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By Christopher Boys

"Many water inflows in Saskatchewan potash mines are linked to salt anomalies. Potash ore and three anomalies in the PCS Cory potash mine in the Patience Lake Member of the Prairie Evaporite Formation were studied to understand the processes involved in their formation. Another goal was to find geological indicators of the proximity of anomalies. A geological model that relates the potash to the salt anomalies has been developed.Up to five post-burial facies may be recognized. These range from carbonate-mud collapse breccias to bedded sylvinite, and probably result from post-burial leaching. In this model, the same fluids that caused widespread recrystallization and possibly enrichment of the potash salts, started by dissolving huge cavities in the evaporites. The effects of the leaching were highly variable, indicated by selectively preserved delicate laminae and chevron textures, to deformed and totally dissolved salt beds. In at least two major events, Late Devonian and Cretaceous, collapse structures may have acted as conduits for overlying formation waters to cause pervasive leaching and recrystallization of the Prairie Evaporite Formation.Geological indicators of the proximity of an anomaly may include: a change in insoluble seam color from greenish-gray to mottled brown and greenish-gray, unusual local increases in ore grade, large patches (e.g., >200 cm2) of sylvite-poor potash crosscutting units near the top of the ore wne, and drops in topography > 10 m of the marker seams. Anhydrite was more common in an anomaly than in ore. The local abundance of anhydrite in ore may indicate the proximity of some salt anomalies. Once an anomaly has been encountered, indicators of a major collapse feature may include: stretched clay seams, folded beds, small collapse features (1 m to 20 m), numerous washouts, or split clay seams with injected salt. Any number, or none, of these indicators may be found close to a major collapse feature."

Jan 1, 1993

By Zhongxue Li

This paper reviews an analytical model that defines the relationship of weight-weighted or volume-weighted average haulage distance with bench height and other related parameters, presents the optimum bench heights under various conditions in terms of minimizing the weighted average haulage distance of ore/waste during the full lifetime of an open pit mine, and discusses the truck haulage economics of mining open pits by high bench, specifically by 15 m, 18 m and 20 m benches through marginal analyses. The observations from these analyses disapprove the previous conflicting assertions that the over-all weighted average haulage distance either increases or decreases directly with bench height. It is concluded that: (1) an increase of bench height to 15 m from 12 m is likely to be viable under the general conditions of large-scale deep open pit mines; (2) the reduction of haulage cost is much limited with the case of increasing bench height to 18 m from 15 m; and (3) the feasibility of mining open pits by 20 m benches is generally questionable. These conclusions may serve as a useful guide for those who advocate open pit mining by high bench.

Jan 1, 1995

By David Dreisinger

Arsenic occurs in nature in association with many valuable metals including copper, nickel, cobalt, gold and platinum group metals. The recovery of these valuable metals is of course complicated by the need to extract and stabilize arsenic in a form suitable for disposal. In this paper, a review of some recent developments related to hydrometallurgical treatment of arsenic bearing materials is provided. The key aspects of metal dissolution, arsenic stabilization and disposal are discussed.

Jan 1, 2014

By Richard W. Hutchinson, Christopher Osterman

The Selebi-Phikwe deposits are hosted by amphibolite to granulite facies gneisses of the Limpopo belt. The sulfide orebodies are generally stratiform and conformable to the foliation of the wallrock gneiss. Sulfide remobilization has occurred during metamorphism and has produced discordant sulfide veins, called piercement structures, which project into the hanging wall and footwall gneisses. These piercement structures are compositionally similar to the stratiform sulfides, consisting mainly of pyrrhotite, pentlandite and chalcopyrite. However, texturally the piercement sulfides are coarse grained and inclusion-free, whereas the stratiform sulfides are fIne grained and packed with tectonically produced wallrock inclusions. The piercement structure sulfides and adjacent stratabound sulfides were sampled and analyzed for major base metals and PGE's for comparative purposes. Most of the piercement structures were enriched in Cu, Ag and Au, whereas they were generally depleted in Ni, Co, Fe and PGE's. Changing elemental associations were observed from the stratabound sulfides and along the length of the piercement structures. This and the degree of depletion or enrichment of various major and minor elements in the sulfide piercement structures may reflect the relative mobilities of metals under metamorphic conditions. The similarities between sulfIde piercement structures and the footwall Cu-PGE veins in some Sudbury deposits are reviewed.

