production of a Copper, a Lead and a Zinc concentrate. The ore reserve could not support a stand alone concentrator so the project was put on hold.Laboratory testwork was carried out at Lakefield Research to confirm compatibility of the East West Caribou ore and the Restigouche ore in their processing."

Jan 1, 1997

By Steve Massman, Edward Wipf, Gary Beerkircher

"As mine size and tonnage continues to increase, material handling/processing equipment has also increased in size with 400 MT haul trucks, 2000 KW crushers, 12 M SAG/AG mills, 8.5 M ball mills, 3000 M3 flotation cells and 12.5 MW HPGR’s all with planned designs to increase in size further. Related equipment including vibrating screens have also increased in size with screens seeing feed rates of 3000 MTPH. Open circuit SAG Pre-Crush and closed circuit HPGR flowsheets are becoming more common with large screening requirements. Large multi-slope (banana) or horizontal screens are commonly used for these applications, however as the size of these screens has increased, the number and size of the brute force/overhead exciters has increased but with limitations. An example is a SAG discharge screen that will see surges of material from the SAG mill which overload the screen, reducing the screen stroke or throw causing a large reduction in screen efficiency with excessive fines & moisture in the screen oversize feed to the pebble crushing circuit. This paper will present some actual examples of the use of Two-Mass screens as a solution to these overloading problems and the advantages of Two-Mass screens in other high tonnage applications.Brute Force Drive Compared to Two Mass Drive Vibrating ScreensThe standard single mass screen as depicted by figure 1 is generally recognized in the mining industry. It is characterized by the screen body – labeled as the single mass (Mt) that is supported by isolation springs (Kiso). The stroke needed to process material is obtained by incorporating large eccentric wheels and/or drive boxes (Fb) directly mounted to the screen body via a drive tube."

Jan 1, 2017

By Richard Maurice

RÉSUMÉ La restauration du site minier Poirier, à Joutel s?est déroulée entre 1998 et 2001. Le principal élément des travaux a été la restauration du parc à résidus et des zones d?épanchement qui totalisaient 4,5 millions tonnes de résidus répartis sur une superficie de 74 hectares. Les résidus sont fortement générateurs de drainage minier acide. La première partie de la présentation consiste en un bref rappel du concept de restauration suivi d?une description des principaux éléments de travaux avec l?emphase sur les leçons apprises de l?exécution des travaux. La deuxième partie de la présentation est axée sur les résultats du programme de suivi en cours depuis la fin des travaux en 2001. Les éléments de suivi se rapportent à la baisse du niveau de la nappe phréatique à l?intérieur de la cellule, au tassement des résidus dans la cellule, aux mesures de température et d?oxygène à l?intérieur de la cellule et finalement à l?amélioration dans la qualité de l?eau de surface. ABSTRACT The reclamation of Poirier Mine, in Joutel, was carried out between 1998 and 2001. The main component of the works has been the reclamation of the tailings basin and tailings spill area which contained a total of 4,5 million tonnes of tailings and occupied some 74 hectares of ground surface. The mine tailings are highly acid-generating. The first part of the presentation will deal with a brief review of the reclamation plan followed by a short description of the main work components laying emphasis on experience gained during construction. The second part of the presentation will deal with the results obtained from the environmental monitoring program still in progress since the end of reclamation work in 2001. The aspects discussed include the drawdown of pore water inside the covered tailing pile, the settlement of mine waste material, the monitoring of moisture, temperature and oxygen underneath the liner and finally, the reduction of loadings in surface water.

Nov 1, 2002

By John Lindsay

Outline ??Recovery plant requirements and concepts ??Common recovery plant unit processes ??Recovery plant design considerations ??Peripheral issues Process Design ??Liberation ??Separation ??Recovery Processing ??Density 3.5 g/cm3 ??Luminescent under x-ray ??Hydrophobic (non wettable) surface ??Non-magnetic ??Inert to strong acids / bases

Apr 1, 2005

By Patrick M. Y. Waye

As mines utilise more automation in mining operations to improve efficiency and safety, a corresponding increasing demand is placed on the transport of information. Some of the recent technological advances in underground telecommunications are described for various data, voice and video applications. In particular, two new innovative underground communication systems are described, one with high speed data at 30 Mbps and the other for mine wide evacuation and safety applications. The high speed data system incorporates stateof- the-art data networking technologies and the existing leaky cable narrow band radio channels. The new system provides over the same basic infrastructure the high speed data network at 30 Mbps TCP/IP Ethernet with 100 Base-T interconnection, plus 32 narrow band radio channels. The second system is a system for mine wide evacuation with "through the earth" communication infrastructure. Emergency situation can be communicated to and from all the miners within seconds through a central control location. The technology involved does not require leaky cable or any other similar transmission media installation. Many applications are possible, including warning miners of emergency situations, mine rescue operation to communicate with trapped miners, regular reporting from miners working alone.

