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By J. E. Dutrizac

Mercury balances have been obtained for the flotation circuits at Pamour Porcupine Mines, Timmins, Ontario, and at Brunswick Mining and Smelting Corporation, Bathurst, New Brunswick. The mineral form of mercury in both deposits has been ascertained. At Pamour Porcupine, the mercury is approximately evenly divided among sphalerite, native silverelectrum and tetrahedrite-tennantite; at Brunswick Mining, this element is contained mostly in the sphalerite, although tetrahedrite (and possibly pyrite) also contains minor quantities.

Jan 1, 1979

By E. Krause, V. G. Papangelakis, S. Garg, R. Mahadevan, E. Edwards

"Bioleaching uses iron and sulfur-oxidizing bacteria to extract base metals from sulfide minerals. As bioleaching involves breaking the iron-sulfur bonds by ferric attack, the biologically mediated rate of iron oxidation is recognized to play a key role in influencing the overall kinetics. In this study, we investigate the catalytic ability of an indigenous AMD culture for oxidizing Fe(II) in solution. This culture was subsequently adapted on pyrrhotite tailings (0.6% Ni) by gradually increasing the solids loading. Results from this study show that such an adaptation reduces the initial lag phase in the biotic oxidation of Fe(II), thereby allowing for a higher Ni extraction when compared to experiments with an un-adapted culture at a similar solids loading. The use of adapted cultures also helps to reduce the residence time for bioleaching of Ni from pyrrhotite tailings. INTRODUCTIONAs the world demand for pure base metals grows; the mining industry is increasingly faced with the burden of processing lower grade ores and mining waste streams in order to recover the occluded metal VALUES ((Watling, 2006). The extractive metallurgy of nickel from sulfide minerals focuses on using a combination of mineral processing, pyrometallurgical (smelting) and hydrometallurgical techniques to extract Ni from its ore bodies.Pyrrhotite (Fe1-xS) is commonly found in association with pentlandite and chalcopyrite in sulfidic Ni ores, such as those found in Sudbury, Ontario, and in Russia, e.g. Norilsk. The vast majority of this pyrrhotite needs to be removed using mineral processing techniques, in order to minimize the Fe and S contents of the concentrates that proceed on to smelting. If all pyrrhotite were left in the concentrate, much more slag and SO2 would be produced, and the smelter throughput would be limited. Beneficiation of Ni sulfide ores leads to the rejection of unwanted constituents as mining wastes, which may still contain extractable amounts of Ni (Edgar Peek et al., 2010)."

Jan 1, 2012

By J. Jung, W. Keller, A. Zucht

"The agitator design for nickel high pressure acid leach autoclaves (HPAL) is critical with regard to the process result, i.e., the recovery rate. Further considerations during the design phase are the avoidance of acid hot spots which reduce the lifetime, due to corrosion of the wetted parts, including components manufactured from titanium. Besides the process knowledge to design HPAL autoclaves, tools such as, Computational Fluid Dynamics (CFD) supplemented by lab testing allow the design of optimized agitation systems. This paper describes the effect that different feed point locations have on instantaneous blending of the reactants. Furthermore, experiments and CFD show where abrasion issues might occur and how to obtain information about the static and dynamic forces acting on internals. We show how simulations can be validated by lab testing to ensure that the CFD models are applied in an appropriate way.INTRODUCTIONAgitated systems in hydrometallurgical processes have to comply with multiple process tasks and in many cases have to withstand extreme operation conditions such as pressure up to 50 bar, elevated temperatures of up to 250°C and exposure to very acidic or alkaline environments and abrasive ores. The process tasks range from instantaneous mixing of reactants, homogeneous suspensions of up to 65% wt. solids with coarse and heavy particles, enhancing the solid-liquid mass transfer for leaching, dispersing large volumes of reactants (gas-liquid, liquid-liquid mass transfer) and moreover to transport generated heat e.g., from exothermic reactions through the vessel walls or internal heat exchangers if required. For economies of scale, agitator systems have reached sizes of 5000 m³ for large open leach tanks with impeller diameters of approx. 6 m, while autoclaves nowadays have exceeded 5.5 meters in diameter with a power demand for a single compartment drive between 300 - 400 kW. In parallel all process industries require a more efficient use of resources, to generate less by-products and higher yields, while ore-bodies tend to be less qualitative and new process routes (e.g. direct leach) are developed. Besides all these facts the mixing solution must be robust and economic. In this paper we want to address our approach in the development and designing of HPAL agitation equipment."