Jan 1, 1994

By D. R. Winchester

"I wish to thank you and your organizers for inviting me to address you at this point in time when we are all concerned for the future of the mineral industry in Canada.My topic ""Some Initiatives of Government Assistance to Industry Applicable to Mineral Processing"" is purposely limited in scope. To cover the entire range of initiatives in detail would take me all day, and at best, would be a mere recital of program titles, and a one sentence summary of the contents of the program. As you know, OREE or Regional Economic Expansion, is in the process of being amalgamated with elements of the Department of Industry, Trade and Commerce. We will become Regional Industrial Expansion or ORIE. If the name Canada Dry becomes popular, I don't think we will object as we hope to become a good mixer. The entire departmental thrust has been re-evaluated, and is in the process of being re-constituted to better serve the nation, and industry as a whole. Amalgamation of the industrial, trade promotion and marketing support skills of IT&C, with the regional development orientation and decentralization program delivery mechanisms of DREE, will, it is believed, provide better support to industry on a national and regional basis."

Jan 1, 1983

By G. Tozsin

A six-stage sequential leaching procedure was used to assess the leachability of heavy metals from waste rock in Antamina Mine. Sequential extractions procedure is well established for fine and small (? 1g) samples. However procedures for coarse and large test samples are lacking. This study presents results of the sequential leaches tests conducted on relatively coarse and large representative samples in terms of the availability and mobility of metals. Selective chemical reagents were used to extract metals from six different fractions where metals released with each subsequent extraction are believed to be bound tighter than those released in prior steps and therefore less likely to be leached.

Aug 1, 2013

By Ben Cottrell

In this paper technical drilling is referred to as the process of collecting engineering and metallurgical parameters for subsequent mine design considerations. Throughout the development of a mineral exploration property there are various opportunities to ?piggy-back? technical drilling onto the routine exploration drilling process, helping to reduce future costs and delays associated with re-drilling and missing information. This article is written from the engineers and metallurgists point of view, to outline some best practices for exploration borehole planning and technical data collection requirements.

Aug 1, 2013

By M. Al-Hilal, G. Rajja, A. Al-Ali, Y. Jubeli

Abstract -A radiometric survey was carried out over clastic sediments in the immediate vicinity of some phosphatic sediments of Cretaceous age in the Wadi Qasser Al-Hallabat basin of central Syria. The objective was to explore for uranium and to define its dispersion pattern. This was based on ground radiometric surveys and geological studies. All ground surveys (using radon emanometry, track etching, gamma-ray survey and geochemistry) gave similar results, outlining the locations of the radioactive phosphatic formations in the basin, and indicating the dispersion pattern of uranium in the clastic sediments in the surrounding area. The dispersal of uranium from upper Cretaceous phosphatic formation occurs by mechanical weathering and chemical leaching by oxidizing surface waters. A rough estimate is that about one-third of the original uranium content of the Cretaceous sediments has been dispersed. Mechanical erosion is responsible for the main part of this released uranium, which now occurs in Recent sediments. However, the occurrences of spotty secondary U mineralization indicates that another small part of the available uranium must have been chemically leached out by the prevailing oxidizing waters, forming minor surficial minerals.

Jan 1, 1998

By G. E. Agar, R. Stratton-Crawley

"The applicability of a hydrocyclone model to simulation of the cyclone banks in a multi-stage sandplant circuit producing mine back fill has been demonstrated. The model ha~; been used in conjunction with a modular computer program for circuit simulation in order to study the effect of changes in the operating conditions. It has been shown that weight recovery to sand fill increases as feed percent solids decreases, and, to a lesser extent as pressure drop across the banks increases. An increase in apex diameter also causes an increase in weight recovery. Increased weight recovery must, however, be balanced against sump an1l cyclone capacity and dilution of sand fill by fines. The predicted results from circuit simulation were in good agreement with plant data.The model has been found to be applicable to widely different ores."