May 1, 2001

By T. Gammatikopoulos, C. Gibson, M. Aghamirian

Lithium is an alkali metal found in brine deposits in the United States, Chile and Argentina, as well as in hard rock deposits in Australia and North America. In hard rock deposits, spodumene (LiAl(Si2O6)) is the major economic lithium bearing mineral. Spodumene is typically upgraded through a combination of dense media separation, flotation and magnetic separation. One of the major spodumene concentrate quality specifications is the iron oxide content because it will help determine if the concentrate is considered ceramic grade for use in ceramics and glass or chemical grade for use in lithium ion batteries. The rejection of iron bearing silicate minerals from artificial ore composites (high amphibole and low amphibole, high quartz/feldspar) from a hard-rock spodumene deposit was investigated using magnetic separation and flotation. The efficacy of Wet High Intensity Magnetic Separation (WHIMS) in iron rejection was found to be dependent on the mineralogy of the iron-bearing silicate minerals including modal distribution, liberation and association. When magnetic separation was conducted prior to flotation, the Fe2O3 grade in the final flotation spodumene concentrate was reduced from ~3% to ~1% Fe2O3 , and improved lithium recovery in flotation was observed. It was determined that it was most effective to conduct WHIMS on the flotation feed after scrubbing and de-sliming because this reduced the required magnetic field to recover iron-bearing minerals, likely because slime coating was greatly reduced. Flotation collector screening of four different collectors with varying rosin acid content demonstrated a potential increase in selective flotation of spodumene over some iron silicate minerals with decreasing rosin acid content in the fatty acid collector. However, due to marginal difference in flotation results with the various collectors tested, further testing is required to confirm the observations made and establish a hypothesis regarding the effect of rosin acid content.

Jan 1, 2017

By Karina Forster

Rock mass characterisation is a critical component of effective stope design. Unexpected excessive stope dilution or uneconomic stope sizes can be the result of rock mass characterisation that is not representative of actual stope conditions. Comprehensive characterisation of the rock forming the stope hanging wall, back, ends and footwall is best done by a rock mechanics or ground control expert, however, this is time consuming and is often limited by available access. There are two general approaches for characterising a stope hanging wall for dilution estimating. Detailed classification and mapping data can be collected in local areas where good exposure is available. Personnel, exposure and time are usually not available to do a thorough analysis for all stopes. The stope hanging walls are then broken into lenses or domains and similar conditions are assumed for each area. The second approach consists of using readily available data such as RQD. Other rock mass properties which influence hanging wall behaviour are estimated based on back analysing a few case histories. Stope design is then based on the variability of the one parameter, such as RQD, that is consistently measured for the rock mass surrounding the ore body. This paper presents a third approach which looks, in depth, at the interpretation of geological core logging data for rock mass characterisation. Several rock mass properties that influence stope design, such as joint alteration, rock mass strength, joint spacing and orientations, have been linked to data collected by the mine geologists. This drill hole logging data was calibrated against underground mapping and used to back analyse the dilution prediction for mined-out stopes.

May 1, 2006

By C. -K. Fang

"Aging effect on the wear resistance of alumina particulate-reinforced 6061 aluminum matrix composites with a block-on-ring wear tester has been investigated. Specimens with various Al2O3 volume fractions of 0%, 10% and 20% were employed in this work. Experimental results indicated that over-aged monolithic 6061 Al had the best wear resistance, as compared with under-aged and peak-aged conditions. For the composite containing 10% Al2O3, over-aging and peak-aging resulted in similar wear resistance, which was higher than that for underaging conditions. For the composite containing a high volume fraction (20%) of Al2O3, the wear resistance reduced with the increase in aging time. Although longer aging time was favourable to the wear resistance of monolithic 6061 Al, it was detrimental to that for the Al2O3/6061 Al composite with high volume fraction of particles. IntroductionMetal-matrix composites (MMCs) have received attention in many engineering applications because of the demands for high specific strength (strength-to-weight ratio) and specific stiffness, good high temperature capabilities and wear resistance. The manufacturing processes of fiber-, whisker-, and particulate-reinforced MMCs have been well developed (Hosking et al., 1982). Because of the reduction in fabrication cost, the applications of MMCs have been widely extended to light weight-bearing sleeves, calipers, automobile parts (brake rotors, drive shafts, connecting rods, piston rings, and cylinder liners), sporting goods, aerospace components, tanks (wheels, speed brakes, and track shoes) and other industrial applications. Among the three types of metal matrix composites, particulate-reinforced MMCs are promising because of their homogeneous and isotropic material properties and low cost. Additionally, they can be formed using conventional metal processing techniques."

