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By Seppo Lähteenmäki, Pertti Koivistoinen, Jaakko Levanaho

"This paper describes the benefits and disadvantages of fully autogenous grinding when compared to grinding with steel grinding media. The study is a real case study based on a low tonnage, high grade mining project in a remote location in a developing country. The study compares the capital and operating costs of using either SAG mill, Ball mill, Crusher (SABC) or fully autogenous (AG) grinding circuits and produces an economical analysis of the project for both options. The economics have been developed for the overall project, including mining, processing, environmental and the infrastructure as well as for the additional cost of constructing a fully autogenous grinding circuit instead of the original plan of a SAG Mill, Ball Mill circuit.The paper also describes the development of the autogenous grinding circuit at Outokumpu Oy, Pyhäsalmi mine. This experience was used to design the autogenous grinding circuit for the case study. Pyhäsalmi Concentrator has over 30 years of experience in operating autogenous grinding circuits and therefore provides a sound base for the new circuit design.INTRODUCTIONGrinding of ore using steel grinding media is currently the most commonly used method in the mining industry. Autogenous grinding, ore replaces iron media, is also common especially in Europe and Africa. Iron ore industry in North America uses autogenous grinding in primary and/or secondary stages extensively. In gold, copper and other base metal industries, autogenous grinding is not as common, although there are operations where pebble grinding is or has been used in the secondary grinding stage. There are many variations of autogenous grinding in use in the mining industry. These variations include different mill sizes, mill length to diameter ratios, ore lump sizes, screening and pebble crushing configurations."

Jan 1, 2000

By N. Hmidi, T. Yalcin, M. Papadakis, B. Hilscher

Mill tailings, containing iron sulphides in particular, pose an environmental concern since they constitute a potential source of acid mine drainage which can damage vegetation, harm soil and living organisms, and contaminate groundwaters. Proper disposal of acid generating tailings is therefore an important issue that must be addressed and resolved in a satisfactory manner. Placer Dome Canada operates a 4000 t/d gold cyanidation facility at Musselwhite mine, in northwestern Ontario, where the mill tailings have been classified as acid generating. This study was conducted to explore the effectiveness of froth flotation in removing the sulphide minerals from these tailings and producing a low-sulphur, non-acid generating material that could serve as a capping material for previously deposited tailings. Laboratory semi-batch flotation tests were carried out in accordance with an experimental design procedure, and a computer simulation program was developed to facilitate the evaluation of flotation performance. In this investigation, pH, collector concentration, and airflow rate were considered as the relevant flotation variables, and their effects were examined both experimentally and by simulation. Results have demonstrated that flotation can successfully desulphurize the Musselwhite mine tailings and render them non-acid generating.

Jan 1, 2004

By J. Ling, L. Racine, P. Cousin, A. R. Laplante

"The problem of gold recovery by gravity from high density gangues is first discussed from a fundamental perspective. Three potential difficulties are presented: poor liberation and fine gold particle size, concentrate bed erosion by coarse dense particles, and slow percolation of gold particle through the high density gangue bed. Two case studies are presented to illustrate the impact of these three problems on circuit performance and the feasibility of gravity recovery. It is concluded that careful testing can determine the scope of the first problem and feed preparation can limit the extent of the second. The third problem is clearly the most serious and results in lower gravity recoverable gold recoveries than would be achieved with the same recovery effort on a low density gangue application.IntroductionSince the commercialisation of the Knelson Concentrator in 1980, gold gravity recovery has experienced a surge in interest, in Canada and the United States first, then Australia, Zimbabwe and Russia, and finally worldwide. Table I details number of units sold in various countries, which corresponds approximately to their importance as gold producers 1. Exceptions. such as the low rank of South Africa or the importance of Zimbabwe, despite the much higher gold throughput of the former, are generally the result of differences in the effectiveness of the local marketing strategies, as well as a reflection of the ""philosophy of recovery"" prevalent in the country.The impact of the Knelson has not been felt equally in all plants. Typically, a highly successful application falls into the following categories: (a) alluvial or hard rock recovery for which gravity is the sole recovery method, (b) hard-rock free gold milling with ores which have a very high gravity-recoverable gold (GRG) content, (c) low grade sulphide copper-gold ores which include flotation ahead of cyanidation and (d) free-milling gold ores ahead of Other applications can be successful, but are not as common. The ""explosion"" of centrifuge concentration, of which the Knelson is the most successful but by no means the sole model, has created a certain euphoria which can be summarized as ""gravity recovery will improve the profitability of gold milling, no matter what."" This presentation is about applications that are not so successful, or even downright unsuccessful. The rationale is not to down-play gold gravity recovery, but to set it in its rightful position: metallurgically, it is not appropriate all of the times; it can become inappropriate if poorly designed; and it can be metallurgically possible but economically unjustifiable. In this paper, this will be illustrated and explained rather than demonstrated, with the use of both industrial plant surveys and laboratory test work. Alternate gravity approaches will be suggested."

