Search Documents

By D. O. Downing

"The 1990s saw enormous changes in the Canadian coal industry and the future promises to be no less turbulent. While the markets served by Canadian coal producers have changed and buying practices continue to evolve, the coal mining, or supply side, has also changed remarkably in response and now provides the basis for an interesting industry story.The dynamic situation in coal mining has led to some surprising outcomes and seemingly contradictory developments. This paper outlines the changes that have occurred, and which are still unfolding in Canadian coal mining, firstly, in terms of mining technology and productivity, secondly, in terms of corporate divestments, acquisitions and bankruptcies, and finally, in terms of resource development. The paper also outlines some plausible futures for the industry looking ahead."

Jan 1, 2002

By C. C. Walden, A. Bruynesteyn

"Chemical and biological aspects of the formation of acidic effluents from sulfide waste materials are discussed. Test procedures to determine the acid producing potential of waste materials, as well as the characteristics of such acidic effluents, are presented. Practical applications of the test procedures are discussed with reference to predictior of environmentally unacceptable drainage and to estimation of metal recovery by dump leaching.INTRODUCTIONNatural leaching of sulfide minerals, exposed to the atmosphere, has been occurring for geological time. For centuries, man has been aware of the acid drainage originating from coal workings, copper mines and waste dumps. With the advent of the technical sciences, the processes involved in acid mine drainage production were considered to be solely chemical in nature. However, in 1947, it was shown (1) that a specific microorganism, called Thiobacillus ferrooxidans, was responsible for acid mine drainage from coal workings. It was demonstrated that under suitable conditions - this bacterium oxidized pyrite and marcosite in the coal to ferric sulfate and sulfuric acid. Numerous studies have subsequently demonstrated that - under suitable conditions - Thiobacillus ferrooxidans can attack most sulfide minerals, producing weak sulfuric acid, oxidizing ferrous to ferric iron and solubilizing other metals present (notably copper and zinc) as their sulfate salts."

Jan 1, 1980

By Z. D. Hora

Several deposits of crystalline magnesite are known in southeast British Columbia. Deposits at Cross River and Marysville have been thoroughly explored, but as yet there has been no commercial production.

Jan 1, 1984

By Gordon R. Peeling

The Problem Five years after the consensus of the Whitehorse Mining Initiative the industry was losing public confidence Public opinion surveys ranked mining just above the tobacco industry Project opportunities were being lost to public and political opposition Operating practices called into question by a number of tailings dam failures CBC broadcast of "The Ugly Canadian" Our social licence was being lost

May 1, 2013

By Z. D. Hora

Sev_eral dozen si lica occurrences have been reported from various parts of Brit ish Columbia. Some represent hydrothermal veins or parts of pegmatite bodies; other are recrystall ized sandstones. Several vein type deposits were mined for smelter flux and as a source of white chips for stucco dash and simi lar products. Some quartzites were studied as potential sources of high-grade silica for ferrosilicon and silicon metal production. The province's only production of silica for ferrosilicon has come from a pegmatitic quartz plug near Oliver in southern British Columbia. Its reserves are now practically depleted.

Jan 1, 1984

By Turcotte. Yves-Laurent

Notre conférencier, Monsieur Yves L. Turcotte, Vice-président et Directeur général chez Promaintech Novaxa est diplômé en génie industriel de l?Université du Québec à Trois-Rivières et détient une maîtrise en gestion de projets de l?Université du Québec à Montréal. Il est une véritable sommité canadienne dans le domaine de l?amélioration de la performance des organisations. Provenant d'entreprises manufacturières et de services, il possède plus de 20 ans d?expérience en tant que développeur de technologies, conseiller et formateur auprès d?entreprises. Il a à son actif la réalisation de mandats dans plus de 400 entreprises. Il est reconnu pour sa grande capacité d?analyse et pour trouver des solutions novatrices et profitables aux problèmes des organisations les plus complexes. Aujourd'hui, il dirige Promaintech Novaxa, une division de DMR, qui a célébré son dixième anniversaire en 2006. Cette organisation ayant des places d?affaires dans la région de Montréal, Québec et Vancouver compte plus de 50 professionnels et a une carte de visite dans 16 pays. Les axes d?intervention sont le Management, la Productivité, la Fiabilité, l?Innovation et l?Amélioration Continue.

Feb 1, 2008

By Dallas W. Davis

Twin - Kennecott Deal Announced April 15, 2004 ! Kennecott earns 56% interest, if in 4 years, spends C$10 million and recovers at least 200 cts of +1 mm diamonds in all dimensions from any contiguous body ! Earn-in can take up to 6 years, but incurs stepped reduction of interest from 56% to 46% or 0% if $C10 and 200 carats not achieved ! By funding all costs through feasibility study, Kennecott earns 71% in 7 years, or, stepped reduction to 62% if completed after 8 years ! By achieving production within 10 years and funding Twin?s share of development and construction costs, Kennecott earns further 4% ! If no election to develop a mine within 2 years of feasibility study completion, Twin may present development proposal which Kennecott has 60 days to elect to follow or transfer management to Twin and dilute to 49% ! Each party has one time right to elect to market its diamond share ! On signing and annually, Kennecott will purchase $C250,000 of Twin shares at 130% of then prevailing market price until achieved earn-in

May 1, 2004

By C. Carlson, W. Muir

"The oxygen demand of the complex lead-zinc-iron feed at the Cyuro Anvil concentrator was determined denendent on the cyanide ion con-contration of the pulp. By redistribution of the cyanide [ ] the grinding circuit in direct proportion to the amount of surface area created, a more activated flotation feed in obtained.Monitoring the oxygen demand of the flotation feed and grinding mill discharge has proved useful in diagnosing metallurgical problems day to day operation."

