Search Documents

By V. N. Rampton, C. F. Gleeson

"Exploration results over three overburden drilling anomalies defined by the Ontario Geological Survey in 1981 in the Kirkland Lake area, Ontario are presented. The anomalies come from lowland areas where overburden is thickest. By mapping the bedrock and surficial geology, by prospecting, humus sampling and shallow till sampling over the surrounding upland surfaces, one can initially evaluate such overburden drill anomalies without costly reverse circulation drilling. The drilling should follow, if necessary, only after surficial base data has been obtained. Preliminary work on these three properties has defined the presence of at least two styles of gold mineralization. One occurs in silicified zones in intermediate volcanics closely associated with northwesterly trending faults and shear zones. The second occurs in quartz-carbonate alternation zones in volcanics intruded by quartz-feldspar porphyry dykes. IntroductionThe three examples presented in this paper present first-hand information on an approach to the follow up of several geochemical anomalies that were found by the Ontario Geological Survey when they carried out reverse circulation overburden drilling as part of the Kirkland Lake Initiative Program (KLIP) in 1980 (Routledge et al., 1981). The initial approach is relatively simple, systematic, and cost and technically effective. It readies the properties for further exploration, or conversely, it could downgrade the properties as viable gold targets."

Jan 1, 1987

Cobalt mostly occurs as a minor, but valuable, constituent in most nickel and a few copper ores, however it is not generally found alone in commercially viable deposits. Its concentration and extraction are therefore intimately linked to the recovery of the primary metals and the major task for the metallurgist is to extract cobalt of commercial grade from a much larger mass of either nickel or copper and sometimes both. With a particular focus on Vale Inco?s operations, this paper provides a brief overview of the mineralogy of the main deposits being currently exploited that contain cobalt as a co or by-product. The concentration and then extraction to metal are reviewed and some advances released into the public domain are discussed.

May 1, 2009

By Michael Li, Arie Moerman

"Paste backfill as a means of supporting underground mining is gaining popularity. Despite this trend, engineering and design of mine paste backfill systems are still largely based on empirical methods rather than established scientific principles. Because of a lack of sound understanding of mineral paste flow, some degree of trial and error is often involved during commissioning and operating of new paste fill systems. New operations often have to be built with flexibilities and contingencies, escalating the overall project costs.Disciplines that can lend some science to mineral paste flow include slurry transport, fresh concrete rheology, and soil mechanics. This paper reviews the applicability of some scientific and engineering principles found in those related disciplines to mineral paste flows. Examples are given to illustrate important points. The phenomenon of mineral paste flow is examined from new perspectives. Gaps in our understanding of mineral paste rheology are identified and from those some future research directions naturally emerge. Status and problems of the current engineering and design practice are also briefly discussed.INTRODUCTIONPaste backfill as a means of supporting underground mining is gaining popularity. Despite this trend, engineering and design of paste fill production and distribution systems today are still largely based on empirical methods rather than established science. One of the weaknesses of such empirical methods is the lack of scalability and transferability of rheological data from pre-engineering test phases to production phases. It is not uncommon that flow fiction data generated from expensive loop pumping tests turn out to be uncharacteristic of the paste in fullscale production. In such a case the operators have to re-climb the learning curve, sometimes with expensive disruptions to the mining operation."

Jan 1, 2002

By Ray Walton, Ron Colquhoun, Ken Thomas, Dwayne Fentie, Barney Burke

"The new Roasting Facility at Barrick’s Goldstrike Mine in Nevada, U.S.A. was developed to process 12,000 tons per day of refractory gold ore. The process consists of crushing, dry grinding, roasting, extensive gas purification, calcine quenching and leaching in the presence of activated carbon. The new plant is integrated into the existing Goldstrike facility, treating ore from both open pit and underground sources.The process design, procurement, construction and commissioning of the Roaster facility was performed successfully over a 3% year period with peaks of 400 engineering personnel and 950 construction personnel supporting the project. The US$330,000,000 project was completed ahead of schedule and under budget. The commissioning was well planned and proceeded smoothly through a rapid start-up to achieve all primary goals within three months of the start of processing of ore.BACKGROUNDAs early as 1992, Barrick’s Goldstrike Mine, located north of Carlin, Nevada had indications of the ore becoming ever increasingly carbonaceous in nature. As the open pit and underground exploration programs proceeded to step out over the years that followed, the accumulative amount of carbonaceous refractory ore and tons had become significant. By 1997, 29 million tons of double refractory carbonaceous ore containing an estimated 11.6 million ounces of gold had been identified. By 2000 the resource had increased to 14.3 million ounces."

