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By R. D. White

"The Cumberland Basin of Nova Scotia has long been considered a structural basin by virtue of the elliptical outcrop and inward dip pattern of the Pennsylvanian outcrops. Recent published and unpublished data indicate that subsidence began in the late Devonian, perhaps resulting from a graben or rift. The Mississippian sediments which filled the growing depression were continental, lacustrine and marine with evaporites. The cessation of the riftforming processes is recorded by the alluvial swamp-type sediments of the Pennsylvanian which filled the depression. In excess of 25,000 feet of Carboniferous rocks are believed to be present in the deepest part of the Basin. Starting with the rift hypothesis, we can speculate on the kinds of sediments, their location and the structural features present beneath the Pennsylvanian surface. Using surface exposures and a limited amount of subsurface data, we theorize that (1) the Mississippian evaporites acted as glide zones which effectively divided the Basin into two horizontal structural layers. The rocks above the evaporites, responding to Appalachian stresses, formed the long diapiric folds with cores of overthickened evaporites. Below the evaporites the structures are related to movements of the rift floor, compaction closures and structures formed by differential horizontal movements of the rift walls. (2) The rift, in its deeper parts, will have more and a greater variety of marine rocks than the outcrops indicate. Should the rift hypothesis be correct, the possibility of finding hydrocarbons is enhanced."

Jan 1, 1972

By L. B. Hale

"Introduction This paper will discuss the current operations of Westar Mining Ltd. and give a brief history of the company and of the Crowsnest Pass area. Westar is an integrated company involved in mining, processing and marketing coal from its mines in southeastern British Columbia and shipping coal from Westshore Terminals at Roberts Bank, located just south of Vancouver, B.C. It is two-thirds owned by the B.C. Resources Investment Corporation and one-third owned by the Mitsubishi Corporation of Japan and a consortium of Japanese coal consumers. Operations in southeast British Columbia consist of four coal mines and two processing facilities (Fig. 1). The Elkview Coal Processing Plant near Sparwood, B.C. receives its raw coal from Balmer operations (Harmer open pit), Balmer South (Panel 6) an underground hydraulic mine, and Balmer North an underground room-and-pillar mine. The fourth mine, Greenhills, an open-pit operation, is located near Elkford, B.C. and has its own processing plant. The Balmer mining and processing complex is the largest metallurgical coal facility in Canada producing up to 7 .5 million tonnes of clean coal per year. The Greenhills operation, completed in mid-1983, has a capacity of 2.8 million tonnes. The high-grade metallurgical and thermal coal produced is primarily for export markets. The major customers are Japan, Korea, Brazil, Pakistan, Chile and Taiwan.Our coal and that produced by other mines in Alberta and British Columbia is shipped to the international markets through Westshore Terminals Ltd., a wholly-owned subsidiary. Westshore will have an annual capacity of 22 million tonnes of coal and accommodate ships of up to 250,000 dead weight tonnes by 1984 when its current expansion program is completed."