Jan 1, 1979

"Cobalt refining at Vale Canada (previously known as Inco) has been associated with Ni production. Because certain compounds of both metals carry risks for adverse health endpoints by inhalation exposure, it is critical to understand the aerosol concentrations of specific substances and the metallurgical processes through which they enter the air. Vale Canada has therefore decided to describe the histories of its Ni-related operations and to report industrial hygiene measurements when available. This paper describes electrolytic Co operations carried out at Port Colborne, Ontario (1954–1966), and provides aerosol measurements (1995–2008) for current Co electrowinning operations.RÉSUMÉ L’affinage du cobalt chez Vale Canada (anciennement Inco) a été associé à la production de nickel. Puisque certains composés de ces deux métaux comportent des risques d’effets néfastes pour la santé par exposition à l’inhalation, il est essentiel de comprendre les concentrations en aérosol des substances spécifiques ainsi que les procédés métallurgiques par lesquels ils entrent dans l’air. Vale Canada a donc décidé de décrire les historiques de ses opérations liées au nickel et de divulguer les mesures d’hygiène industrielle lorsqu’elles sont disponibles. Le présent article décrit les opérations électrolytiques effectuées sur le Co à Port Colborne, Ontario (1954–1966), et fournit des mesures de la teneur en aérosol (1995–2008) pour l’extraction électrolytique actuelle du Co."

Jan 1, 2015

By Chris M. Healey

"Perhaps the single most significant variable in the evaluation of a mining project is the reserve estimate. Many parameters are considered when estimating reserves, among them geology. This paper examines the link between the quality of a reserve estimate and a good understanding of the geological controls for the deposit. A clear understanding of the geometry is essential to the accurate definition of the shape and size of the deposit. This includes the definition of any structural controls as well as the proper interpretation of the stratigraphy. Further when the distribution of grades is erratic and there is consequently a high nugget effect, there are significant problems in estimating the true grade of the deposit.Two Saskatchewan examples are presented, one with good knowledge of the controls and therefore good estimates of reserves, and the other with a poor understanding of the geology and resultant problems in deriving good estimates. In both cases the reserve estimates at various stages in the project development are compared to actual results from underground work. The first example is the Star Lake Mine where just about all the estimates were within 10070 of the actual on both tonnage and grade. The Laurel Lake deposit is discussed to show how problems in interpreting the geological data make reserve estimation very difficult. Laurel Lake has the additional problem of erratic grade distribution."

Jan 1, 1992

By Farzad Mohammadi, Patrick Littlejohn, David Sanguinetti

Arsenic levels in metal concentrates are increasing as mining companies turn to developing low grade and complex ores. When arsenic bearing minerals are smelted, arsenic deports as gases which must be neutralized by a scrubber system. The resulting scrubber effluent is high in dissolved arsenic and requires treatment before the wastewater can be discharged or re-used. Conventional arsenic removal relies on lime addition followed by calcium arsenate formation and precipitation as hydroxides. As an alternative, arsenic removal with sulphide precipitation is receiving more attention due to potential advantages of the technology. Process streams high in arsenic often contain concentrations of dissolved metals that may be selectively recovered during sulphidization, producing a product that can be reprocessed and reducing waste generation. This paper will review laboratory testing completed for arsenic removal through sulphide addition and precipitation of arsenic (III) sulphide in combination with metals recovery to offset arsenic removal costs.

