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By Don Thompson

Canada’s oil sands are a controversial topic and virtually every newsmaker and layperson seems to have an opinion about this 179 billion barrel resource. The oil sands represent 97 per cent of Canada’s remaining oil reserves, but misinterpretation and misrepresentation of the facts are threatening development of a resource that generates significant employment and tax revenue for Canadians. Join Don Thompson, president of the Oil Sands Developers Group, as he dispels the top ten myths about Canada’s oil sands and presents an alternative perspective on an industry that can play a critical role in North America’s economic recovery.

Jan 1, 2010

By J. A. Vallejos

Re-entry protocols are a tactical approach for controlling risk after blasts or large events in seismically active mines. Based on the results of a survey on 18 seismically active mines, mostly in Ontario, current re-entry practices are summarized. Over half of the mines in Ontario use event decay rate analysis as their primary re-entry decision making parameter. We study in detail the applicability of the Omori?s law as an equation for describing the event decay rate for more than 250 mining-induced aftershock sequences in seven different environments. Practical guidelines for the use of the Omori equation as a re-entry criterion are proposed.

May 1, 2009

By J. Paraszczak

For mining companies facing strong international competition and unfavourable commodities’ prices, automation of underground operations has the potential to increase productivity and help cut costs. However, despite considerable technological progress in this field, there still remain many problems to overcome. Furthermore, successful implementation of automation depends also on numerous operational, organizational, and even human factors. In this context, this paper briefly reviews technological progress with regard to different underground operations. Following that, several issues related to implementation of automated equipment and systems are presented and discussed. Particular emphasis is put on the factors whose importance is often underestimated. Some recommendations in this respect are also given. It is stated that the success of an automation project is a function of many “winning conditions,” which may be created through very thorough planning and preparation. It is also underlined that despite achievements made, a vision of a man-less underground mine is not yet as much a matter of near future as it may seem.

Jan 1, 2004

By Alfred Annor

Deep mining requires innovative approaches in ground control technology and the search for new ground support materials including backfill. There is a need to look at mine waste materials that may be available in deep mines to assess their suitability for use as composite backfill. Composite materials are widely used in all areas of engineering because of their unique and often superior structural properties compared to those of the singular constituent materials. Over the past few years, there has been a growing interest towards the investigation and use of various types of composite backfill materials as special applications fill in mines. A research project is being conducted at CANMET- Mining and Mineral Sciences Laboratories, Natural Resources Canada, to investigate the properties of potential ground support materials for use in deep mines. As part of this investigation, composite backfill materials were prepared by combining waste rock aggregates and mill tailings in various ratios, to determine their optimal mix proportions for strength development. A few cemented rockfill and straight tailings paste backfill samples were also prepared and were used as controls for the study. Two sample sizes were used for the investigation in order to evaluate the scale effects on the material behaviour. A set of samples were cured at 44 EC to simulate the anticipated temperature conditions in deep mines. A second set of samples were cured at 23 EC to provide engineering reference data. The test results show that compared to either the cemented rockfill or the straight tailings pastefill material, the composite backfill samples were the strongest and stiffest of all the test materials investigated in this study. The composite backfill samples also produced the lowest void ratio and porosity values compared to the cemented rockfill and the straight tailings backfill material. This paper will present the results of the laboratory investigations to date. It will also outline the on-going work at CANMET - Mining and Mineral Sciences Laboratories to further assess the ground support potential and viability of using composite fills in deep mines.

May 1, 2003

By B. Samanta

Abstract - Ore reserve estimation, based on sparse drill hole data, was conducted for a placer gold property in Nome, Alaska. A problem with sparse data is that random subdivision of the data into modelling and evaluation subsets (as is commonly done) becomes a problem, as random selection may result in biased/skewed subsets. Therefore, a technique that combined data segmentation with genetic algorithms (GA) was applied to divide the samples into three equivalent subsets: training, validation and testing. Data segmentation was done on the basis of the distribution of gold values. Neural network and a variety of kriging techniques were used to estimate gold grades. A multi-layer feed forward neural network along with "early/quick stop" training was used for neural network modelling. A comparative evaluation of kriging and neural network methods was then performed. The results revealed that neural network was generally superior to the kriging techniques for gold grade estimation in the Nome deposit.

