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By Michel Dostie

Un séchoir à vis chauffé par induction électromagnétique a été développé et implanté chez Mines Niobec pour le séchage d?un concentré de niobium. Ce séchoir a permis une réduction des émissions de poussières et des gaz à effet de serre de l?usine. Il offre une grande souplesse de contrôle, une meilleure efficacité énergétique et peut être utilisé pour le séchage de granulats, de poudres ou autres substances habituellement traitées dans un four rotatif ou à l?aide de vis chauffées par un caloporteur. Le principe de fonctionnement du séchoir est simple. Trois inducteurs opérant à la fréquence du réseau électrique assurent le chauffage des parties métalliques du séchoir, dont des vis qui servent à convoyer le matériel. Le contact du matériel avec les parties métalliques chaudes permet le transfert de l?énergie requise pour le séchage. La conception de ce type de séchoir requiert un équilibre adéquat entre les besoins associés au chauffage par induction et ceux liés au transfert de chaleur par contact et au transport du matériel dans le séchoir. Cette première implantation industrielle a nécessité des efforts de développements importants et une collaboration des différents intervenants. Une revue des principes de conception, des difficultés rencontrées et des performances obtenues sera présentée.

May 1, 2007

By W. H. Stheeman

"The high rock pressures at the deeper levels of the Tsumeb Mine have necessitated the changing of the mining methods and the introduction of cable bolts. After two rockfalls in the cable-bolted stopes, the mechanics of cable bolting were investigated. Practical methods were developed to find the best grout mixtures, the bond stresses between cables and cement, the bond stresses between rock and cement and the load on the cable bolts, which was mathematically calculated from data observed underground. The design of the cable bolt support system as used at the Tsumeb Mine is explained. GeneralThe Tsumeb Mine is in northern South West Africa/Namibia, approximately 400 km by road from the capital city, Windhoek, at an elevation of 1300 m above sea level. Mining operations in Tsumeb were started in 1905 by the Otavi Minen und Eisenbahn Gesellschaft and continued, with an interruption during the Depre ssion, until 1940, when the mine was closed and taken over by the Custodian of Enemy Property. The present owner, Tsumeb Corporation Limited, obtained the mine in 1947 and restarted the underground mining operations in 1949 after the mine was dewatered. Currently, the stoping operations are between 26 Level (840 m below surface) and 38 Level (1260 m below surface). In addition, the mine is an important silver producer and has produced 670,100 kg of silver since 1947."

Jan 1, 1982

"The Crescent, DM, and Pothook zones are copper-gold porphyry deposits which formed in association with alkalic intrusions of the early Jurassic Iron Mask batholith. The characteristics of the Crescent and DM deposits are nearly identical. Both formed along the contact between the Cherry Creek monzodiorite and Pothook diorite phases of the batholith. Permeable intrusion breccias along the contact concentrated the flow of hydrothermal fluids. Early, pre-ore alteration is represented by pervasive, sulphide-barren potassium metasomatism. The precipitation of copper-gold ore occurred during subsequent fracture-controlled potassic alteration, and is most strongly developed in chlorite-sulphide veins and their alteration envelopes. A central zone of potassic alteration is surrounded by a propylitic, pyritic halo in both deposits. The DM zone is unique among alkalic porphyry deposits in its high abundance of quartz-sulphide veins.The Pothook deposit formed at the westernmost contact of the Iron Mask batholith with enclosing Nicola Group volcanic rocks. Pervasive potassium metasomatism, similar in style to that at Crescent and DM, is associated with intrusion of the Cherry Creek monzonite. Pervasive and fracture-controlled albitic alteration is associated with intrusion of the Sugarloaf diorite and introduced minor copper-gold mineralization. Most of the copper-gold mineralization was introduced during formation of veins and breccia matrices dominated by magnetite/hematite and sulphide. Late-stage chlorite veining may have remobilized or introduced additional gold mineralization.Copper and gold assays in the Crescent deposit are well-correlated and have a nearly constant Cu:Au ratio, suggesting that the metals coprecipitated during a single hydrothermal event. In the Pothook deposit, copper and gold do not correlate closely, lack spatial correspondence, and suggest that transport and/or deposition of the two metals were not identically controlled and that they may have been introduced at different times by separate hydrothermal events."