Jan 1, 1985

By C. Prévost, V. Leclerc, R. Pinto, M. Ruel

"A buffer’s ability to dampen production variations is directly related to its size. Small buffers cannot handle large variations in production, resulting in production losses when their inventory is depleted or saturated. This paper presents a predictive control algorithm used to regulate the inventory in a buffer of limited size, subject to large production variations caused by an upstream batch process. The algorithm was designed to manage the acid flow rates in an acid regeneration process, servicing batch leach reactors at Rio Tinto Fer et Titane, in Sorel-Tracy, Québec. The objective was to increase production by reducing equipment downtime caused by imbalances in the acid tanks servicing the leach reactors. The controller attempts to maintain acceptable acid tank volumes by optimizing the leach reactors acid/slag ratio and reaction time as a function of anticipated acid needs, all while maintaining product quality.INTRODUCTION Some beneficiation processes in extractive metallurgy require processing bulk material in batches. Typical examples of metallurgical beneficiation batch processes are smelting, leaching, electrowinning, elution and carbon-in-pulp. These processes are often situated midstream in an ore beneficiation flow sheet and either receive or transfer ore to continuous processes. Batch processes, by their very nature, introduce large variability in the flow sheet, because they process large finite quantities of material at nearly periodic time intervals. In order to dampen variations in production, various buffers–tanks and stockpiles–are utilized to accumulate ore upstream and downstream of batch processes. A buffer’s ability to dampen production variations is directly related to its size (Phillis & Gumede, 2011). Small buffers cannot handle large production variations, resulting in equipment downtime when their inventory is depleted or saturated (Everett, 2010, Berton et al., 2013). Consequently, the batch equipment production rates must be adequately managed to minimize production losses, attributed to depleted or saturated inventories, while maintaining product quality. Algorithms that anticipate or predict future production variations are often utilized to regulate buffer inventories, subject to large flow rate variations (Salvo et al., 2002; Bonvin, 2013). This paper presents a predictive control algorithm used to maintain an acceptable volume in a spent acid tank servicing several batch leach reactors. The algorithm is implemented at the acid leach plant of Rio Tinto Fer et Titane, in Sorel-Tracy, Québec."

Jan 1, 2017

By P. L. Richard

An open pit a mine can be thought of as a business unit, with capital, operating and maintenance costs that exceed those of many large business enterprises. Truck-and-shovel operations have an inherent ?looseness? to them, unlike manufacturing or processing operations where production components are tightly coupled (through conveyors, material flow in pipes, assembly lines, and so on). Effective monitoring and control of truck-and-shovel operations requires a combination of both information systems and performance management. Production monitoring systems can impact operations at three levels: minute-by-minute decisions during the shift, procedures, and policies. The technology of production monitoring ranges from real-time data collection to manual entry of time card data into a computer. Time card information is too coarse to effectively manage a multi-million dollar fleet of mobile equipment, so a higher level of production monitoring is required. People issues affect whether the implementation will be a success or a disappointment. Considerations that affect the people issues are discussed, including common obstacles, and key success factors. A balanced scorecard approach must be used, since uni-dimensional measures of performance like tons produced give no indication of whether the production was achieved at the expense of another factor.

May 1, 2004

By P. L. Richard

An open pit a mine can be thought of as a business unit, with capital, operating and maintenance costs that exceed those of many large business enterprises. Truck-and-shovel operations have an inherent “looseness” to them, unlike manufacturing or processing operations where production components are tightly coupled (through conveyors, material flow in pipes, assembly lines, and so on). Effective monitoring and control of truck-and-shovel operations requires a combination of both information systems and performance management. Production monitoring systems can impact operations at three levels: minute-byminute decisions during the shift, procedures, and policies. The technology of production monitoring ranges from real-time data collection to manual entry of time card data into a computer. Time card information is too coarse to effectively manage a multi-million dollar fleet of mobile equipment, so a higher level of production monitoring is required. People issues affect whether the implementation will be a success or a disappointment. Considerations that affect the people issues are discussed, including common obstacles, and key success factors. A balanced scorecard approach must be used, since uni-dimensional measures of performance like tons produced give no indication of whether the production was achieved at the expense of another factor.

