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By A. Farzanegan, D. A. Lowther, A. R. Laplante

"Off-line optimization studies are often necessary to improve the efficiency of grinding circuits. These studies are primarily based on the mathematical modelling of processing units (e.g., ball mills and hydrocyclones) and computer simulations. To complete an optimization task, process engineers must possess skills and knowledge of different subtasks involved in such efforts, e.g., plant audit, laboratory tests, and data analysis. Such know-how can be in part provided by Knowledge-Based Systems (KBSs). One such system, being developed in C Language Integrated Production System (CLIPS), is presented here, with focus on the estimation of ball mill selection functions for the purpose of both diagnostic and simulation, and its use for the optimization of ball size. Some of the interpretation and diagnostic rules will be presented, as well as grinding kinetics and classification data likely to fire them.IntroductionSince the late eighties there has been a growing trend in applying Knowledge-Based Systems (KBSs) to mineral processing [Meech 1990, Bearman and Milne 1992). Table l lists some KBS (often referred to as expert systems) applications that have been used mainly as tools for improving on-line monitoring and control of grinding circuits. However, there has been fewer attempts to add the symbolic processing powers of KBSs to conventional off-line grinding simulators. Figure 1 shows a relatively standard procedure to perform an off-line optimization study [Napier-Munn and Lynch 1992]. In brief, a typical program includes taking representative samples from a number of streams, running laboratory tests on collected samples, estimating model parameters which describe physical processing units (e.g. ball mills and hydrocyclones) validating model predictions and using models for simulation trials. One inevitably needs to be familiar with concepts of process modelling and simulation as well as various computer programs to be able to complete all steps of the study. Much of this ""expertise"" can be captured by KBSs, given their inherent capabilities for symbolic knowledge representation and manipulation."

Jan 1, 1997

By M. Tanaka, H. Narita, T. Fuchikami, K. Morisaku, K. Nagao, T. Yoshida, K. Kuroda

The effect of various N-substituents on the performance of amide-containing tertiary amine compounds in the extraction of Rh(III) from HCl solutions was investigated to optimize the structure of these compounds for industrial use. It was found that N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide)amine and tris(N-di-2-ethylhexyl-ethylamide)amine, which have long, branched alkyl chains, were suitable for Rh extraction, because they were soluble in a practical diluent (80 vol% n-dodecane?20 vol% 2-ethylhexanol) and stable against highly concentrated HCl/Rh solutions, and showed high selectivity for Rh(III) over Pd(II) and Pt(IV).

Jan 1, 2014

By T. Schmidt, J. Merza

"This study considers two lead/zinc/silver orebodies which have historically had a problem with pyrite, pyrrhotite and sphalerite contamination in the lead circuit. The problem was previously addressed with high dosages of sodium cyanide as the primary depressant. However, large amounts of cyanide led to environmental problems in the effluent, especially during winter months. The objective was to reduce cyanide consumption while maintaining or improving overall lead grade and recovery via the reduction of the undesirable sulphides.Extensive laboratory and mill testing was necessary to determine the optimal operating parameters for continuous plant application. Evaluation of data received from this testing has shown that selective addition and optimization of the dosage of Unimax SD100 to specific areas of the flotation and grinding circuits has resulted in improved Pb grade and recovery. Parameters such as pH control, regrind operation, the cyanide/Unimax ratio and sulphide mineral content may also affect the performance of the depressant. Each factor is discussed and optimal operating conditions were determined based on the testing.Results are presented for two case studies. Both indicate that Unimax SD100 improves the lead grade/recovery curve by increasing iron and zinc rejection while reducing cyanide consumption and the resulting environmental concerns. 1. Hart"