Jan 1, 2003

By M. B. McClenaghan

"This paper summarizes diamond exploration techniques used in glaciated terrain, focussing on indicator mineral and geochemical methods applied to glacial sediments. Understanding the ice flow history, depositional history, and stratigraphy of glacial sediments is essential to successful sampling, interpretation and follow-up of indicator mineral and geochemical anomalies related to kimberlites. Kimberlite indicator minerals survive glacial transport over long distances and the relative abundance of each mineral in till is a function of the primary mineralogy of individual kimberlites. Indicator mineral distributions observed at a regional scale define the net effect of glacial dispersal, often along different ice flow directions. Local-scale distributions define individual dispersal trains. The medium sand (0.25 mm to 0.5 mm) fraction of heavy mineral concentrates, * GSC Contribution No. 2002028 prepared from glacial sediment samples, is best suited for indicator mineral surveys. The application of till geochemistry to diamond exploration is increasing because it is significantly cheaper than indicator mineral analysis and it can be performed quickly. The <0.063 mm (silt+clay) and 0.5 mm to 2.0 mm (coarse sand) fractions provide the best geochemical contrast between background and kimberlite-rich till. Kimberlite pathfinder elements that provide good contrast include Ni, Cr, Ba, Co, Sr, Rb, Nb, Mg, Ta, Ca, Fe, K, Ti and LREE, the relative importance of which will depend on kimberlite composition and that of the surrounding bedrock.IntroductionIn Canada, glacial erosion is the principal means by which kimberlite and its associated minerals have been dispersed, from a few tens of metres to tens of kilometres down-ice. Post-glacial weathering has had little impact on kimberlite debris in the glacial sediments, thus boulder tracing, indicator mineral methods and trace element geochemistry of the fine fraction of till (“drift prospecting” methods) can be used to detect kimberlite dispersal within areas covered by glacial sediment. This paper provides a summary of drift prospecting methods for kimberlite exploration in glaciated terrain, and includes examples of reconnaissance- , regional- and local-scale kimberlite indicator mineral and till geochemical distribution patterns.Weathered kimberlite is more susceptible to glacial erosion than the surrounding bedrock, thus many kimberlites in glaciated terrain are found in low or swampy ground, under small lakes, or covered by thin (< 1 m) to thick (>50 m) glacial sediments. Glacial erosion has removed varying amounts of the pre-glacially weathered kimberlite and, in some cases, the hard competent kimberlite below. For example, glacial erosion of the Peddie, McLean and Seed kimberlites near Lake Timiskaming, Ontario, removed pre-glacially weathered kimberlite, leaving a polished striated subcropping surface (McClenaghan et al., 1999a). In contrast, glacial erosion of the B30 kimberlite, near Kirkland Lake, Ontario (Fig.1), was much less vigorous and left a >10 m cap of soft and highly weathered dark green clay-rich kimberlite (McClenaghan et al., 1996). The thickness of remaining pre-glacially weathered kimberlite will influence the geophysical signature of the kimberlite."

Jan 1, 2002

Safe underground mine backfilling with hydraulic fill requires efficient fill drainage and stable fill retaining walls or bulkheads. If any or both the above two requirements are not satisfied, such a backfilling operation creates unsafe conditions and may lead to backfill retaining wall failures. Mine backfill retaining wall failures are always associated with economic losses, fatalities and interruption to mine production. Mining industry wants to either reduce or eliminate these fill retaining wall failures. The fill retaining wall failures could be effectively avoided through the use of fibre reinforced shotcrete fill retaining walls and engineered drainage systems through the retaining walls. This paper presents the experience of the author in developing, implementing, and monitoring several hundred fibre reinforced shotcrete fill retaining walls at a mine in Australia with the highest safety standard. The details on the mine backfill drainage system and fibre reinforced shotcrete fill retaining wall designs are also presented.