Jan 1, 2001

By Rayleen Riske

Why do we look for better reconciliation when times get tough? Why wait? Mine reconciliation should be a priority throughout the good times too. In fact, with good reconciliation, those good times are going to be even better and will help pave the way to success through those preventable bad times. Reconciliation throughout the entire mining value chain requires the capture, validation, and analysis of copious amounts of data. This task can be daunting for a team in a small mine, let alone reconciling across a suite of large mines. This paper will outline the different ways we can reconcile across the value chain, why we should reconcile over differing periods of time and how Snowden?s solution to proving reconciliation can be a simpler, reliable and transparent process. Snowden?s Reconcilor is proving to be a valuable tool on any mining scale, by capturing, validating, sorting and reporting data for timely decision making by the site geologist through to corporate management. By instigating vigorous reconciliation, you are setting your mine up for the future. Not only will you have the means to analyse your current processes and measures, but you will have the opportunity to identify and improve your mine?s performance from the resource model through to the final product.

May 1, 2010

Westwood Quebec Long Life, Low Cost CONSTRUCTION UPDATE ? Shaft advanced to 840m (after 1 year), 3 km of down ramp and 2 km of exploration drift ? Head frame and hoist room structure completed ? 2009, 84,700m drilling program completed (increase 9%) 2010 OUTLOOK ? $102 million expenditures planned ? Shaft to advance to 1,300m and the first loading excavate 71,500m drilling program planned

May 1, 2010

By M. J. Fairweather

"The development of means to maximize the selectivity between galena and sphalerite in lead zinc ores is extremely important to the lead-zinc industry. Two challenging studies recently undertaken by Cominco will be reviewed. The first required an unusually fine grind to achieve liberation between galena and sphalerite. The second contained partially altered galena which resulted in unusual early activation of sphalerite under normal flotation conditions. Means by which lead and zinc separation were optimized in these two ores will be discussed.There are two important factors in the separation of minerals by froth flotation: particle size distribution (grind) and pulp chemistry. Pulp chemistry includes a number of factors including pH, Eh, collector type and concentration, inorganic depressants, organic depressants and activators.Grind is important for two reasons. A sufficiently fine grind is required to optimize liberation. However, if the mineral dissemination is too fine, mineral selectivity in the flotation process is impaired. Due to the hydrodynamic constraints of conventional mechanical flotation cells, flotation works best over the single decade size range between 10 and 100 microns. The majority of new ores treated by Cominco until relatively recently were comparatively simple. The major factor in their treatment was defining optimum grind size. Accordingly, the focus within mineral processing at Cominco was on grind and supporting liberation studies. The relationships between grind, liberation and flotation response are intuitively easy to understand. An idealized relationship is shown in the first figure."

Jan 1, 1991

By J. Don Scott

Analytical predictions of the rate and magnitude of settlement of deposited oil sands tailings slurries generally overestimate how fast pore pressures will dissipate. Field deposits of nonsegregating tailings to mature fine tailings show continued high pore pressures near the surface which impede surface reclamation. In geotechnical analyses which predict the consolidation behavior of soft soils a finite strain theory is used. Effective stress-void ratio and void ratio-hydraulic conductivity relationships determined from laboratory large strain consolidation tests, are used in the finite strain predictions. This theory, however, cannot predict the full range of sedimentation, consolidation and pore pressure dissipation which occurs in large scale deposits of thixotropic tailings slurries. A new large strain consolidation model which assumes that the creep rate of the slurry exceeds the pore pressure dissipation rate is being investigated. This model is relevant for rapidly deposited, low permeability thixotropic slurries where the upwards drainage path increases by several meters a year, such as, in oil sand fine tailings ponds and nonsegregating tailings deposits. The model will be verified by analyzing the 10m high column of fine tailings at the University of Alberta which has been monitored for over 20 years and in which the excess pore pressures are still very high.

