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By Junior Santos

Kinross Paracatu started the operation of the new gold processing plant in the end of 2008, being composed by one SAG mill and two ball mills. During the first year of operation the plant had several problems related to stability and throughput capacity, mainly due to low grinding efficiency of the ball mills. In this period many actions were taken to maximize the throughput rate. Among the actions are reducing the size of balls in the mills, increasing the ball charge in the SAG mill, changing cyclone configuration and return of circulating load to SAG mill. With better stability of the circuit, the second stage of improvements has begun with the objective of increasing throughput rate and also reducing operation costs. Among the actions are the optimization of ball charge in the mills and a better operational control of cyclone parts. After two years of operation was obtained a significant increase in plant capacity, but still requires the addition of a third ball mill in order to maximize the use of SAG mill, which has spare capacity.

Jan 1, 2012

By Paul D. Merica

This year of 1926 marks the 40th. anniversary of nickel mining in Canada. Although the first nickel mine of the Sudbury basin was discovered in 1883, it was not until 1886 that the Canadian Copper Company was organized and actually began to mine copper-nickel ore from the Lady McDonald, Stobie and Evans mines. The intervening years have witnessed some exceedingly interesting nickel history, particularly interesting and gratifying as well to Canadians. Forty years ago, at the inception of Canadian nickel mining, the world's consumption of that metal was about 1000 tons per annum and this was supplied largely from New Caledonia ores refined in France. This nickel was used principally for the production of nickel-silver, coinage alloys, and for nickel-plating. No processes were then known for refining the Sudbury ores nor for the separation of copper from nickel. Consequently, the pioneers in Canadian nickel mining faced the double problem of finding a method of treating their ores, and of finding a market for the nickel when and if they could extract it.

Jan 1, 1926

By Dolea Gabriel Gheorghe

In the present paperwork is proposed an economical-mathematical model (fuzzy) that aims optimize the technological variants of the mechanized coal face. By fuzzification, the issues to solve become more flexible and allow the decision maker to acquire more variants for the functions objectively established. The description of technological solutions is carried out by a set of controllable variables of "category" type by which the type of the machinery is defined within the frame of the actual geological & mining conditions. In the paperwork are used concepts of "successions graph" and "matrix of compatibilities"; with their help a methodology to choose between different technological variants of coalfaces is proposed. It treats the problem of developing the functions that express the membership degree in vague concept. In the end it is presented an assessment procedure for the technological variants of mechanized coal face.

Oct 1, 2009

By L. M. Gould

"Syncrude Canada operates the largest oil sands crude oil production facility in the world and produces over 13% of Canada’s total oil requirements. To achieve this, Syncrude mines the oil sands in open pits, extracts the raw oil known as bitumen from the sand using water-based processes and upgrades it into sweet light crude oil by fluid coking, hydroprocessing, hydrotreating and reblending. The final product, Syncrude Sweet Blend (SSB), is sent by pipeline to three Edmonton area refineries and then to pipeline terminals which ship the SSB to refineries in Canada and the United States.As parts of the Mildred Lake base mine reached their economic life, they were replaced with new facilities at the Aurora Satellite mine. Aurora is situated on Oilsand Leases 10, 12 and 34, 35 km northeast of the Mildred Lake facility (Fig. 1).In 2000, the first hydrotransport low-energy extraction production train started up at Aurora. A second production train is scheduled for start-up in 2003. Open pit mining at Aurora occurs using two hydraulic shovels, two cable shovels, and trucks ranging from 320-ton to 380-ton payload capacities (Fig. 2).Once the oil sands is excavated, the trucks dump the ore into a crusher designed to break up the big lumps of oil sands and rock at peak rates of 11 000 t/hr. The ore is then transferred by conveyor to a surge pile and then to a mixing box which combines the oil sands with hot water. Following bitumen separation in the primary separation vessel, froth is delivered to Mildred Lake for processing via the intersite pipeline (Fig. 3).The goal of this paper is to illustrate how high precision shovel GPS (HPGPS) is being used at the Aurora mine to aid in mine planning. This can be accomplished by first describing the function of the mine planning department, describing the Aurora orebody, and finally explaining how the HPGPS system functions and how it is employed at Aurora.The short range mine planning department ensures a steady supply of ore is delivered to the plant at the desired grade in a sequenced and economical manner. This is done by creating a mine plan that consists of shovel dig locations that require the shovels to mine in a specified area at a specified elevation."