Jan 1, 1992

By P. B. Demarsh

"Location: - On highway 59, 17 miles east of Val d 10r near junction of Montreal highway in Northwestern Quebec.Life; - Started production 1952, ceased 1965.Ore: - Pyrite, chalcopyrite and small amounts of free gold and goldsilver tellurides in narrow quartz-carbonate-tourmaline veins in granodiorite. Specific gravity 2, 70.Capacity: - 700 tons daily Bevcon ore supply, l 000 tons daily when custom ore available.Assay: - Heads 0 .140 oz. per ton; tails 0. 009 per ton; extraction 92.5%.Grind: - 75% minus 200 mesh at 700 tons; 68% minus 200 mesh at 1000 tons. Detention time 28 hours and 21 hours respectively.Treatment: - Cyanidation process.Reagents: - Per ton. Aero Cyanide (NaCn) 0, 50; crushed unslaked lime 1. 75; zinc 0. 03; litharge 0. 10; steel consumption 2. 25.Water: - Pumped from land-lock spring fed lake l 1/2 miles distant.Cost: - Per ton. Crushing 0. 13; grinding 0 .32; filtration 0. 07; cyanidation 0.14; miscellaneous 0.29; total 0.95.Power: - Hydro-electric, 25 cycle, 12, 000 volts reduced to 550 volts.Labour: - Predominantly French Canadian, nucleus English Canadians.Tailings: - Impounded low lying pond.Personnel: - 15 including supervision.Flow sheet: - Canadian Mining Manual l 9 5 6 .Building: - Wood truss construction: 3/ 4 in. siding, ten test and 1/ 4 in. transite outside. Corrugated galvanized iron roof. Ground level foundations. Internal self induced heating. Wood stave tank equipment."

Jan 1, 1966

By K. E. Waters, N. Brodusch, R. Gauvin, H. Demers

"Rare earth elements are becoming increasingly in demand, due to their prevalence in both renewable energy devices and high-end electronics. The characterization of the composition, morphology and volume fraction of the various phases that have valuable rare earths in the ores are needed to find the optimal industrial process to extract the ores containing the rare earths. Rare earth-bearing minerals contain many elements with the M-and L-lines overlap, requiring a high degree of resolution, pushing the boundaries of scanning electron microscopy quantitative analysis. Enhanced microscopy at a high spatial resolution with improved x-ray quantitative analysis enables the accurate determination of the distribution of the desired rare earths in various mineral phases. INTRODUCTIONRare earth elements are becoming increasingly in demand, due to their prevalence in both renewable energy devices and high-end electronics. From batteries (lanthanum and cerium), to magnets (dysprosium and neodymium) and lighting (yttrium), the rare earth elements are crucial to the advancement of technology, and to energy saving devices (Crow, 2011). The goal of this project is to characterize the composition, morphology and volume fraction of the various phases that have valuable rare earths in the ores in order to estimate the economical VALUES (of the ores and to find the optimal industrial process to extract the ores containing the rare earths. High spatial resolution imaging and x-ray microanalysis are needed to reach this goal. In this work, the results obtained with a cold-field-emission scanning electron microscope (FE-SEM) and a silicon drift detector (SDD) energy dispersive spectrometry (EDS) detector at low accelerating voltage are compared to experimental conditions typically used with electron probe microanalysis (EPMA) instrument.With this improvement, a detailed scientific analysis of the composition of these, and other, ores will become possible with a SEM/EDS system. This will help to better understand how such ores were formed, hence assisting in finding them, and to better understand how to process them in preparation for high end industrial applications, namely through mineral processing."

Jan 1, 2012

Experimental Mine, Val d'Or, Quebec, Experiments on the ignition of sulphide dust clouds by explosives have been conducted in a 1 m3 explosion chamber. The explosives tested are ANFO, emulsion, aluminized emulsion and Detasheet. By controlling the composition of the ANFO and the emulsion explosive the oxygen balance could be changed in order to identify the dominant factors in the ignition of sulphide dust clouds by explosives. Experimental results, combined with theoretical calculations, show that the temperature of the detonation products is the most important parameter in the ignition of the dust cloud while the combustible detonation products are of secondary importance in the case of non-aluminized mining explosives. In the case of aluminized explosives and explosives having very negative oxygen balance the ignition of the dust cloud is assisted by the large amount of combustible detonation products.

Jan 1, 1993

By Junior Santos

Kinross Paracatu started the operation of the new gold processing plant in the end of 2008, being composed by one SAG mill and two ball mills. During the first year of operation the plant had several problems related to stability and throughput capacity, mainly due to low grinding efficiency of the ball mills. In this period many actions were taken to maximize the throughput rate. Among the actions are reducing the size of balls in the mills, increasing the ball charge in the SAG mill, changing cyclone configuration and return of circulating load to SAG mill. With better stability of the circuit, the second stage of improvements has begun with the objective of increasing throughput rate and also reducing operation costs. Among the actions are the optimization of ball charge in the mills and a better operational control of cyclone parts. After two years of operation was obtained a significant increase in plant capacity, but still requires the addition of a third ball mill in order to maximize the use of SAG mill, which has spare capacity.