Jan 1, 2012

By J. W. Craig

CHROME ore, which is used in Canada in the production of ferro-alloys, in a variety of refractories, and indirectly in many chemical industries, is both commercially important and scientifically interesting. The sight of chromium metal is familiar to all of us in the home, the office, the automobile. Chromium is synonymous with armaments: it is understood to be one of several essential metals in tanks, which played an important role in the defeat of France in the spring of 1940. Chromium, in other forms, comes into our daily lives by way of paint and leather, of the familiar green ginger-ale and beer bottles, and more indirectly in every pound of steel produced in the .Dominion. Necessary to our civilization in peace and war, the ores of chromium occur in many corners of the earth. This paper attempts to describe the chemical constitution of chrome ores, their world distribution, and the various chrome products and their industrial applications in Canada.

Jan 1, 1940

By C. Allen

In 2004, Boliden Odda underwent an extensive modernisation project targeting mainly the leaching section of the plant. Direct leach technology was introduced as part of this project. The Direct Leach process, developed by Outokumpu, is an atmospheric oxidative leach of zinc sulphide concentrate. The effects of this new processing operation on behaviour of iron in the plant are discussed. As well, the filterability of the new residue on belt filters prior to its deposition in mountain caverns is also discussed. The solids from the direct leach process have been analysed by scanning electron microscopy, and the results of these analyses are presented.

Jan 1, 2006

By A. Alfantazi, E. Asselin

"The corrosion of commercially pure titanium (CP-Ti) was studied from room temperature up to medium temperature (~160°C) under conditions relevant to medium temperature chalcopyrite leaching processes. The corrosion rates were measured by immersion and electrochemical tests in sulfuric acid. The influences of chloride, cupric and ferric ions on the corrosion rate and behavior were also investigated. Corrosion of the CP-Ti did not account for the total current density measured by linear polarization tests. The corrosion rates of CP-Ti under medium temperature leaching conditions were surprisingly high. The corrosion rate measured in ferric containing solution at 160°C was approximately 20 mm/yr.INTRODUCTIONTitanium exhibits excellent corrosion resistance in many aggressive environments because of the formation of a very chemically stable, highly adherent, and protective oxide film on its surface (Mitsuo et al., 2002). Because titanium is the only metal available at a reasonable cost that resists the high temperature corrosive slurries in many leaching processes, it is often chosen as autoclave liner material where it is subjected to severe conditions of acidity, temperature and pressure (Grauman and Say, 2000).A number of distinctly different hydrometallurgical processes for the pressure leaching of chalcopyrite have been developed and patented by various companies and they can be classified into low, medium and high temperature regimes (McDonald and Muir, 2007). For example, chalcopyrite concentrate may be processed at medium temperatures (115-175°C) and pressures of 800-2200 kPa (Dreisinger, D., 2006; Sahu and Asselin, 2011). The lixiviant may contain 20 to 55 g/L sulfuric acid, 8 to 12 g/L chloride ions, 10-25 g/L Cu2+ (Jones, 1995, 1997, 1999), and less than 1 g/L Fe3+ (Defreyne et al., 2005). The amount of these additions is determined by the grade of the ores and details are shown in Table 1."

