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By K. Lillkung, J. Kourunen, M. Latva-Kokko

"Carbon-in-leach (CIL) and carbon-in-pulp (CIP) processes utilize activated carbon to adsorb solubilized gold for recovery. Due to carbon attrition and non-ideal carbon management, however, some of the gold is lost in carbon fines and to the solution. The carbon attrition mechanism inside CIL/CIP reactors is mainly abrasion-related. This is critical to gold loss since gold loading takes place predominantly in the outer shell of the carbon particles. Thus fine carbon dust has a relatively high gold content and such a small particle size that it cannot be captured with safety screens. The attrition rate depends on ore and carbon characteristics, but it is always proportional to the mixing power intensity. This rate can be minimized by continuous suspension level measurement and control of agitation speed. In addition, a novel tank bottom structure can significantly reduce the required mixing power input compared to a flat bottom tank. A major challenge in carbon management is infrequent and inaccurate measurement of carbon concentration in the reactors. In order to reduce soluble gold losses by means of improved carbon management, Outotec has been developing a continuous in-situ measurement for carbon concentration that is tolerant to changes in slurry density.INTRODUCTION Cyanide leaching has been utilized since the late 19th century as a standard technology for hydrometallurgical gold production. Since then, gold and silver recovery rates have increased due to technological development, but very similar recovery methods are still being used. The original recovery method was to use zinc precipitation – similar to the Merrill-Crowe process, which is still common for feed materials with low throughput and high silver content. However, in most cases, activated carbon recovery is preferred due to its improved efficiency. The carbon-in-pulp process (CIP) and its modification, carbon-in-leach (CIL), have a lower residual soluble gold level and are not similarly affected by soluble base metals. The main alternative for the use of carbon is ion exchange resins. The principle of resin processes is similar to the CIL/CIP processes, with a different type of adsorbent material. Carbon processes are usually preferred over resin processes due to the significantly higher cost of resin material and the possibility to use simpler, well-established technology with carbon processes."

Jan 1, 2017

By Y. Kashiwaya, J. Yagi, P. R. Austin

The problems of global environment and resources have become important issues in recent years, and the iron and steelmaking industry is requested to decrease energy consumption and carbon dioxide emission. The improvement of efficiency of ironmaking system is one of the countermeasures for these problems because more than a half of total energy input to the integrated steelwork is input to the ironmaking system. Various approaches to improve the blast furnace process have been made. The authors examined their performances through mathematical simulations of blast furnace operation, and confirmed the improvement of blast furnace efficiency under some operating conditions. The ironmaking system consists of various processes, and the materials and the energy are transported among these processes. Thus it is necessary to evaluate the efficiency of the novel operation of blast furnace based on the ironmaking system. In this study, the balances of material and energy on ironmaking system that consists of blast furnace, coke oven, sintering and hot stove processes were analyzed. The operation status of each process in the system was adjusted according to the results of the operation simulation of the blast furnace under novel operating conditions. The analysis clarified the effect of the blast furnace operation on the energy balance and CO2 emission of the ironmaking system.

Jan 1, 2015

By A. Robles-Vega

Personnel of Mexicana de Cobre, a subsidiary of Southern Copper located in Nacozari, Sonora Mexico have been working in the past few years on the development of a process to treat and manage, in an environmentally accepted practice, the residues and effluents generated during the process. To date, this team has been reviewing existing technologies and also has explored new alternatives. At the end of this phase, a novel, efficient and complete process has been configured which will be able to treat some solid and liquid streams such as Teniente converter dust, Peirce Smith converter dust, a Sb-rich precious metals slag, copper refinery electrolyte bleed, acid plant blowdown and an acid bleed of the precious metals plant. The process will consist of a leaching stage, followed by a very selective copper precipitation using novel technology which has been named as back reactions. After copper precipitation, impurities (As, Sb and Bi) will be precipitated mainly as arsenic trisulfide (As2S3) using H2S(g) which will be generated by means of a new process developed in our company. At the end of the process, small volumes of arsenic trisulfide will be vitrified and then disposed as a stable residue.