Jan 1, 2012

By E. Lovera

ABSTRACT: The current study analyzes the feasibility of an odd operation: to obtain, using a properly tailored drilling and blasting scheme, blocks suitable for the production of dimension stone from tunnel driving. Clearly, a compromise must be found between the rate of progression and the achievement of workable blocks. As a case study, a civil work under consideration in northern Italy was examined. The work was planned to cross a conglomerate that has traditionally been locally exploited for the production of highly prized paving and lining stones with excellent strength and aesthetic features. Natural exposures and mined-out quarries were available for tests. The relevant rock data are given, blast designs are shown (within the limitations of contour accuracy), and the test program is described.

Jan 1, 2011

By F. Melo, M. Pawlik

Fine coal aggregation in concentrated coal-water suspensions was studied through steady-state rheological measurements. The wettability of coal particles was modified by dry oxidation of a bituminous coal. The degree of hydrophobicity was monitored using film flotation. The rheological measurements revealed that hydrophobic coal particles aggregate in aqueous suspensions, over a wide pH range, and produce slurries with high yield stresses. As the degree of coal oxidation increases, the coal particles become more hydrophilic and such suspensions exhibit lower yield stresses values. The yield stress values for suspensions prepared from oxidized/hydrophilic coal become a strong function of pH and correlate well with the surface charge as determined through electroacoustic measurements. These results indicate that the yield stress of aqueous suspensions of coal, and hence coal particles aggregation, is strongly affected by the wettability of coal particles.

Jan 1, 2004

By Richard W. Hutchinson, Christopher Osterman

The Selebi-Phikwe deposits are hosted by amphibolite to granulite facies gneisses of the Limpopo belt. The sulfide orebodies are generally stratiform and conformable to the foliation of the wallrock gneiss. Sulfide remobilization has occurred during metamorphism and has produced discordant sulfide veins, called piercement structures, which project into the hanging wall and footwall gneisses. These piercement structures are compositionally similar to the stratiform sulfides, consisting mainly of pyrrhotite, pentlandite and chalcopyrite. However, texturally the piercement sulfides are coarse grained and inclusion-free, whereas the stratiform sulfides are fIne grained and packed with tectonically produced wallrock inclusions. The piercement structure sulfides and adjacent stratabound sulfides were sampled and analyzed for major base metals and PGE's for comparative purposes. Most of the piercement structures were enriched in Cu, Ag and Au, whereas they were generally depleted in Ni, Co, Fe and PGE's. Changing elemental associations were observed from the stratabound sulfides and along the length of the piercement structures. This and the degree of depletion or enrichment of various major and minor elements in the sulfide piercement structures may reflect the relative mobilities of metals under metamorphic conditions. The similarities between sulfIde piercement structures and the footwall Cu-PGE veins in some Sudbury deposits are reviewed.

Jan 1, 1994

By A. G. Eccles

"INTRODUCTIONWestern Mines' copper-lead-zinc operations are located in Strathcona Provincial Park, near the geographic centre of Vancouver Island. This park includes Buttle Lake, which flows into the Campbell River water system. The latter provides domestic water for the Town of Campbell River, approximately fifty-eight miles from the mine site.Operation of the concentrator commenced in December 1966, at which time the tailings were discharged into a small tailings pond near the plant. On May 8, 1967 Permit No. 185 was granted to the company, allowing discharge of the tailings, through a submerged outfall, to the bottom of Buttle Lake.Needless to say, the concept of operating a mine within a park, and the discharge of tailings into Buttle Lake generated considerable controversy. However, this has all but been eliminated over the years by the proven effectiveness of Western Mines' pollution control program. In 1973 this program was further upgraded with the addition of an alkaline chlorination plant. Effluent treatment by this method became necessary as a result of process modifications, and has been effective in maintaining the levels of characteristics in the tailings within the ever increasing pollution control requirements imposed on the industry."

Jan 1, 1977

By Cardm Jeffrey W.