Jan 1, 2004

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 N. T. Oo, L. D. Hutton

"The Banora Point Upgrade Project is a 2.5km long six-lane divided freeway in northern New South Wales, Australia. The geology at the project area comprises a volcanic succession of variably weathered basalt flows and agglomerate deposits that reach 48m in thickness and overlie Mesozoic sedimentary rocks. A site specific rock classification system was developed that characterised all the rock units based on the engineering properties governing the rock mass behaviour i.e. intact rock strength and defect characteristics (spacing, aperture, infilling, wall roughness and weathering) irrespective of the geological origin. This approach simplified the design and the on-site verification processes. Based on this classification system, rigorous quantitative statistical assessments of the available geological information including various laboratory and field testing were performed to derive the geotechnical design parameters for various rock classes. These parameters were used to complete geotechnical designs of retaining wall systems. INTRODUCTIONThe Banora Point Upgrade Project is a 2.5km long six-lane divided freeway in northern New South Wales, Australia. The key features include two interchanges, a 300m long viaduct, a large cutting through Sexton Hill with an associated 100m wide Land Bridge and retaining walls reaching 490m long and up to 22m high. This paper focuses on the derivation of representative geotechnical parameters for geotechnical design of the retaining structures supporting Sexton Hill Cutting including bored pile retaining walls and soil nail walls. The geology at the project area comprises a volcanic succession of variably weathered basalt flows and agglomerate deposits that reach 48m in thickness and overlie Mesozoic sedimentary rocks. Due to the complex geological nature of the site, an understanding of the regional and local geology, the typical behaviour of individual geological units and the implication of onsite variations from design intention are the ultimate challenges to the geotechnical engineer in order to select representative geotechnical parameters for design."

Jan 1, 2015

By Mike Dry, Mani Manimaran, Mykolas Gladkovas, Mariam Melashvili, Chris Fleming

Development of a new hydrometallurgical flowsheet requires quantitative description and optimisation of all chemical processes in each step in the process, as well as mass and energy balances across a fully integrated circuit incorporating all the unit operations. This paper covers steps leading to early modelling of a gold processing plant based on a bromine/bromide lixiviant. Research conducted at SGS Lakefield in collaboration with Albemarle provided the data that were used in the development of this model. A previous investigation in this series described the leaching behaviour of various mineral types in Stabilized Bromine reagent. This paper is concerned with the gold recovery operations associated with a conceptual bromine leaching process. The recovery of gold by different types of resin and activated carbon was studied, along with various methods of stripping the gold from the extractant. The circuit is closed by electrolysing the spent leach liquor to oxidize some of the contained bromide back to bromine that would allow recycling the regenerated leach solution back to the leach step in the process.

Jan 1, 2015

By D. Holz

In this work we present a novel level set-based model for the real-time simulation of soil deformations. A level set defined by a signed distance function and sampled in a regular 3D grid represents and tracks the soil volume under deformation. Moving away from classical 2.5D heightfield representations of soil to a full 3D volume representation allows for improved tracking of cutting tool operations and the simulation of near-vertical or vertical soil faces. The proposed level set representation furthermore provides a versatile mathematical platform for modeling additional effects such as soil slip, and does not suffer from the sampling limitations of commonly used heightfields. Cutting forces applied to the tool are simulated via a formulation based on the Fundamental Equation of Earthmoving, modified to support inclined soil surfaces and transient states of tool motion. Discretisation of this 2D cutting force model with respect to the tool surface allows capturing the effects of irregular 3D terrain shapes on blades and buckets. The surcharge created during cutting operations is tracked in the form of particles and included in the soil failure force computation. We make use of an adaptive, hybrid level set-based and particle-based soil deformation scheme, which allows the soil deformation to be simulated in real-time.

Aug 1, 2013

By R. G. Helberg, S. M. Rebelo

"Copper and cadmium are removed from the zinc sulphate solution in primary purification by cementation reaction followed by filtration. The solids are sent to the cake leach section where zinc and cadmium are recovered from the copper rich slurry. The copper solids from cake leach are filtered, bagged and sold. In order to achieve a lower cadmium copper cake, an altered process flow is suggested. It is proposed the primary purification be split into two steps for individual removal of copper and cadmium. INTRODUCTIONCopper cake is a product of primary purification, also known as copper and cadmium removal. Copper and cadmium are removed by cementation reaction in four stirred reaction tanks. The slurry is then filtered through Shriver manual plate and frame presses with the solution advancing to the next stage of purification, hot zinc purification (HZP). The solids from primary purification are further processed at the cake leach section where zinc and cadmium are separated from the copper rich slurry. Cadmium and zinc are dissolved in the cold cake leach tanks using spent electrolyte. Cadmium is recovered from this cadmium rich solution by cadmium sponging, leaching and electro-winning circuits. The residue from this cold leach step is further leached using spent electrolyte at a temperature of 85°C. The copper rich solids from hot cake leach are filtered on a drum filter and bagged in 1 ton bulk bags for shipping to buyers.Current assays of copper cake are shown in Table 1. The goal is to produce a copper cake product that is below 0.5% cadmium."

