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By William DeWit

When rivers are contaminated from industrial operations, as often occurs near repositories of spent mine tailings, decision-support tools can be critically important in evaluating the effectiveness of various engineering impact-management measures. Even where data describing river flows and quality are sparse, simple mixing-zone models can be constructed that can contribute greatly to understanding how impact-management measures can differentially affect existing river-chemistry regimes. There can be circumstances where accumulated surface waters near contaminated land can bear contaminant loadings that could be acceptable to river regimes if there were methods available to evaluate optional discharge rates and to predict post-mixing consequences on river chemistry. Nomographs can be constructed to evaluate discharge regimes that appear capable of releasing contaminated accumulated pond water without compromising water quality in a nearby river. River-mixing zone models also contribute to predicting rates of acceptable discharge and release to the receiving environment.

May 1, 2011

By J. Roth

"While not taking issue with the general thesis expressed in Dr. Ridge's analysis of the role of genetic concepts versus observational data in ore exploration (Ridge, 1983), the criticism could be offered that the author tends to slight the importance of conceptual (i.e. theoretical) models in mineral exploration.As a general rule, observational data in science lacks significance and utility without a theoretical construct to organize those observations. Theory in turn dictates what observations are made-and which ones are judged important. Thus, for example, prior to the elaboration-and acceptance- of the current model for volcanogenic base metal deposits, the structural aspect s of these deposits were most closely observed and studied by explorationists. The nature of the enclosing rocks and any attendant alteration was given minimal attention, and certainly didn't figure prominently as an exploration guide.Similarly, the importance of alteration features to exploration for porphyry copper-molybdenum deposits was only perceived when a theoretical model was developed to account for these aspects. Indeed, many of these porphyry copper deposits were regarded as epigenetic vein deposits by geologists of an earlier era observing and examining on a different physical scale-and with a different theoretical bias.In constructing and evaluating such conceptual models, explorationists primarily rely on observation data and proximate associations; speculative thoughts as to ultimate provenance or crustal evolution clearly play a subordinate role, as Dr. Ridge argues. This, however, should not obscure the fact that concepts and theories do indeed exert a major influence in mineral exploration."

Jan 1, 1983

By Jacques Nantel

Mechanical-electrical personnel are present in all phases of the mining industry; the coverage is broad and diversified. Concepts of energy accounting are reviewed to pinpoint the sectors with a large energy consumption. Four sectors are reviewed: underground hard-rock mines, underground soft-rock mines, open-pit mines and mineral processing. In each sector, five or six technical innovations are analyzed as to their contribution to a more efficient use of energy.

Jan 1, 1979

By Gordon Thompson

"Development of the unique Mine Games exhibition at Science World British Columbia is the largest ever collaboration of many interests to present the story of mining and the issues of mineral development delivered to the public by a science education centre.IntroductionMineral education programs have long been a major focus of the British Columbia mining community. Mine Games and its tremendous potential to enhance industries image and the public's awareness of mining is unequalled in the field of Issue Based Education Exhibits.The main goal of the exhibition is to look at the future of resource industries in a rapidly changing world of economic activities, new technologies, and growing public concern for the environment. Three challenges were the aim of the exhibition: to increase participation, to serve as a tool to increase interest in science and technology, and to draw an increasing number of school students to the interests of geology and the earth sciences. Mine Games is to serve as a meeting place for discussion of issues and where reliable information can be shared and new ideas explored.The exhibition is designed to develop new approaches to hands on learning that encourages visitors to explore and generate discussion and thinking with respect to resource development activities.The role of author, beginning in 1993, was, with senior industry leaders, to coordinate the raising of $1.3 million to complete the funding of the $1.6 million project total. The second and most interesting challenge was to work with the many minds that were collaborating to create the exhibition and to assure that the facts and science were correct. This involved the coordination of ""expert groups"" that verified the science and technology and the issues that the creative design team at Science World planned to use in development of each exhibit module."

