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By D. M. Hausen

"Refractoriness in Carlin-type gold ores results mostly from fine locking of gold in pyrite, locking in various gangue phases, notably quartz, and a ""preg robbing"" condition attributed to organic carbon. All three conditions may occur in any given deposit, including Newmont &apos;s Carlin and Gold Quarry deposits in Nevada, where types of ref ractoriness occur locally in minor amounts.Measurements of specific gravity, water absorption and screen size distributions of gold in alteration rock types from Gold Quarry show transitional changes from siliceous cherts through decreasingly silicified and increasingly argillized siltstones.Low permeability of siliceous ores contributes to ""size dependent"" refractoriness in cyanidation test work. Colligative physical and chemical measurements demonstrate that silicified cherty ores are difficult to grind, poorly permeable, and less amenable to cyanidation. Refractoriness in pad or column leaching of coarsely crushed siliceous siltstones and cherts is shown to correlate with interrelated measurable mineralogic and physical parameters.IntroductionMetallurgical treatment of variably amenable and refractory types of gold ore may be guided by both analytical and mineralogic data on the interlocking of gold (microscopic an d sub- microscopic) in assorted gangue/sulphide phases. Most oxidized ores from the Carlin gold mine, north of Carlin, Nevada, are amenable to direct cyanidation. The permeability of most oxidized ores from Carlin coupled with the fine size of the gold < 1.5 um) yields rapid extractions and high recovery without fine grinding.Small portions of the Carlin ore body, and also the nearby Maggie Creek and Gold Quarry orebodies, are less amenable to cyanidation, and are classified as refractory. Refractory conditions may be attributed mostly to the association or interlocking of gold with pyrite and /or microcrystalline quartz or chert, and also by the adsorption of leached gold by deleterious forms of carbon, termed ""preg-robbing"" carbon. Each of these conditions are described and defined, with emphasis on a form of silica-locking, which has been referred to as "" size dependent"" refractoriness."

Jan 1, 1985

By Seunghoon Lee

The increase in the number of higher and larger buildings is expected to require the buildings&apos; outer wall maintenance process, which includes cleaning, painting and monitoring, still depends on manpower. In this study, we proposed the robotic building maintenance system and aimed to reduce the jerk effect through the motion control of the system, improve the performance of the maintenance task, and ensure longer life and safety by improving the stability of the building structure and robot system. Through the results of the motion control and field-test with the proposed system, in specific, horizontal sliding module (HSM) showed that the jerk oriented by impact force was significantly reduced, feasibility of the proposed method was verified, and the robotic challenges were explored.

Aug 1, 2013

By C. J. Rockingham

"A comparative study of sulphide textures has been carried out on samples from four Archean copper-zinc massive base metal sulphide deposits: Kidd Creek, Ontario; Lake Dufault -Norbec, Quebec; Hood River-41, N. W. T.; and Geco, Ontario. These deposits have undergone metamorphic recrystallization under a range of conditions, and results of this study indicate that certain sulphide textures may be used as qualitative indicators of metamorphic grade, whereas other cannot.The sulphide textures of most value in this regard are sulphide grain sizes, which increase with increasing metamorphic grade, and the presence or absence of sedimentary/diagenetic textures, which are destroyed at the lower amphibolite facies of metamorphism. Chalcopyrite and pyrrhotite intergrowths in sphalerite increase in size, in degree of coalescence and in the ratio of unmixed pyrrhotite to chalcopyrite inclusions with increasing metamorphic rank. With increased metamorphic grade, the pyrrhotite intergrowths change from rounded inclusions on grain boundaries to rod-like shapes along sphalerite twin planes. There is also a general increase in the relative proportion of pyrrhotite in the deposits. Textures that appear to have little value as indicators of metamorphic grade are sulphide deformation textures, and triple junction point angles and their standard deviations, which show little variation from the lower greenschist to the upper amphibolite facies of metamorphism. The presence or absence of myrmekite-like magnetite also has little value in determining the relative metamorphic history of these deposits, as it is a product of local contact metamorphism."