Jan 1, 2012

By D. Vanin

"Conventional single heading track drifting in the hard rock mining industry has not shown any significant improvements in advance rates, despite the advent of modern track jumbos and igh speed muck handling systems .This paper presents Kiena 's experience in using a 7 ft 2 in. diameter larva Mark 6 Tunnel-Boring Machine (TBM) for driving 6000ft of drift.IntroductionKiena Gold Mines is located about 5 miles west of the town of Val d'Or, Quebec, approximately 300 miles north of Montreal. The mine commenced production in October 1981 and has gone through various expansions of ore production with 287 916 metric tonnes in 1982 to reach 453 800 metric tonnes in 1986.Due to the majority of claims being covered by a lake, a grassroots exploration drive of remote areas of the property was required to allow diamond drilling on a yearly basis. High speed sequential excavation methods (SEM) of single heading drifting in the mining industry has not progressed much in the past 20 years despite the advent of electric-hydraulic jumbos, Haggloader and Hagglund type cars. Certain examples of record SEM drifting advances have been performed in the past but only under very specific ground and cost conditions."

Jan 1, 1987

By Lex L. Udy

External-detonation-generated plasmas, highly ionized zones of reacting material ejected from the surface of detonating explosive charges, are shown to be the cause of channel desensitization, i.e., the self-quenching of a detonating explosive column loaded in a borehole with an air annulus between the explosive and the borehole wall. The effects of this phenomenon on several explosive compositions and types are demonstrated and discussed. The explosives tested include aluminum-sensitized and explosive-sensitized slurries, ANFO, liquid explosives and dynamites. Various techniques are described that can be used to reduce or eliminate the plasma effect.

Jan 1, 1979

By J. R. Giegerich

THE problem of dust control in metal mines has, of late years, received considerable attention. In 1932, a detailed study of dust conditions at the Sullivan mine was undertaken and, while there are no actual data available regarding conditions prior to that date, there has unquestionably been a great improvement as a result of the investigation and of the preventive methods adopted. In attacking the problem, three main factors were considered: first, and most important, how to prevent dust from being formed; second, how to depress or collect it if formed; and third-if unable to accomplish these-what precautionary measures must be adopted to prevent inhalation of this dust. Seven distinct methods of dust control are now practised at the Sullivan. Six of these are employed underground; they are tabulated below in the order of their relative importance. The seventh method is used in the crushing plants on the surface. (1) Improved ventilation (2) General use of water sprays and atomizers (3) Curtailment of secondary blasting during shift hours ( 4) 100 percent wet drilling-primary and secondary (5) Wearing of protective equipment (6) Change from carbide to electric lamps (7) Installation of dust collectors

