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In 2009 Newmont Mining Corporation?s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Nov 1, 2011

By D. Milne

Laser profilometers exist for obtaining very accurate two and three dimensional profiles of joint surfaces. The application of this technology is not commonly applied to the collection of field data on discontinuity surface roughness. Rugged and portable field devices are not commonly used and the value of the possible field data that can be collected has not been well recognised. This paper reviews commonly used field techniques for assessing discontinuity roughness, discusses the value of this data and presents a new laser profilometer design for field application.

May 1, 2009

By J. Olsson

The paper describes and discusses the use of stainless steels for leaching plants emphasising the duplex family, i.e., austenitic-ferritic stainless steels. This group has generally twice the proof strength of the more common 300-series austenitic grades, which implies possibilities to reduce the gauge at construction of pressure vessels and atmospheric tanks and vessels and thereby possibilities to reduce the weight. The duplex grades have also higher surface hardness resulting in better resistance to mechanical wear, i.e., abrasion and erosion corrosion. The lower contents of nickel and molybdenum imply lower cost and a more stable price considering the present market situation for these alloying elements. Corrosion data from laboratory and pilot plant tests, as well as examples of applications of duplex and highly alloyed austenitic grades, are presented. Cu2007 - Volume IV (Book 1) The John E. Dutrizac International Symposium on Copper Hydrometallurgy Edited by P.A. Riveros, D.G. Dixon, D.B. Dreisinger, M.J. Collins Toronto, Canada,

Jan 1, 2007

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By João Felipe Costa, Jair Carlos Koppe, André C. Zingano

Abstract - Traditional mine planning based on block models built with interpolation techniques such as kriging does not take into account the uncertainty associated with the estimates. These models are inadequate for short-range mine planning. In contrast, conditionally simulated models reproduce the actual variability (histogram) and spatial continuity (variogram) of the attributes of interest. Conditional simulation can be used to address the problem of measuring the uncertainty associated with an estimate. This paper outlines how the sequential Gaussian conditional simulation algorithm can be used to assess uncertainty of grade estimates and also illustrates how simulated models can be incorporated into mine planning and scheduling. A case study demonstrates the efficiency of the method in assessing risk associated with geological and engineering variables.

Jan 1, 2000

By José Carlos Marques

This paper addresses recent calls to study the role of the state in private regulation. Using an historical, organizational-field approach, I trace and explain the evolution of public debates and interaction of different forms of regulatory initiatives dealing with Canada?s mining industry. The empirical evidence presented calls attention to the interaction amongst different regulatory forms, as well as the conditions under which the state will encourage fragmented initiatives, rather than facilitate and catalyze regulatory strengthening and consolidation. As such, my analysis: problematizes the underlying assumptions used as a starting point by the growing literature on the role of the state in private regulation; connects and juxtaposes recent scholarship to more established literature on regulatory state failure and self-regulation. I also contribute to the discussion on Canada?s CSR policy, outlining the likely regulatory effects of the current policy framework.

Aug 1, 2013

By C. T. Morley

The steadily increasing interest in high pressure grinding rolls (HPGR) as a legitimate alternative comminution technology for hard rock applications has led to a proportional increase in the demand for trade-off studies comparing HPGR with more established approaches, typically SAG-based but including AG and stage-crushing designs. The primary trade-off is between a) the higher capital cost typically incurred with HPGR-based designs and b) the higher operating costs of the more traditional technologies. However, if, through circuit design innovation, the capital cost penalty of HPGR circuits could be eliminated or reversed, then the need for trade-off studies would diminish.

Jan 1, 2012

By Owen Owens, W. P. Armstrong

The process of arriving at the size and grade of: (a) a newly-discovered body of mineralization, (b) a potential ore resource, (c) an orebody proposed for mining, or (d) the ore reserves in a mine, requires fundamental geological, and geometrical determinations as well as physical and chemical analyses. This paper outlines geological and geometrical features considered critical, in the authors' experience, in realistic reserve determination. These are discussed under the headings "The Four Cs". They include the Character, type or nature of the mineralization; the Continuity of various types of mineralization in the deposit; various key concerns in the Calculation besides the mathematics; and the Classification section which refers to basic considerations in classifying a mineral estimate. It is suggested that the responsibility for the calculation of a Resource or Reserve should be that of a geologist experienced in the ore type under review. Further, it should be the responsibility of the board of directors of the company owning the deposit to ensure that a sufficiently experienced person is chosen to carry out the process.