Jan 1, 1997

By G. P. Gormley

"Future open pit metallurgical coal mines in western Canada will be developed in complex geological environments. The success of these operations will be influenced by the mine operators' ability to prepare accurate mine plans and to predict and, subsequently, 10 control both out-of-seam dilution and coal recovery. Quintette Coal Limited has been mining its tightly folded and severely faulted Mesa depo sit at annual rates of up to 9 Mt of raw coal, since October 1982. Ongoing development drilling combined with continuous utilization of blast hole information, has been required to achieve an acceptable geological data base for short range mine planning. Thrust faulting has been a primary geological cause of difficulty in selectively mining waste and coal, which has resulted in higher than expected dilution in plant feed. The same geological phenomenon has also increased reserves by 6.3% and allowed for expanded mine plans to include a lower thrust plate, ultimately doubling the mines original reserve base. This paper illustrates the geology of the Mesa deposit and the type of work involved in its interpretation. Regional GeologyThe Quintette Coal Limited (QCL) property is located in the Peace River Coal Field of northeastern British Columbia. In this area, northwesterly-trending folds of the Rocky Mountain foothills are commonly cut by multiple, low-angle thrust faults, which dip to the southwest. The Lower Cretaceous Gates Formation, of near shore continental origin, contains 5 to 7 mineable seams of medium volatile bituminous metallurgical coal (Figs. I and 2). These seams normally range in thickness between 0.75 m and 9.5 m and have an aggregate thickness of between 15 m and 22 m."

Jan 1, 1988

By E. L. Jones

THE concentration of tin in the tailing from Sullivan ore has been de-scribed by H. R. Banks, superintendent of the Sullivan concentrator, in a paper presented at the annual meeting of the B.C. Division of the Institute in October, 1941(1). The reduction of the concentrate EARLY EXPERIMENTAL WORK Experimental work on the smelting of Sullivan tin concentrate was done in Trail. Preliminary tests in the laboratory indicated that the concentrate could be successfully treated in an electric furnace. A small electro-thermic pilot plant was built and, at the same time, reduction tests were made in an oil-fired reverberatory furnace. Both types of treatment gave satisfactory results. It developed that no fluxes, other than those already in the ore and in the ash of the reducing agent (either coke or coal), were needed. By using an excess of iron, a complete recovery of the tin in the slag was obtained, but with 20 to 30 per cent iron in the tin. A counter-current treatment was thus indicated, viz., the primary slag was first treated with hard-head (iron-tin alloy) from the refining and final slag smelting, producing tin with 2 to 4 per cent Fe. This secondary slag was subsequently treated with scrap iron to produce tin-iron alloy, and a final slag low enough in tin to waste. By following this line of endeavour, a tentative flow-sheet was drawn up and a successful operation was established. Without resorting to electrolytic refining, a metal comparable in purity to standard tin was produced. Metallurgical results and operating costs were found to be very similar with an electric furnace or a fuel-fired furnace. 'However, electric furnace smelting was chosen because the furnace required was smaller, and because some doubt existed as to the cleaning of the final slag in the reverberatory furnace reduction.