Jan 1, 1936

By S. Hunt, S. Jayasekera, J. Kyle, N. Perera, K. Stone

A preliminary investigation has been conducted to determine the conditions for the precipitation of phosphate from the liquor produced after a hydrochloric acid pre-leach and rare-earth recovery from a rare earth containing fluorapatite concentrate from the Nolans rare earth deposit in the Northern Territory of Australia. The results show that at 50oC the phosphate can be precipitated in two stages using limestone to produce a Stage 1 precipitate containing most of the impurities including iron (94%), aluminium (92%), fluoride (98%), uranium (84%) and thorium (94%), followed by a relatively pure Stage 2 dicalcium phosphate precipitate (DCP) containing only 0.05% Fe, 0.05% Al, 0.1% F, 0.01% U, and <0.01% Th. The initial Stage 1 precipitate contained about 25% of the phosphate while the remaining 75% reported to the Stage 2 phosphate precipitate. Depending on the required radioactivity specifications, the amount of phosphate in the Stage 1 precipitate could be reduced. Reagent requirements were 11.4 kg limestone (as pure CaCO3) per cubic metre of solution for the Stage 1 precipitate and 39.7 kg limestone (as pure CaCO3) per cubic metre for Stage 2. The analysis of radionuclide balance indicated that radionuclides deported mainly to the final filtrate (86.4%) compared to Stage 1 precipitate (5.4%) and Stage 2 precipitate (8.2%). Settling and pressure filtration tests indicated the precipitates were both readily settled and filtered. The final moisture contents of the Stage 1 and Stage 2 precipitates were 62.5% and 49.3%, respectively.

Jan 1, 2014

By P. D. Waters

"Mineral deposits are where you find them; they have no allegiance to territorial boundaries. Over the past decade much of the new investment in mining has been outside of continental North America, let alone Canada. The larger Canadian Banks have pursued this offshore business through their multi-national organizations; this reflects both the increasingly international orientation of today&apos;s business environment, and to a degree, the competitive advantage of these offshore developments.The current oversupply situation in mineral markets and the increasing maturity of the Developed World Economy reduces the need for new mining projects relative to growth&apos; in GNP. Those that are brought on stream in the future due to their competitive advantage, will continue to be pursued by lenders and equity investors alike. IntroductionProspects facing those who search for mineral wealth were described rather well more than 200 years ago by a Scottish professor of moral philosophy, who also happens to be the father of modern economics.In search for new mines, Adam Smith wrote in The Wealth of Nations, ""there seems to be no certain limits either to the possible success or to the possible disappointment of human industry"".How true that statement remains today, where we are seeing economic cyclical problems compounded by basic fundamental structural change within the mining industry.Despite the enormous advances in earth sciences during the past two centuries, the rewards of mineral exploration still remain uncertain. Even though a promising orebody is found, ultimate profitability may still depend on the vagaries of the marketplace, where large and unanticipated changes in supply, demand and prices can play havoc with the best of calculations.The Canadian mining industry has had its share of disappointment during the past few years, with savage competition, shrinking demand, declining prices, and disappearing profits. But it has also had some share of success, such as at Hernlo, which now seems certain to provide some of the lowest cost gold production in the world"

Jan 1, 1986

By Stéphane Robert

This document presents estimates of future "total cash cost per ounce" and "minesite cost per tonne" that are not recognized measures under United States generally accepted accounting principles ("US GAAP"). This data may not be comparable to data presented by other gold producers. These future estimates are based upon the total cash costs per ounce and minesite costs per tonne that the Company expects to incur to mine gold at the applicable projects and do not include production costs attributable to accretion expense and other asset retirement costs, which will vary over time as each project is developed and mined. It is therefore not practicable to reconcile these forward-looking non-GAAP financial measures to the most comparable GAAP measure. A reconciliation of the Company&apos;s total cash cost per ounce and minesite cost per tonne to the most comparable financial measures calculated and presented in accordance with US GAAP for the Company&apos;s historical results of operations is set forth in the notes to the financial statements included in the Company&apos;s Annual Information Form and Annual Report on Form 20-F, for the year ended December 31, 2009, as well as the Company&apos;s other filings with the Canadian Securities Administrators and the SEC.

May 1, 2011

By P. Cheung, J. Gulyas, R. Clary

Over the past 50 years, the use of autoclaves in the metallurgical industry has evolved from final metal recovery (hydrogen reduction) and purification (sulphide precipitate oxidation) to treating whole ores and concentrates. Recent process developments, such as the use of autoclaves for laterite leaching, have necessitated higher temperature and pressure operations, which in turn have seen marked advancements in technology and manufacturing capabilities to keep in step with process demands. This paper will discuss the advances in technology in terms of design, materials and construction of autoclaves and liners, typical dip tube design and geometric layout. This paper will also address specific auxiliary equipment, such as acid and steam injection systems, and components, such as agitator seal systems.