Jan 1, 2007

By P. Belley

Prior to 2006, the filtration unit for leached sludge treatment (filter press) permitted the filtration, washing and drying of cake to 17% (w/w) moisture. That year saw moisture content abruptly increase to 20% (w/w), drastically changing the rheological properties of the cake. The cake became sticky and agglomerated. This led to major disruptions of operations and plant capacity (cake release and cake conveyor problems, complicating the subsequent steps of the process). The conditions for the filtration, washing and drying, were simulated to ease cake unloading without aggravating dust emissions (moisture about 17% (w/w)). All of the laboratory tests yielded a moisture content above 17% (w/w). Therefore, we concluded that the moisture problems were not due to a recipe change in primary material, but to an operational problem in the filter press. Through the laboratory results, the filter press operating conditions (washing ratio, drying pressure and drying time) were optimized to enable a reduction in cake moisture to 17% (w/w).

Jan 1, 2007

By D. R. BUDINSKI

Clinton Creek Mine in west-central Yukon produced 0.94 million tonnes of fibre from 15 million tonnes of asbestos ore between 1968 and 1978. The mine closed in 1978. The deposit lies along the margin of a medium sized ultramafic pluton that intrudes schistose and gneissic rocks of the Yukon Metamorphic Complex. Country rocks are metamorphic equivalents of a mixed sedimentary and volcanic assemblage deposited during Precambrian or early Paleozaic time. Movement along the north west-trending Tintina Fault System probably caused the fairly high meromorphic grade that altered the original rocks to schists and gneisses. The ultramafic pluton hosting Clinton Creek Mine is one of several bodies that were emplaced along a deep seated imbricate fault system parallel to the Tintina Trench. Most of rhe intrusions were hydrothermally altered to serpentinite, bur apparently only the one at Clinton Creek contains commercial quantities of asbestos. The Clinton Creek pluton was probably injecred slowly at relatively low temperatures into the crustal rocks as a "mush" that cooled gradually, allowing sufficient time for serpentinization and chrysotile fibre crystallizarion.

Jan 1, 1984

By V. Estrada, G. Aguilera

"Since the most of mineral processing are wet, and for more specific applications where it is necessary to increase the purity through leaching and / or concentration, the proper dispersion is the first, and perhaps more crucial stage in the whole chain of processing. This specific process is based on the formation of a dispersion or suspension of mineral, trying to make the mixture as homogeneous as possible, and with specific rheological conditions. Sometimes it is not enough agitation to make it happen, so that chemical additives are used as an aid. However, the addition of chemicals strongly alters the viscosity and other rheological properties of the suspension factor to consider for subsequent steps to ore beneficiation. In other hand, in a process where no chemicals used often employ large quantities of water to achieve dispersion. But if an efficient chemical agent, which optimizes said dispersion through a specific physicochemical effect on the particle surface is used, also it can generate rheological advantages, besides achieving rational use of water and increase the recoveries of the product main about also optimal costs. The aim of this work is to find the optimal rheological conditions for a dispersion of kaolin as study case, looking for stability, best disaggregation, viscosity and pseudoplasticity.To find the optimal additive, the evaluation parameters were: 1) Best degree of dispersion of the suspensions according to the analysis of the flow curve; 2) Best level of disaggregation of particle chemical analysis delaminated by Particle Size Distribution; and 3) Best thixotropic rheological parameters and pseudoplasticity. Finally the optimum additive as one that meets the best combination of parameters is proposed.INTRODUCTIONKaolin is a clay material formed by altering of feldspar composed mainly for kaolinite. Depending on the application, the kaolin as raw material must be refined and processed because the ores of clays contain usually a lot of impurities derived of its sedimentary source, such as feldspar, mica and quartz (Torres, et. al., 2011). According to the experience on the plant floor and the publication of several scientific papers, it is known that the dispersion is a crucial stage in mineral processing (Greene, Duke, & Hunter, 1965) (Raghavan, et. al., 2004), not only because of the disaggregation of particles, besides because of the humectation of them. Is clear that disaggregation of particles give to the suspensions rheological stability, and the humectation improves the effect of further processes like grinding or chemical treatment. The dispersion process involves making a suspension of the mineral with a solvent which is usually water, to obtain a homogeneous dispersion, with the aid of energy of stirring. Sometimes is not enough the agitation (even with high energy) for this to occur, so is necessary the use of dispersing substances which introduce ions and molecules as modifiers of chemical potential, forcing the molecules of the material to disperse. Sometimes their use even could affect the pH of the suspension in a non-desirable condition. (Flores, 2013)."