Jan 1, 2012

By J. R. Fisher

"Uranium may be leached to some extent in situ from the Blind River conglomerate uranium ores by using the products of bacterial activity from the bacterium Thio-bacillus ferrooxidans his paper describes some of the laboratory techniques used to investigate the characteristics of the bacteria, and to utilize their properties in uranium leaching. The application of some of the laboratory results underground at the Milliken mine of Rio Algom Mines Limited are de-scribed, along with the method of uranium recovery from the mine waters."

Jan 1, 1966

By M. Solomon

Abstract -Giant, sediment-hosted lead-zinc deposits in northern Australia formed during development of Mid-Proterozoic extensional basins that overlie Lower Proterozoic basement. The basement in the Mount Isa area, exposed by folding and faulting, contains fractionated, high-heat-producing granites. These granites generate heat at a rate of about 6 ?Wm-3, probably sufficient to form giant lead-zinc deposits either by (a) driving episodic convection of saline basement and basin fluids for periods of 105 to 106 years at temperatures of about 230°C, or (b) heating basin fluids moving under the influence of topographic relief or fault movement. The presence or absence of such granites may form a vital component of the genetic model. Ore-forming fluid flow was probably initiated by continent-scale, extensional basin fracturing.

Jan 1, 1992

By Eric Johnson

"IntroductionHistoricalCyanidation is a leaching process, in world-wide use, to extract gold (and silver) from ores and concentrates. The process has many inherent advantages on account of its adaptability:a. to any scale of operation;b. to a wide range of ore types and mineral associations;c. to a wide range of physical characteristics of the gold particle size, alloy (electrum) or mineral (telluride);d. to relatively simple plant controls and operating procedures;e. to simple marketing procedures and quick cash return.The basic idea for cyanidation was first described and patented by a German chemist, L. Elsner, in 1846. Some forty years later, J.S. McArthur, a metallurgical chemist and R.W. and W. Forrest, medical doctors, all of Glasgow, Scotland, came to realize the import of the discovery and accordingly, registered patents in Great Britain in 1887 and in the United States in 1889. The keystone of the McArthur-Forrest patent registration was the use of weak (0.05o/o) instead of strong (1.0%) solution.The years 1890-1910 saw much progress in equipment design and the advance from batch to continuous processing to increase efficiency and reduce operating costs.In later years, technological progress followed advances in materials of construction and control systems. Current innovations include large-scale equipment, high-capacity thickeners, belt type filters and Steller, candle-type filters for plants using zinc dust precipitation. As well, environmental protection is increasingly a major concern.The technology of gold adsorption from cyanide solution onto activated carbon has made rapid strides in recent years. This has followed the initial efforts of Potter, Salisbury, Zadra and their colleagues of the U.S. Bureau of Mines Research Station in Salt Lake City, Utah, and the field work of Homestake Mining Company personnel, in Lead, South Dakota."

Jan 1, 1989

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Jan 1, 2012

By J. P. Wiser

THIS paper discusses testing and quality control of milled asbestos fibre. It has been composed with the intention of: (I) Summarizing past, present and probable future methods of testing and classifying the various grades of commercial asbestos produced by the Quebec asbestos industry. (2) Acquainting those unfamiliar with the methods used for evaluating, testing and controlling the grading and the quality of Quebec chrysotile asbestos fibres with some of the physical and chemical procedures currently used for that purpose. (3) Discussing some of the complications facing the producers, such as variations in the orebody and special requirements of asbestos manufacturers. ( 4) Detailing some of the present quality control methods. SUMMARY OF PAST, PRESENT AND PROBABLE FUTURE TESTING METHODS Past During the first years of production of commercial asbestos in the Province of Quebec, fibre testing and quality control were based principally on dry screen analysis and visual inspection. These methods were gradually expanded during the period from 18, 90 to 1932. In 1932, standardization