May 1, 2007

By Guillermo Turner-Saad

"Best practice in the economic evaluation of mining projects and operations is based on the integration of geological, mining, metallurgical, environmental, marketing, economic and corporate information and strategies. Fundamentally, the economic evaluation takes into account mining, blending, stockpiling, processing, smelting, refining and marketing ore resources with grades estimated by geostatistical methodologies.Nevertheless, a realistic economic evaluation consists of a concurrent and integrated optimization process that maximizes the concentrates or products of liberated and selected ore minerals from mineral deposits. The optimum solution is obtained through a trade-off among mining, blending, stockpiling and processing ore reserves with distinct mineralogy and texture characteristics. The concurrent optimization determines both the practical mining sequence of ore reserves and the dynamic and robust mineral processing flowsheet design over the expected life of mining projects and operations.A combined risk-adverse and concurrent optimization process takes into account the spatial uncertainty of the mineralogy and texture characteristics of ore reserves. Additionally, a variety of mineral processing linear, non-linear, additive and non-additive parameters modeled spatially. The spatial uncertainty of these ore reserves characteristics and parameters has a direct impact in the expected mining sequence, mineral processing flowsheet design, concentrates or products quantity and quality, and economic value of mining projects and operations.Geometallurgical domain constrained stochastic geostatistical methodologies and multivariate mathematical models are applied for spatial uncertainty modeling of ore reserves characteristics and parameters. These mathematical models correlate the mineral processing liberation and selectivity responses of the mineralogy and textures within each geometallurgical domain. These models, in turn, are defined based on results of mineral processing and environmental testwork of unbiased and representative samples chosen for their variability. These samples are selected within mutually exclusive spatial geometallurgical uncertainty domains with similar mineralogical and textural characteristics in mineral deposits.Geometallurgical domains are defined by applying and combining multivariate statistical analysis and implicit modeling methodologies. These involve determining and constraining mineral processing liberation and selectivity properties explicitly contained in the extensive and integrated exploration drillhole database."

Jan 1, 2010

By Tassos Grammatikopoulos, Vladimiros Papangelakis, Douglass Duffy, Cheryl Washer, Srinath Garg

Flotation operations in Sudbury, Ontario, seeking to separate pentlandite and chalcopyrite from mixed sulphide deposits, produce pyrrhotite tailings that have been disposed of in tailings ponds for over 50 years. These reactive tailings are viewed as waste, despite containing ~0.8 wt% Ni, and represent an environmental liability because of their acid mine drainage (AMD) potential. Given the large quantities of pyrrhotite currently stored in Sudbury, and declining ore grades elsewhere, these tailings have shifted from being viewed as a waste to a potential resource. Recent advances in the bioleaching of low-grade sulphide ores have raised the prospect of bioleaching as a potential low-cost processing option. However optimization of this proposed process requires a thorough understanding of the mineralogy of the pyrrhotite tailings that would be leached. The work presented here addresses the characterization of two distinct Sudbury pyrrhotite tailings, namely from the Vale and Glencore operations, using electron microprobe, XRD and QEMSCAN analysis. Particular focus is given to how the mineralogy may affect bioleaching as a processing option, through the deportment of nickel and the various phases present

Jan 1, 2015

By Kretschmar. U. H.

Fieldwork in the Meguma of Nova Scotia and Archean equivalents shows that bedding-parallel quartz lode gold veins (LVs) commonly occur at the top of graded elastic sequences. We define a "gold cycle" (GC) by analogy with Bouma turbidites and show that most "shear zones" and "lamprophyres" correspond to the upper pelagic-pelitic (E) division. We describe GCs from Archean Chester Twp, ON; Elmhirst, ON; Bourlamaque, QC; "intrusions" and interpret them as crystal tuffs and tuff-breccias. Extensive early Archean pyroclastic volcanism is implied: the genesis of trondjhemite-tonalite-granodiorite (TTG) rocks must be re-examined. The geopetal nature and asymmetric alteration of LVs indicates genesis from sea-floor hydrothermal vents. Textures suggest that often quartz was deposited as a gel. Vent geometry (fracture, point source or diffuse seep), bottom topography and vent spacing is reflected in wade-thickness plots. GC facing directions survive metamorphism. The Bourlamaque batholith was a flat-lying sheet of quartz-feldspar-hornblende crystal tuff, and isoclinal folding has repeated one or more gold-bearing horizons. Syngenesis clarifies and simplifies LV formation with major implications for models. Exploration becomes more cost-effective. Basin analysis, whole rock geochemistry, ore lens geometry and vent spacing can be used.