Jan 1, 1980

By Shahé Shnorhokian

Numerical modeling is increasingly being used as a tool to examine complex geomechanical issues related to rockmass behaviour and stability of underground openings. The in-situ stress regime and the evolution of mining-induced stresses during the life of an operation, taking into account the planned stope sequence, are topics that can only be handled through the use of a realistic and calibrated numerical model. This paper presents a case study of a deep underground Canadian mine in northern Ontario. A FLAC3D model was constructed and calibrated based on in-situ stress measurements. In the first stage, the evolution of stress regime was studied and compared with the occurrence of rockburst events during a period of three years. The locations of clusters were examined and compared to the mining sequence during that period. In the second stage, stresses within a diminishing ore pillar were examined based on the planned stope sequence and compared to levels deemed acceptable to the mine. Based on the results, an alternative sequence was arrived at to reduce stress accumulation in the pillar, or induce it to occur at a further distance from a brittle dyke in the vicinity of the orebody.

Aug 1, 2013

Red Chris Project Project Status ? Tahltan, Iskut First Nations MOU ? Bankable Feasibility Study ? BC Environmental Assessment Certificate ? CEAA (Federal Environmental) ? EPCM contracts LOI?s ? US$110 million Project Debt Financing(credit approval pending) ? 1st5 years concentrate production sold ? 99,150 m of drilling in 371 holes First Nations Participation Agreement ?Advanced stage negotiations

May 1, 2006

INTINERARY ?What is SRI? ? How do we define good corporate social and environmental performance in the mining and petroleum industries? ? Why should you care? MJRA Inc. ? Established in 1992 ? Canadian Social Investment Database (CSID) launched in 1993 ? Jantzi Social Index launched in January 2000 ? created in 2000 SRI is ?the incorporation of social and environmental parameters into the investment decision making process.

May 1, 2002

By Patrick J. Williams

Defining Features of IOCGs ? Sulphur-poor Cu-Au(-Fe) deposits ? Contain low-Ti iron oxides ? Hydrothermal origin (breccia, vein, replacement) ? Local structural controls (no ?causitive? intrusions) Common Features (Economically-Significant Terranes) ? Regional space-time association with plutons ? Association with widely metasomatized crust ? Na ? Na-Ca ? K ? Variable enrichment in F, Co, Ba, LREE, U ? Little hydrothermal quartz (cf. porphyry deposits)

May 1, 2006

By Philippe Portella

Current Ownership : AREVA NC-France & affiliates (63.4%), ONAREM-Niger (36.6%)Related Mines : Ariège, Artois, Arlette(initial Somaïrlease) and Tamou, Taza, Takriza, Tamgak(SMTT lease)Mining Method : Open Pits Reserves : about 14 000 tU Average grade : 0.3 % UEnvironmental Management : Certified ISO 14001 since November 2002Key figures :2003 output : 1126 tU number of employees at year end : 565 Current Ownership : AREVA NC-France & affiliates (34%), ONAREM-Niger (31%), OURD-Japan (25%), ENUSA-Spain (10%) Related Mines : the Akouta mine provides access to several adjacent orebodies(Akola, Akouta, and coming Afasto with Ebba North / South)Mining Method : Underground ?mainly room & pillars Reserves : about 29 000 tU Average grade : 0.40 to 0.50 % U3O8Environmental Management : Certified ISO 14001 since January 2003Key figures :2003 output : 2017 tU number of employees at year end: 1070

May 1, 2006

By Paul Johnston

or is it? Mining Automated Loader Technology Application ? Intelligent software mounted in hardware on a remotely controlled scoop. ? Led by INCO, Sudbury, with ? C-CORE, St. John?s ? Automated Mining Systems, Aurora ? Bell Canada, Sudbury ? Laurentian University, Sudbury ? University of Western Ontario, London Completed: March 2000

May 1, 2008

By Stanley G. Butcher

Predictions of coal cleaning plant performance from the washability data are traditionally used at the conceptual design stage of a coal preparation plant to confirm process selection. The development of computer programs which simulate the operation of a plant facilitates the optimization of product yield and quality, and ultimately proceeds. It is shown that the optimum is sensitive to changes in mine operations and market price structure. A computerized review of operations is thus recommended as an on-going activity .