Jan 1, 1995

By D. E. Gill, A. Piche, S. Dufresne

"SOMMAIREUne méthodologie de prévision des coûuts de forage en galeries est proposée. Cette méthodologie a été élaborée pour les perforatrices pneumatiques manuelles. Elle est composée de quatre modèles: (1) un modèle de pénétration conduisant à la prévision du temps de forage; (2) un modèle d'estimation de la durée de vie des fournitures; (3) un modèle d'estimation de fa quantité d'énergie consommée; et (4) un modèle de calcul de couts. Elle fait intervenir la résistance en compression uniaxiale de la roche du massif foré, le diamètre des trous, Ie type de perforatrice utilise, fa pression d'air d'opération, la longueur des fleurets, les temps morts associes au forage ainsi que le rendement des compresseurs, des perforatrices et du réseau de distribution de l’air comprime. L 'application de la méthodologie est illustrée à l’'aide d'un exemple, suivi d'une courte analyse de sensibilité et d'une brève discussion. ABSTRACTA drilling cost estimation methodology for underground headings is described. This methodology has been developed for percussive hand-held drills. It comprises four models: (1) a drillability model used for the prediction of the drilling period; (2) a model for the prediction of bit and rod lives; (3) an energy model; and (4) a cost model. It makes use of the uniaxial compressive strength ofthe rock drilled, hole diameter, drill type used, operating air pressure, drilling rod length, dead times that may occur during the drilling operation as well as compressor, air distribution network and drilling machine efficiencies. The application of the methodology is illustrated with an example, followed by a short sensitivity analysis and brief discussion."

Jan 1, 1994

By P. J. Poirier, J. A. Meech, H. Raabe

"An Expert System has been implemented to assist operators in applying knowledge about froth conditions in the control of the flotation circuit at Highland Valley Copper. For some time, the personnel at Highland Valley Copper have recognized that froth type is a useful indicator of good operating conditions. However, the operating strategy based on froth type recognition is an ad-hoc skill in which different operators use a variety of terms, features and procedures to identify and solve problems. The first phase of this project developed an on-line consultative system to advise and tutor so that the diffuse expertise could be rationalized and consolidated into a standardized format.The second phase has brought this knowledge into a real-time environment to advise the operators on the floor in identifying froth types and troubleshooting corrective action. This paper describes the steps taken to acquire the knowledge, to design the required system features and to implement the real-time version of this system.INTRODUCTIONThe use of expert systems in the mineral industry has been gaining popularity in recent years. Minnova Inc, Les Mines Selbaie, Wabush Mines, Potash Corporation of Saskatchewan are just a few examples of Canadian mining companies that use expert systems to monitor or control their plants. Applications in the field of flotation include Brenda Mines (Edwards, 1992), Mt Isa Mines Ltd (Lacouture et al, 1991), Outokumpu (Karhu, 1989) and Kidd Creek (Burrows et al., 1989).Expert systems are defined as ""computer systems that apply reasoning methodologies on knowledge in a specific domain in order to render advice or recommendations much like a human expert"" (Turban, 1988). The main areas of application are diagnosis, training, process monitoring and control, and design. There are basically two main types of expert systems: Consultative systems, which are off-line applications in diagnosis and design, and on-line realtime systems, used for supervisory process control and real-time advising."

Jan 1, 1993

By Corby G. Anderson

"Laboratory testing using industrial electrowinning solutions was performed to determine the best Faradic cell efficiency for copper cathode recovery. The variables tested were solution flow rate, recycle ratio, reagent addition combinations of guar and thiourea, and addition amount of acid mist suppressant CAL FAX DBA-70. The ideal flow rate was determined to be 37.85 litre/min. Additionally, the ideal recycle ratio was determined to be 10:1. The reagent addition scheme from testing which showed the highest efficiency was with 680 g/tonne guar of cathode copper won and with 135 g/tonne thiourea of cathode copper won. These values for reagent addition only reflect the best efficiency and should not be assumed to be the best reagent concentration for copper purity. The amount of foaming agent that showed the best efficiency was the test with 2 ppm of foaming agent. Again this amount of reagent is based on efficiency and should not be taken as the amount of reagent that does the best acid mist suppression. Additional proprietary surface characterization work indicates these additives may have enhanced the cathodic reduction surface morphology of some noble minor impurities. Subsequently, these operating parameters were introduced into the plant operation and proved successful after their implementation.BACKGROUNDCopper electrowinning has become a dominant technology for the production of marketable high grade copper cathode products. The literature is robust with applications, optimizations, additives and developments in this field (e.g., Classens & Harris, 1990; Pfalzgraff, 1999; Tozawa, Su, & Umetsu, 2003; San Martin, Otero, & Cruz, 2005; Houlachi, Edwards, & Robinson, 2007; Romero, Avila, Fester, & Yacher, 2007; Marsden, 2008; Beukes & Badenhorst, 2009; Vainio & Weatherseed 2009; Bender, 2010; Joy, Staley, Moats, Perkins, Uhrie, & Robinson, 2010; Khouraibchia & Moats, 2010; Moats, 2010; Rutledge & Anderson, 2015).Tests of forty hours duration and at room temperature were performed for this project using samples of actual industrial electrowinning solutions. These industrial solutions were comprised of 60 g/L Cu plus 65 g/L Ni, 3 g/L Fe, and 30 g/L free sulfuric acid. Other confidential minor impurities were also present including some solubilized precious metals. The testing apparatus utilizing stainless steel anodes and cathodes is illustrated in Figures 1 and 2."