Jan 1, 2002

By W. Yang, R. Rajasingam, K. Mohanarangam

"Copper Electrowinning (EW) is a complex electrochemical process that involves the production of LME grade copper from copper rich electrolyte. The process involves the deposition of the copper ions onto the cathode from copper rich electrolyte with the production of oxygen bubbles at the anode. The process setups up a complex flow pattern within the cell as it is subjected to varying density gradients due to the deposition process along with oxygen bubble driven flow. It is a necessity to understand and quantify the flow behaviour within these cells in order to maintain the production of highest grade copper. In fact, the oxygen bubbles originating from the process is responsible for the generation of acid mist which is a designated as a carcinogen a major health hazard around EW tank houses. Hydrodynamic assessment of the process has so far been restricted to simple mass balances and some limited numerical modelling. All the models are based on assumed boundary conditions which has not so far been verified by any real-time physical measurement. This apparent gap has led to models which could not be directly used to track process changes or troubleshoot problems in EW tank houses. In order to address this gap, CSIRO has established a full size (width and height) transparent cell capable of simulating plant operating conditions (across the range currently used). With the use of sophisticated diagnostic analytical tools and measurement techniques it was possible to study all the operating variables (current density, flow rate, temperature, etc.) independently and their effect of bubble size, bubble velocity, gas hold-up as well as acid mist generation and its size. In order to address safety concerns in tank houses around acid mist early results outlining the factors contributing to its generation as well as the effect of various barriers to mitigate acid mist is outlined below.INTRODUCTIONA significant part of today’s copper production is through hydrometallurgical route which predominantly involves leaching, Solvent eXtraction (SX) followed by ElectroWinning (EW). Producing copper using this approach have shown to be environmentally friendly (Dresher, 2001) compared to the traditional smelting process. EW is the final step in the production of LME grade copper using the hydrometallurgy route. The electro-chemical process involves the use of a lead anode (Pb-Sn-Ca) and a stainless steel cathode to produce copper sheets using the copper rich electrolyte from the SX process and with the applications of direct current to the electrodes. This electro-chemical reaction results in the deposition of copper ions on the cathode with oxygen released from the anode as a by-product. Hydrodynamically, the oxygen bubbles create a bubble driven flow within the EW tanks with the surrounding electrolyte. A direct result of this could be seen from the quality of the copper deposited on the cathode. Most of the copper plates produced from the traditional tank houses have a rough texture at its bottom one-third while the top two-thirds have a smooth finish with a finer grain structure."

Jan 1, 2016

By G. C. McKerrow

"Mr. G.C. McKerrow, Assistant Manager of Noranda Mines and formerly Smelter Superintendent attended the meeting to answer questions as to why smelters imposed penalties for too much zinc in a copper concentrate or too much copper in a zinc concentrate, etc.D.W. Bridges -Mattagami Lake MinesWhat limits do you set on zinc and lead in a copper concentrate?G.C. McKerrow - At Noranda, we allow 5% zinc free and charge 25 cents for every unit above that. For lead, it is 1% free and 25 cents per unit above that. Lead is a much more harmful impurity than zinc because it tends to recycle more in the smelter circuit and creates a greater health hazard in the plant.E. Thornton - Sullivan GroupWHat harm does fluorine do in the smelting process?G.C. McKerrow - Fluorine usually does not occur in harmful concentrations in non-ferrous smelters. Fluorides are present in exhaust gases in the aluminum and phosphate industries. If these fumes escape into the atmosphere, they may settle out on forage grasses in concentrations that are harmful to livestock.Thorton - Sullivan GroupI have asked this question other places and have been told that it is hard on brick linings and causes gold and silver to be lost up the stack.G.C. McKerrow - Almost any volatile constituent in a smelter charge will aid in carrying other metal values. To this extent it may be harmful.E. Thornton - Sullivan GroupMr. Tait mentioned before a smelter where they have a copper-tin ore and they pay for copper, tin, bismuth and silver but object strongly to indium in the concentrate. Why would this be?G.G. McKerrow - 1 can't see why indium would be a serious impurity. It does tend to concentrate in flu dusts and if you get enough of it you can recover it and sell it but I have never heard of anyone putting a penalty on it.Question - I once ran into a small copper mine in Peru that had cadmium in the copper concentrate but no zinc. The copper smelter charged a penalty for the cadmium. Why would this be?"

