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By Wallace R. Horn

"MR. CHAIRMAN AND GENTLEMEN :I begin this talk by making a couple of comments which are of the nature of disclaimers.Firstly, and as the Chairman has otherwise indicated, I was neither ""born into"" nor have I spent more than a few years of my professional life in the mining industry. I mention this because many might, and perhaps rightly, consider that an added qualification in presenting a report of what the industry has accomplished. Indeed, I am not here to blindly defend all of its actions and inactions in respect to environmental control over the years. Nor am I here to seek absolution of the industry's past transgressions - if indeed that is the word. Mistakes might be a better one. I concluded some time ago that the effects of those mistakes are too difficult to assess against the sea of errors of our total society. I should mention too that I am not an environmental engineer or specialist - only a portion of my interest is involved with this field. Perhaps this permits a perspective which allows a more accurate and objective view.One further comment here. My job today, as I understand it, is to generally report upon the nature and extent of the response of the metals mining industry to control of the environment. In the case of an industry operating at more than a hundred locations and for various reasons at various stages of progress, it is not an easy job. On the other hand, I wanted to avoid the use of generalities because, especially within the context of environmental or ecological opinion and of the practice of condemnation of industrial segments, I think we've had about enough of generalities until we know far more than we do.Finally, I am quite aware that a statement of future plans to achieve environmental control does not impress or satisfy as many people as it may have done some years ago. Public opinion demands to know what is currently underway, today."

Jan 1, 1972

By Gregg S. Hill, Bert J. Huls

"This paper on coarse particle recovery (CPR) summarizes a process to capture coarse particles that are not recoverable by regular flotation. Several porphyry copper operations in the world operate analogous circuits that recover non-floated copper from tailings; however, the case presented here is unique in that extensive underlying test work has allowed us to elucidate some fundamental principles behind recovery enhancement. This paper discusses an overview of the flow sheet that is proposed to Minera Escondida Ltda., the nature of copper in the feed to the CPR circuit, and the various unit operations within the recovery circuit. Details of the technology behind each unit operation will be presented in later publications.INTRODUCTIONSince 1996 BHPBilliton and MEL (Minera Escondida Ltda.) have developed a process to recover copper from coarse particles in the rougher tailings. Copper recovery from fresh tailings is not new. Several operations in Chile, such as Chuquicamata, El Teniente (AMEC, 2003), Mantos Blancos and others have operated various forms of tailings circuits. Both Chuquicamata and El Teniente practice cascade flotation scalping off froth containing fine copper particles after allowing sufficient retention time, air inducement and, sometimes, additional reagent addition. Chuquicamata tailings are not segregated but floated in sequential cascade and conventional large cell arrangements. At the Valle Central operation of El Teniente a coarse fraction of mill tailings is ground and floated, with the rejects recombined with fine tailings and subjected to cascade flotation through a sequence of concrete launders as the tailings flow towards their final deposition area. Mantos Blancos cyclone the rougher tailings and blend the underflow with scavenger concentrate from elsewhere in the principal circuit prior to flotation in Wemco Cells. Kemess in BC, Canada operates a 160 m3 Outokumpu cell to reduce the tailings sulfur content (Rasmussen, et.al, 2004)."

Jan 1, 2005

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

"This paper describes some of the methods and equipment used for fine milling of minerals, and gives particular attention to the Vibro Energy system.In addition, the paper describes a specific application in the gold mining industry. This is the 200 tpd plant built by Anglo American Corporation at the President Brand Mine in South Africa in 1985, now a division of Freegold. This plant treats a gold bearing pyrite flotation concentrate which is finely ground to 15 microns prior to cyanidation and carbon-in-pulp (CIP). l .0 INTRODUCTIONFree milling gold ores are those that yield acceptable dissolution and recovery of the gold following grinding to what can be described as normal fineness, frequently between 50% and 90% passing 74 microns.Increasingly, gold metallurgists are faced with ores that are refractory. The traditiona1 treatment route for refractory gal d ores and concentrates has been by roasting, but for environmental reasons this is becoming less acceptable, or in some areas of the world, totally unacceptable. New methods of treating refractory gold ores are being developed and applied in practice. These new methods include pressure and biological oxidation. Higher gold liberation can also be attained by increasing the fineness of grind, although with conventional systems there are economic limits to this.In flowsheet development and test programs on new deposits, a standard procedure is to establish the relationship between the grind and subsequent go 1 d extraction. The normal situation is that gold extraction increases as the ore, or concentrate, is ground finer. Typically, this relationship is as shown in Fig. l, where the incremental additional extraction is very small once an optimum, or economic, grind has been achieved. This generally app1ies whether the material is free milling or refractory. The limits to grinding are set by the type of equipment which is commonly in use, usually ball mills. These mills have the obvious advantage of high capacity, however, they are increasingly inefficient as finer grinds are required. In general, ball mills are used to reduce ore to some agreed percentage passing 74, or possibly 53 microns."