Jan 1, 2014

By Tyson C. Birkett

Initial indicator mineral sampling covering 425,000 square km of northern Quebec and subsequent follow-up of positive results convinced the Ashton ? SOQUEM joint venture to acquire mineral rights to 380,000 hectares prospective for diamond in late summer, 2000. Drilling in 2001 and 2002 identified eight kimberlitic bodies, all significantly diamondiferous. Commercial size stones (retained on a square mesh sieve with openings 0.85 mm) and encouraging grades have been returned by several bodies tested to date: The Renard bodies are formed by steep-sided breccia pipes with kimberlitic matrix surrounded by irregular outboard breccia zones within country rock. These bodies were emplaced in high-grade metamorphic rocks of the Superior Province of Archean age. Orthogneiss with lesser tonalite hosts the breccias, although regionally paragneiss is also present. Diatreme facies portions and nearby country rock are intruded by minor to major (Renard 1) amounts of hypabyssal-facies kimberlitic rock. Renard bodies are macrocrystic, with large olivine crystals set in a groundmass of olivine, phlogopite, monticellite, spinel, carbonate, apatite and serpentine. Proximity of various Renard bodies, with most in a core area of 0.5 square km will allow planning of an efficient mining operation. Geophysics, especially magnetic surveying, has contributed to identifying bodies of kimberlitic rock.

May 1, 2003

By Bradford C. Wesstrom

An overview of the challenges encountered at the Freeport McMoRan El Paso Copper Refinery with higher concentrations of antimony electrolyte will be shared. The observations will cover the detrimental effects on copper starting sheets, commercial cathodes and anode slimes. The study will show negative effects on quality and productivity. Experimental work will utilize a test cell to study the effects on electrolytes by different Antimony, Arsenic concentration and anode molar ratio. Best practices will be shared for producing high quality cathodes while effectively managing the detrimental effects of higher antimony electrolyte.

Jan 1, 2014

By Lawrence Devon Smith

What is a Failed Project? For mining projects, some key indicators of a ?failed? project are: ? Cost is more than it should be (particularly capital) ? Schedule ? It takes longer to build than expected ? It takes longer to ramp-up than expected ? It does not do what it is supposed to do ? Poor performance; output, product specifications; ? Low revenue ? High costs ? No one is happy about it: Management, Shareholders, Bankers ? Does a project fail if it does not meet expectations that were unrealistic and unattainable? ? Caution: Failure may not become evident until years later

May 1, 2010

By C. Jay Hodgson, Adrienne C. L. Larocque

The Mobrun VMS deposit in northwestern Quebec does not fit the classic Noranda type model, but exhibits characteristics more consistent with a Mattabi-type deposit. The orebodies are underlain by fragmental volcanic rocks indicative of explosive volcanism in shallow water. Felsic volcanic rocks are more abundant than mafic rocks. Alteration assemblages comprise chlorite, carbonate, sericite, and quartz. Broad semi-conformable alteration occurs high in the footwall to the 1100 lens. Mobrun occurs higher in the stratigraphic sequence than most of the other deposits in the Noranda camp. In this part of the stratigraphy, zones of pervasive carbonatization may be more useful guides for exploration than zones of silicification.

Jan 1, 1993

By D. J. Bowen

"The Great Dyke extends for 540 krn along strike, to unknown depth, and varies in width from 3 krn to 11 krn. Rb/Sr age determinations gives values of approximately 2470 Ma.The Dyke consists of a variety of mafic and ultramafic rocks, many altered to serpentinites. These include, from top to bottom, successions of gabbro/norites, pyroxenites, peridotiteslharzburgites, and dunites/picrites.The layers dip in from either margin, steepest at the edges (20°) and flattening toward the central sections. Four separate complexes are present. From north to south these are termed the Musengezi, Hartley, Selukwe and Wedza Complexes, and are described as 'boat-shaped' or 'pig-troughed'. All are similar in petrological sequences. Physiographically, the Dyke is spectacular in the north, where as a mountain range it meets the Zarnbezi Escarpment. Elsewhere in the central parts there is little surface expression and wide open treeless vleis. Dyke rocks cut through granite and schist belt terrain and are termed 'The Magnesia Belt'.Vast mineral resources exist. These include chrome, asbestos, platinoids, nickel, copper and gold. Up to eleven chrome seams numbered from top to bottom occur in the lower ultramafic sequences. Seams are narrow at 10 em to 30 em but of high grade. The platinum occurs 10 m to 40 m below the norite/pyroxenite contact.A 60 m wide zone of Light Sulfide Mineralization (LSM) of less than 1070 sulfides extends from the lower gabbronorites into the upper pyroxenites. In this LSM, four enriched zones carry up to 5% sulfides. The most widespread is termed the Main Sulfide Zone (MSZ), below which is No. 2, No.3 and No.4 Sulfide Zones. The MSZ carrying pyrite, pyrrhotite and chalcopyrite is a multielement ore with components of PGE (pt-Pd-Rh), nickel, copper and cobalt, and gold and silver.Extensive exploration programs have been carried out and the intention is to begin large-scale mining. However, with Russia supplying metals to the western markets, South Africa's cutback on production, and an end to the Cold War, delays have arisen."