Jan 1, 1995

By A. O. Dufresne

The mineral wealth of pre-Cambrian rocks in Canada has been the subject of much study by geologists and engineers (members of this Institute), particularly so in the past few years, following discoveries of mineral deposits in areas far a part. This interest is well worth sustaining knowing the numerous rich producing mines within the pre-Cambrian formations, and the vast area covered by its rocks throughout this country. The pre-Cambrian has yielded minerals, both metallic and non-metallic; of these a much diversified list could be made. In more than one district we can point to mining as being responsible for the opening up of new sections, attracting a population into regions which otherwise would have remained virgin land of little commercial value. In these pre-Cambrian formations are found the rich copper deposits of Michigan, producing without interruption since 1845, and from which seven billion pounds of copper has been won; while in Minnesota and the adjoining district, at the head of Lake Superior, are mined iron ores which have rendered possible the great steel manufacturing industry of United States, the base of the economic structure of that wealthy country. The pre-Cambrian has given Canada the nickel-copper mines of the Sudbury district, the silver deposits of Cobalt and the gold camps of Porcupine and Kirkland Lake. With all of these our members are familiar; and it suffices to mention them to bring to mind pictures of the wealth and 'the growing population, in a word the importance of mining in?those sections of the country.

Jan 1, 1926

By R. Guimarães, L. Silva, J. Milboume

The São Bento concentrator was built by Gencor in 1985 to treat refractory gold-bearing flotation concentrate. The plant was the first commercial application of pressure oxidation for refractory gold ore following about a year after the first use of pressure oxidation on a whole ore at Homestake's McLaughlin operation in California. Ore from the Sao Bento mine is remarkably consistent in gold grade and arsenic and sulphide concentration as is typical in banded iron formations (BIF) (l). Gold content is approximately 9 g/t with approximately 30 - 40% free milling. The balance is associated with arsenopyrite and pyrrhotite. An expansion of both process facility and mine was undertaken between 1996 and 1998, raising the treatment capacity from 32,000 t/mo to 45,000 t/mo.

Jan 1, 2004

By Hermann A. Derbuch

Twin Mining made a conscious decision when it changed from gold mine explorer and developer to become a diamond explorer in Canada?s Arctic. It was a decision of survival in an environment that saw junior gold companies either disappear or turn into dot com companies. Twin Mining learned fast and staked within weeks of that decision the first 50 sq. km of claims on, what became, its TORNGAT property at 59½° latitude on the east coast of the Ungava Bay in northern Quebec. This land position, 724 diamonds later (including 322 macro diamonds of gem quality, white and transparent) grew to 507 sq. km today. The 74° latitude called when Twin Mining exercised the option to acquire 3 claims owned by Helix Resources Inc. which revealed exceptional diamond potential. A gem quality 5.4 mm (0.768 carat white and transparent) diamond and the discovery of 16 pipes on 15.2 ha convinced Twin Mining?s board to sanction the deal. Both properties have outstanding features. Kimberlite Dykes and Pipes are in outcrop. The property locations have deep-sea access near existing infrastructure. Their locations are in an environment that is stable and development friendly and has a positive track record with successfully operating mines near-by.

May 1, 2001

By K. K. Dehn

This study focused on determining the stability of thin shotcrete fill fences at a hard rock mine in northwestern Ontario during increased pour rates of paste backfill. Determination of the stability of the fence is needed for both personnel safety and to avoid failure of a fence. Failure of a fill fence during backfill activities would have severe impacts on production and potential hazards to nearby workers. Approved fill fences at the mine are a slender design of 10.5 centimeters of shotcrete applied to a rebar framework with burlap lined ?bedspring? backing. Approved mine standards dictate that fill rates may not exceed 1.5 meters of paste depth per 10-hour shift when pouring behind a flat fill fence. To decrease the backfill cycle time the study looked at fence stability during increased pour rates of 2.5 meters paste depth poured within a 10-hour shift. An instrumentation design was developed including pressure cells, strain gauges, and tilt-meters that were built into experimental fences to observe the effects of increased pour rates on lateral wall pressures, strain development in the rebar and shotcrete reinforcement, and physical deformation patterns along the face of the fence. The data was analyzed for overall stability.