Jan 1, 2016

By B. J. Cunliffe

"Filter cloth in the mining industry is an ambiguous title asthis suggests filter cloth use from underground ventilation to the refining processes. The time allowed for this paper would be better served in con-centrating on vacuum filters common to all mine mills and to offer some simple guide lines to the mill metallurgists in the choice of filter cloth for this type of filter.The requirement of the filter cloth is to separate solids from liquids under a vacuum head by forming a permeable layer of solids or cake, through which liquids can flow until the panel or disc sector leave the slurry tank and to continue to pass residual moisture from the cake formed during the cake drying cycle, and to discharge the cake on air-blow so that the cycle can be repeated.Whilst the mill metallurgist should not be expected to under¬stand all aspects of filter cloth manufacturer, it is however, advantageous for him to understand a little of the textile language associated with filter cloth for his own protection against ""trial-and-error"" methods, which are both time consuming and costly.If improvements are to be made over existing filter cloth in use an examination of the limiting factors of the cloth used should be made and the major causes for removal determined, e.g. cloth blinding, high moisture in cake, poor cake discharge on air blow, mechanical damage to cloth.As each of the limiting factors mentioned has a bearing on the choice of fibre used, the yarn type and weave of a suitable cloth, an under-standing of these points will assist the mill metallurgist in avoiding repetitive trials offering little degree of success."

Jan 1, 1971

By G. R. Baiden

"An Automatic Haulage Truck (AHT) has been developed for manless tramming of run-of-mine material in an operating mine. The AHT has a 70-ton capacity and uses an electric trolley system in combination with a computer control system to operate the vehicle. The purpose of the AHT was to provide a high capacity, high productivity material transfer system where conveyor belt applications are not immediately practical.The AHT project was started in 1983 at Inco Limited, Ontario Division as a result of the need for rapid material transport to match increased extraction rates resulting from bulk mining methods. The original concept was to use a continuous loader with the truck. However, in order to minimize development problems the truck project was considered a stand-alone project.The AHT project consisted of concept development, preliminaryand detailed design, manufacture, surf ace testing and mine implementation.The AHT was manufactured and ready for testing in 1988. At this point the truck was first moved onto the test track for debugging. This proved successful and in 1989the decision was made to install the AHT at Little Stobie mine on 2000 level. Commissioning of the system was started in 1990and at present a fully functional automated haulage system is in place at Little Stobie mine producing 3000 tons/day.This paper describes the project presenting results achieved to date."

Jan 1, 1992

By T. V. Lord

Minerals containing uranium have been successfully pre-concentrated by flotation at Queen's University, Kingston. In particular, uraninite, uranothorite, euxenite, and fergusonite, have responded to flotation to yield grades of 0.2 to 6.0 .per cent U .o. with recoveries of 85 to 98 per cent, from heads analysing approximately 0.10 per cent U3Os. Of the ten or so radioactive samples examined to date, two distinct groups were recognizable, firstly, those samples in which uranium was the sole constituent of economic interest, and, secondly, those in which Columbium (with minor amount of tantalum) was present in addition to uranium. For the purpose of this paper, the results of investigation on two samples of each of the above groups have been selected as typical.