Jan 1, 2002

By S. C. Tadolini, J. M. Goris, J. L. Gallagher

Cable supports offer several advantages over traditional secondary support methods by enhancing stress redistribution to pillars and gob areas, minimizing or eliminating timbers and cribs that reduce ventilation, eradicating material-handling injuries related to placement of crib supports, and providing a cost-effective alternative to secondary support. The U.S. Bureau of Mines (USBM), researching alternatives to traditional roof support methods, designed and installed high-strength cable supports to improve the stability of longwall gate road entries in a western U.S. coal mine. With the cooperation of industry, methods were developed to install and evaluate cable supports in a tailgate area using traditional resin cartridges. The cable-bolted areas successfully maintained roof support throughout the developed entries. Cable supports have replaced wood cribbing as secondary support in the bleeder entry system and have minimized or eliminated the use of cribbing in the longwall tailgate entries. This paper describes the theory, application, and advantages of cable supports and presents some mine measurements made to assess the cable performance during the retreat process of longwall mining.

Jan 1, 1999

By D. P. R. Smyth

The limestone reef reservoir at Swan Hills consists essentially of a "buildup" of successively smaller atoll-like layers. Precipitation of calcium carbonate within the lagoonal area of each layer essentially kept pace with growth of the outer organic lattice. Within the reef mass, six de-positional environments characterized by specific suites of fossils (or fossil fragments) and associated limestone textures are recognized as follows: ( 1) Aerated moderately agitated water of normal marine salinity (widespread shelf or submerged reef-built platform). Thamnopora-type corals, Amphipora, "pancake" stroma-toporoids, crinoids, articulate bra-chiopods, rare rugose cup corals, and ostracods occurs in light gray-buff skeletal microgranular limestone of low permeability. (2) Semi-stagnant quiet water of normal marine salinity (leeward side of reef). Crinoids, articulate brachio-pods, rare thamnopora-type corals, Amphipora, pancake and bulbous stromatoporoids, rugose cup corals, ostracods and gastropods occur in impermeable dark brown argillaceous skeletal calcilutite with thin black bituminous shale beds and rare dark chert nodules.

Jan 1, 1961

By A. P. E. Dirige

Extensive field study has been performed to assess the capabilities of thin sprayon liners (TSLs) and conventional spray-on support systems for preventing rock and support material damage that often results due to mining-induced rockbursts. Support performance was studied using field scale explosive detonation trials to simulate dynamic failure effects that are known to develop during typical rockburst events. Multiple seismic and high speed photographic monitoring techniques were used to provide detailed information concerning rock motion, surface fracturing, ejected fragment motion, and support liner survivability characteristics. Results of this study have demonstrated that TSL?s and variant layer combinations may be as effective as or better than conventional support materials for mitigating rockburst or like damage in highly stressed mine environments. In this study, field results have been verified using numerical modeling procedures to better understand the support behaviour of TSLs when subjected to highly stressed mine environments and mining-induced rockbursts, a factor that is essential when designing any rock support system. A series of numerical modeling assessments were conducted using FLAC3D modeling of a half circular TSL-lined tunnel, influenced by anisotropic stresses and simulated mining-induced rockbursts, to investigate the support potential of TSLs under prototype conditions. The effect of a mine rockburst was simulated using the three-dimensional dynamic analysis option of FLAC3D. Results of TSL-lined tunnels in highly stressed and mine rockburst conditions indicated exceptional effectiveness of TSLs for suppressing rock deterioration resulting from stresses and rockbursts. The rock support potential of TSLs on tunnel surfaces was compared with that of thin shotcrete linings, and results indicated that thin spray-on lining products currently available may be equally as effective in support as shotcrete materials.