May 1, 2007

By G. G. Campbell

"HistoricalBARYTES was mined in Nova Scotia as early as 1874 from a deposit at Five Islands, on the north shore of Minas Basin. The first record of the presence of the mineral at the Walton site appears in a report by Selwyn in l893, who states: ""Barytes in considerable quantity occurs in veins in lime-stones at Walton and Pembroke"". The exact site of the present workings was marked •on a map published by Fletcher in 1905.The economic •possibilities of this deposit, however, were not recognized until 1940, at which time we were at war with Germany, who up to that time had supplied 50 per cent of the world's requirements.At that time the Nova Scotia Department of Mines, recognizing the need for certain strategic minerals, induced Canadian Industrial Minerals, Limited, to send prospectors into 'the area to look for manganese. No manganese deposits were found, but a deposit of barytes was directed to their attention, and exploration and development work on the occurrence was proceeded with.IntroductionThe south shore of Minas Basin between the Avon river at Windsor and the Stewiacke river at Maitland has long been known as a potential source of mineral wealth. It had attracted the attention of mineralogists and in the past had produced considerable tonnages of manganese ore and gypsum. Depletion of ore in surface and near surface deposits resulted in a dwindling production, until today only deposits of gypsum are worked."

Jan 1, 1952

By Dave Ecobichon, Éric Côté, Simon Nickson, Michel Leclerc

The feasibility assessment of a mineral deposit requires the construction of a geo mechanical model of rock mass properties, for the purpose of preliminary mine design. The Noranda Technology Centre has been involved in the development of geomechanical models for several mineral deposits at the feasibility stage. Each model is constructed through intact rock testing, geotechnical core logging, geotechnical mapping and rock mass classification. Rock mechanics principles are used to develop conceptual stope designs and propose possible mining sequences. This methodology is applicable to both new mining projects and to the development of new areas within anoperating mine. This paper explains how the geomechanical model is developed and reviews its application to several case studies.

Jan 1, 1996

By K. Iturralde

The article discusses the possibility of automation in refurbishment processes of social dwelling built from 1950 to 1970. These massively produced buildings were mostly designed prior to the law enforcement regarding thermal insulation or accessibility. Nowadays, many of these buildings are being retrofitted. The article focuses on the works in the external envelope. The task of renewing the whole social building stock is big and it requires a systematic process that facilitates a rapid upgrading, without neglecting the specific situation of each case. How could an automatic refurbishment process of these buildings be defined? The process should start with the data collection of the building and the creation of a 3D model using software such as BIM. The project, drafted in 3D, should facilitate the manufacture of building elements by robotics. In turn, it should be noted that during the assembly at the site, the pieces must be fixed quickly and efficiently. Is it possible to implement an automated process for the refurbishment of apartments built in the second half of the twentieth century? To approach the answer, a virtual refurbishment project is performed. The article focuses on the rehabilitation of the building envelope. Furthermore, it gives special attention to the double skin facade. It is well known that a second skin in this type of building can be an element that integrates several functions. Finally, needless to say that refurbishment of residential buildings is a need in our society. By extending its life cycle, robotic refurbishment provides more favorable socioeconomic and environmental capabilities than the sole construction of new buildings.

Aug 1, 2013

By J. Nsasi Bakambu

This paper describes an autonomous platform for exploration and navigation within networks of tunnels, as those typically found in underground mines and caves. In the exploration mode, a remotely located supervisor instructs the platform to move through successive sections of the network, gathering range data that is, then, concatenated into 2D/3D survey maps of the environment. In the navigation mode, the supervisor specifies high-level missions on the previously acquired survey maps. A motion planner, then, translates each mission into a set of consecutive navigation actions, separated by natural landmarks. Mission execution consists of detecting landmarks, self-localizing and performing the planned navigation actions.

May 1, 2003

By The Staff

IT is a high compliment to be invited to present a pap::r on the subject of "Mining in the National Economy". To cover it adequately would need the knowledge of the economic geologist and of the technical mining engineer, together with the arts of the statistician and of the economist in general, allied with generous psychic powers. Further, one should embellish the tale with a touch of drama. It is comforting that the subject is so broad that whatever may be said within the compass of a paper like the present, can hardly be criticized as going beyond the terms of reference. A conventional approach would be to begin with the noteworthy statistics of the mining industry of yesterday and today. But in the present company this would be "carrying coals to Newcastle"-or to give the venerable metaphor local colour, "nickel to Sudbury". Such statistics are available in all their stimulating detail in our official publications. Let us tackle at once, therefore, as a less hackneyed theme, the relationship of mining to other phases of the Canadian economy. RELATION TO TOTAL PRODUCTION While mining occupies a position of less importance than manufacturing or agriculture in Canada, its relative contribution has greatly increased during the post-war period. Due to the fall in wholesale prices, the net value of production in Canada has shown a decrease averaging about 1.5 per cent per year during the post-war period, though its volume of course has gone up. Mineral production on a value basis, on the other hand, showed a gain of 2.8 per cent per year. Mineral production was only 5.14 per cent of the net value of production of all kinds of commodities in 1919, bur from 1929 to 1936 the proportion rose steadily rill it reached no less than 12. 76 per cent in the latter year.