Jan 1, 1993

By Alessandro Navarra

Discrete event simulation provides a computational framework in which the use of smelting equipment can be analyzed and optimized, leading to the development of alternative modes of operation. Much of the complexity of copper and nickel smelters is centered on the converter aisle. These converters operate in parallel, produce batches, and set the tempo for the downstream operations. In practice, smelter staff schedule daily operations to coordinate the smelting furnaces and converters with downstream operations. Thus, a realistic simulation of smelter operations, over hundreds of days, should incorporate converter scheduling algorithms as presented in this paper.

Jan 1, 2014

By T. Yalcin

"This paper describes a process that can provide high rates of dewatering and that has the potential of bringing significant savings in tailing disposal costs. It involves a three-stage, closed-circuit operation employing a hydrocyclone, a settling cone and a thickener. The mill tailing, with adjusted pulp density, is first fed to the hydrocyclone. The underflow from the hydrocyclone goes to the settling cone for further dewatering. The overflows from the hydrocyclone and the settling cone are sent to a thickener which, with the addition of a flocculant, gives a clear liquid effluent and a dilute underflow which is recycled back to the hydrocyclone. The underflow of the settling cone is a material with as high as 78% pulp density and is suitable for direct disposal or for use as mine backfill.INTRODUCTIONDewatering is an essential process for the disposal of mill tailings and forms an additional cost item in milling operations. Cost-cutting measures are therefore desirable in this area as in any other stage of milling. One way of achieving this is through increased rate of dewatering which would require smaller dewatering units with correspondingly lower capital and operating costs."

Jan 1, 1987

By Arnaud Faucher, Amar Sabih, Sudarshan Martins, Tristan Martin, Sami Makni, Peter Radziszewski, Poorya Hosseini, Francois-Raymond Boyer

The measurement of acoustic signals produced by a tumbling mill has been previously used to determine the operating state of the mill and correlate the variations of the sound intensity with the operating conditions of the mill. Separately, the discrete element model (DEM), a software simulation of the mill, was developed to provide insight into the operation of the mill. Presently, there has not been much work reconciling the DEM simulation of the mill with the acoustic signal. Working from basic principles of linear, time-invariant systems, agreement between an acoustic DEM simulation and the measured signal is sought. First, the impulse response function of the mill is measured. The DEM provides the forces applied to the mill shell as a function of time. A convolution of these simulated shell forces and the transfer function gives the simulated acoustic signal. This signal is compared to the measured acoustic signal, both in the time domain and the frequency domain. Finally, a discussion of the results is given.

Jan 1, 2012

The successful application of color sorting machines has established sensor-based sorting in the mineral industry in recent years and is considered today as a significant innovation in processing technology. However, we are only at the beginning of (market) introduction. New sensor systems have been developed, which exploit material properties such as electrical conductivity, magnetization, molecular structure, thermal conductivity etc. This opens up new exciting pre-concentration and upgrading possibilities for many applications such as nickel, gold, copper and other ores as well as for industrial minerals, diamonds and other gem stones.

Oct 1, 2009

By Andrew Bamber

Outline ?Background to Mine-Mill Research at UBC ?Mine Mill Integration ?In situ mining methods ?Underground Pre-concentration ?System Design and Supporting Technologies ?Case Studies: ?INCO -McCreedyEast Mine ?Placer Dome ?Porcupine JV ISL Study ?Musselwhite, South Deep ?Falconbridge ?Fraser Copper ?Thayer Lindsley ?Wayside Gold, other scoping studies? ?System Designs ?Summary ?Future work ?Conclusion

May 1, 2006

By Bradford C. Wesstrom

An overview of the challenges encountered at the Freeport McMoRan El Paso Copper Refinery with higher concentrations of antimony electrolyte will be shared. The observations will cover the detrimental effects on copper starting sheets, commercial cathodes and anode slimes. The study will show negative effects on quality and productivity. Experimental work will utilize a test cell to study the effects on electrolytes by different Antimony, Arsenic concentration and anode molar ratio. Best practices will be shared for producing high quality cathodes while effectively managing the detrimental effects of higher antimony electrolyte.