Jan 1, 1976

By David W. H. Ellis

This presentation will discuss over 2 dozen past, present and future oils sands projects in Alberta. The very early projects as well as the most recent along with the ones that never got off the ground and the ones in production are all included. For each, the following will be given (where known): owners, location, type (mining/SAGD/refinery), production, capital budget, spent to date, status. Some overall impacts will be discussed.

May 1, 2004

By C. D. Shackelford, J. F. Muñoz, M. Vauclin, P. Rengifo, A. Suazo

The results of a field-scale study involving in situ leaching of copper ore tailings using sulphuric acid as the leaching agent, injection wells to introduce the leaching solution and extraction wells to recover the copper-enriched pregnant leaching solution are presented. The study was performed at an abandoned tailings disposal site using a battery of injection and extraction wells. The medium was characterized through the determinations of physical, chemical, mineralogical, and hydro-dispersive properties based on laboratory and field tests, including a tritium tracer test, a pumping test, particle size analyses, and hydraulic conductivity tests. Numerous horizontal strata with different hydraulic conductivities were identified. A previously developed model was used to simulate the leaching of copper ore tailings. Although the study confirms the feasibility of using in situ leaching for recovery of residual copper from tailings deposits, the efficiency of the technology depends significantly on the medium stratigraphy and hydraulic conductivity.

Jan 1, 2001

By R. E. Jones

"INTRODUCTIONCominco Limited, one of the free world's largest producers of lead and zinc having majority ownership in Pine Point Mines Ltd., operates a mining and concentrating complex on the south shore of Great Slave Lake in the Northwest Territories. The mine was developed in 1963-64 and commenced operation late in 1964 with the direct shipping of high grade ore. The concentrator started production in November 1965 at a design throughput rate of 5,000 T.P.D.In 1968, the Company acquired the mining rights to a large ore body located to the east of the Pine Point claims and subsequently an expansion program at the concentrator raised the throughput rate to 8,000 T.P.D. The expansion included a third grinding circuit and additional flotation capacity. The flotation capacity took the form of a completely separate circuit from the existing flotation plant. In 1972, the zinc flotation circuits were modified to include two additional stages of cleaning. This change concluded the ""Pre-Consolidation Flotation"" circuit at Pine Point.In considering these modernization programs of the flotation section of the concentrator, the philosophy was to utilize the largest available machine having proven and modern technological changes. With the advent of the large capacity machines available in the late 1970's, it was considered a suitable time to revamp the entire flotation circuit at Pine Point in 1979. The Circuit Consolidation Project was developed to meet this requirement."

Jan 1, 1982

By Alan D. Akerman

This paper describes the significant advantages and improvements in operational availability, reduced breakdowns, and overall cost reductions that can be achieved through the application of a Reliability Centred Maintenance (RCM) program, including Condition Based Maintenance (CBM) and Equipment Health Monitoring (EHM), in a mine environment. It uses a case study to illustrate the essential elements that constitute the basic requirements to establish such programs. This CBM case study analyzed the Load-Haul- Dump (LHD) vehicle sub-systems and their dominant failure modes, as a precursor to the development of condition indicators. The case study describes a disciplined process to enable condition indicator development and qualification in support of a CBM program. The identified condition indicators vary from readily applicable off-the-shelf monitoring systems and techniques, through to "leading edge" technologies that require further research and development. The paper also explores the developments that have been made in the combination of expert system software associated with modern computer based control systems, and the availability of "intelligent? sensor technology that complement the control system capability.