Jan 1, 1937

By S. Masambi, S. M. Bradshaw, C. Dorfling

The presence of iron in base metal leach solutions complicates nickel and copper recovery processes. Leach solutions are commonly purified by precipitating iron as hematite, jarosite or goethite. Fast oxidation of ferrous to ferric is an important step to remove iron by precipitation at low pH values. This study reviews the ferrous oxidation mechanism and reaction rates in chloride media using molecular oxygen. This work contributes to the development of a better understanding of iron precipitation processing steps, which continues to be an important matter in hydrometallurgy. The specific objectives were to investigate (1) the effect of key process variables (acid concentration, copper concentration, and temperature) on the rate and extent of ferrous oxidation by dissolved oxygen and (2) the oxidation mechanism by varying chloride and hydrogen ion concentrations separately. Batch oxidation tests were performed using synthetic chloride solutions containing 45 g/L Fe and 3 g/L Ni at 50 and 80°C, dissolved Cu concentrations (0.3 to 3 g/L) and HCl concentrations (2 to 4.6 M). Regression analysis indicated that the significance of the effect of different variables on the extent of oxidation achieved after five hours decreased in the following order: HCl concentration > Cu concentration > temperature. Increasing the HCl concentration from 4 M to 4.6 M caused the degree of oxidation achieved after two hours to increase from 58.3% to 98.1%. The catalytic effect of dissolved copper on ferrous oxidation was more significant at low acid concentrations. Experimental data suggest that rapid oxidation of ferrous is possible at high HCl concentrations for two main reasons. First, the formation of ferrous chloride complexes allows ferrous oxidation to proceed without the formation of superoxide as an intermediate product (the rate limiting step in dilute acid solutions). Second, the formation of ferric chloride complexes stabilises the oxidation product.

Jan 1, 2016

By K. Law

"The Hatch Product Transport (HPT) system is a highly flexible and configurable route selection and sequencing system for controlling large bulk material handling facilities. The system has a generic control algorithm that can be configured to suit any material handling facility. It can also be easily reconfigured to cater to plant expansion or modifications without incurring significant disruption to the existing production, costs in testing, and re-commissioning, thus achieving cost savings throughout a facility’s lifecycle.This new material handling control system has been installed at BHP Billiton’s Port Hedland iron ore terminal to facilitate its expansion to beyond 100 Mt output capacity."

Jan 1, 2006

By C. Graham

Mechanisation has been a predominant theme of the past 50 years in the mining industry, particularly underground mining. As the level of technology employed has increased, the anticipated productivity gains have not been realised and the differences are not explained by the demand for higher standards of safety and security. Now, mining costs are so high and productivity so low that the resultant return on investment for many Canadian operations has fallen to levels considered unacceptable in a competitive capital market. Simply continuing technological development cannot reverse this trend and its financial implications. The focus on technological development has distracted us from some basic truths. Systems that are more complex are more likely to fail and cost-effective processes depend on the continuity of productive activity and the flow of material. When putting these facts together, it becomes clear that in a system that has fixed external conditions, the single most crucial issue is the effective management of the operational cycle. By its nature, technology focuses our attention on what gets done and how it gets done, while the crucial issue is the increasingly longer periods in the operational cycle when nothing productive is being done. What is required is to match the level of technological complexity to the fixed system conditions, which are virtually unchangeable. This paper looks at the overall system and objectives and attempts to present an appropriate level of technology for the Canadian mining industry, now and in the foreseeable future.