May 1, 2009

By Rita Michael

"The Marmara Ironworks was not the earliest ironworks in Ontario, but it was distinguished from other early works in a number of ways. It was established on an ambitious scale as a self-sufficient and, for the time, sophisticated community. In effect it was an iron plantation on the scale and scope of those at Hopewell, Pennsylvania and Saugus, Massachusetts(1). It was, besides, the only one of the few early ironworks in Upper Canada which operated almost to the end of the nineteenth century, albeit in fits and starts, and which used magnetic ores rather than bog iron ores (limonite). Furthermore it is the only works which has produced archaeological interest over a number of years. The ironworks is on the east bank of the Crowe River near Highway 7, on Lots 7 and 8, Concession 4, Marmara Township, Hastings County, Ontario. It is the property of the Village of Marmara, and the extant remains encompass about 2. 5 acres of the original 2000 or so which made up the original grant. The mineral riches of the Canadian Shield had been known since the days of the Jesuit missionary-explorers. A consortium headed by Alexander Henry and the Duke of Gloucester planned to exploit the copper near Sault Ste. Marie during the last part of the eighteenth century, but nothing came of the venture(2). This attempt may have grown out of Lord Dorchester's suggestion that private enterprise be encouraged in order that the iron ore which ""abounds"" in Canada might be exploited(3). John Graves Simcoe, the first Lieutenant Governor of Upper Canada was also anxious to see iron working develop. Simcoe was eager to encourage many enterprises, among which ""the development of iron mines""(4) - Governor Gore had been approached by John Mason for help with his ironworks in Norfolk County (5). Three Americans had applied for permission and support to erect an ironworks on the Gananoque River at the falls to become known as Furnace Falls. They were granted 1000 acres of land in fee simple to encourage their endeavor(6). Sir Peregrine Maitland, only a few months after taking up his duties as Lieutenant Governor in 1818, intended to visit the ""bed of iron ore on the Crow River"" (7) - Maitland was to provide a good deal of support, both moral and substantive, to Charles Hayes when he came to Canada in 1820."

Jan 1, 1999

By James A. Robertson

"The Pronto Mine located at the east end of Lake Lauzon, Long Township, some 12 miles east of Blind River is of historic note being the discovery locality and the first producing mine of the Elliot Lake uranium camp. Radioactive bedrock was discovered in 1949, a commercial deposit was verified in 1953 and production commenced in 1955. Production continued to April 1960: total tons milled 2,264,404 from which 4,643,835 pounds U,O, were recovered at a recovered grade of 2.05 pounds U3O8 per short ton.The orebody is in a bed of pyritic quartz pebble conglomerate at the base of the Matinenda Formation of the Elliot Lake Group of the Huronian Supergroup. The rocks strike east and dip 15 degrees to 20 degrees south and unconformably overlie Early Precambrian granite, the upper surface of which is marked by a regolith. Several diabase dykes cut the orebody which is also affected by albite, chlorite, and carbonate-rich alterations. To the south the orebody is cut by a fault. The orebody is 6to 10 feet but locally 10 to 15 feet thick, has a strike length of 3,500 feet and extends down dip for 3,600 feet to a depth of 1,000feet. Some 300,000 tons of ore grade mineralization remain in the deeper portion of the mine.IntroductionThe Pronto Mine, (Photo I) at the east end of Lake Lauzon in Long Township some 12 miles east of Blind River, is of particular interest as being the discovery site and the first producing mine of the Elliot Lake camp.Production at the Pronto Mine commenced in 1955 and continued until 1960 when the mill was converted to treat copper ore from the nearby Pater Mine at Spragge. A description of both mines, based on material provided by the mine staff, was given in the report on ""Geology of the Spragge Area"" (Robertson, 1970).As little study has been done on Pronto geology or petrology since mine closure, the earlier description of exploration and geology is essentially repeated, but shortened, here- the main change being that the stratigraphic terminology has been amended as recommended by the Federal-Provincial Committee on Huronian Stratigraphy (Robertson et al., 1969)."

Jan 1, 1986

By Peter Dunn

London Mining Plc. is developing an iron ore project in Sierra Leone. The Marampa mine is a brownfield development effort, having been operated by others since the 1930?s until low iron ore prices forced closure. Peak production of the prior operations was approximately 2.5 Mt/a in the 1960?s. Following civil war In Sierra Leone, London Mining obtained the mining license in 2006 and commenced activity to redevelop the Marampa mining and processing operations. There are two ore deposits of interest for development as well as a resource comprised of tailings from previous operations. Phase 1 will be the mining of the tailings resource with a 1.8 Mt/a plant producing 66 per cent Fe sinter feed, expandable to 3.6 Mtpa. The first phase is currently under construction with start-up expected in the third quarter of 2011. Phase 2 will include development of the two ore deposits. These deposits are weathered secondary ore and the main primary ore resource. Phase 2 is currently under prefeasibility study and targets a final 16 Mt/a concentrate production in 2016. Outotec partnered with London Mining on testing efforts to develop the magnetic separation flowsheet using SLon VPHGMS machines to process the Marampa material. This paper explains the flowsheet development process for the weathered and primary ores commencing with sample characterization and detailed parametric investigations to evaluate SLon performance. The final flowsheet configuration is explained, including expected circuit recoveries and concentrate quality, clearly demonstrating the performance of the SLon VPHGMS circuit in iron ore tailings treatment applications.