Jan 1, 2011

By R. Siy, O. Neiman, B. Hilscher

"A full-scale prototype of “Jameson Downcomer” technology has been installed and tested on a Tailings Oil Recovery (TOR) vessel in Syncrude’s Mildred Lake extraction plant. Jameson Downcomers are a type of mineral flotation equipment used in the coal industry that Syncrude has extended to the recovery of secondary bitumen in the oil sand extraction process. The TOR vessels are currently being operated as single-gravity separation vessels, in series with the Primary Separation Vessels (PSV’s). We have developed a model to differentiate between “floating” and “non-floating” bitumen in the PSV’s, and then applied it to verify that the current TOR performance only captures the “floating” bitumen by simple separation. The existence of “non-floating” bitumen provides an opportunity for recovery enhancement by means of the Jameson Downcomers. To achieve bitumen recovery enhancement, middlings slurry is withdrawn from the TOR vessel, and passed through a number of parallel Jameson downcomers, within which the slurry is accelerated to a high-velocity free jet, and impinged upon the slurry surface inside the downcomer, in the presence of air. The aerated slurry is returned to the middlings zone inside the TOR, resulting in an incremental recovery improvement of bitumen in the TOR. The operation of the downcomers is thought to produce suitably small air bubbles for the flotation of bitumen, either by fluid shearing during the slurry jet impingement, and/or by micro-bubble nucleation. This full-scale prototype design has met or exceeded the recovery expectations of the original Research piloting, recovering at least 40% of the non-floating bitumen. In Syncrude Extraction, this provides high business value by a separation efficiency gain achieved with modest expenditure. As well, the system has demonstrated excellent operability and maintainability.INTRODUCTION Syncrude Overview Syncrude Canada Ltd. is one of the largest producers of crude oil from oil sands. Our crude oil production facility has the capacity to produce over 15% of Canada's total oil requirements. To do this, we surface mine oil sand, extract the raw oil known as bitumen from the sand using water-based processes, and upgrade that bitumen into sweet light crude oil by fluid coking, hydro processing, hydro treating and reblending. Our final product, Syncrude Crude Oil (SCO), is sent by pipeline to three Edmonton area refineries and to pipeline terminals which ship it to other refineries in Canada and the United States. The Syncrude operation is comprised of four major technology areas: Mining, Extraction, Upgrading and Utilities. As well, Syncrude invests more than $40 million annually in science and technology, and is among the top 50 companies in Canada for Research and Development (R&D) investment. Syncrude holds 21 active Canadian and U.S. patents."

Jan 1, 2012

By W. J. González

"With the increasing demand for minerals, technologies to maximize mineral recovery are paramount to a mine’s economic success. Many mining process waters have the potential to form calcium-based inorganic scales, which inhibit effective mineral recovery. Often, the solution to inhibit these deposits is the implementation of a chemical antiscalant program. This paper examines the application of a fouling analyzer to continuously monitor the formation of inorganic scale in mining process streams. The fouling data can be used to compare antiscalant programs and to optimize antiscalant feedrates. Case studies validate the ability of this technology to help optimize mineral recovery processes.INTRODUCTION The mining industry uses significant quantities of water. From quarrying, to crushing, to flotation, leaching, and refining, water is often the integral motive force to move slurries, separate or agglomerate fines, and extract and purify minerals. As well, water is used in a number of ancillary applications at mines, including dust suppression, gas scrubbing, and utility processes such as boiler, cooling, and waste water operations. For many processes, the quality of water being used is inconsequential. However, for certain processes, such as flotation, leaching, and desorption / stripping, water quality plays a key role in the ability of the operation to economically recover the target minerals. Dissolved solids such as calcium and magnesium salts can concentrate in process waters, exceed their solubility limits, and precipitate as scale on metal surfaces such as feed and transfer pumps, piping, and equipment. Some of the more common scales that form in mining operations include calcium carbonate (CaCO3, or calcite) and calcium sulfate (CaSO4, or gypsum), and to a lesser extent, calcium and magnesium silicate compounds. Any scale that deposits in a process stream will negatively impact mineral recovery, and increase the operational costs of the mine site. Whether it is acid washing a scaled heat exchanger in a carbon strip at a gold operation, replacing plugged emitter tubes in a leaching operation, or hydroblasting process lines in a scrubber unit, there are costs associated with labor, cleaning chemicals, repairs, and replacement parts. These costs pale in comparison to the potential costs of downtime and lost production, should the scale deposits occur in a process that is critical to the recovery of the target mineral."

Jan 1, 2014