Search Documents

By G. S. Headley

At the Sullivan Mine, recent experience with sulphide fires, locally referred to as " hot muck", has necessitated extensive modifications to pillar mining design and operating procedures. Potentially hot pillars are now being designed and mined to prevent fires. Unusual safety hazards and difficulties are encountered in working with, and adjacent. to, existing pillar fires. Operating procedures developed for these conditions have proved successful for safe and continuing production. These changes have minimized the impact of hot ore on current operations and have promise for an improved future.

Jan 1, 1977

By D. G. Minnes

Many non-metallic minerals and structural materials are produced in Ontario to serve the needs of domestic manufacturers and export markets. In 1982 production was estimated to have a value of $765 million. Approximately 81 per cent of this was represented by structural materials, nearly 12.8 per cent by salt, and the remainder was other industrial minerals. Total mineral production in Ontario in 1982 was estimated at $3 .16 billion, down nearly $1.5 billion from 1980's high of $4.58 billion.

Jan 1, 1984

By Greg Barnes

Agenda ? The Mining Stock Life Cycle ? Current Environment ? Valuation ? Golds ? Valuation ? Base Metals ? Case Study ? Quebrada Blanca Hypogene Commodity Investment Cycle ? Macro-Economic Indicators ? LME Inventories ? watch the trend; rising inventories ? bad for prices, declining inventories good for prices ? OECD Leading Indicators ? PMIs ? Purchasing Manager Indices ? Industrial Production ? more important for metals consumption than GDP ? Housing Starts ? US, Europe ? Auto Sales ? All things China ? metal imports/exports; SHFE inventories; SRB stockpiling ? Seasonality ? it does play a role ? What is Chris Dutton (TDSI Quantitative Analyst) saying?

May 1, 2010

By Qing-Xun Low

Ni current collector has excellent electronic conductivity and mechanica, properties. However, nicke, cannot be used in H2S-containing syngas SOFCs due to sulfur poisoning and coking. Copper coated nicke, is prepared by electrochemica, deposition. XRD, SEM, and EDX techniques are used to characterize the samples. After high temperature treatment in syngas containing, the coated samples exhibit high resistance of coke formation and sulfur corrosion compared to pure nickel. Therefore, copper coated nicke, is a promising anode current collector for H2S-containing syngas SOFCs.

Jan 1, 2010

By Somchet Vongpaisal

This paper presents the R&D results on the development of a new knowledge-based system for predicting stope instability and associated unplanned dilution in deep underground mining operations. A new prototype was developed based on databases generated from 3D non-linear elasto-plastic finite element stress analysis, heuristic rules, and case histories. This prototype aims to assist mine operators to make decisions on strategic mine planning and feasibility in a quick and efficient manner thereby minimizing risk on ground failure and optimizing mining costs.

Jun 1, 2012

By Greg Gosson

These materials are provided for general information purposes only and do not constitute legal advice. Readers are advised to seek specific legal advice from their own counsel in relation to any decision or course of action contemplated. Outline ??What is meant by a ?current technical report? under NI 43-101? ??When is a current technical report required? ??Who makes the decision regarding whether a technical report is current? ??Examples of the types of information that make a technical report no longer current for securities filing purposes.

May 1, 2009

By R. A. May, P. J. Brooks, W. M. Smith

"Neill and Gunter Limited (NGL) has prepared a preliminary design and a cost estimate for a ferric chloride leach plant to recover copper, lead, zinc, and silver from a typical complex sulphide ore. This plant design is specifically intended to treat unconcentrated ground ore (flotation feed), but can be readily adapted to treat bulk concentrates. Samples of ground ore and bulk concentrate were obtained from Heath Steele Mines, Miramichi, New Brunswick, laboratory testing, and preliminary process flow sheet preparation was carried out by the Research and Productivity Council in Fredericton, New Brunswick. Approximately thirty drawings have been produced, including process and equipment flowsheets, process piping and instrumentation drawings, and preliminary general arrangements. Preliminary capital and operating cost estimates were prepared for a plant that would treat 1000 t/d of crushed and ground ore to produce about 30 000 tpy of zinc. Capital and operating cost estimates were also projected for plants up to 4000 t/d of processed ore. Recoveries of 99% for zinc, 98% for lead, and 96% for copper were achieved in laboratory tests on unconcentrated ore. These recoveries were higher than the overall recoveries obtained from bulk concentrate, yielding approximately 10% more revenue.A 1000 tonne per day plant was determined to have a low return on investment, however, depending on the size and type of mining operations employed and the FCL plant throughput. DCF-ROI projections of 20% to over 30% were calculated for 100% equity financed “green field” mine, mill and FCL plant operations of 2000 t/d and higher"