May 1, 2011

By André van Wageningen

Long-term mine scheduling is one of the most difficult optimization problems. The problem is said to be NP-complete in that the best possible solution cannot be found any quicker than checking all possible permutations and combinations. Although a number of techniques have been used in the past, many include significant simplifications or fail to produce acceptable results within the required timeframe. Genetic Algorithms (GAs) are among the most promising optimisation techniques within operations research. They are based on natural selection and evolution of solutions to complex problems. They have been known to quickly converge within a few percent of the optimal solution by examining only a fraction of the solution search space. The GA itself contains very little problem specific information and as such, has been linked to a discrete-event simulation (DES). The DES feeds information regarding the feasibility and quality of the solutions back to the GA during the optimisation process. In this paper, GAs and DES are described and the coupling of the two methods is outlined. The GA coupled DES is then used to ?optimise? a problem and the results are discussed.

May 1, 2004

"Under the term ""paleogeomorphology"" are grouped together all geo-morphological phenomena which are recognizable in subsurface geology. Since geomorphology is the science of the earth's relief features, paleogeomorphology is the science of buried relief features. Such features are of importance to the petroleum geologist whenever they lead to the trapping of hydrocarbons. In areas where these features abound -and western Canada certainly is such an area -pale-ogeomorphology ranks in importance with stratigraphy and structural geology as a hydrocarbon-finding tool. Hydrocarbons may be trapped either directly or indirectly due to paleogeomorphological processes. Both types of traps may occur either below the morphological surface or above (against) it. Several examples of types of paleogeomorphological traps are given. A new classification of geomorphological .features is proposed, with a subdivision into two main groups: constructive and destructive geomorphic processes. Of the many geomorphic classifications, some are of greater interest to the petroleum geologist in western -Canada than others. In the present paper the morphology of reefs and of buried erosional land forms are discussed in greater detail. In dealing with the reefs of the Devonian Leduc formation in Alberta, it is found that several groups of reefs can be distinguished and that each group presents a separate set of morphological characteristics. The effects of erosion and weathering are exemplified mostly in the Devonian, Mississippian and Jurassic of Alberta, Saskatchewan and Manitoba. Hydrocarbon traps occur below the highs on the erosional surface as well as in sands laid down in the lows of that surface. The rules which govern the formation of ancient landscape forms are worked out, using an area in southeastern Saskatchewan as an example."

Jan 1, 1960

By F. W. Gray

IN 1922, the writer communicated to the Institute a paper entitled The Development of the Coal Industry in Canada (1), which summarized the considerations set out in a series of papers (2) concerned with coal-mining in Canada which he had presented in 1920 and 1921. This paper contained a forecast by decades, commencing 1920, of Canadian coal production, importation, consumption, and exports, based on anticipated rate of population increase, and continuation of the gradual increase in the per capita rate of coal consumption in Canada that had taken place every year up to 1920. The following comparative statement brings our the differences between the forecast and actual experience:

Jan 1, 1936

By Adrian Rosen

When one thinks of innovation and leadership in wireless communications, one would rarely consider a potash mine to be leading the way. Agrium Incorporated has proven that they are leaders and innovators, as is evident in their recent deployment of a large-scale 802.11 wireless network in their underground potash mine located at Vanscoy, Saskatchewan. 802.11 is an IEEE standard for Wireless Local Area Network (WLAN) technology. Rather than simply replace an aging communications infrastructure, Agrium chose to let technology provide the framework for future success

May 1, 2006

By M. H. B. Nasseri

Barre granite?s samples have been tested for fracture toughness under mode I along two different directions with respect to microstructural fabrics were investigated. 3D objects counter algorithm technique is applied on micro CT images to identify physical properties such as crack induced porosity, crack density, generated total surface area and contribution of individual mineral grains within the damaged zone.The result obtained justifies very well the fracture toughness anisotropy in Barre granite, and explains the difference in the structure of the damage zone evolving as a result of test crack interacting with pre-existing microstructural fabrics. The present study has potential application in the fields of rock mass stability, oil reservoir stimulation, rock fragmentation and damage in blasting and emplacement of dykes.