Jan 1, 1979

By M. P. Filion, K. Ferguson, L. L. Sirois

Acidic drainage is the largest single environmental problem facing the Canadian mining industry today. Technologies to prevent acidic drainage from occurring in wasterock piles and tailings sites, and on the walls of open pits and underground mines, need to be developed and demonstrated. There are two groups in Canada which have accepted this challenge: the national Mine Environment Neutral Drainage (MEND) program and the British Columbia Acid Mine Drainage (BCAMD) Task Force. This paper summarizes the activities of these two organizations.

Jan 1, 1990

?NWCC has the highest number of Aboriginal students of any post secondary institution in BC and the region served includes 25 bands ? Chair of the Board of Governors is Irene Seguin (Hagwiloo K?am Saxwhl Giis) from Gitwinksihlkw ? FN council ? 39 First Nations Members * focus is to develop policy recommendations to increase student success rates

May 1, 2009

Fatalities Incident Four people perished May 15 ? 17, 2006 ??Doug Erickson ??Bob Newcombe ??Kim Weitzel ??Shawn Currie Incident details available at: ??http://www.mediaroom.gov.bc.ca/sullivan_mine/ ??sullivan_mine.htm Outline Immediate facts/observations from incident ?? #1 Shaft Waste Dump closure program ?? Technical investigations under Panel guidance ?? Findings to date and direction ?? Broaden awareness of potential risks

May 1, 2008

By R. D. Studer

"The Snow Lake massive sulphide deposits are hosted by Aphebian volcanic rocks of the Flin Flon - Snow Lake greenstone belt, which in this area were deformed and metamorphosed to the amphibolite facies during the Hudsonian orogeny. All the known deposits occur in felsic rocks a short distance below the contact with an overlying mafic rock unit.The Stall Lake copper deposit occurs close to the top of an explosive felsic volcanic sequence. Rocks stratigraphically underlying the deposit have been hydrothermally altered by the mineralizing fluids. The sulphides were probably deposited from submarine volcanic vent(s) on the flanks of a felsic dome. The ore has been tightly folded, flattened and elongated parallel to the northerly trending lineation of the surrounding rocks during the several periods of deformation. Strike lengths of the lenses range from 60 to 300 feet and plunge-to-strike ratios are as much as 15:1.Ore lenses I to 4 typically consist of massive coarse-grained pyrrhotite, chalcopyrite and pyrite. A stratigraphically higher lens differs in that it contains fine-grained pyrite and chalcopyrite, with an increase in sphalerite toward its hanging wall. The No.4 orebody has a distinct footwall alteration zone characterized by brecciation and abundant chlorite-staurolite- garnet schist, with minor kyanite, anthophyllite, cordierite and anhydrite, as well as sulphide minerals. Chemically, the alteration zone is distinguished from the unaltered felsic rocks by Na20 depletion and Mg-Fe enrichment"

Jan 1, 1982

By Patrick J. Williams

Outline -An Australian View On: ?IOCG defining features and occurrence ?Variable exploration characteristics ?Extracting value (gold metallurgy) ?Recent exploration experience(case study)

Apr 1, 2005

By Doug Ashbury

Diamond Miners? Challenges ? Remote ? 300 kilometres from Yellowknife ? Sub-Arctic conditions ? permafrost, climate ? No power ? No all-weather roads ? Ore bodies difficult to find ? Caribou, fish of special concern ? Communities with low education, little experience, but high expectations ? Major investment required ? Diavik C$1.3 billion