Jan 1, 2016

By G. W. Toop

"The Cominco smeller in Trail, British Columbia, is a large integrated lead-zinc production facility. In the plant description, emphasis is given to the pyrometallurgical operations including zinc concentrate roasting, lead singer-blast furnace processing and silver refining. Production figures for the main metal products - zinc, lead, silver and gold - are provided.IntroductionIncorporated in 1906, Cominco Ltd. is an integrated natural resource company with principal activities in mining, smelting and refining, mineral exploration, fertilizer production and electrical power generation.Cominco is one of the world's largest producers of zinc and lead, accoW1ting for about 10070 of mine production in the western world. The company also produces and sells copper concentrate, copper sulphate, copper arsenate, sodium antirnonate, silver, gold, cadmium, bismuth, indium, and germanium dioxide and a range of fertilizers and sulphur products.Zinc OperationsRoastingThe roasters currently treat about 1400 t/d of zinc concentrates. Over half of the total concentrate treated originates from the Red Dog Mine in Alaska. During the summer, concentrate is shipped from Alaska to Vancouver where it is loaded into rail cars and hauled inland, transferred to trucks and delivered to Trail. The remainder of the roaster feed is made up of Sullivan concentrate and various custom concentrates. These arrive either by train or by truck.There are three roasters available for roasting the concentrate. The two major roasters are Lurgi fluid bed units. Each Lurgi roaster can process concentrate at about 1:7 tonnes per hour (tlb). A smaller Cominco suspension roaster with a capacity of 10 tlb is also used. The flowsheet for the high temperature section of the fluid bed circuit is shown in Figure 1.Concentrates fed to fluid bed roasting are conditioned with 7 1/min water to give 8% moisture in feed. Two slinger belts throw the mixture into the fluidized bed. The fluid bed roasters are 10.4 m in diameter with a bed depth of 1 m. Grate area is 84 m2• Normal operating conditions include bed temperatures of 930°C to 950°C, fluidizing air at 750 Nm3/min and a wind box pressure of 2000 mm H2O."

Jan 1, 1994

By J. Walenzyk

This report investigates the limited use of super large backhoes in surface mines around the world. The demand for super large (> 700 t) hydraulic excavators is rising and most of the machines are sold as front shovel (FS) application. Despite advantages in faster cycle times super large backhoe (BH) machines are a minority (ca. 1% of the total machine population). This investigation is based upon the comparison between the volumes available to the BH and FS in one block and before the machine needs to move. The working conditions are created with standard parameters as given by Original Equipment Manufacturers of hydraulic excavators regarding bench height, angle, and material density. The travel amount of both machine types is derived from these volumes and compared. Furthermore, the travel amount of super large BHs is compared to the travel amount of smaller mining BHs and evaluated based on attachment length and bucket size. The calculations conclude that the volume of material recoverable in a single spot is about 75% higher for FSs. This leads to an increased travel for BHs. The combination of both the increased appearance of electrical driven machines (in the class of > 700 t excavators) and the travel amount lead to a high risk of damaging the cable or the excavator. Enlarged wear on the travelling parts is also attended by the higher travelling. A direct comparison of commonly found working set ups shows that the ratio between volumes is 32% which leads to an increased travel amount. In comparison with a 250 t BH, the calculation shows that the smaller BH is able to reach nearly 50% of the volume of the super large BHs. The main reason for this is the respectively high reach on smaller machines which, combined with other factors, leads to a significantly higher number of BHs in lighter classes.

Aug 1, 2013

By D. H. Wilson

"This paper examines the increasing need for mechanical-electrical people within the industry and some of the reasons why such a shortfall exists. It is suggested that, in part, it is image related. The present industry-education relationship in addressing the situation is examined and some thoughts are expressed on how these may be built on, in order to help solve the problem of attracting people to this critical area.IntroductionAs a long-time proponent of plant engineering and maintenance as a management function, I would like to review the progress made by the industry/ educational approaches in satisfying the needs in that area. In doing so, I would like to make the following points:1) that there has been an accelerating shortfall of mechanical-electrical people relative to the needs of the industry;2) that the condition will probably get worse before it gets better; ,3) that the past industry I educational approaches to alleviate the problem have met with limited success; and finally4) I would like to review some of the things being done and consider how these efforts might be extended."