Jan 1, 1997

By E. Ghali

"Corrosion of support system components (e.g., bolts, mesh, plates) is a safety and economic concern in underground mines. This paper reports the results of a five-year study wherein corrosion coupons were installed at select locations in participating mines, recovered at regular intervals, analyzed for signs of corrosion, and tested to quantify loss in capacity. Complementary tests were conducted on recovered mesh and friction bolt specimens. The data provide insights into contributing factors for support systems corrosion, which aid in the selection of appropriate support strategies and reliable assessment of the useful life and need for rehabilitation of a support system.RÉSUMÉ La corrosion des composantes des systèmes de soutien (p. ex. boulons, grillages et plaques) est une préoccupation économique et de sécurité dans les mines souterraines. Cet article présente les résultats d’une étude de cinq ans pendant laquelle des coupons de corrosion ont été installés à des endroits spécifiques dans les mines participantes; ces coupons ont été retirés à des intervalles réguliers, analysés pour des signes de corrosion et mis à l’épreuve pour quantifier la perte de capacité. Des essais complémentaires ont été effectués sur les grillages récupérés et sur les échantillons de boulons d’ancrage. Les données aident à comprendre les facteurs qui contribuent à la corrosion des systèmes de soutien, ce qui est utile dans le choix de stratégies appropriées de soutien et pour une évaluation fiable de la durée de vie utile et du besoin de remise en état d’un système de soutien."

Jan 1, 2015

By Linda Hodgson

1. Introduction ?Northgate Minerals Corporation is a mid-tier gold and copper producer with mining operations, development projects and exploration properties in Canada and Australia. ?Kemess Mine is Northgate?s principal operation. Where in the world is Kemess? ?Kemess is located in north-central British Columbia,430 kilometres northwest of Prince George. ?The Kemess South complex consists of an open-pit mine, a 52,000 tonnes per day mill and various ancillary support facilities including maintenance shops and housing for Kemess' 340 full-time employees.

May 1, 2010

By G. J. Simandl, H. -L. Jacob, S. Paradis, G. Valiquette

"Nos travaux de terrain dans le Grenville, effectués dans le cadre d'un projet d'inventaire des gîtes de wollastonite, ont démontré qu'il existe un secteur exceptionnellement favorable à l’exploration pour la wollastonite. Ce secteur s'étend de la municipalité de Grenville jusqu'au pare du Mont-Tremblant (nord de St-Jovite). D'autres secteurs favorables a 'exploration pour la wollastonite ont été délimités dans les regions du Lac-Saint-Jean, de Shawinigan et de la Gatineau. Neuf categories litho-structurales de gites de wollastonite furent identifiées. L'importance d'un système ou vert pour la formation des gîtes de hautes teneurs fut établie. Un guide de prospection pour la wollastonite propre à la province tectonique de Grenville fut développé. Plusieurs des indices sont prometteurs et mériteraient des travaux de raise en valeur afin de determiner s'ils représentent une source de wollastonite exploitable à profit. Lac-Saint-Jean, Shawinigan and Gatineau areas. Deposits may be classified into nine categories depending on their relationship to intrusive rocks, discordant or concordant contacts with the host rocks, morphology, and major structural controls. Deposits consist mainly of wollastonite, calcite and clinopyroxene. They may contain one or several of the following minerals: feldspar, scapolite, quartz, titanite sulphides, zoisite, clinozoisite, garnet, idocrase and prehnite. Wollastonite content may reach over 70%. Some deposits are associated with graphite veins. Better understanding of the geology, combined with the proposed classification provides new exploration guide for wollastonite. Several deposits have grades of economic interest. Further work is needed to determine if any of these deposits can be exploited for profit."

Jan 1, 1990

By Frank Mucciardi, Zhongsen Yuan

A new heat transfer technology --- termed Thermopump technology has been developed. This technology originates from conventional heat pipe configurations but has now evolved into its own class of heat transfer units, which we refer to as `Thermopumps (TP)'. A key feature is that Thermopump technology can be applied to high temperature / high heat flux environments where conventional heat pipe technology fails. Moreover, when implemented in less demanding applications where heat pipes appear to operate, Thermopump units have been found to function more smoothly and reliably. This paper will introduce Thermopump technology and several applications of this technology in steelmaking and refining will also be discussed. In addition, this paper will focus on three classes of applications: 1) waterless, non-consumable, high efficiency Thermopump oxygen lance and/or burner for EAF's, 2) Thermopump ladle lance for the desulfurization process, and 3) Thermopump cooling panels for furnace walls and roofs. Facilities equipped with Thermopump technology are expected to he better than the current corresponding ones in terms of increasing productivity and energy efficiency while at the same time lowering operating costs.