The decay of 222 Rn yields a series of short-lived decay products which become attached to the surface of a plate or wire exposed in a 222Rn-bearing atmosphere. The alpha-activity of two of the decay products, 218Po and 214Po, can be measured by simple counting techniques. This phenomenon may have direct application to uranium exploration. Laboratory studies have shown that: (a) radon decay products can be collected on a wide variety of materials (including various kinds of metals and plastics); (b) activity increases as a function of the surface area of the 'collector; and (c) the collection of the decay products is enhanced by applying a negative charge. The new technique was used in situ to delineate the anomaly above the South March uranium-copper occurrence. A related technique was developed to measure radium in soil samples. The results of both studies compared favourably with those obtained from conventional methods.

Jan 1, 1979

By P. E. Weidmark

"CANMET InformationPART 1-Published PapersAsmis, H. W., ""The dynamic response of caverns in discontinuous rock""; Proc 22nd U.S. Symposium on Rock Mechanics, Cambridge, Mass, June 1981, 272-277; 1981.Austin , M.W., Bray, J.W. and Crawford, A.M., ""A comparison of two indirect boundary element formulations incorporating planes of weakness"" ; Technical Note; Int J Rock Mech Min Sci Geomech Abstr; 19:339-344; 1982.Barrett, J. R., ""Applying geotechnical theory to underground metalliferous mining""; Proc 1st Intnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of AIMMPE; 210-222; 1983.Barron, K., Wright, P.L. and Smales, T., ""Guideline s for the design of coal pillars in the No .4 seam at Mclntyre Mines Ltd ., Grande Cache, Alberta""; Proc 1st Intnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of A IMMPE; 559-578; 1983.Bauer, A., ""Wall control blasting in open pit mines""; Mining Engng; 34:155-158; 1982.Bieniawski, Z.T., "" Improved design o f room-and-pillar coal mines for U.S. conditions""; Proc 1st Intnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of AIMMPE; 19-51; 1982.Blackwell, G.H. and Calder, P.N., ""Practical aspects of wall stability at Brenda Mines Ltd., Peachland, BC""; 3rd Intnl Conf on Stability in Surface Mining; Vancouver, BC, June 1981; SME-A1ME; 3:573-608; 1982.Blake, W., ""Microseismic monitoring for underground stability "" ; Proc 1st Intnl Cont on Stability in Underground Mining; Vancouver , BC, August 1982; SME of AIMMPE; 272-294; 1983.Brawner, C.O., ""Stabilization of rock slopes"" ; 3rd Intnl Conf on Stability in Surface Mining; Vancouver, BC, June 1981; SME-AIME; 3:289-310; 1982.Bridges, M.C., ""Review of open stope mining in Australia""; Proc 1st lntnl Conf on Stability in Underground Mining; Vancouver, BC, August 1982; SME of AIMMPE; 813-828: 1983."

Jan 1, 1983

By Sergio Fuentes

During the past fifteen years, mines utilizing the block caving method have improved performance and systematically reduced total mining costs. This paper describes improvements in mine design, mine planning and mine management, including methods enabling the Chilean and International mining industry to ensure cost savings and productivity growth while using the block caving method. These improvements have encouraged the re-evaluation of underground operations at operating and closed open pits, and challenge surface mining applications as the only low cost mining method. This paper describes a strategy to estimate the optimum open pit to underground transition time during the life of a mine.

May 1, 2003

By John D. Lupton

This paper will discuss the benefits and advantages of using 3D survey data in stope analysis. Obtaining detailed 3D survey data of underground mine progress and production is a challenge. It is almost impossible to ?see? around corners, underneath overhangs, or deep into dark, dusty, humid underground voids. Thus, valuable ore can remain permanently encased in backfill. Without the benefit of 3D survey data, underground mines have the difficult task of meeting grade quotas without the benefit of knowing exactly what has been mined. Lack of this data usually results in unfavorable month end Reconciliation factors, where grades must be adjusted to match grades assessed by the Mill.

Apr 1, 2005

By L. C. Bird, N. T. L. Landgren, M. W. Mikhail

"Through funds made available in 1972 by the Nova Scotia Department of Mines and Energy (DME) and the federal Department of Regional Economic Expansion, a program was initiated to recover saleable coal from mine waste dumps adjacent to the existing Acadia wash plant in Stellarton, Nova Scotia.Following evaluation of these dumps in 1972, the Acadia wash plant was modified to treat high-ash material. The first production was recorded in late 1974. By the end of 1979, a total of 738,202 t of dump material had been processed, yielding a total of 205,212 t of thermal-quality coal.The successful Stellarton operation led to considering the possibility of recovering thermal coal from other dumps. Evaluation of the Westville dumps indicated total recoverable reserves of 1,346,617 t averaging 53.8OJo ash.Parameters for plant design were defined from the washability characteristics of the dump material and the results of a bulk test. Two options were proposed; one was to use the existing plant with some modifications, the other was to build a modular mobile plant that could be used at future dump sites in the province after Westville. At the 25% ash level, the potential recovery of coal from the dump was estimated at 41% yield (by weight) or 549,679 t."