Jan 1, 1994

By G. A. Sutton

This paper, describes a case example from San Manuel mine, where in situ copper leaching of the supergene zone was done over a 14 year period (1986–1999) in conjunction with underground and open-pit mining operations of a copper porphyry deposit. In 1993–1994, testing of well fields was done to determine the amount of copper that would be recovered from in situ leaching of the supergene zone, which was composed primarily of chrysocolla and copper-clay minerals. It was determined that the leach fluid would reach 70% (‘sweep efficiency’) of the copper minerals and that 75% of them would be leached for a recovery of 52% of the acid soluble copper. However, the final results from Zone 6, which had the longest leach history, showed that approximately 42% of the acid soluble copper was recovered, indicating that the `sweep efficiency’ was closer to 55%. Comparison of drill-core assay data from two holes, one drilled before (ARM158) and the other after (SMO9607) leaching, also indicate that approximately 42% of the acid soluble copper was recovered. The discrepancy between the predicted (52%) and actual (42%) recovery is probably related to a combination of factors, including difficulty in maintaining fluid saturation, channeling effects and gypsum precipitation. INTRODUCTION In situ copper leaching at the San Manuel mine, Arizona, was initiated in 1986. It was recognized that some of the copper oxide resource was not going to be economically recoverable by conventional open pit and heap leach methods using solvent extraction and electrowinning (SXEW). A high stripping ratio would be required to access part of the resource. At the time, in situ leaching was becoming popular in the uranium industry but the approach was virtually unknown in the copper industry, especially not at a large scale.

Jan 1, 2019

By Andreea Catalina Gluhoi

Oxidation and reduction reactions of N-containing molecules have been studied over different types of gold-based catalysts, Au/MOx/Al2O3 and Au/MIOx/MIIOx/Al2O3 (M, MI, MII=Li, Rb, Mg, Ce, Zr, Mn, Cu) prepared by deposition precipitation with urea. In general, all the catalysts were already active at low temperatures. NH3 oxidation was effectively catalyzed by Au/CuO/Al2O3, a catalyst which also gives the highest yield in N2. NO reduction by H2 performed over gold-based catalysts produced N2O, N2 and NH3 and N2O reduction resulted in the formation of dinitrogen. For all the reactions, large synergistic effects have been obtained by addition of different kind of additives.

Oct 1, 2003

By Robert B. Parsons

"Canadian investment abroad has been the focus of considerable attention in recent years. Canadian mining companies have been heavy investors in Latin America and are taking a hard look at Central Asia and the Pacific Rim. This international flow of capital is not one-way however. Foreign mining companies continue to make substantial investments in Canada's mining industry. This month. Tax Notes addresses some of the main Canadian income tax implications of foreign investment in Canada.Foreign Investment in CanadaThere are two basic forms of foreign investment in a Canadian company: share capital and debt. The following comments deal with each of these investments separately. It is appreciated that the relevant tax legislation is, as always, quite complex, and that the notes that follow are intended only to serve as a guide. This article should not be relied on as a substitute for professional advice."

Jan 1, 1994