Jan 1, 1981

By R. Noriega, M. Suazo, V. Murariu

Current AG and SAG mill circuits have continued the trend to larger, fewer mills. These large mills place a significant additional load on the discharge systems and it has become imperative that the designs of these mill discharge systems are evaluated carefully to ensure maximum efficiency and have the capacity to be able to handle the increased mill discharge volumes. The current generation of multiphysics modeling tools allow a detailed analysis of AG and SAG mill discharge performance. The combination of Discrete Element Method modeling and Computational Fluid Dynamics allows the designer to model in detail all aspects of a mill discharge performance. This includes a detailed description of the build-up of solids and slurry in a mill discharge, the recycle of material back into the mill through the grates, the relative wear rates and the occurrence of overloading at the pinch points. These tools allow intelligent decisions to be made regarding the type of discharge arrangement, pan lifter geometry, and discharge cone design, so as to ensure that the discharge is capable of handling the duties required for a specific installation. This paper details the current state of the art in these modeling tools, and provides an overview of some recent applications.

Jan 1, 2012

By A. C. Bonnier

"INTRODUCTIONI have been asked to make available our method of determining the ""Live Inventory"" within a gravity type thickener. The ""Live Inventory"" being that tonnage compatible with the optimum underflow density that satisfies the process requirements.One prerequisite of the calculations is the proper determination of the final pumpable underflow density. A further requirement is that, prior to shutdown, the thickener has been operated properly, particularly that it has not been operated for storage capacity.Until recently I had few chances to check the method. However, I was most fortunate to have had a recent opportunity covering several months on a 300 ft diameter thickener at a plant in the U.S.A., wherein the method was tested and verified many times. The method proved accurate in that our calculated tonnage checked with the actual dried physical inventory of the drying facility.At the precise moment that the feed to the thickener was shut down, a per cent solid determination was made at the critical place and the tonnage in ""Live Inventory"" determined. Let us say that at the moment the thickener U' Flow solids was 20%. The thickener then was allowed to cperate until the U' Flow solids dropped below 20%, at which time the thickener was deemed to be relieved. Anything much less than 20% was not suitable to the subsequent centrifuge operation.Most large metallurgical thickeners have a configuration of three slopes at the thickener ""bed"". These slopes are dictated by the raking blades and are shown on the manufacturers' erection drawings. The first slope is from the outer periphery and generally takes up a distance of about 60% of the radius, the second slope generally taking up the remaining 40%. Within this 40% area, there is usually another slope taken up by the cone on ""B"" type thickeners or an actual steeper inner slope on ""C"" type thickeners."

Jan 1, 1989

By Charles A. Schacht

"Relining, lining maintenance, and ladle repair can represent a significant cost in steelmaking. Therefore, the objective of all steelmaking shops is to minimize this cost and to maximize the lining life. However, the thermomechanical behaviour of the ladle lining is highly complicated and sometimes misunderstood. The ladle design also has a significant influence on lining life. Other factors which have a direct influence on lining life are the shop lining installation practices and manner in which the ladle is used. The objective of this paper is to provide an understanding of the impact of these factors as related to improving the integrity of the lining and increasing lining life.Fundamentals of Steelmaking Ladle Lining Expansion ForcesNumerous studies have been conducted by the author on steelmaking ladles with molten metal capacities ranging from 110 ton s to 350 tons. The steelmaking ladle typically has a sidewall plate with a slight taper and for analytical purposes can be classified as a cylindrical vessel.A typical ladle is described in Figure I. The ladle sidewall lining usually consists of a working lining and a safety lining. Although the type of refractory used in the working lining varies based on the type of steel produced and other metallurgical requirements, the refractories typically used are: 70% alumina brick; direct bond mag-chrome brick; resin bond dolomite brick; and direct bond dolomite brick. Fireclay brick, high alumina brick, or a similar strength brick is used as the safety lining.Normally, the ladle lining is exposed to a through-thickness temperature gradient and restrained by the ladle sidewall plate, is described in Figure 2. The hot face side of the refractory lining develops a compressive thermal force and the ladle sidewall plate develops an equilibrating tensile force. The radial joints open on the cold side of the working lining as the lining joints have little or no tensile strength. A radial compressive load (P) develops between the working lining and the vessel shell due to the thermal restraint imposed on the lining by the shell. The radial compressive load is transferred from the working lining through the safety lining onto the ladle sidewall. Therefore, the safety lining must have the strength to accommodate the radial compressive load (P)."