Jan 1, 1981

"The Upper Mannville unit commonly consists of interbedded marine and non-marine sands and shales, but in northwestern Alberta the unit consists of marine shales of the Spirit River Formation. A thick tongue of marine shale (Clearwater Formation) ex-tends eastward into the Athabasca area below sandy Grand Rapids beds. Correlation of Upper Mannville rocks to the southeast is difficult, but in the Cold Lake area a thick sandy depositional cycle (Mannville ""C"" of this paper) appears to be approximately correlative with the Clearwater Formation. In the Lloyd-minster region, tongues of marine sedimentary rock occur in the lower part of the Upper Mannville unit. Most of the Upper Mannville oil occurs in the Grand Rapids Formation at Wabasca, in the thick ""C"" unit and younger Mannville sands at Cold Lake, and in the Sparky and General Petroleums sands of the Lloydminster region (Figure 2).The Lower Mannville unit was deposited on an erosional surface of considerable relief that truncated the Jurassic and older strata of the Western Canada basin. Continental, probably fluviatile, sedimentation persisted over much of the Western Canada basin during deposition of the Lower Mannville unit, but an Arctic or Boreal sea lay over part of northern Alberta. At the end of the depositional episode, the sea transgressed southward and eastward (Figure 3) and re-worked the Bullhead and McMurray sands of northern Alberta into the glauconitic Bluesky and Wabiskaw sands. Topography on the sub-Cretaceous erosion-al surface had a considerable effect on the deposition of the Lower Mannville (Rudkin, 1965), and the highest hills on this surface were not completely on-lapped by Lower Mannville sediments (Figure 3). The coarser elastic material was derived both from a western Cordilleran region and from an eastern Canadian Shield region (Glaister, 1959, p. 620; Mellon, 1956)."

Jan 1, 1966

By Pierre Gratton, Gordon Peeling

The Mining Association of Canada launched the Towards Sustainable Mining initiative in 2004. TSM’s goal is to improve the mining industry’s performance by aligning its actions with the priorities and values of Canadians. The initiative currently includes performance indicators for four areas: tailings management, energy use and greenhouse gas management, external outreach and corporate crisis management planning. Over the past year, the association has been designing a performance assessment and verification system for these performance areas, as its members prepare to move to external verification of their performance in 2006. The presentation will describe the initiative and its evolution, as well as the challenges faced in developing a verification system applicable to an entire sector.

Jan 1, 2006

By K. Law

"The Hatch Product Transport (HPT) system is a highly flexible and configurable route selection and sequencing system for controlling large bulk material handling facilities. The system has a generic control algorithm that can be configured to suit any material handling facility. It can also be easily reconfigured to cater to plant expansion or modifications without incurring significant disruption to the existing production, costs in testing, and re-commissioning, thus achieving cost savings throughout a facility’s lifecycle.This new material handling control system has been installed at BHP Billiton’s Port Hedland iron ore terminal to facilitate its expansion to beyond 100 Mt output capacity."

Jan 1, 2006

By Robert L. Tremblay

Dans le but de voir si une région comme la Gaspésie, qui a subi la derniere glaciation , se prête avantageusement à la méthode de prospection alluvionnaire, environ 800 concentrés de minéraux lourds furent prélevés dans les districts électoraux de Matane et de Gaspé-Nord. Les différentes phases minérales présentes dans les concentrés ont été examinées à la loupe binoculaire. Afin de mieux valoriser ce type d'inforrnat ion, nous avons été arnenés à expérimenter et à mettre en oeuvre des techniques multivariables adaptées au traltement d'une information semi-quantitative en utilisant le principe d'un codage logique préalable. La structuration des résultats de la Gaspésie a conduit à l'élaboration de cartes de synthèse qui constituent un support nécessaire à l'interprétatlon des répartitions plus ponctuelles des minéraux "utiles" sur le plan de la recherche minière.

Jan 1, 1978