Jan 1, 1945

By T. W. Wlodek

"AbstractIn this paper a new type of durable 'spiral-rolled' drill set is introduced and its performance discussed. Efficient and economical mine drilling-depends to a great extent on durability of the drill-set employed. Premature failure of this element damages the drill bit and is costly when tungsten carbide bits are used.Time of drilling of 'spiral-rolled' drill sets introduced at present in Canada is considerably larger than for the presently used drill steel, but laboratory simulated service tests and practical field tests show that the 'drilling life' of the spiral-rolled drill set is several times that of ordinary drill steel.Some features of differential plastic deformation and differential surface rolling, so called 'spiral-rolling', are given.Relations between the drilling machine drill set and characteristics of the ore are discussed. The effect of shims on conical drill rod attachments, the mechanism of failure of drill steel, .and stresses during mine drilling, are analysed.IntroductionIN MINE DRILLING operations, the main interests are: the drilling machines as a source of working energy, the drill set as the tool transferring the working energy to the cutting edges of the bit, and, finally, the drilling characteristic of the .ore or waste rock.This paper includes a review of the possibilities of metallurgical and mechanical improvements in the drill set, with particular attention to drill steel and the attachments.For economical and efficient mine drilling operations, a durable drill rod, attachment, and drill bit are essential. Premature failure of any of these parts interferes with mining operations and is costly."

Jan 1, 1955

By Tony B. Szwilski

"The efficiency of operation and life of an advancing longwall coalface depends, to a great extent. on the face-end roof strata conditions and the stability of the gateroads. The factors that influence the rate of closure of gateroads are examined, in particular the gateside pack and the coal rib (crush) pillars. The performance of mechanized packing systems is briefly discussed. Gateroad deformation surveys were carried out at two coal mines to determine the influence of the rib pillar width on gateroad stability; also, the influence of the gateside pack on the immediate roof and floor strata is analyzed based on strata bed displacement measurements from instruments installed in the gateroad and pack-hole of a longwall advancing face operating in a thick seam (7.55 m). Concluding, an evaluation of the fac e-end systems examined is given and recommendations made f or the most suitable rib pillar width. face-end geometry and roof strata reinforcement.IntroductionKevword s: Coal mining, Pillars, Rib pillars, Ground control, Longwall mining, Gateroads , Packing systems, Roof control. The face-end region of a longwall advancing face is the center of mining activity, being the turn-around point for the coal cutting machine. and the place of gateroad formation and movement of special face-end supports. The design of face-end layouts can be aided by knowledge of strata control parameters, such as the effective loading of the immediate roof strata , convergence of the roof and floor, magnitude and distribution of fractures in the roof strata around the face-end , optimum placement of supports, coal seam thickness and strength characteristics, geometry of layout and interaction from neighbouring workings. Generally, the gateroad is formed by one of three face-end methods: (a) advanced headings, (b) in-line system (gateroad formed at the face) or (c) conventional ripping with or without stable elimination (also halfheading). The quality of gateroad is influenced principally by the face-end system employed, standard of gateside pack and width of pillar. A good standard of gateroad is generally achieved by employing the half-heading face-end system, the gateside pack and coal rib pillar having comparative support/ yield (stiffness factor) characteristics. However, the halfheading is often not favoured due to face operation restrictions."