Jan 1, 2004

"In response to needs created by intensive exploration and accelerating expansion of coal mining in the Western provinces, Canadian R & D on coal is progressively widening its scope. Principal interests continue to lie in coal geology, preparation and processing, carbonization, combustion and transportation, but much active work is also in progress with respect to mine environments, mined-land reclamation, and environmental consequences of coal mining, processing and use. Long-range 'basic' research, which characterized much of the R & D pattern in the fifties and early sixties and which was often no more than an attempt to prevent total extinction of a dying industry, has been somewhat de-emphasized, except insofar as it relates to 'safe' coal storage and to coal-based carbons (which are beginning to command attention as pollution control media).In this review, recent exploration, mine development and new preparation facilities are noted, and current R & D in transportation, processing, handling, carbonization and combustion is summarized. Reference is also made to investigations bearing on non-fuel uses of coal (notably as source-materials for carbons and agrobiological products)."

Jan 1, 1970

By E. Ghali, A. D. Bas

There is a lack of electrochemical studies of oxidized gold ores since the majority of previous studies were conducted with sulphidic gold ores. In this study, the influence of agitation and iron oxide minerals, i.e. magnetite, hematite, and maghemite on gold leaching was investigated by means of galvanic and passivation phenomena. Cyclic voltammetry studies of Roasted Gold Ore (RGO) in de-aerated electrolyte have shown one oxidation and one reduction reaction while three oxidation and one reduction peaks were observed with gold electrode. Galvanic coupling results by Zero Resistance Ammeter (ZRA) mode indicated that magnetite showed a negative effect on gold dissolution while maghemite and hematite showed a positive effect, relatively, as a result of higher galvanic corrosion rates. Generally, gold dissolution was found to increase in the initial 15 minutes. Increasing agitation speed from 100 to 400 rpm resulted in higher galvanic corrosion rates for RGO, magnetite, and maghemite electrodes, while 250 rpm was found to be optimum for hematite electrode. Passive products such as silver and iron-oxide were identified by XPS and SEM-EDS analysis, respectively.

Jan 1, 2015

By Benoît Valley

Optimization of the mining sequence in terms of economics (maximizing net present value) often leads to multi-front mining methods generating pillars. Significant resources are tied up in these pillars, but mining them is often challenging. In order to improve our understanding of rock mass behaviour while extracting these pillars, an extensive monitoring program has been designed and implemented at Vale?s Coleman mine (Sudbury, Canada). The program focuses on existing and new technologies that have potential for monitoring deformation and rock mass property changes. It includes both active and passive methods: gravimeters, multi-point borehole extensometers, fiber optic strain meters, fixed and portable three-component seismic arrays, borehole imaging and sonic logging, and, repeated LiDAR surveys. This paper reports results from an initial project phase, when only a small amount of mining has taken place. The goal was to test and compare technologies in order to assess their sensitivity, accuracy, repeatability and suitability for underground mining conditions. Value is gained by having a broad range of monitoring devices running side by side, enabling comparisons and benchmarking.

Jun 1, 2012

By S. Kelebek, E. Yalcin

"Diethylenetriamine (DETA) and/or triethylenetetramine (TETA) are reagents that can generally be categorized under ""flotation modifiers"". These polyamines are known to be effective for the deactivation/depression of pyrrhotite that is present in Canadian nickel-copper sulphide ores in large quantities. Recent bench scale testing on some of these complex ores indicated that chalcopyrite flotation can also be adversely affected under certain conditions involving polyamines, which may be taken to be an evidence of their specific affinity towards chalcopyrite. In general, DETA shows no significant depressant action on chalcopyrite while TETA's promotion of hydrophilicity for this mineral has been observed even in the presence of xanthate. This prompted an investigation on thermodynamic equilibria involving these polyamines and copper ions. Results serve a useful purpose to identify conditions for deactivation phenomena. CuDETA2+ and CuTETA2+ chelates as products of sequestration have large predominance areas covering a wide range of redox and pH conditions, where copper xanthate species are not stable, especially in the presence of TETA."