Jan 1, 1944

By L. W. T. Weitzel

"This paper reviews the Falconbridge- SMRQ’s Raglan project in northern Quebec and the process that was used in developing its current long-term mine plan. Challenges were many and not only limited to the longevity of the project, numerous ore deposits (both underground and open pit), and a 40 km property strike length. As a result of its remote northern location, other factors such as progressive reclamation, leachable mine waste, water treatment, and waste management were also part of the plan. A combination of modern planning tools were used to formulate the plan including DataMine, Mine 2-4D, AutoMod Simulation, and an Excel-based financial spreadsheet to bring the total plan together. The focus of the paper is to show the complexity of modern mine planning and associated economic modelling of mine processes. IntroductionThe Raglan project is located 1660 km directly north of Quebec at the northern tip of the Quebec Peninsula in Nunavik. The main property is 40 km in length stretching from the Donaldson airport area at the eastern edge of the property to East Lake at the western edge. The Deception Bay port is 90 km north of the main complex/mill situated at Katinniq which lies approximately in the middle of the property (Fig. 1). The mine processes 1 000 000 tpy of ore from both open pit and underground sources. The mill is forecasted this year to produce more than 150 000 t of concentrate grading more than 18% nickel. All personnel and critical cargo are transported to the site via a company-leased 737 jet from Rouyn-Noranda where the main administration office is located. The majority of cargo is shipped to the site via Deception Bay from Quebec and on the return trip, nickel concentrate is shipped back. From Quebec, the nickel concentrate is sent by rail to the Falconbridge smelter in Sudbury and on the reverse rail haul, nickel matte from the smelter is sent to Norway via Quebec."

Jan 1, 2003

By G. G. Campbell

"HistoricalBARYTES was mined in Nova Scotia as early as 1874 from a deposit at Five Islands, on the north shore of Minas Basin. The first record of the presence of the mineral at the Walton site appears in a report by Selwyn in l893, who states: ""Barytes in considerable quantity occurs in veins in lime-stones at Walton and Pembroke"". The exact site of the present workings was marked •on a map published by Fletcher in 1905.The economic •possibilities of this deposit, however, were not recognized until 1940, at which time we were at war with Germany, who up to that time had supplied 50 per cent of the world's requirements.At that time the Nova Scotia Department of Mines, recognizing the need for certain strategic minerals, induced Canadian Industrial Minerals, Limited, to send prospectors into 'the area to look for manganese. No manganese deposits were found, but a deposit of barytes was directed to their attention, and exploration and development work on the occurrence was proceeded with.IntroductionThe south shore of Minas Basin between the Avon river at Windsor and the Stewiacke river at Maitland has long been known as a potential source of mineral wealth. It had attracted the attention of mineralogists and in the past had produced considerable tonnages of manganese ore and gypsum. Depletion of ore in surface and near surface deposits resulted in a dwindling production, until today only deposits of gypsum are worked."

Jan 1, 1952

This paper describes the back analysis of the Pavoncelli tunnel, an hydraulic tunnel which was excavated between 1904 and 1915 in South of Italy and experienced severe damages during the 1980 Irpino-Lucano earthquake. A numerical simulation which is intended to study the behaviour of the tunnel during this seismic event is presented, also accounting for the swelling phenomenon that took place during and after construction.

May 1, 2009

By L. Veleva, Garcia. A., G. Perez

Aluminum is a metal used for the transmission of electricity of high voltage, in the construction industry and other areas. In atmospheric conditions aluminum forms an oxide layer (Alz03'H20) as a result of its corrosion, entering the passive state. The oxide layer can be destroyed by the presence of ions (Cr, SOx-n) developing localized (non uniform) corrosion attack by pitting, difficult for evaluation. The concepts of fractals and self-similarity were used in this study for the characterization of the development of localized corrosion. Images obtained with a scanning electron microscope (SEM) of samples of electrolytic aluminum wire that have been exposed during one year in ruralurban and marine-coastal environments of the humid tropical climate of Mexico, have been processed. The development of pitting has been studied as a function of time, making a statistics of the frequency of appearance of pits versus the area occupied by them. The data show that the distribution of the pits follows a power law. Therefore, the concept of self-similarity can be applied for the study of the phenomenon of localized corrosion, describing their development with time.