May 1, 2004

By H. C. L. Reemeyer

One of the fundamental trade-offs for copper concentrators is between grinding circuit product size and copper recovery. The capital and operating cost savings and throughput increases for a coarser grind should be evaluated against potential recovery reductions. Other benefits of coarser grinds, such as GHG emissions reductions and favourable effects on tailings and water management should also be considered. This paper assesses the formation of laboratory and pilot test programs, design of process flowsheets, equipment selection, and evaluation methods to determine the most appropriate and economical grind size for a given deposit. The paper will include an evaluation of case studies. INTRODUCTION The majority of the world’s mined copper comes from sulphide deposits, which are mostly processed using crushing, grinding, flotation and dewatering flowsheets to produce copper-bearing concentrates for smelting. Ores must be ground to a sufficiently fine size to achieve an acceptable level of liberation to allow both high recovery of copper and valuable by-product minerals while efficiently rejecting gangue to tailings. Therefore, a key design parameter in process plant design is the grind size of the flotation feed. Copper concentrators use a variety of grind size targets that depend on various factors, including ore mineralogy and the grain sizes of valuable and gangue minerals; the sensitivity of valuable mineral recoveries in the rougher flotation stages to grind size, ore hardness; electricity costs; and mining vs. processing throughput constraints. Typically, copper and by-product recovery increase as grind size is reduced, which can improve revenue, but finer grinds increase power and grinding media operating costs and may have implications for tailings management. This paper explores the trade-offs that should be assessed in determining the optimum grind size, and to answer the question if coarser grinds are worthwhile. METALLURGICAL AND FLOWSHEET FACTORS Recovery-by-size behaviour of sulphide-bearing particles In base metals sulphide flotation, it is typical that flotation recoveries vary by particle size. Metal sulphide particles rendered hydrophobic by collector in intermediate size ranges (e.g. 10 to 100 um) usually show very high recoveries, often approaching 100%. Recovery usually falls away in finer size fractions (<10 um) as fine particles have little inertia and can move around bubbles without colliding and attaching to them. Coarser particles (>100 um) are susceptible to particle-bubble detachment and dropback (Jameson, 2019).

Jan 1, 2019

By John Crusius

? 3-year research program overview ? initial results- MainZone pit Waterline pit ? questions raised ? increasingly common in western N. America ? frequently low-pH waters with elevated concentrations of many metals ? water quality controls poorly understood ? some in U.S. are Superfund sites

May 1, 2002

By F. E. Goodwin

Since the last CIM Zinc and Lead Conference ten years ago, significant technical and market forces have influenced how these metals are used, and the geographic distribution of their uses. Unprecedented price fluctuations have opened competitiveness issues, while the rapid growth of the Chinese market has created challenges both inside and outside China. Recent technical developments in battery energy storage, coatings, castings and chemical applications of lead and zinc will be reviewed together with the influence of these trends on end use markets.

Jan 1, 2008

By A. Demers, M. Chapman, N. Reynier, R. Lastra, M. Courchesne, C. Laviolette

Historic medical isotope production at Canadian Nuclear Laboratories (CNL) in Chalk River involved the dissolution of irradiated isotope targets prior to extraction of Mo-99. This process generated liquid waste that was cemented in 5-gallon containers and transferred to an outdoor waste-management facility for intermediate storage. Research was undertaken to develop an innovative method for uranium, mercury and cesium recovery from the radioactive cemented waste (RCW). Regulations prohibit the removal of active radioactive waste from the Chalk River facility. Thus, CanmetMINING produced surrogate material following the same procedures and conditions to those used at CNL. The selective recovery of the uranium from the surrogate radioactive cemented waste (SRCW) could offer CNL more disposition options for the resulting wastes. Leaching tests were performed using four different SRCW at 1 kg scale. Different conditions, operating parameters, and the presence of plastic and corrosion products were evaluated on solubilization. The research investigated the use of potassium iodide with the sulphuric acid leach to increase metals recovery. Iodine improves the solubilisation of metals and the U dissolution reached 99%. The increase of leaching time reduces the U solubilization due to silica gel formation. Therefore, it will be important to control leaching time to avoid the loss of U during the pilot scale experiments. For Hg, the solubilization ranged from 60 to 80% due to the presence of metallic mercury and mercury sulphide found in SRCW cured at 60°C and/or aged for 30 months. Ion exchange (IX) was found the best method to separate the uranium from the impurities and produce a purified and concentrated uranium solution suitable for yielding a uranium product (yellow cake).

Jan 1, 2020

By H. R. Oliveira, C. R. Aragonez de Vasconcellos

Pipeline operation and maintenance necessarily involves geotechnical studies at points and areas with deflagrated instabilities or still to map and monitor areas prone to geotechnical problems. Landslides, erosions and debris flows are some examples of natural hazards, that not rarely, can bring high consequences to pipelines, sometimes leading them to high stresses levels and ruptures. Bolivia-Brazil Natural Gas Pipeline has 2.593 kilometers since Rio Grande City in Bolivia until Canoas City, in south Brazil. The pipeline crosses a lot of types of geological fields and difficult topography. The south spread of the pipeline has the most prone areas to geotechnical hazards because of its hard topography combined with the variety of geological materials, such as, colluvium deposits and debris flow areas. The aim of this paper is to present the right-of-way geotechnical risks that affect pipelines, presenting some practical remedial works done by TBG at Bolivia-Brazil Natural Gas Pipeline as well as the integrity plan and the adopted actions in way to prevent geotechnical accidents.

Jan 1, 2005