May 1, 2004

By W. Pawlak, J. Janiak, C. Rodkiewicz, B. Ignasiak

"There is a general consensus that, in order to widen the utilization of Western Canadian coals, a major effort must be devoted to their transportation, utilization of fines, beneficiation and mining techniques. It is postulated that the concept studied extensively over the last four years at Alberta Research Council (ARC), and based on a combination of hydraulic mining, selective agglomeration with bitumen and/ or heavy oil, pipeline transportation and oil recovery from agglomerates, offers a particularly attractive solution to the problems associated with extraction, beneficiation, transportation and utilization of Western bituminous and subbituminous coals. Results of preliminary experimental work on the feasibility of pipeline agglomeration of metallurgical coal and hydraulic transportation of agglomerates are presented and discussed in the context of conventional agglomeration techniques in stirred tanks. IntroductionAlberta is endowed with enormous reserves of low-sulphur coals which could attract considerable attention of potential customers, but the remote location of this province handicaps its competitiveness on the world market. It is known that Alberta's Cretaceous, particularly metallurgical, coals differ significantly from their Carboniferous counterparts; current R&D work on indigenous coals should continue to expand in order to encourage overseas client s to use these coals more extensively.There is a genera l consensus that, in order to widen the utilization of Western coals, a major effort must be devoted to their transportation, utilization of fines, beneficiation and mining techniques."

Jan 1, 1986

By Ben Bradshaw

Context ? Community engagement has become an increasingly significant and challenging part of mineral exploration and mine development; indeed, opposition from communities proximate to a proposed mine site has been known to derail technologically- and financially-sound projects. ? These cases suggest that mining firms need to better understand how to engage constructively with local communities in the pursuit of their claims. ? While a range of publications exist promoting various community engagement strategies, these recommendations, when viewed as a whole, are disjointed and largely untested in real development contexts. Aims of Presentation 1. Synthesize industry, NGO, government and academic publications focused on community engagement best practice in order to highlight those practices that are most commonly recommended. 2. Review the (Canadian) mining industry?s experience with some of these strategies based on existing case material in order to identify the extent to which commonly prescribed strategies are used and validated in practice.

May 1, 2010

By Jason Rrno

The emergence of Impact and Benefit Agreements (IBAs) in the Canadian mining sector has been read by many as a positive governance innovation. Negotiated directly between mineral resource developers and Aboriginal communities with limited government interference, IBAs serve to manage impacts associated with a mining project and deliver tangible benefits to local communities. Notwithstanding their increasing use and significance, limited systematic analysis has been undertaken to determine whether they are, in fact, working. This paper reports on the effectiveness of a number of IBAs negotiated in support of three northern Canadian diamond mines, drawing on evidence from time-series data, key informant interviews, and focus group meetings in Yellowknife and Dettah, NWT, and Kugluktuk, NU. While some deficiencies were apparent and perceptions of effectiveness varied somewhat by Aboriginal community, the IBAs were generally found to be meeting their objectives, especially with respect to the delivery of benefits. For Aboriginal communities affected by mineral development in the Canadian North, this represents a significant change to typical outcomes of the past. Moving forward, research on IBA effectiveness needs to adopt a longer timeframe and begin to gauge the degree to which IBAs are able to address long-standing concerns associated with hinterland resource extraction beyond their agreement-specific objectives.

May 1, 2010

By G. Simard, M. J. Gagnon, A. Charette, G. Péloquin

"In the Bayer process, flocculants are introduced in the feed well to enhance the aggregation of red mud particles. To gain a better understanding of the flocculation process taking place in the feed well, shearinduced flocculation was achieved using concentric rotating cylinders (Couette system). Our previous work has shown the effect of the shear rate on the aggregate’s settling rate and on residual turbidity of the Bayer liquor. In this study, the data demonstrated that the aggregates at selected shear levels appear as a population with a widespread size distribution. By using an imagery apparatus, it was possible to measure the size, the shape, and the sedimentation velocity of the larger red mud aggregates. Marked differences were noticed in the characteristics of the aggregate populations obtained under various shear conditions. IntroductionIn the Bayer process, red mud particles are separated from the liquor in primary clarifiers and washing circuits under the action of synthetic polymers. The agitation in the feed pipe and in the feed well affects the flocculation since the aggregates are formed by the interaction between the red mud particles and the polymers. A minimum shear rate is needed to initiate the aggregation process of fine particles (Warren, 1975).Different systems have been used to study the effects of shear on the flocculation process (Tampo and Watanabe, 1979; Klimpel and Hogg, 1986; Scott et al., 1996; Biggs and Lant, 2000). The Couette flow system has been used in some studies on shear-flocculation (Oles, 1992; Farrow and Swift, 1996a, 1996b). The importance of the physical properties of the aggregates in determining the efficiency of the solid-liquid separation process within a given gravity thickener has been demonstrated (Farrow and Warren, 1989a)"