Jan 1, 1971

By J. Kan

In order to determine the recovery functions in an oil sand circuit it is necessary to have more than a minimal determination the mass flows in the network. This over-determination is essential in order to allow for measurements within the flow matrix "to flex" according to an error function. It is then possible to identify the flows and composition at all points with maximum likelihood. These so-called full mappings are not easily obtained. However, in order to obtain an unequivocal determination of all the unit operations recoveries such a balance is needed. When databases are constructed exclusively with coherently balanced sets of data it is possible to obtain a maximally accurate process model by maximizing the probability of correctly identifying the process causality. Indeed, it is doubtful in cases of normal complexity that any sense can be made of data that is not so balanced. Coherent mass energy balancing is a tool developed by mineral processing scientists and engineers. Its rigorous application to oil sands is the subject of this paper. The additional element associated with hydrocarbon requires special considerations. It is shown that at least one currently available mineral processing tool will solve the full-mapping problem for an oil sand operation. Experimental design constraints are discussed in this paper relating to the development of databases for the development of effective process models.

May 1, 2004

By J. Lazareck

"XPotential Products Inc. has developed technologies to convert auto shredder residues and other forms of plastic waste into useful products such as posts suitable for retaining walls and parking curbs. The technology is competitive provided low-cost plastic waste is available, and could have applications throughout the world. The paper describes the technology used and illustrates the various processing steps. Development of the TechnologyPresently, state-of-the-art auto shredding yields approximately 75% ferrous and non-ferrous metals and approximately 25% by weight of auto shredder residue (ASR). Advances in metal shredding and non-ferrous metal separation technologies turned XPotential Products Inc.’s attention to ASR as a potential revenue source, or at least a means to markedly reduce the cost of disposal. This abundance of nuisance ASR was, in the company’s view, a potential resource as derelict autos and white goods were similarly perceived 40 years ago. As owners of General Scrap & Car Shredder Ltd. in western Canada, XPotential faced significant disposal costs for four shredders. This journey began over 10 years ago and took many twists and turns until a final course of action was chosen. The recovery of the metallic portion of vehicles and white goods has reached technological maturity and attempts to add value are now achievable only in very small increments."

Jan 1, 2004

By W. G. Johnson

"As we move into 1983, Canada is not only in a deep recession, there are major changes taking place.International competition is growing fiercer.Major core industries such as automobile, steel, mining, oil, agriculture, forestry, fishing, major manufacturing and others are just not expanding.If and when recovery comes starting in mid-1983, as many predict, don't expect industries to suddenly resume former growth patterns. It's just not possible.Companies, by necessity, are becoming lean and mean, and they are still in the process of reducing staff to meet changing times and conditions. Many of the staff now being released may never return to fulltime work with a single employer, particularly if they cannot measure up to more exacting performance standards and management expectations.There are clear cut instances of people who lose a job for reasons beyond their control. A merger, the loss of function, or a major reorganization sometimes creates casualties of people who were excellent performers. Such people can survive well, based on the tongue of good report and with some help from associates or others. However, even good performers often have difficulty in adjusting to the rigors of finding a new job and to become their own personal salesman."