Jan 1, 1981

By Chri Langille, Dougal McCreath, Samantha Espley

"In 1993, trials of two innovative applications of liner support involving the replacement of bolts in the ground support system were undertaken at Inco mines. The first trial involved an evaluation of the effect of dynamic loading on mesh-reinforced boltless shotcrete in a sub-level cave mining area on 2400 level at Stobie Mine. The second trial involved an evaluation of the MIROC Mineguard spray-on liner as a replacement for bolts and screen support, or as a replacement for screen support alone, in a topsoil heading of a bulk, VRM (vertical retreat mining) stope on 3240 level at Lower Coleman Mine.In the Stobie Mine trial, an uppers retreat heading was supported using a two-pass system. First, shotcrete was applied 2 inches thick, followed by pinning of mesh screen to the back and walls. A second pass of another 2 inches of shotcrete was then performed. For recovery of the ore zone, a vertical slot was created using a Borepak blind boring machine. The uppers rings were blasted, one or two rings at a time, starting at the slot and retreating out of the heading. During blasting of the production rings, blast monitoring was used to record the ppvs (peak particle velocities). For a series of 5-ring blasts, the maximum ppvs were measured to be 0.4 m/s (16 in./s) with a maximum charge weight per delay of357 kg (800 Ib). Six 5-point convergence measurement stations were set up and after each blast the total rockmass convergence was measured using a tape extensometer. Although a maximum displacement of 100 mm (4 in.) was measured, the shotcrete still managed to provide some support junction. A support damage assessment was also done to try and relate blast vibration to effectiveness of the mesh reinforced shotcrete liner. This trial demonstrated the effect that blasting has, on a support system, and it also demonstrated the necessity of having the mesh reinforcement properly placed within the shotcrete."

Jan 1, 1995

By L. B. Tsymbulov, L. Sh. Tsemekhman, A. N. Golov

Gipronickel Institute, JS is developing a process of continuous converting of Nicontaining copper matte and concentrates resulting in the production of blister copper and fluid NiO-containing slag in a two-zone Vaniukov furnace. The process under development is an alternative for the existing technology of blister copper production in converters, the latter being characterized with insufficient sulphur utilization, low direct copper recovery and the production of inconvenient for further processing solid slag on the basis of NiO and NiFe20 4- The results of pilot testing on processing of copper concentrate obtained from high-grade matte (HGM) separation in the two-zone Vaniukov furnace with the hearth area of 11.4 m2 are presented.

Jan 1, 2007

By S. Kaushik

The control room in a mineral processing plant has become increasingly complicated with complex unit operations coupled with rapidly evolving systems of sensors and control. Even with significant automation, human intervention is required to counter various scenarios that play out every day. A typical control room operator must monitor over 300 individual points of data in order to ensure the safe and efficient operation of the plant. At the same time, the experience of the workforce is decreasing as operators retire and the new generation enters the concentrators. Global competition for skilled operators continues to be strong and the opportunity to apprentice has diminished. The challenge is to provide a skill foundation for the operators so that they can be effective in the concentrator in a timely and safe manner. Progressively, the industry is turning to dynamic simulation tied into the control system. The simulator environment operates behind the control system to emulate the plant operation, reacting as the plant would when a change is made. The operator drives the process, with realistic feedback, which enables learning in a safe environment. This paper will take the reader through a green-field case study and discuss the effectiveness of integrating an operator training simulator (OTS) on the operator’s learning curve.

Jan 1, 2014

By V. Schenk

Dust exposure resulting from the exploitation and winning of natural resources below ground has presented a serious health problem since the beginning of mining. The boom phase of the German hard coal mining industry after World War II with at times up to 500,000 employees saw an increase of dust exposure of miners below ground as the mechanization of road heading and mining increased significantly. More and more miners were diagnosed with coal-workers-pneumoconiosis (CWP), a chronic and irreversible lung disease resulting in a significant impairment of pulmonary function. This realization led to a reduction of CWP in the German hard coal mining industry in the 1960s. The successful fight against CWP began with the introduction of technical dust prevention measures. By infusing the coal seam with water before mining, sprinkling and spraying of heading and mining machines as well as canopies with water, aspiration in places with high amounts of dust and the suppression of dust with chemical substances it is possible to significantly reduce the miners? dust exposure. All operating points below ground are checked and measured regularly with regard to dust exposure. Through the combination of these values together with the individual shift data a relatively precise profile of individual dust exposure can be obtained. This profile allows the targeted work assignment when certain predetermined limits have been reached, moving the miner to a work place with less dust exposure and thus reducing the chronic dust exposure. The state of health of the individual is known because since about 60 years ago extensive occupational health checks have been carried out regularly at least every two years which means that work restrictions can be imposed depending on the findings. Since the beginning of the 1980s more value has been attached to not only situational but also behavioral prevention. Given the comprehensive provision of protective masks, having a protective effect as well as the required comfort when being worn, each miner has the opportunity to protect his respiratory organs depending on the specific dust exposure. Through a combination of all these measures the German hard coal mining industry has succeeded in beating the classic coal miner?s disease CWP. For mines in the Ruhr valley this means that a miner who started work after 1978 will no longer develop CWP.