May 1, 2009

By Deborah A. McCombe

"There are a number of important dates that must be disclosed when a Qualified Person (QP) is preparing a technical report for securities purposes. The dates are discussed in NI43-101 and the Form of the Technical Report, NI43-101F1. •,Effective date of the technical report •,Possible revision date of the report •,Effective date of mineral resources and mineral reserves •,Date of the personal inspection (site visit) •,Signature date of the date report (execution date) •,Date of the certificate of the QP •,Date of the consent of the QP The effective date of the report is basically the cut-off date for the information that is included in the technical report. The effective date should be close to the signature date. If there is too long a period between these dates, the QP runs the risk of new material information becoming available and then the technical report would no longer be current. The effective date is disclosed on the title page of the report and on the signature page. If a technical report needs to be revised to correct problems or disclosure deficiencies identified by the regulators, the QP will normally need to include a revision date on the title page of the report to distinguish the revised version from the original version. In these circumstances, the regulators will request that the original date of the report remain on the title page and the revised date will be below it. When a technical report must be revised, the QP must resign and date the signature page of the report and provide a new certificate and consent."

Jan 1, 2003

By Margarete Kalin

"Difficulties arise in implementing environmental technologies in the mining sector because important fundamental processes, which lead to the environmental degradation, are ignored. Weathering rates, the role of bacteria in the process and the incomplete application of the matching principle of accounting at the time the mining disturbance take place. Mining is a multi-stakeholder activity and the environmental problems have multivariate dimensions also effecting process.The limiting factors in the contaminant generation process are the transport of oxygen by advection, convection or diffusion in air or water and the associated microbial activity. Weathering products are transported from the mineral surface by atmospheric precipitation to surface and groundwater. This contamination takes place at different rates, requiring a long time to evaluate technological choices.Restoration efforts have to focus on slow reaction rates in the contaminant generating processes. Technology, which does not address the reaction rates and is selected based on inappropriate time scales, will not provide long-term solutions. Natural approaches to reduce acid generation, based on Ecological Engineering principles have required decades of research and field testing, but now show promise in addressing the cause of AMD and ameliorating its effects."

Jan 1, 2005

By Daven N. Compton

The optical properties of Au nanoparticles have been known for some time, with both Au colloids and Au nanoparticles embedded in glasses having been extensively studied. In this study, Pt nanoparticles have been incorporated into Au colloids, and the linear and non-linear optical properties investigated. UV-VIS spectrophotometry, fluorescence spectroscopy and the z-scan method have been used to examine the effects of such additions.

Oct 1, 2003

By D. C. Kaliampakos, A. G. Benardos

The existence of quarries near or even within the boundaries of urban centres is the cause of many environmental problems, despite their significant contribution to the cities’ development. Hence, the question arises as to how quarrying activities can be compromised within the spirit of sustainable development in big cities. In the case of Athens, two dominant, though opposite opinions have been formed. The first argues that all quarries must be forced to suspend their activities as soon as possible; the second presses for the continuation of quarrying. Consequently, the question is transposed on the dilemma between improved environmental conditions and economic development. This paper demonstrates that if a complete redesign is employed to specific, nonvisible quarrying sites, the continuation of quarrying activities is acceptable. It is a good compromise between the economical demand and environmental protection.

Jan 1, 2000

By Michael Samis

The real option valuation method is often presented as an alternative to the conventional discounted cash flow (DCF) approach because it is able to recognize additional project value due to the presence of management flexibility. However, these two valuation methods can be separated on a more fundamental level by their differences in risk discounting. Real option valuation applies the risk-adjustment to the source of uncertainty in the cash flow while the DCF method adjusts for risk at the aggregate level of net cash flow. This seemingly small difference is the reason why the real option method is able to differentiate between projects according to each project?s unique risk characteristics while the conventional DCF approach cannot. This paper provides an overview of the real options and DCF valuation frameworks and discusses the differences in risk discounting that exist between the two methods. Using grade-school mathematics, this paper clearly demonstrates how, with real options, a unique project risk discount can be calculated which is directly linked to the project?s unique risk profile. It also highlights why the DCF method fails in this regard and shows why a call to ?increase the Risk-Adjusted Discount Rate? is an incomplete solution at best. Finally, a heap-leach project and satellite reserve development project are valued with both techniques and the difference in investment conclusions is explained in terms of the risk-discounting concepts discussed here.

May 1, 2003