Jan 1, 1983

By R. W. Boyle

"PREFACEThis paper comprises two parts. The first part discusses lithochemical surveys based on major, minor and trace elements in whole-rock samples from primary enveloping halos. The second part continues with discussions of surveys based on leakage halos, zonation of elements, stable and radioactive isotopic distributions, geothermometric, geobarometric, thermolumin escent, pedochemical, hydrochemical, atmochemical and biogeochemical methods. A selected bibliography follows the second part of the paper.ABSTRACTAreal (two-dimensional) geochemical surveys, based mainly on secondary dispersion halos and trains in media such as surface waters, soils and drainage sediments, have proven particularly successful in recent years and have greatly assisted in the discovery of a large number of varied mineral deposits. Three-dimensional surveys based on primary halos and leakage halos have received relatively little attention by research organizations and the mineral industry. Such surveys offer many novel approaches for discovering blind mineral deposits deeply buried below overburden or within their host bedrocks. This paper reviews detailed methods for the discovery of blind mineral deposits based on sampling rocks (lithochemical methods), soils and other types of overburden (pedochemical methods), waters (hydrochemical methods), gases (atmochemical methods) and biological materials (biogeochemical methods) . All are applicable to the discovery of blind deposits; the efficacy of each or in combination depends essentially on the type of mineralization, the extent of the development of the primary and secondary dispersion halos, and the finances available for sampling techniques employing overburden drilling, bedrock drilling, and sophisticated water, gas and vegetation collection."

Jan 1, 1982

By R. W. Schutz

"Titanium possesses an exceptional and wide-range resistance to chlorides and their compounds when compared to most corrosion-resistant engineering alloys (CRAs) used in the chemical process industry. This natural resistance to chlorides stems from titanium’s protective, tenacious, and readily rehealable titanium oxide surface film, which is chemically stable over a wide range of pH and redox potentials in aqueous environments. This passive film explains titanium’s elevated resistance to anodic pitting, crevice and stress corrosion, and erosion-corrosion in aqueous chloride environments.Guidelines for successful selection and application of industrial titanium alloys are derived from an extensive laboratory test database and more than forty years of industrial/chemical service experience. These guidelines are simplified, and alloy corrosion performance is assessed with respect to four basic aqueous chloride service categories where selection or consideration of titanium is highly merited. An overview of historical titanium alloy applications in chloride-rich environments in a wide variety of process industries substantiates their exceptional chloride tolerance. These industrial titanium alloys are cost-competitive with stainless steels and nickel alloys, readily commercially available, and routinely fabricated and welded in the shop and field via well-established methods."

Jan 1, 2002

By R. W. Boyle

"EDITOR'S NOTEPart 1 of this paper, published in the August issue, covered lithochemical surveys based on major, minor and trace elements in whole-rock samples from primary enveloping halos.Part 2, which follows, continues with discussions of surveys based on leakage halos, zonation of elements, stable and radioactive isotopic distributions, and geothermometric, geobarometric, thermoluminiscent, pedochemical, hydro-chemical, atmochemical and biogeochemical methods. It concludes with a selected bibliography.Surveys Utilizing Leakage HalosLeakage halos can be used as scalar or vector quantities in thesearch for deeply buried blind mineral deposits. In the first case, the occurrence of a leakage halo (e.g. a small pitchblende seam) may simply indicate the possible presence of pitchblende mineralization or orebodies; in the second case, the areal or three-dimensional distribution of leakage halos may, by their increasing frequency and I or increasing metallic or gangue element content, provide a means of vectoring in on loci of mineralization and orebodies. Examples of both cases are given in the following text.Leakage halos are of many types, as shown in Figure 2 (Part 1), and are best discussed with respect to their associated mineral deposits. Furthermore, it should be noted that leakage halos are frequently offshoots or extensions of enveloping halos. Where this occurs, careful tracing of the leakage halo(s) downward or upward respectively will often lead to the apex or nadir (bottom) of the enveloping halo(s) and ultimately to mineralization or ore."