Jan 1, 2002

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 Mike Robotham

When RFQ?s are received they often contain detailed technical specifications which suggest a departure from the suppliers own customary approach to the design. Both client and end user are quite rightly influenced by their own experiences. The question is who is right, the client and his consultant, the supplier or perhaps a combination of these. This paper looks at some of the fundamental variances that often occur in the approach to the mechanical design of drum hoists, based on our experiences of recent years. Director of Engineering, Mike Robotham is a chartered engineer and has been with DavyMarkham for over 30 years. Having completed a craft apprenticeship he later joined the engineering department as a junior engineer. He has a wealth of experience of working on medium to large engineering projects in the field of mechanical, electrical and hydraulic equipment

May 1, 2011

By Barnard Foo

Topics of Discussion ?Location ?Production & Mining Operation ?Mineralization ?Mining Method ?Rock Mechanics Issues ?Ground Control Problems ?Numerical Analysis ?RockmassBehaviour ?Conclusions & Recommendations ?Discussion

Feb 1, 2008

By Andrea McGlynn

Iron Ore Company of Canada, Labrador City 2011?Canada's largest iron ore producer, leading global supplier of iron ore pellets and concentrates ?Rio Tinto (58.7%), Mitsubishi Corporation (26.2%), Labrador Iron Ore Royalty Income Fund (15.1%)

May 1, 2011

By S. R. Knowles, R. J. McDonough

"The purpose of this paper is to introduce to the minerals processing marketplace a viable alternative to conventional mechanical agitation and pachuca airlift agitation. What follows is a brief introduction to the Atara Corporation and the fundamentals of how an Atara ""cannon"" mixer operates. The main body of the paper is concerned with the results of a study to evaluate the cannon mixer for a gold cvanide leach application. A brief summary of research and testing for other metallurgical applications is also presented.1. 1 THE COMPANYThe Atara Corporation is a privately owned Canadian company, headquarted in Dorval, Quebec. Its subsidiary, Atara Incorporated, located in Paramus, New Jersey services the municipal wastewater treatment market in the United States. Dorval focuses on industrial mixing applications in Canada and the US. The Atara Corporation provides design, engineering and specifications of agitators for mineral land other) processing applications. Fabrication of mixers is pursued in either Canada or the US, depending on the ultimate destination.Although Atara and its unique static in-tank mixer are relative newcomers to the mining industry, the cannon mixer has demonstrated its value over the past 20 years in municipal wastewater treatment services. In the past four years the Atara unit has been developed for industrial applications; the bulk of the development work has been for metallurgical applications. To-date the cannon mixer has been evaluated for mixing slurries in the following applications: nickel-copper concentrate storage, copper concentrate storage, coal slurry storage, gold cyanide leaching, uranium acid leaching, silver leaching and zinc acid leaching. Atara mixers have been installed with successful performance in full scale tanks containing nickel-copper concentrate slurry (Falconbridge) and gold cyanide leach pulp (Dome"

Jan 1, 1984

By Kevin O?Callaghan

Applying Legal Concepts - The Crown must consult, and where necessary accommodate, when: - Crown has knowledge, real or constructive, of the potential existence of Aboriginal rights or title and contemplates conduct that might adversely affect it - Duty to consult is triggered at a low threshold - How much consultation necessary? - Proportional to the strength of claim and potential impact - Spectrum: notice to direct involvement in decision making - Not duty to agree or to get consent (no veto) - Reciprocal: Duty requires good faith and sincere engagement on both sides Role of Proponents: Crown may delegate procedural aspects of its legal duty

May 1, 2010

By J. Parreira

This paper presents a deterministic/stochastic model that was created to compare an autonomous haulage truck system to a manual one by calculating and estimating benchmarked Key Performance Indicators (KPIs) such as productivity, safety, breakdown frequencies, maintenance costs, labour costs, fuel consumption, tire wear, and haulage cycle times.

Aug 1, 2013

By M. L. Goble

"Inco Metals Ltd. (Manitoba Division) operates a mining, milling, smelting and refining complex, 500 miles north of Winnipeg in central Manitoba. The Thompson Mill is presently operating at 12,000 S.T.P.D. on ore from both underground and open pit mines. The ore is treated in two separate milling and flotation circuits utilizing a common crushing system which is located inside the main mill building. The milling facility employs approximately 43 operating employees, 30 maintenance employees and 20 staff in supervisory or process development roles.In recent years an increasing awareness of the potential hazards of contaminants in the work place has made it mandatory that all employers maintain careful and accurate records of the work environment to which each employee has been exposed during his working career.The importance of this record keeping and general observation of the work place cannot be over emphasized. Proper monitoring of the work place provides an accurate and complete record of the contaminants and physical agents to which an employee is exposed during his work career. This can aid in studies which might be conducted in the future and can also be used as a basis for instituting improvements to the workplace."

Jan 1, 1980