Aug 1, 2013

By H. Rafiei Renani, C. D. Martin

"The Cohesion Weakening Friction Strengthening (CWFS) is adopted in numerical analysis to capture the observed progressive failure of hard rock pillars. As a case study, pillars at the Elliot Lake mines with width to height ratios of 0.5 to 3 were analyzed in FLAC3D. Pillars with width to height ratios of 0.5 and 1 show a very similar strain softening behavior while with width to height ratios of 2 and especially 3 indicated prolonged strain hardening. The CWFS model successfully captured the mechanism of progressive failure observed in hard rock pillars including initiation of spalling at the corners, progress of spalling towards the centre and formation of hour-glass shaped pillar, and eventually shearing through the width of pillar. Both the CWFS model and site specific empirical formula successfully separated the stable and failed cases in the Elliot Lake mines. While both models are in reasonable agreement for width to height ratios of less than 2, the empirical formula gives increasingly lower strength values for wider pillars which may result in excessively conservative and uneconomical design.INTRODUCTIONPillars are the portion of in situ rock left between the adjacent openings to maintain the stability of excavations. Conditions of equilibrium require that the loads previously carried by the excavated rocks be transferred to the pillars resulting in elevated stresses within the pillar. Hence, prediction of the behavior of pillars under these loads is important for underground design. Determination of the strength of pillars is a classic subject in underground mining. In conventional mining methods such as room and pillar operations, economic incentives point towards higher excavation ratios i.e., leaving smaller pillars between the mined excavations, while safety and stability requirements favor wider stronger pillars. In some mining methods such as caving operations, the problem is even more challenging. On one hand, the whole operation is directly dependent on the proper continuous flow of caved ore between the drawpoints which requires optimizing the spacing between drawpoints and thereby often leaving narrower pillars. On the other hand, the pillars should be wide enough to ensure the safety of mining operation. Both the blockage of drawpoints as a result of wide pillars and uncontrolled failure of narrow pillars can jeopardize the investments and mining operation.Therefore, design of pillar poses a somewhat unique challenge to rock engineers where simple conservative approaches frequently used in other design methods are no longer acceptable. The behavior of pillar under elevated loads should be predicted accurately."

Jan 1, 2015

By J. Lebl, S. Bharti, D. J. Cornett

"This paper presents the design and application of blasthole mining to an area at Strathcona Mine previously employing post pillar cut-and-fill. Extensive mining in the area had led to gradually deteriorating ground conditions and post pillar stoping was no longer considered acceptable. Alternative methods had to be investigated.Conventional methods for mining in poor ground were rejected because of the high cost. Blasthole mining was selected because iI offered good productivity and safety with acceptable costs. The design of this approach involved field investigations and the use of numerical modelling to simulate the different blasthole options and their impact on ground stability. The blasthole design incorporated reinforcement with cablebolts, use of a radio-controlled remote LHD unit, large-diameter holes, blast design and wall control. Potentially unstable areas were outlined during mining with ground monitoring instruments and the results used to modify mining plans during the production phase.IntroductionIn underground metal mines there is a need to improve safety and productivity and lower mining costs in order to maintain reasonable rates of return on investment. This requires the application of good engineering design to both mine planning and ground control in order to optimize production and costs and to forecast potential problems during mining. The task becomes more important when extensive mining leads to gradually deteriorating ground conditions, making existing mining methods and techniques no longer acceptable from a safety point of view. Alternative mining methods must, however, be sufficiently productive to ensure profitability. This paper presents an example of the engineering design and operating approach used by Falconbridge in dealing with such a situation at Strathcona Mine."