Jan 1, 1962

By R. C. Hartviksen, B. H. Boyum

"The Sherman Mine, Temagami, Ontario, is an iron ore pellet operation rated at one million tons per year capacity. Mining is done from three open pits in two bands of Keewatin iron-formation intercalated in a 'greenstone belt' thought to be part of the Archean 'Abitibi Belt'. The bands of iron-formation are tabular and steeply dipping, averaging 75 degrees. The principal ore mineral is magnetite.Blast holes, 1214 inches in diameter, are drilled on 28-foot centers, each hole being sampled and assayed for both total iron and magnetic iron. Concentration tests are made in the laboratory to determine the anticipated concentrate grade. Two classes of ore are recognized -'liberating' or 'refractory'. Blending is done on iron con-.tent, degree of ease of liberation (i.e. grain size) and chunkiness. The latter is important, as primary milling is done in autogenous mills. Actual daily mill results are compared with predicted grade from blast holes, exploration diamond drill holes and pit inspection. Hourly mill samples are analyzed by the X-Ray Fluorescent Analyzer, with emphasis on silica grade. In 1969, the pellet grade was improved from 7 .01 per cent silica natural to 5.50 per cent silica natural."

Jan 1, 1970

By C. M. Diaz, S. W. Marcuson

In the late 19th century, the discovery of rich nickel-copper sulfide ore bodies in Sudbury and the need for tonnage quantities of the metal to be used in nickel steel armor provided the foundation for establishing the Canadian nickel industry. For almost 50 years, International Nickel was the key player. In 1930, Falconbridge Nickel entered the field. These two companies remain the key Canadian nickel producers. This paper discusses the factors that have influenced the evolution of nickel smelting processes. The initial Sudbury ore smelting and nickel copper separation technologies were imported from abroad. It was only in 1937 that International Nickel established a process research laboratory in Copper Cliff The explosive post WW II industrial development created a strong demand for a broader variety of nickel products. For both International Nickel and Falconbridge, R&D became an essential business tool to succeed in the new market scenery. In the last few decades, new technologies were developed and commercialized to respond to the raising cost of energy, society pressing environmental concerns, the advent of nickel laterites as an important source of new metal, the incorporation of new nickel producers to the market, and, therefore, the need to increase productivity. Canada thus became an important exporter of technology. In this paper, the authors review this history with the objective of highlighting the forces that have triggered the most important changes in Canadian nickel smelting.

Jan 1, 2005

By R. F. Robertson

"Adsorption isotherms of hexyl mercaptan vapour on synthetic sphalerite, zinc sulphide and zinc oxide were de-termined with a gravimetric McBain-Baker micro balance incorporated in the B.E.T. apparatus. Isotherms are given for hexyl mercaptan on synthetic sphalerite at 25°C, 0.5°C and 50°C; on zinc sulphide at 25°C and 1.5°C; and on zinc oxide at 25°C. All these isotherms are sigmoidal, with a definite change in slope at or close to the mono-layer. The amount of mercaptan adsorbed below the monolayer increases almost linearly with relative pressure to P/P0 = 0.8.Above this value, the amount adsorbed increases very rapidly with relative pressure. Hysteresis loops appear in the isotherms for all adsorption-desorption cycles. These loops are completely reversible. It is not possible to desorb the mercaptan monolayer from any of the adsorbents, even at elevated temperatures."