May 1, 2002

By Bruno Bussière

Le drainage minier acide (DMA) provenant de la circulation des eaux à travers les rejets miniers sulfureux est sans doute le principal problème environnemental auquel est confrontée l?industrie minière. Afin de prévenir les problèmes environnementaux reliés au DMA, on doit restreindre la présence de l?une et/ou de l?autre des principales composantes menant à la production d?acide, soit l?eau, l?air et les sulfures. Pour ce faire, différentes techniques ont été proposées au cours des dernières années, dont la désulfuration environnementale et les couvertures avec effets de barrière capillaire (CEBC). Dans ce papier, on propose d?utiliser ces deux techniques en combinaison. Ainsi, on produirait un rejet désulfuré à l?usine de traitement qui pourrait, par la suite, être utilisé comme matériau pour la couche de rétention d?eau de la CEBC. Dans un premier temps, on présente les résultats d?une étude de laboratoire qui montre qu?il est possible de désulfurer les rejets de concentrateur à l?aide de la flottation non sélective jusqu?à l?obtention d?un résidu non générateur d?acide. Par la suite, des essais en colonne ont permis de démontrer qu?il est possible de limiter la production de DMA d?un résidu sulfureux à l?aide d?une CEBC dont la couche fine est constituée de résidus désulfurés. Des prédictions théoriques estiment même que la présence de sulfures résiduels dans la fraction désulfurée utilisée comme matériau pour la rétention d?eau peut avoir un effet bénéfique en réduisant la migration d?oxygène. En effet, les sulfures contenus dans la couche de rétention d?eau peuvent consommer l?oxygène qui tente de migrer vers le bas et, ainsi, réduire les flux d?oxygène qui atteignent les rejets réactifs.

Nov 1, 2002

By C. J. Brown

Since its commercialization thirty years ago, the Recoflo® short bed ion exchange process has been extensively utilized for the recovery of a wide variety of acids and metal salts. In addition to a reduction in resin bed height from 200 cm to 300 cm to 15 cm to 60 cm, the process has a number of features such as utilization of fine mesh resins in a compressed bed which together make it ideal for a number of applications. The process has been extensively exploited, for example, in the metal finishing industry for recovery of valuable chemicals from electroplating, anodizing, etching and pickling wastes. More recently, it has also been applied in the primary metals industry for purification of copper electrolytes and metals recovery from leachates. The paper discusses several of these applications and some of the issues that were found to be key to their success.

Jan 1, 2004

By D. S. Rogers

"Throughout the history of mining at the Dome, gold has been found in a number of different rock types and in association with a number of different structural settings. Diamond drilling plays an important role in the evaluation of the stratigraphic and structural features which control ore deposition. The main function of diamond drilling is to locate favourable areas of mineralization.To date, over 20,000 diamond drill holes have been drilled from combined surface and underground programs. Needless to say, a great many significant intersections, carrying a wide range of gold values, have resulted from the total of over 756 miles of drill cores which these programs have produced.However, the term ""significant"" takes on new meaning in light of the experience of diamond drilling in a number of ore-type situations at the Dome Mine. Drilling through individual ore veins, such as the Fuchsite Vein or the Quartz-Tourmaline Vein, often intersect the vein structure; however, assays from the veins frequently fail to yield any ore grades. Similarly, drill cores through stringer-type occurrences such as dacite or conglomerate, when assayed, fail to indicate the true size or grade of the orebody ultimately mined.IntroductionOver the years, those who explore for gold and those who have the slightly less fickle task of actually mining gold have shared a common dilemma. That dilemma lies in the failure to relate the results of diamond drill information to a positive ore situation, or ultimately to reconcile ""diamond drill indicated ore"" to actual ore reserve tonnages.Drawing on the knowledge of more than 72 years of mining history at the Dome operation in the famous Porcupine Camp, this paper will review a number of drift and stope situations in which the grades of the ore material extracted will be compared with the anticipated grade of that same drift or zone as calculated solely on the basis of diamond drill assays."

Jan 1, 1982

By E. Lampard

Mines must manage variability from within their operations as well as those imposed upon them by external forces. This paper provides a framework to manage both internal and external variability through the review and adjustment of the mine plan where applicable to minimize lost production and maintain operational safety. KEYWORDS Mine plan, mine schedule, variability, safety, lost production, float days, update, adjustment, operations, Maintenance

May 1, 2011

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 R. Nendick

"IntroductionThe Ancient Egyptians recovered gold from the mud in the bottom of ponds by having teams of maidens sit around the pond dipping goose feathers dipped in grease into the mud. The gold would preferentially stick to the oily surface and was periodically washed off to give a gold concentrate. This was a forerunner of today's flotation processes.In Greek mythology Jason and the Argonauts pursued the Golden Fleece, which was a primitive form of gravity concentrate produced when gold ore slurry was passed over a sheeps fleece. The heavy gold settled and was caught in the fleece, producing a rich concentrate that allowed Jason & Company to perform the first recorded case of highgrading. The process was a forerunner of todays shuiceboxes used in placer mining.From these simple beginnings, gold metallurgy has progressed to a state where very complex flowsheets are proposed, sometimes to perform a simple metallurgical task. Figure (i) shows a hypothetical flowsheet to identify the range of unit processes that might be brought to bear on a refractory ore. The flowsheet identifies the three primary areas of gold metallurgical operations:Ore PreparationExtractionRecovery."

Jan 1, 1986

By Sylvie Brassard

Available information ?? InfoMine: mineral properties ?? Metals Economics Group: budgeted exploration expenses ?? MineScan: Canadian and American Mining Companies ?? Statistics Canada: Canadian Direct Investment Abroad, by Sector in the world OR all sectors by Country

May 1, 2008

By Mario Bureau

Need for a lab assembly reaching better and consistent static anchorage capacities

May 1, 2013