Jan 1, 2006

By Jr. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Jan 1, 2012

By B. I. Whittington

This paper examines the effect of cation type (i.e. NH4+, Na+ and K+) and anion type (i.e. SO42- and C1-) on the extraction of nickel during the pressure acid leaching of a Western Australian laterite ore. The results are compared with testwork conducted with other Western Australian nickel laterite ores and the possible process implications of adding an additive to a plant autoclave are considered. Addition of either (NH4)2SO4, Na2SO4 or K2SO4 increased both the nickel extraction and the acid consumption, provided that the level of additive was not too great. For example, the nickel extraction of 93% increased to above 96% in the presence of additives, but decreased to 94% when, for example, NH4 levels increased from 7 kg/t ore to 21 kg/t ore. The relative stability of the jarosite species formed when additives were present influenced the amount of jarosite in the residue and, hence, both the final free acidity and overall nickel extraction. The use of Cl- versus SO42- salts as additives had little effect on overall nickel extraction or overall free acid values, although the presence of SO42- additives appeared to enhance nickel extraction kinetics over the first 60 minutes of the reaction. In contrast, manganese extraction was enhanced by the presence of Cl- additives.

Jan 1, 2004

By L. B. Kilius

The composite cathode system based on Ce0.9Gdo.1O2_,5 electrolyte with a painted cathode was used for an intermediate temperature (500-700°C) solid oxide fuel cell. This cathode system was chosen due to its excellent thermal expansion match to the electrolyte, its relatively high conductivity (115 S cm-1 at 700°C), and its low activation energy for oxygen reduction (99 kJ/mol). It was found that the decrease of sintering temperature of the composite cathode system produces a significant decrease in charge transfer resistances to a level of 0.25 SI cm2. The conductivity measurements of porous samples produced values between 40 and 88 S/cm for porosities of 30-40%.

Jan 1, 2005

By J. Molgaard, J. Masounave, J. Prinsen, P. Beaulieu, G. Huard

"A study carried out on behalf of the National Research Council (NRC) indicates that economic losses due to wear in the Canadian mining industry are in excess of $700 million annually. Severe wear, mainly by abrasion, was identified as the most important wear mechanism in terms of possible savings. One way to reduce losses would be the proper use of databases. A joint project of The Canadian Institute of Mining and Metallurgy (CIM) and NRC (Tribology laboratories at IMRI) has been initiated to create a factual database containing all relevant experience in the area of wear in the Canadian mining industry. As a first step, a prototype covering slurry pumps is being built. This should help to answer many questions, such as the number of people involved, interest from industry, cost vs benefits, etc.IntroductionTribology is concerned with the understanding of the mechanisms of friction, wear, and lubrication.Tribology is concerned with the correct use of materials for interacting solid surfaces, with the interaction of those surfaces with lubricants, with the chemistry, physics and use of lubricants and their additives. It is concerned with the reduction of friction and wear (or, in the case of belts, brakes, clutch plates, and similar devices, in achieving optimum friction with minimum wear) and is concerned with the avoidance of associated failures in machinery.Lubrication is usually the solution to a problem of friction and wear. Yet far from all the problems of friction and wear are solved by lubrication. The wear of grinding rods or shovel track pads can hardly be solved by lubrication, to name just two examples with which mining engineers will be familiar. There are indeed many situations of wear and friction where the surfaces in contact are unlubricated.In part, tribology is a matter of design. A major aspect, however, has to do with the choice of materials, to satisfy external constraints upon the component design or choice. The operating conditions for much industrial equipment, particularly in mining are, often very severe. The development of wear resistant materials, including materials which are applied as coatings, is clearly an important technology from the point of view of tribology."