Jan 1, 2009

By T. Yeomans

NVI Mining’s Myra Falls operation is a forty-year-old underground mining operation feeding a 4,000 metric tonnes per day concentrator. The current mill, built in 1985, was designed to process a massive sulphide ore-body. This orebody, known as the HW, contains about 50% pyrite. Minerals of value are chalcopyrite and sphalerite, with precious metals occurring in all mineral types. By 1997, mining of a new ore-body, known as Battle-Gap, commenced. Mineralogically complex, the new orebody contains about 15% pyrite copper minerals, including primary chalcopyrite and secondary bornite, chalcocite and tennantite, combined with increased galena and sphalerite. Flotation performance generally decreased with increasing amounts of Battle-Gap ore types, with both copper concentrate quality (increased lead and zinc content) and copper recoveries being affected. Following significant metallurgical test-work, a new, fully sequential copper-lead-zinc flotation flow sheet and reagent scheme was developed. This sequential flow sheet was progressively installed and commissioned during 2006. Copper concentrate lead and zinc smelter penalty contents have been reduced by some 40%, while increasing copper recovery by 10%.

Jan 1, 2009

By James R. Yeager, Eric L. Hoffman, John R. Clark

"Abstract -This paper describes fire assaying and ‘high tech’ alternatives for gold analysis, including advantages and disadvantages of each method. These ‘high tech’ methods include INAA (instrumental neutron activation), aqua regia digestion/AA (atomic absorption), GFAA (graphite furnaceatomic absorption) or ICP/MS (inductively coupled plasma emission mass spectrometry) and a combination of cyanidation with AA, GFAA or ICP/MS methods.Fire assay remains the stalwart among analytical methods for gold but, even with its multiple analytical finishes, is not fool-proof for recovering 100% of the gold present. Consumers of assays should not blindly trust the assay results without consideration of quality control data. Laboratories can and do make mistakes. Some of these can be easily discovered if you do your own due diligence. All these measures should ensure that gold analysis values from successive campaigns and from different laboratories meet acceptable levels of accuracy and precision, and can be correlated together, particularly when they occur in neighboring holes. This is essential just as much for prospect evaluation as for project feasibility."

Jan 1, 1998

By M. Gangal, M. Grenier, D. Mchaina, S. Hardcastle

"Exposure to airborne respirable silica in surface and underground mine operations is known to be the cause of industrial lung diseases. For this reason, silica is a regulated substance and worker exposure must be monitored regularly. Diesel exhaust also contains substances which are potential caricinogens. In an underground setting, diesel particulate may be the main component of what is referred to as respirable combustible dust (ReD). Although diesel particulate or soot is not at present a rigorously regulated substance, new epidemiological data is prompting North American institutes and agencies to regulate diesel soot or RCD exposure. This paper describes a method where by silicaand RCD exposure may be determined using a single personal sample. In this method, an airborne respirable dust sample is obtained and analyzed nondestructively for silica components using an on-filter X-ray diffraction method. Filters are then ashed at 500°C in a muffle furnace over a four-hour period to determine mass loss due to RCD burning. Using on-filter X-ray diffraction analysis as opposed to redeposition of dust samples onto another analytical substrate allows the"

Jan 1, 1992

By Cosmin Carpinisan, Erich J. Hofmann, Stephen J. Hall

"Since presenting a technical paper regarding their unique capabilities in Forged Steel Mill Gearing at the SAG-2006 Conference, Australian heavy engineering company Hofmann Engineering has pioneered a number of new manufacturing processes and design concepts for components of large comminution equipment. These include: 1. Novel design improvements for HPGR Rolls with forged steel tyres and a unique patented tungsten carbide insert designed to improve wear life, enhance autogenous layer build-up, and to reduce breakage & chipping under load. 2. Development of forged fabricated Mill Heads using rolled & welded high-tensile steel plate as alternatives to cast conical mill heads. 3. Insitu Girth Gear measurements for profile and wear via portable 6-axis CMM. 4. Gear and Pinion designs to AGMA-6114 for SAG mills of 38’-40’ diameter to 24MW and for Ball Mills of 26’ diameter to 18MW. The paper presents case studies from the Australian heavy manufacturing facilities of Hofmann Engineering, combined with news of their new gear manufacturing and gearbox overhaul facility in Canada."

Jan 1, 2012

By R. H. Wallis

Weighted moving-average contour maps have been constructed for molybdenum, copper and zinc using 7850 stream-sediment samples from 5430 square miles (14,063 sq. kms) of south-central British Columbia. Regional trends for molybdenum and zinc are northeast, north and northwest and those for copper are north and northwest. These trends are interrupted by zones markedly low in metals . The metal-rich trends cross rocks of different lithology and age and thus appear to be structurally controlled. The northeast trend may have exerted control on metal distribution at two different times.

Jan 1, 1978