Jan 1, 1982

By D. Prince, G. Nollet

"Since 1994, Aur Ressources has operated Louvicourt mine, a zinc and copper mine close to Val d’Or, at a rate of 4300 t/d. Ever since the start-up of the plant, management has encouraged innovative approaches in reliability.The first of three papers will discuss the vibration monitoring program in place. The program will be described and two examples will be given: detection of a rolling bearing defect on a pinion driving the ball mill and identification of wear on the bearings of the flotation cells. Figures on the return on investment and the costs of a monitoring program will also be given.The second article will discuss the lubrication aspect. Since the establishment of a good monitoring and oil analyses, Louvicourt mine decreased its oil consumption by more than 38 000 L/yr. In addition, the company set up an oil regeneration system that restores the original properties of oil.The third article will cover the management aspect. Work organization as well as the management philosophy enabling the employees to push predictive technology to higher levels will be examined in detail. The key elements which made it possible for Louvicourt mine to position itself among world-class companies in the organization of maintenance will be discussed. IntroductionThis article is the second of three on predictive maintenance at the Louvicourt mine operated by Aur Resources Inc. The first article, published in the October 2002 issue, was about vibration analysis for rotating machines. This article describes how lubrication and oil analysis for stationary machines permitted Louvicourt to save more than $150,000 within two years and presents the evolution of the oil analysis program.Louvicourt mine, located near Val-d’Or, Quebec, is a copper and zinc mining and milling operation that processes 4300 t/d of ore and employs 289 people. Production began in 1994. Louvicourt mine is a partnership between Aur Ressources (30%), Teck Corp. (25%), and Novicourt (45%)."

Jan 1, 2003

By Dwight Newman

This paper discusses the author?s work identifying international law norms of consultation with indigenous communities and poses a potentially counterintuitive argument that corporate stakeholders? interactions with indigenous communities may have effects on the content of those norms. The claim is counterintuitive because the international law of pertinence is customary international law, which arises from consistent state practice and opinio juris (a belief by states that they are acting in a way they are legally bound to do so). Customary international law traditionally has no reference to corporate conduct per se. The paper first surveys several sources on developing international law on consultation obligations. Then it references the impact these norms can have on corporate stakeholders in industries like mining. Then, it poses an argument as to an economic ratcheting effect that can occur through various agreements between corporate stakeholders and indigenous communities that then feeds through into international law via several mechanisms. The consequences for mining companies are diverse and include the possibility that conduct by one company can have longer-term implications for the obligations of other companies and, indeed, of states. The effects will differ in the context of different competitive environments and may actually have effects on the economics of different competitive models.

Aug 1, 2013

By Jean-François Lessard

The performance of rock pass systems has a significant contribution to the economics of underground mines. Operational concerns include hang-ups due to arching of material, blockage and degradation of the rock pass. This papers presents the preliminary results of a comprehensive rock pass database on the engineering and operation of rock pass systems in Quebec underground mines.

May 1, 2002

By Larry M. Southwick

Extraction of gold and other metals from ores suspended in liquid slurries often involves gases (such as oxygen) as a participant in the reaction. An important factor then in setting the rate of extraction can be mass transfer of the gas into the liquid and/or solids. A number of recent studies have indicated that as solids loadings increase, mass transfer rates of gas into solid-liquid mixtures decreases. This would seem to imply that lower solids loadings would be beneficial to increased reaction rates. However, since it is the solids which are being reacted, a most intriguing paradox is created. More solids should lead to more surface area to react, but it seemingly also provides less gas to react. So is the reaction faster or slower as solids loadings increases? The creation of this paradox is imbedded in how mass transfer and reaction data is collected and measured, how it is analyzed and correlated, and finally on the rate controlling steps in the reaction. An alternative analysis of these studies is presented which clarifies and eliminates the paradox. The analysis applies to water slurries as used in gold or other metal leaching processes or in bio-hydrometallurgy, as well as to molten metal/solid/gas mixtures such as might be encountered in submerged gas injection.