Jan 1, 1966

By David J. Kerr, Robert Mason

"From1927 to1989, the Hornemineproduced53.7 Mt of ore grading 6.1 g/t Au and 2.2% Cu from two large volcanogenic massive sulphide deposits composed primarily of pyrrhotite, pyrite and chalcopyrite. The ore bodies were hosted by a package of chlorite-sericitealtered epiclastic rhyolite tuffs which were deposited in a narrow palaeo-graben located on the flank of a major felsic volcanic centre. M ineralizingfluids percolated upward through the permeable footwall rocks and were further focussed along syn-volcanic, graben-bounding faults. Sulphides were deposited by a process of sub-seafloor replacement of the rhyolite tuffs.Gold-copper-(zinc) mineralization, including ore zones mined between 1985 and 1989 as the REMNOR ore zones, is present throughout the 900 m of felsic volcanic stratigraphy at the Horne. All the deposits were formed by syn-volcanic hydrothermal processes active during felsic volcanism. There is no evidence to indicate that any economic gold mineralization was introduced by a post-volcanic hydrothermal episode.RESUMEDe 1927 a1989, /amineHorneaproduit53.7 Mt de minerai avec une teneur de 6.1 g/t Au et 2.2% Cu provenant de deux grands amas de sulfures massifs volcanogeniques comprenant esentiellement de la pyrrhotite, de la pyrite et de /a chalcopyrite. Ces gites font partie d'une séquence de tufs rhyolitiques epiclastiques chloritises et sericitises qui ont ere déposes dans un paleo-graben étroit situe sur le flanc d' unimportant centre vo/caniquefelsique.Lesfluides mineralises ont circule de bas en haut a travers /es roches perméables sous-jacentes; ils ont été également canalises par les failles syn-volcaniques en bordure du graben. Les sulfures se sont déposes par remplacement des tufs rhyolitiques immédiatement et sous /e plancher océanique.Les zones minéralisées en or et cuivre (±zinc) - y compris celles qui ont ere exploitees au cours de l’opération Remnor (1985-1989) - se retrouvent, sans discontinuité, à travers les roches volcaniques felsiques dont l' epaisseur atteint 900 m. Ces gites se sont formes par le biais d' un processus hydrothermal qui ag issait pendant le volcanisme felsique. II n'y a aucune évidence de minéralisation aurifère d'importance économique qui soit postérieure a l' activité hydrothermale syn-volcanique."

Jan 1, 1990

By J. G. Stevens, S. W. Colley

"Selective separations of metals and ions in mineral extraction and refining are becoming more challenging as ore bodies become more complex and environmental pressures increase. The separation and containment of mercury produced in gold mining are a factor in the profitability and operability of mines. This paper will discuss the development and implementation of the Johnson Matthey HgFree selective mercury removal process. The process is designed to selectively recover co-leached mercury from either heap leach pregnant solutions at ambient temperature and low mercury concentrations, or electrowinning pregnant solutions at elevated temperature and high mercury concentration, without affecting gold or silver recovery. The process utilizes a highly selective adsorption-desorption step in which mercury is removed quantitatively by the HgFree adsorbent without adsorption of gold, silver or other metals present. Development of the original HgFree adsorbent has resulted in a process whereby mercury can be recovered as an inert salt and is never present as the free metal. The HgFree adsorbent can be regenerated and recycled in situ, and is capable of being reused multiple times. The overall process is compatible with existing gold mining and recovery practices and offers significant environmental and sustainability benefits, including reduction or elimination of the need to retort mercury with a subsequent reduction in potential mercury air emissions. Development of the HgFree adsorbent and process will be discussed along with a pilot operation at two operating mines.INTRODUCTIONMany gold ore bodies contain high concentrations of mercury which when extracted with cyanide, co-extract with the gold and other metals. This mercury is carried through the process with the gold, posing environmental and technical issues when it is separated from the doré. This paper describes a method to selectively adsorb mercury from the gold recovery circuit while it is in a soluble form, leaving gold to be processed as normal. The removal of mercury from the circuit eliminates the need for mercury retorting of doré and so reduces the potential environmental impact of fugitive emissions of elemental mercury."