Jan 1, 1987

By Phil Keele

Canadian Natural ??Business Approach Efficiency and Execution ?Drive to be the low cost producer ?Focus on exploitation ?Augment exploitation with strategic acquisitions ?Maintain Discipline and Strength while Delivering on the Defined Plan ?Maintain flexibility and control allocation of capital ?Strive for balance (asset portfolio) ?Maintain financial strength

May 1, 2010

By Silvana Costa

In the last two decades, there have been nearly no new mining towns built in Canada. Governments and mining companies have viewed long distance commuting (LDC), commonly known as fly-in-flyout or fly-in mines, as a way to avoid problems associated with building a new community and providing for its sustainability after mine closure. LDC is also considered more cost-effective than building a mine town. The intensification of the use of LDC in the Canadian mining sector has been quite rapid, particularly in northern regions. However, LDC has implications to employees, their families and communities, which deserve further examination, particularly considering the significant expansion in Northern mining and Aboriginal participation in this sector. This paper presents a review of the major issues in long distance commuting, both from an industry and community perspectives. It is a result of preliminary investigation for a PhD research project that will be pursued by a Bridge Fellow and UBC Mining Sustainability Working Group member, and guided by an interdisciplinary research team at the University of British Columbia (UBC). The Bridge Fellowship Program is research-training program linking the UBC?s Faculties of Medicine, Engineering and Graduate Studies. Its mission is to develop creative evidence-based prevention measures for public, environmental and occupational health problems. The SWG is an interdisciplinary student group based in the UBC Department of Mining Engineering, committed to respond to the complex sustainability-related challenges currently faced by the mining industry. In other to pursue this project, it is paramount that industry and local communities alike participate in the development and clarification of research questions as well as in the research design. It is hoped that this paper will function as an invitation for industrial and community partners for such study. The main themes identified for this research are occupational health and safety of LDC employees, family life impacts and community health impacts of this model of resource development.

May 1, 2004

By M. Veiga

"Mining is an energy and water intensive activity. Increasing energy efficiency and reducing water consumption are two of the key requirements in moving toward a more sustainable mining industry. Water reduction, reuse and recycle options are reviewed, identifying cases where these options have been implemented. Then a novel mine water network design method is described, which analyzes a mine/mill water system in order to identify areas where water requirements and water system energy requirements can be reduced. First, a site water balance is determined and major water consumers and sources are specified. Next, multiple possible combinations of supplying water to mine and mill consumers are compared. Finally, low energy and water combinations are identified.INTRODUCTIONMining consumes vast quantities of energy: The whole mining and metals sector consumes over 12% of the world’s energy (DOE, 2009). Mining also requires large quantities of water, although mining water consumption is a relatively small portion of the overall world water use. Even in relatively dry, mining-intensive countries like Australia and South Africa, mine water consumption is only 2-3% of national water demand (Brown, 2003). However, at the local level, when mining takes place in areas where water is scarce, mine water consumption can severely impact local supplies. In addition, acid rock drainage, leaks from waste impoundments, or direct disposal of tailing into waterways can contaminate surface and groundwater (MMSD, 2002). Mine water systems can be large energy consumers, but better mine water systems can reduce both water and energy consumption. Improving water system design and practice are key strategic requirements in moving toward a more sustainable mining industry.This paper addresses conventional base-metal or precious-metal mine sites, which consist of an underground or open pit mine and a mineral processing plant, or mill. Ore is extracted and processed through the plant to produce a saleable product. Tailing, or waste material, is then deposited in a tailing storage facility (TSF). Any rock removed from the mine with no economic value, or waste rock, is stored without being processed."

Jan 1, 2010

By D. G. Brophey, J. A. O’Neill

"High costs, both in terms of human resources and financial costs, have long been the end result of accidents involving vehicles which continue to occur too often throughout our industry.For example, radio remote control LHDs too often seriously injure their operators in underground operations. Costly efforts are required by mine owners to provide safety bays and platforms from which their operators can work safely. In open pit operations, large heavy haulers have too frequently backed over vehicles or turned into vehicles unfortunate enough to be situated in their large blind spots. These are just two examples of situations that have occurred again and again under similar circumstances.Meanwhile, electronic methods of detecting proximity to vehicles have continued to develop. The time has come for the industry to think “outside the box” to evaluate whether many of these new methods can solve these recurring problems.This note takes a look at various types of proximity detection technologies that are in use today in other industries, and discusses the various potential applications within our industry."