Jan 1, 1988

By H. A. Bilgin, G. G. U. Aldas

"Ground vibration is the natural result of the blasting process. Many empirical formulae and methodologies including analysis of travel path effects have been developed. The scaled distance, which is the most popular approach for the calculation of the attenuation of particle velocity in the ground, has led to significant advances in the prediction of particle velocity when both explosive charge and distance vary. However, this approach does not consider the effect of ground anisotropy and existence of structural geological features on ground vibration. Therefore, in this study, the effects of these rock mass properties on types, amplitudes, and frequencies of ground vibration waves at four surface mines are examined. The results, which were implemented at Kangal coal mine, Bastas quarry and Kíbrís quarry, provided guidance for the extensive study at Orhaneli surface coal mine.As a result of the study, the authors came to the conclusion that vibration amplitudes change depending on the ground on which sensors were deployed and the conditions depending on whether measurements were done near major structural geological features. It was determined that the vibration amplitudes, measured at equal distances from the source but in different directions, change because of the propagation velocity anisotropy. Besides the change of wave type due to the kind of ground at the measurement location, it was determined that vibration anomolies were due to structural features."

Jan 1, 2004

By Sadan Kelebek, S. O. Fekete, Gerhard W. Heinrich, Peter F. Wells

"For many years, rejection of pyrrhotite at the milling stage has been a viable method for sulphur dioxide abatement. Pyrrhotite rejection options have included the use of selective pyrrhotite depressants in flotation; a depressant which has recently come into use is diethylenetriamine (DETA). This reagent has been the subject of recent research and development efforts in the processing of nickel-copper sulphide ores.In the present study, adsorption trends for DETA have been monitored under the dynamic conditions of flotation using a spectrophotometric method which has been adopted for this purpose at Falconbridge Limited. The results indicate that the adsorption of DETA is quite fast and in the majority of cases, accounts for the disappearance of 75-95 % of this reagent from pulp's liquid phase. The adsorption decreases linearly with an increase in the DET A dosage from 100 git to 600 git. The tailings produced in flotation tests were subjected to washing with deionized water at 60 °C to examine the desorption of DET A. These results indicate that the amount desorbed increases with increasing DETA dosage used during flotation but is less than 7 per cent of that adsorbed. It was found that adsorption of DETA alone, even at relatively high levels, does not always cause depression of pyrrhotite. A new combination of reagents identified in the metallurgical laboratories of Falconbridge Limited utilizes sulphur dioxide with DETA. These reagents together are capable of efficient depression of pyrrhotite on a consistent basis."

Jan 1, 1995

By D. Stüben, G. P. Glasby

"Abstract - Shallow submarine hydrothermal fluids from Paleohori Bay off the Greek Island of Milos have been investigated in detail. The extensive gas and warm (max. 93°C) water vents are enriched in major components such as C1-, Na+, Si, Ca2+, Mn, PO4 3-, NH4 +, K+, Sr2+, H2S and CH4 and depleted in Mg2+, O2 and SO4 2- relative to ambient seawater. Based on zero-Mg calculations, it is deduced that the submarine vent fluids are related to the geothermal reservoir beneath Milos which has a similar chemical composition. Fluid samples from each vent in Paleohori Bay represent a mixture of hydrothermal end-member fluids derived from the upper and deeper geothermal reservoir systems of Milos, a mantle-derived source, a high-chloride fluid resulting from phase separation of geo thermal fluids and a steam-heated CO2-rich meteoric water. Résumé - À l’île de Milos dans la mer d’Égée, des fluides sous-marins hydrothermaux en eau profonde ont été récherchés en détail près de la baie de Paleohori. Les larges émanations de gaz et d’eau chaude (temperature maximale: 93°C) sont enrichies en constituants principaux tels que de Cl-, Na+, Si, Ca2+, Mn, PO4 3-, NH4+, K+, Si, Sr2+, H2S et CH4 et appauvries en Mg2+, O2, SO4 2- comparé à l’eau de mer environnante. Selon le calcul du zéro-Mg, nous en déduisons que les fluides sous-marins hydrothermaux sont dérivés du réservoir géothermal sous l’île de Milos car leur composition chimique est la même. Les prélèvements des fluides de chaque source hydrothermale représentent un mélange de fluides hydrothermaux dérivés des réservoirs géothermaux supérieur et inférieur, d’une source dérivée du manteau, d’un fluide très enrichi en chlorure produit par la séparation des phases et de l’eau météorique enrichie en CO2 et chauffée par la vapeur."