Jan 1, 1999

By William Petruk, J. R. Schnarr

The behaviour of minerals during flotation of a fine-grained pyrite-rich base metal ore was investigated by studying the feeds. concentrate and tailings from every flotation cell in the mill of Brunswick Mining and Smelting Corp. Ltd. Bathurst. New Brunswick. The samples were analyzed for Zn, Pb, Cu. Fe, Ag. Sb, Sn, Bi, In. Hg, Mo and As. Mass balances were computed and recoveries of all metals from each cell. from each circuit and from the mill were calculated. The percentages of sphalerite. galena and chalcopyrite occurring as free grains in each product were determined with an image analyser, as were size analyses for free mineral grains and middling particles, and compared with screen analyses. The results show that the behaviour of minerals is defined much better by the recovery of free mineral grains than by the recovery of elements. The recovery of free sphalerite in the zinc circuit is 96 wt %, whereas Zn recovery from the same circuit is 88 wt %. the difference being due to unliberated sphalerite. The recovery of free sphalerite from the mill feed is 88 wt % and Zn 78 wt %. The recovery of free galenafrom the mill feed is 88 wt % and Pb 64 wt %. The recovery of free chalcopyrite is 75 wt % and Cu 45 wt %. Size analyses show that more sphalerite and chalcopyrite can be liberated by regrinding. but the galena is so fine grained that regrinding would not necessarily improve liberation. Silver occurs mainly in tetrahedrite and galena; the main loss in the tailings is due to large (+ 26 um) and small (-1 um} free and unliberated tetrahedrite grains.

Jan 1, 1981

By P. Cain, B. Martens

"Grande Cache Coal (GCC), an investor-owned Alberta company, is in the final stages of the regulatory process leading to the resumption of coal mining in the Smoky River Coal Field of Alberta. Although many opportunities for low-cost, high-yield mining remained on the property, GCC opted for a long-term production plan that ensures stability for the local economy, sustainable use of the resources in the area, environmental responsibility and a satisfactory return for its investors.GCC entered the Alberta coal approval process in late 2000 with a public disclosure document. In October 2001, GCC formally submitted an application for mining approval and an environmental impact assessment (EIA) to the government and the public. The application covered the proposed Grande Cache Coal project, which includes the No. 7 underground mine, No. 8 surface mine and coal processing operations. The EIA provided a comprehensive investigation of environmental sensitivities in the project area, matched with environmental protection programs. The project is based on commencement of operations in late 2002. GCC’s plans are founded on a commitment to sustainable development and has framed this commitment in the context of a long-range mine development plan that will sustain the community of Grande Cache over the next 25 years. The Grande Cache coalfields offer extensive coal reserves and opportunities, for both surface and underground mining. Combining highly productive U.S.-style room and- pillar underground mining methods and conventional truck-and-shovel open pit mining, GCC’s approach to sustainable development encompasses community involvement and reclamation of mine sites to productive land uses after mining."

Jan 1, 2002

By M. R. Henzinger, G. Lenz, A. Gaich, Pötsch, W. Schubert, P. Wagner

"The better the information on the rock mass and its fracture system, the better is the basis for any rock mechanical decision that is required during the excavation process. While in conventional tunnelling free view to the tunnel face is available, possibilities are limited for mechanised tunnelling using a tunnel boring machine (TBM). An approach, already formulated in 2005, is used that produces digital photographs through openings in the cutting wheel of a TBM and merges them into a circular three-dimensional image. The 3D image is then used for geometric rock mass characterisation purposes including geological mapping, for example to measure spatial orientations or determine joint spacing. In the paper the basic concept is described together with first results from a pilot test.INTRODUCTIONA three-dimensional image unites digital photographs with spatial information on the objects/surfaces it shows. Since they combine geometric and visual information they are a straightforward source for geometric rock mass analysis and geological mapping. Their obvious benefits among others are: (i) they allow spatial measurements even in inaccessible regions, (ii) they provide objective and reproducible records of the rock mass conditions, and (iii) they increase working safety (Gaich et al. 2004).Pre-requisite for the generation of 3D images is the acquisition of at least two photographs from the region of interest. From the photographs the imaged object surfaces are reconstructed by means of image analysis using methods from photogrammetry (Slama, 1980) and computer vision (Hartley & Zisserman, 2001). See also Figure 1."

Jan 1, 2015