Jan 1, 1991

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 C. J. Cattarello

"The Langmuir Mine is located seventeen miles south-east of South Porcupine in Langmuir Township.The property was developed as a Joint Venture between Noranda Mines Limited and the International Nickel Company of Canada with Noranda responsible for the operation of the property.The Mine came into production in June 1973 at a rate of 700 tons per day of nickel ore.MINING The mining method selected for the Langmuir Project was a sub-level retreat method. This consisted of driving sub-levels longitudinally in the ore body at 35 foot, intervals with the sub-levels being connected by a ramp from each main level for the use of trackless mining equipment.GENERAL GEOLOGY OF THE LANGMUIR MINE The deposit is situated about 1,000 feet west of the shore of Carmen Bay at the south of Nighthawk Lake in Langmuir Township. The area is underlain by andesite and rhyolite flows with iron formations which are intruded by gabbro, diorite, peridotite and late precambrian diabase dikes."

Jan 1, 1975

Spatial information Critical to a project since it underpins: ?Discovery of mineral resources ?Orebodydefinition and technical assessment ?Mine design and planning ?Profitability and project value Data ?Single most import asset. ?Good interpretation of quality data underpins project growth and success. TEAMWORK

May 1, 2002

By I. H. Redeker

North Carolina is the leading state in the USA in feldspar, mica, and spodumene production. Mixed feldspar, spodumene, mica and quartz are mined from hard rock, open pit deposits and recovered by flotation from the fresh pegmatite type ores. Potash feldspar, mica, clay and quartz are recovered from weathered decomposed pegmatites. The North Carolina State University has a Minerals Research Laboratory in Asheville with trained personnel and flexible pilot plant equipment. The flowsheets for the feldspar, spodumene and mica producing companies and for large phosphate and glass sand flotation plants were developed and tested in Asheville. Examples and problems of pegmatite flotation are demonstrated with flowsheets and slides.

Jan 1, 1981

By G. V. Lewis

"INTRODUCTORY REMARKS""I believe we need to communicate as much as possible with the industry. I don't think that we should be a body that just goes around doing dust surveys and writing nasty letters. We should get together on these problems and try and solve them as a group. I've only been with the Department a little over 12 months. I haven't visited all of your plants. I've visited most of the major open pits and I have had a chance to observe a lot of problems that you have encountered and a lot of the problems that you have brought up this morning. I thought the best thing I could do is perhaps mention a few of the approaches to the problems that my superior has suggested to me and we have discussed in the Department, and then perhaps go over a few of the evaluating problems and what we are trying to do with our dust surveys and perhaps ways and means of improving the present setup."""

Jan 1, 1976

?Introduction to the Delphi Group ?Why is carbon important to your organization ?Key elements of a carbon management strategy ?Inventory ?Risk & opportunity scan ?Mitigation options and financial mechanisms ?Identify targets and develop policy ?Communication and improvement ?Manage for success

May 1, 2009

By W. A. Grell

"The oxygen meter has been in use at MacLeod Cockshutt Gold Mines for over a year, At MacLeod about 200 tons per day of reground concentrate containing roughly 10% pyrrhotite and 20% pyrite is cyanided in four 181 x 18' Dorr agitators. A survey by the Department of Mines showed that oxygen content of some of the agitators was rather low. Experience with our oxygen meter indicates that the oxygen content must at times have been too low for good gold dis solution.We have found that in winter, when pulp temperatures drop to about 50° F, oxygen saturation in the agitators is not difficult to maintain. In summer, however, when pulp temperatures rise to 70or 75°F, the oxygen content will drop very readily. It was found that a high oxygen content can be maintained readily if the pulp is sufficiently dilute. Thus at 50° F, a pulp of specific gravity 1. 75 i.e., about 55% solids, will saturate; but at 70 or 75° F, the specific gravity must be decreased to 1 .45, equivalent to about 40% solids, in order to maintain saturation. Very thick pulps, such as thickener underflows, are noticeably difficult to saturate in the laboratory, and lose their oxygen rapidly.Clear solutions, on the other hand, absorb oxygen readily and hold it. The primary thickener overflow, before agitation, is 100% saturated; after storage of 3 to 4 hours it is still 100% saturated at re clarifier tank. Barren solution after spraying in a launder is 100% saturated.We have not yet attempted to determine what percentage saturation is necessary for good extraction, but it is known that there is a point at which extraction decreases rapidly. So far, the measures required to maintain over 80 or 90% saturation have coincided with measures required to hold the reducing power to the point believed necessary."

Jan 1, 1964