Jan 1, 1999

By Paul Toor

The operation of SAG mills is variable over time due to their continually changing liner shape, mass and subsequent load motion. However, this tends to be poorly accommodated in liner design and mill control, with only limited compensation made for this influence, usually in the first few weeks after a new liner is installed. With ever-increasing ore competency, increasing energy costs and decreasing ore grades, simplified design and operational approaches that compromise the achievable mill efficiency are no longer adequate. This paper presents a methodology that has been developed to measure and account for the changes in mill performance as the liner wears. This involves monitoring all liner profiles ? in other words the three-dimensional liner shape - over the life of the liner, then conducting controlled surveys at different stages of the liner wear life, and correlating the mill performance to the liner profiles. The measured liner mass is modelled to provide an ongoing meaningful load mass measure that excludes the liner mass.

Jan 1, 2012

By C. P. Moore, G. W. Taylor

Vertically dipping lenses of nickel-copper ore at Dumbarton Mines Limited are being mined by a modified blasthole stoping method. The principal access to the mine is provided by a 15-degree decline, which, in conjunction with the use of ramps and declines for secondary access, maximizes the accessibility and mobility of trackless mining equipment. Sublevels are driven in ore on 80-foot vertical intervals and subsequently the ore, ranging in thickness from 15 to 30 feet, is slashed to its limits by a procedure of face sampling and test holing. Two longhole drill jumbos are used to drill off 40-foot vertical slices above and below these levels. Following blasting, the ore falls by gravity to the 500-foot horizon, where it is removed from drawpoints by load-haul-dump units and transported by truck to the main orepass. The rock is crushed to minus 3-4 inches and conveyed to surface by a 30-inch-wide wire rope suspended conveyor. This is achieved in two flights, a lower one of 290 feet and a main flight of 2260 feet. All aspects of the mining operation are discussed in the paper, including ventilation, services and safety.

Jan 1, 1973

By L. W. Vigrass

Porous and permeable rocks deeply buried in sedimentary basins contain immense volumes of hot water with the potential to supply low-grade heat energy. A part of Canada with sizeable potential for low-grade geothermal energy is the northern Williston Basin of southern Saskatchewan. In this region, the University of Regina has conducted a geological study investigating the feasibility of producing large quantities of warm water suitable for space heating in the Regina - Moose Jaw area. The study has shown that the most favourable geothermal reservoirs are in the Basal Clastic Unit (Cambrian Ordovician), which, at an approximate depth of 2,000 metres has predicted temperatures of 71°C to 74°C. We anticipate sustainable flow rates from these reservoirs of 100 to 300 ms/hr. The water contains about 150,000ppm of total dissolved solids, mostly sodium chloride. It is anticipated that the sulphate content will be 3,000 to 6,000 ppm, that the dissolved oxygen and hydrogen sulphide content will be small, and that the waters will be neutral to slightly alkaline. It is anticipated that the piezometric level will be 46 m below the ground surface for reservoirs in the upper part of the Basal Clastic Unit and 141m below the ground surface for the lower reservoirs of the unit. Plans are to build a low-grade geothermal research, testing and demonstration facility at the University of Regina. To be a practical demonstration, the facility will have to handle very large volumes of water. Because of high salinity, the water will be re injected into a subsurface reservoir. We do not anticipate insurmountable problems because of salinities or as a result of corrosion provided that the waters are not aerated during handling

Jan 1, 1979

By Filip Rochette, Yvan De Busscher

Extraction of minerals can be achieved by a variety of technologies; one of them is ion exchange. There are several ion exchange configurations and mechanical set-ups available, but only one technology will provide more process performance and flexibility compared to the other. The multiple column Continuous Countercurrent Ion Exchange (CCIX) technology provides the highest form of process flexibility with also the highest mineral recovery feasible through ion exchange. In comparison with a fixed bed system, the PuriTech CCIX system offers the benefits of continuous counter-current contact mode. This way the resin capacity is fully exploited leading to reduction in resin inventory and, at the same time, in chemicals and water consumption, and product dilution. For any set of operating conditions the mass transfer zone has a characteristic length (MTZL). The MTZL can be expressed in duration, column length, or volume, but is the measure of the quantity of resin in the system that is doing "work" at any given moment in the process. The objective of continuous ion exchange processing is to eliminate all resin volume from the process equipment that is not within a mass transfer zone. In most commercial ion exchange processes for the recovery of metals, CCIX engineering can eliminate as much as 20 - 80 % of the ion exchange resin inventory. Consumptions of water and chemicals are typically brought down around 40% or more. For each type of resin the selectivity/affinity towards a particular metal depends on the basic process conditions such as pH, concentrations of other competing metals in solution. By changing the pH in the ion exchange process phase, the selectivity of the resin can be changed. By doing this, a split elution, or extraction of metals separately can be achieved and the effect of other competing metals (cross-contamination) can be reduced. For example the DOW resin XUS43578 is commonly used for the recovery of copper or nickel/cobalt separation.