Jan 1, 2004

By S. Kariyawasam, R. McNealy

Pipelines are subject to multiple threats often requiring quantification of pipeline risk and engineering evaluation of in-line inspection and other data to effect discovery of conditions defined by the regulation. Public concern and pressure from regulatory bodies are accelerating the need for pipeline operators to formalize and intensify their approach to integrity management. Most operators need a phased approach to progressively adopt the most relevant and needed assessments. The organized and relevant assessment steps need to be introduced according to data available and maturity of the integrity management program. Each refinement to the quantification offers distinct advantages to the user. In this paper, the progressive integrity assessment solutions using quantitative methods are presented. Methodologies for engineering evaluation of integrity in-line inspection data for immediate and future integrity are summarized. Corrosion is used as an example, but the approach is applicable to any time-dependent defect based hazard. Strategies for pipeline integrity management are discussed.

Jan 1, 2005

By A. K. Mahto, B. Samanta

"A heuristic model was developed to simultaneously generate the ultimate pit and production scheduling at a mining project. The method consists of a preprocessing step to select a starter pit, the implementation of a genetic algorithm to optimize the pit and schedule of the starter pit, and a network-flow algorithm–based postprocessing operation to finalize the ultimate pit and production scheduling. Applied to an iron ore mine, the model pit and schedule produced a net present value 21% higher than the reference pit and schedule prepared by experienced field engineers.RÉSUMÉ Un modele heuristique a ete developpe pour generer simultanement l’ordonnancement de la fosse finale et de la production dans le cadre d’un projet minier. Cette methode comprend une etape de pretraitement visant a selectionner une premiere fosse, la mise en oeuvre d’un algorithme genetique pour optimiser la fosse et le calendrier d’execution de cette premiere fosse, ainsi qu’une operation de posttraitement basee sur des algorithmes de flux reseaux pour finaliser l’ordonnancement de la fosse finale et de la production. En l’appliquant a une exploitation de minerai de fer, ce modele de fosse et d’ordonnancement a genere une valeur actualisee nette (VAN) superieure de 21 % a l’approche de reference pour la fosse et l’ordonnancement developpee par des ingenieurs de chantier chevronnes. INTRODUCTIONLong-term planning for an open-pit mine involves two important activities: developing the ultimate pit and determining the optimum production schedule. To accomplish this, an ore deposit is discretized into a number of smallsized elements called blocks, which are presented in a 3D block model structure. Because of economic and slope criteria, only a certain set of mining blocks can be extracted from the deposit constituting a pit. During mining, these blocks must be extracted in a specific sequence known as the production schedule."

Jan 1, 2017

By G. B. Harris

It has long been appreciated that chloride chemistry has a number of advantages over the more traditional sulphate route for both extracting and separating metals. Modern materials of construction, coupled with the development of a more cost-effective and efficient hydrochloric acid regeneration technology mean that chloride-based processes are now more competitive and attractive. Such processing routes are able to recover more of the contained metal values in a feed, including iron in a benign and/or marketable form, and particularly the so-called rare and rare-earth elements which are increasing in demand in our electronic age. These factors, therefore, add appreciably both to the overall economics of a project, but also offer a much more sustainable approach to our dwindling natural resources. Additionally, chloride-based flowsheets can be much more environmentally-friendly, offering practical alternatives to two of the biggest headaches faced by the industry, namely cyanide usage and the generation of red muds. This paper presents a brief theoretical background, focusing on the latest developments of ferrous iron oxidation and the low-temperature, selective hydrochloric acid regeneration process, which is the key unit operation for any chloride flowsheet, and discusses in general the advantages of the chloride approach. Several recently-developed flowsheets, which have been tested at the miniplant level, are presented for gold, base metals, titaniferous magnetites and lead-silver ores wherein the advantages of considering a chloride approach are highlighted.

Jan 1, 2014