Apr 1, 2005

By R. D. Studer

"The Snow Lake massive sulphide deposits are hosted by Aphebian volcanic rocks of the Flin Flon - Snow Lake greenstone belt, which in this area were deformed and metamorphosed to the amphibolite facies during the Hudsonian orogeny. All the known deposits occur in felsic rocks a short distance below the contact with an overlying mafic rock unit.The Stall Lake copper deposit occurs close to the top of an explosive felsic volcanic sequence. Rocks stratigraphically underlying the deposit have been hydrothermally altered by the mineralizing fluids. The sulphides were probably deposited from submarine volcanic vent(s) on the flanks of a felsic dome. The ore has been tightly folded, flattened and elongated parallel to the northerly trending lineation of the surrounding rocks during the several periods of deformation. Strike lengths of the lenses range from 60 to 300 feet and plunge-to-strike ratios are as much as 15:1.Ore lenses 1 to 4 typically consist of massive coarse-grained pyrrhotite, chalcopyrite and pyrite. A stratigraphically higher lens differs in that it contains fine-grained pyrite and chalcopyrite, with an increase in sphalerite toward its hanging wall. The No.4 orebody has a distinct footwall alteration zone characterized by brecciation and abundant chlorite-staurolite-garnet schist, with minor kyanite, anthophyllite, cordieriteand anhydrite, as well as sulphide minerals. Chemically, the alteration zone is distinguished from the unaltered felsic rocks by Na20 depletion and Mg-Fe enrichment.IntroductionThe Stall Lake copper deposit is located aproximately 4 miles southeast of Snow Lake in northern Manitoba (Fig. 1). The Snow Lake district has been a producer of gold (Rex, Bingo, Laguana and Nor-Acme Mines) and, since the fifties, of copper and zinc from deposits of Hudson Bay Mining & Smelting Co., Ltd . The district is located near the eastern limit of the Flin Flon - Snow Lake greenstone belt, which contains Amisk metavolcanic rocks of Aphebian age."

Jan 1, 1982

By Ken Wood, Luc Duval

"The development and operation of the milling circuits treating the different Selbaie orebodies are discussed in this paper. The project is reviewed from metallurgical evaluation through construction to present operating status. The current flowsheets are described, with discussion of some unusual features.IntroductionThe Selbaie concentrator commenced initial production in August 1981, treating underground B zone copper ore in a single 1500 t/d circuit. Throughput was increased to 1650 t/d in 1985. The mill was expanded in 1986 to treat ore from the A-I zone open pit; an independent circuit was added to selectively treat 5000 t/d of copper-zinc ore. Current total mill throughput through both circuits averages 7200 t/d with the production of approximately 270 t/d of copper concentrate and 230 t/d of zinc concentrate.This paper describes the stages involved in bringing the project from initial laboratory testing to its current status as one of the most important producers of silver, copper and zinc in Quebec and a major employer in the region."

Jan 1, 1990

By Holly L. O. Huyck

Disseminated hypogene sulphide mineralization in the Lakeshore porphyry copper deposit (also called the Cyprus-Casa Grande deposit) of Arizona occurs in both a granodiorite stock and associated volcanic rocks. Structural development and vein paragenesis at Lakeshore are similar to other Laramide porphyry copper deposits of the southwestern U.S. Two major structural trends are present: intrusive contacts, copper-bearing potassic alteration veins and major post-mineralization Basin-and-Range type faults trend N-NW, whereas phyllic veins and secondary post-mineralization faults trend N-NE, and deep propylitic veins trend NE-ENE. Lithologic permeabilities, caused by fracturing in all rocks and by grain size distributions in volcanic rocks, controlled the distribution of copper mineralization. Differences in chemical compositions of host rocks did not affect are grade. Structural control, through density of chalcopyrite-rich veins, was the major control of are grade. Fracture density of other potassic vein types did not strongly affect grade. Within volcanic lithologies, permeability, as indicated by grain size distribution, provided a second-order, but significant, control of mineralization.

Jan 1, 1990

By Richard Lavallée

La Mine Louvicourt est une mine hautement mécanisée exploitant un gisement polymétallique avec des chantiers transversaux minés et remblayés selon une séquence primaire-secondaire. Dans certaines parties du gisement, il n&apos;y avait qu&apos;un accès à la coupe inférieure, car il n&apos;était pas rentable d&apos;avoir aussi un accès par coupe supérieure. Le minerai situé au-dessus des chantiers avec trous ascendants était considéré comme ressource non rentable par minage mécanisé. L&apos;option de miner ces ressources avec des sous-niveaux avec accès par monterie alimak et forage long-trous de petit diamètre fût donc étudiée et démontra une rentabilité intéressante, particulièrement en considérant les tonnes ainsi minées comme tonnage supplémentaire au tonnage planifié. Dans ces chantiers, les détonateurs électroniques ont été très utiles et de plus, les coûts d&apos;explosifs ont étés réduits considérablement par l&apos;utilisation d&apos;émulsion pompée en vrac.

Oct 1, 2004