Jan 1, 2016

?General Facts:Barrick?sFirst Mine in Peru Production started in November 1998 ?The Facilities:Open Pit, Primary and Secondary Crusher Valley Fill Heap Leach PadMerrill Crowe PlantRefinery Environmental Facts: High Rainfall - Average Annual Precipitation of 1,200 mm (47 inches) Rainfall Events: Common 20mm daily events High Altitude Site - Elevations range from 3900 to 4250m. Steep topography - Terrain ranges from 3:1 slopes up to cliffs. Water Issues: Sediment Control - Open Pit PAG Encapsulation - Waste Dump Stormwater control - Leach Pad Erosion Control Techniques ? Offsite impacts mitigation Social Issues: 11 communities surrounding the property Town of Huaraz

May 1, 2003

By J F. Short

The jet piercing process, developed by Union Carbide Canada Ltd., is well established in blasthole production in open-pit mining. By this process, holes can be drilled, shaped and chambered for blasting. In suitable ore or rock formations, a considerable cost reduction can be achieved. This paper reviews the equipment used, relates how cost savings may be accomplished, and concludes with a mention of the most recent developments in this field. JET piercing and chambering, a process for blasthole production in open-pit mining, leads, in many instances, to improved drilling and blasting techniques and costs. It is a method of working rock with a supersonic flame and, to be most effective, depends upon a characteristic of the rock called spallability. Spalling, in this case, is the breaking away of surface particles from the rock body due to stresses caused by the thermal shock of the jet flame. Various rock properties contribute to this action, but, in general, the harder the rock the greater the spallability and the more effective and economical is the jet process. The jet process has the capability to drill, ream, shape and chamber holes for blasting.

Jan 1, 1965

By J. A. Russell

MR. M. W. Boom: I would like to congratulate Mr. Russell on his fine paper. One very good point which has always appealed to me is the smooth working of a steam hoist as compared with electrical. He does not mention the steam hoist at Springhill which has been working there for a good many years. MR. S. R. NEWTON: I have read with a great deal of interest the paper presented by Mr. Russell on the development of haulage engines in the mines of the Dominion Steel & Coal Corporation. He is to be congratulated on having produced a comprehensive article showing, step by step, the various improvements that have been made over the years in the design of such engines. I am quite in accord with Mr. Russell's statement that the positive tooth clutch can have too many teeth, and also that the method of driving a sliding clutch hub of any design should be by means of a hexagon or octagon on the shaft. Where the clutch hub does not of necessity slide on the shaft it can be pressed on and keyed to the shaft in the normal manner. With regard to the 'Cramp' internal-expanding jaw-type clutch, while it is true there are more moving parts than with the clutch consisting of a ring with internal cut teeth and a driver having a fewer number of teeth as .described by Mr. Russell; there are compensating advantages to the internal expanding jaw-type of clutch. The V shaped profile of the teeth permits of engagement of the clutch with very much less 'jockeying' of the drum. This is particularly the case in vertical-lift mine hoists, where it may be necessary to engage and disengage the clutching mechanism at frequent intervals.

Jan 1, 1944

By P. Favreau

This paper describes the progress accomplished at the Noranda Technology Centre in the field of three-dimensional computer-aided underground blast design. Traditional methods of laying out underground blasts are reviewed, and the new computer-aided approach is described. Time savings achieved through the use of BLASTCAD can be advantageously used to better engineer blasts, using models and blast vibration analysis. Future work involving the attachment of blast models directly to the system is also addressed.

Feb 1, 1993

By H. C. Gunning

In spite of the fact that mining has been more or less active in the northern part of Vancouver island since the late 'nineties', there seems to be a remarkable lack of information regarding the nature and development of the region. Recently the operations at the Old Sport mine of the Coast Copper Company, Limited, and spectacular copper discoveries in the vicinity of Nimpkish lake, have directed the attention of the mining fraternity to the district. The writer spent the summer of 1929 making a reconnaissance examination of the general geology and mining properties of the area between Quatsino sound and Nimpkish lake, and he feels that a short paper describing the nature and mining possibilities of the region should be of interest at this time. A more detailed account of the ?geology and of the mining properties will be published in the forth- coming Summary Report of the Geological Survey. A short paper dealing with the Nimpkish Lake district was presented at the Annual Meeting of the British Columbia Division, held recently in Vancouver.