Jan 1, 1998

By Derek Apela, Coralee Heske, Bunyamin Kahraman, Muhammad Adi

Effective blast fragmentation is essential in underground mining, as it directly influences downstream processing efficiency and operational expenses. This study investigates the application of Non-Newtonian Fluids (NNF) as stemming materials, presenting a novel method to enhance energy confinement, minimize environmental impact, and optimize blast performance. NNFs exhibit shear-thickening behaviour, enabling them to transition between fluid-like and solid-like states under stress, which renders them suitable for regulating explosive gas ejection during blasting. Field trials were performed by Vale Base Metals in Thompson, Manitoba, in their underground nickel mine to evaluate conventional slag stemming against NNF-based stemming in production-scale blasts. Emulsion explosives were employed, and blast performance was assessed through velocity of detonation (VOD) measurements, vibration monitoring, and AI-assisted fragmentation analysis using WipFrag. Preliminary results indicate that NNF stemming improves fragmentation, resulting in a reduction of D50 by as much as 38%, enhances energy confinement, and may decrease the incidence of hole plugging and re-drilling in subsequent blasts. This study presents an alternative to conventional stemming methods, highlighting potential advantages for enhanced safety, efficiency, and sustainability in blasting operations. Additional research and field trials are necessary to improve implementation protocols and facilitate the widespread adoption of this unique method in the mining sector.

May 4, 2025

By Tarrant Elkington

Underground mine planning practices are typically manual and time consuming and will often produce sub-optimal solutions due to the application of generic rule-of-thumb assumptions or ?tried and tested? choices. The development of computer-automated tools for underground mine planning enable a wide range of scenarios to be considered rapidly in arriving at an optimised solution, subject to input assumptions. We have applied these tools to demonstrate ?optimised? solutions that challenge industry standard practices. Further, we have incorporated grade and price/cost uncertainty into these tools to gain an understanding on how the consideration of uncertainty may further alter strategy selection. Finally, we enable the tools to dynamically adjust cut-off grades in conjunction with the evolution of prices/cost.

May 1, 2010

By D. F. Sangster, P. J. Hood, G. A. Gross

"Some results are presented of an integrated geological and geophysical study of Precambrian magnetite-quartz iron-formation in the Kapiko Iron Range north of Nakina, Ontario. Detailed geological and topographical mapping was carried out in conjunction with detailed geophysical investigations such as vertical magnetic field, vertical magnetic gradient, hammer seismic, horizontal-loop electromagnetic and magnetic susceptibility surveys. In addition, oriented drill cores were obtained for magnetic polarization studies.Vertical-force magnetic anomalies within individual rock units showed a strong positive correlation with topographic relief. Moreover, magnetic intensity was found not to be quantitatively proportional to the magnetite content in the rocks, due to the presence of high remanent magnetization of the magnetite. Also, the remanent polarization direction was sub parallel to the plunge of the fold structure and mineral lineation in associated rocks.Vertical magnetic gradient measurements were found to be more accurate in locating buried contacts between magnetite-quartz iron-formation and country rock than the vertical magnetic force data.An in-situ magnetic susceptibility meter was used to measure the magnetite content of iron-formation, and the measurements were subsequently compared with vertical-force magnetic results.The results of the EM survey were inconclusive; some magnetite-rich zones produced anomalies in the out-of-phase component. whereas others did not. The reasons for such inconsistencies are not yet apparent.Longitudinal seismic wave velocities measured parallel to the bedding in magnetite-quartz iron-formation ranged from 10,600 ft/sec. to 14,500 ft/sec. The seismic velocity appears to increase with an increase in deformation of the rocks."

Jan 1, 1966