Jan 1, 2014

By M. Maeda, H. Sasaki

Dissolution characteristics of metals vary significantly when they form alloys with other elements. Because hydrometallurgical processes are essential in separation and refining of non-ferrous metals, it is important to study behaviors of alloys in aqueous solutions. The authors have studied dissolution characteristics of precious metals in acid solutions using electrochemical measurement. When precious metals are alloyed with Zn, its dissolution is promoted by an increase in surface area caused by the preferential dissolution of this metal. The electrochemical study also revealed that precious metals dissolved from some alloys at unusually negative potentials; the underpotential dissolutions are explained by activations of these metals in the dealloying.

Jan 1, 2014

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By J. F. Shirley

"Very seldom, if ever, is a molybdenite by-product plant operated exactly the way the process design engineer visualizes it. The best thing the design engineer can do is provide a sound, basic circuit with enough room and flexibility in order that the operating staff can make the necessary modi fi cations to optimize the process. The plant, with minor modifications, should be capable of handling more than one process. This is especially true when the client is having the plant designed for a new process.The writer would like to propose the following ten ""rules-of thumb"" for designing by-product molybdenite plants where the molybdenite is floated out of a copper concentrate. The term rules-of-thumb is used, because there are probably valid reasons for not using one or more of them in a particular plant design. In fact it was 1980 before the writer was all owed to start up a plant where all of these rules were honored in the plant design. This was after 19 years of experience in the design of molybdenite by-product processes and plants. The main reasons for not following the rules are available capital, available space, and the client's experiences based on pilot plant and laboratory test results."

Jan 1, 1981

By K. Adham, C. T. Harris

Arsenic is often associated with copper, nickel and gold in sulphide deposits. This paper describes a two-stage high-temperature fluid bed reactor for the removal and fixation of As from ores and concentrates. The first (bottom) stage of reactor removes the As through a neutral roast, by volatilization as mostly sulphide species. The second (top) stage of reactor captures the As from the gas phase through oxidative fixation, as a stable iron arsenate, by reaction with an appropriate iron source (sulphide or oxide). The second stage is placed on top of the first, so that their combined function can be achieved in a simple two-stage fluid bed arrangement, with the bottom stage off-gas providing the top stage fluidization.

Jan 1, 2014

By Lo-Sun Jen

Introduction ? Canada is one of the largest miners and explorers in the world and is a world leader in the production and export of many key mineral commodities ? Canada has a stable political regime and a competitive investment and business climate ? Canada is endowed with mineral resources, advanced technology and management know-how ? Canadian stock exchanges are the world?s leading centres for raising equity financing for exploration and mining projects anywhere on the globe As with some other countries, Canada has experienced a recent decline in major mining developments

May 1, 2002

By Robert B. Parsons

"The Canadian tax treatment of mining operations outside Canada is not as attractive as the treatment of Canadian operations. Further, the Canadian company that invests abroad a host of complex rules. This month, Tax Notes examines some of the major Canadian tax considerations confronting the Canadian company that wants to invest abroad. IntroductionCanadian-based mining companies are investing abroad more than ever before. These foreign investments trigger a complex set of tax rules that are distinct from the rules that apply to Canadian investments. In most cases, careful tax planning is mandatory if the company's tax liabilities are to be minimized. This article summarizes the main tax considerations that need to be taken into account with respect to a mining investment outside Canada.Branch Versus SubsidiaryOne of the first questions that arises in connection with a prospective foreign investment is ""Should we invest directly (that is, in a branch operation), or should we invest through a foreign subsidiary?"". In the case of a branch operation, the Canadian company owns and operates the business directly - that is, the foreign business assets are part of the Canadian legal entity. In the case of a foreign subsidiary, the foreign business operation is owned and managed by that subsidiary. The tax treatment of a branch and a subsidiary can be quite different."

Jan 1, 1994