Jan 1, 1930

By José L. Carvalho

"Time-dependent swelling deformation of several shaley rock formations in Ontario is a wellknown phenomenon. In shales and mudstones with a higher salt concentration in the pore fluid than the ambient fluid, the outward gradient generates an osmotic pressure which acts as the driving force for swelling. The swelling phenomenon appears to be related to ion exchange between the rock porewater and the surrounding water.The swelling potential is expressed as the percent swelling strain that occurs per log cycle of time, in either the vertical (perpendicular to bedding) or horizontal (parallel to bedding) directions. In addition, the swelling potential is also noted to be stress dependent. In practice, therefore, the conditions required for swelling are (i) the accessibility to water, and (ii) an outward salt concentration gradient from pore fluid of the rock to the ambient fluid. The relief of in-situ rock stress during excavation serves an initiating mechanism (Lo and Micic, 2010).INTRODUCTIONTime-dependent swelling deformation of several shaley rock formations in Ontario is a well-known phenomenon. In shales and mudstones with a higher salt concentration in the pore fluid than the ambient fluid, the outward gradient generates an osmotic pressure which acts as the driving force for swelling. Swelling is also controlled by the inter-particle bonding; if the bond strength exceeds the osmotic pressure, swelling will not occur, and vice-versa. The bond strength can be reflected by the calcite content which forms cementation bond between rock particles."

Jan 1, 2015

By Ian D. Pirie

Presentation outline ?Project location ?Geology ?Resources and reserves ?Results of the FEED study ?Social and environmental considerations ?Project path forward

May 1, 2010

By G. Goodall, D. Mercier, M. Brochu, C. Kaplin

A nanostructured CoNiCrAlY coating was obtained by thermally spraying cryomilled feedstock powder using the high-velocity oxy-fuel (HVOF) process. The oxidation behavior of the nanostructured powder and coating were compared to their conventional counterparts by performing static oxidation tests at 1000°C for durations ranging from 1 to 96 hours. It has been found that oxidation of the conventional powder yielded a duplex oxide scale composed of an inner layer of Al2O3 and an outer layer composed of Cr2O3, NiAl2O4 and other spinels. Interestingly, oxidation of the as-sprayed nanostructured coating yielded a similar duplex oxide scale while oxidation of the polished coating resulted in a single Al2O3 layer. These findings indicated that surface oxide seeds act as nucleation sites for the growth of the mixed oxide layer. Also, it was determined that nanostructuring of the coating promotes the nucleation and growth of a single and adherent a-Al2O3 layer by increasing both the number of diffusion channels and the aluminum concentration at grain boundaries.

Jan 1, 2010

By G. G. Bowser

THE time has come when, as your President, 1 turn the helm over to my worthy successor. When 1 was reminded by our Secretary that 1 had to prepare an address for this meeting, 1 was at a loss for a subject. In the hope of inspiration 1 perused the records of our Society for some years past. 1 found in these records that many problems in need of solution relative to industry in Nova Scotia were discursively dealt with and that sound thought was given to the solution of these problems, with a natural leaning, of course, to problems pertaining to the mining industry. 1 found also that some of the reasoning was remarkably prophetie. Some of these subjects and problems were: The use of pulverized coal to generate power instead of hydro-electric power; rural electrification; the importance of youth training for an efficient place in industry; the proper marketing of coal; the fuels competing with coal; the need for better in-dustrial relations between employer and employee; better education for success in the social field as applied to industry; and Canadian unity. The issue of some of these copies has been forced upon us by war. For instance, there appears to be no marketing problem for coal, nor does there ? seem to be a marketing problem for anything just at present. The problem of the coal producer just now is supply and transportation. Also, at present, coal fe.ars no competitors, such as oil-and not even hardwood. Many large companies now have an industrial Relations or Personnel Manager and department. Furthermore, we have been compelled of necessity to train our young men, and women also, for both industry and war. However, war does not solve these problems and, with the return to normal times, we may be faced with the same troubles in even greater measure. My reason for mentioning these copies is to point out that, as mining men, we are aU desirous of progress in every industry, not only the mining industry; and that mining men are able to see clearly ahead. In normal times, especially in matters not directly affecting the mining industry, we are inclined to let matters take their own good rime, or let the government do it. We do not seem to realize that these necessary and desirable changes can be made in times of peace-instead of being forced upon us by war or other social upheavals-by the method of sound thought and action to the desired end.

Jan 1, 1943