Jan 1, 1983

By V. C. Wittchen, T. R. Yu, J. E. Croxall

"The consolidated rockfill at Kidd Creek Mines is a weakly cemented, minus 15 cm aggregate which posed problems for conventional drill/blast drifting methods. Consequently, lateral access to mineable ore adjacent to backfilled areas was gained by drifting around the fill in shattered rock.In mid-1987, Kidd Creek Mines began to investigate means of mechanically excavating drifts in backfill . The results of this investigation led to a trial program using a Dosco MK-2A Roadheader to excavate the required drifts in backfill.The roadheader was tested at Kidd Creek Mines from July to November 1988, in 28-735 X /C to be used as the top access for drilling and blasting 32-74/ ST. During this period, the roadheader excavated 54 m of a 4.3 m by 3. 7 m arched drift in backfill. Cutting rates over the period averaged 0.8 m/cutting hour as projected with a daily high of 2.0 m/cutting hour.Wood-lagged 2-piece steel arches on 1.2 m centres were chosen as ground support for the trial. Shotcrete will be tested in a roadheader drive for its potential to improve productivity by replacing the steel arches.The trial program included evaluations of point-attack picks, two sizes of cutter motor, 20 MPa (3000 psi) water-assisted cutting, cuttings-removal systems, and environmental control devices."

Jan 1, 1990

By A. I. A. Salama, M. W. Mikhail, R. J. Mikula

"The Coal Research Laboratory (CRL) of CANMET along with other research organizations in coal-producing countries envisage major benefits from computer applications in coal preparation, Some of these benefits are greater system flexibility, improved coal preparation plant performance efficiency and efficient utilization of manpower, all of which result in economic benefits. Computers can be applied for both on-line and off-line purposes; this paper focuses on the on-line applications from the process control point of view.A critical discussion of the different analog and digital process control systems is presented. Recent developments in Great Britain, West Germany, Poland and Australia on automation and instrumentation using on-line measurements of coal ash and moisture contents are identified.The CRL research and development strategy aimed at achieving on-line computer control of an automated coal preparation plant is presented.IntroductionIn the past twenty years an enormous progress in the area of computer technology has been noticed. Computer applications in industrial processes offer greater system flexibility, improved plant performance efficiency and efficient utilization of manpower. Significant computer control development in mineral processing has already been achieved. Although progress has been made in the area of computer applications in coal preparation, more effort is needed to utilize the full potential.The computer applications in coal preparation can be viewed as off-line and on-line. Considerable progress has been reported in the area of off-line computer applications, especially in the areas of modelling, performance evaluation/prediction and statistical analysis. However, only modest progress in on-line applications has been reported(1-7). This paper will focus on: online instrumentation and process control applications, different analog and/or digital control systems, on-line automation and instrumentation in other countries and CRL strategy toward pilot plant automation."

Jan 1, 1985

Mirador - Overview ? Located in Andean foothills of SE Ecuador ? Copper-gold porphyry hosted by calc-alkaline Late Jurassic granitic and porphyritic rocks ? 438 MT of 0.61% Cu and 0.19 g/t Au measured and indicated resources (at 0.4% Cu cut-off) ? Additional inferred resources of 235 MT of 0.52% Cu and 0.17 g/t Au ? Initial 25,000 tonnes/day production, expanding to 50,000 in year 6 320 MT of 0.62% Cu, 0.2 g/t Au ore mined at an average 1.4:1 strip ratio over a 21 year mine-life

May 1, 2006