Jan 1, 2016

By C. H. Lee, T. T. Wang

"Exampling of the tunneling task in the Tsengwen Reservoir Transbasin Diversion (TRTD) in southern Taiwan, this study investigates the application of the Drilling Survey System (DRISS) in both Drilling and Blasting (D&B)- and Tunnel Boring Machine (TBM)-excavated sections. In the D&B section, a nonlinear relationship exists between drilling energy and uniaxial compressive strength of rock mass, in which a reasonable coefficient of determination can be analyzed statistically. Additionally, the DRISS accurately predicted an unfavorable section with a valuable position. The magnitude of uniaxial compressive strength back calculated using DRISS data also matches those acquired from geological investigations with different approaches. Study results indicate that the DRISS is an effective tool for fore-probing of both D&B- and TBM-excavated tunnels. INTRODUCTIONModern advancements in geological and geophysical investigations, and drilling techniques, have provided valuable information for detecting and interpreting geological conditions of rock tunnels with a resolution of several to ten of meters (Brückl et al., 2001, 2008, Lorang et al., 2005). Nevertheless, construction risks remain considerable during tunnel excavation, especially when a tunnel was excavated by a Tunnel Boring Machine (TBM). Predictions of the local fault, shear zone, and other minor geological features, which may cause moderate collapse or excessive deformation of rocks surrounding the tunnel, before tunnel excavation is highly desirable for high-quality tunnel construction and economically efficient project management.Rather than conventional geophysical prospection methodologies, which always favor large-scale investigation with moderate precision, this study focuses on the drilling method probing ahead of a tunnel. The goal of such an investigation is not only to prevent catastrophic collapse, but also to provide quantitative or semi-quantitative information for estimation of the mechanical parameters of rock mass.For the tunneling task in the Tsengwen Reservoir Transbasin Diversion (TRTD) in southern Taiwan, a drilling survey system is adopted for fore probing. Data collected from both drilling and blasting (D&B) and TBM-excavated sections are analyzed statistically and discussed. The applications of the Drilling Survey System (DRISS) are addressed accordingly."

Jan 1, 2015

By Leon J. Perrier

The paper describes the equipment in use, haulage grades, road conditions, tire sizes, tire performance and related problems. Various types of failures and causes, corrective action taken, tire records and reporting for control are also discussed.

Jan 1, 1977

By Roger J. Berdusco

Kaiser Resources Ltd. owns and operates a 5-million-tonper- year open-pit and hydraulic coal mine near Sparwood in southeastern British Columbia. Since 1969, Kaiser has maintained a field-scale reclamation program dedicated to the reclamation of disturbances associated with past and present mining and exploration activities . Since that time, over 1400 acres have been treated using modified forestry and agricultural techniques with encouraging results.

Jan 1, 1978

By Samuel O. Akande

"Gold occurs as native metal, in electrum, and in a telluride mineral in quartz carbonate veinlets of three vein systems at the Ross Mine, northern Ontario. The 14 Vein System is made up predominantly of concordant veinlets within layered ankeritic dolomite stratabound by, and conformable with, andesite tuff Individual veinlets contain pyrite, sphalerite, galena, chalcopyrite, tennantite, pearceite, proustite, native gold and electrum in a matrix of quartz, dolomite, ankerite and calcite. The 2B Vein System is made up of both concordant and discordant veinlets within andesite tuffs. The veinlets contain pyrite, chalcopyrite, sphalerite, bornite, tennantite and free gold in quartz, calcite and dolomite. The 18 Vein System is comprised of stockwork veinlets in and around intrusive syenite which has both sharp and gradational contacts with enclosing andesite tuff The veinlets contain pyrite, chalcopyrite, bornite, chalcocite, native gold and calaverite. Sulphide and silicate minerals in veinlets and wall rocks are stable assemblages for the regional metamorphism of greenschist rank. ,The 14 Vein System is interpreted as a metalliferous siliceous carbonate chemical sediment, the components of which were leached from the underlying volcanic rocks by convecting sea water and subsequently deposited on the sea floor between the extrusion of flows and pyroclastic rocks. Subsequent regional metamorphism and intrusions remobilized and redistributed the syngenetic stratabound material into dilatant fractures in adjacent tuff, as in the 2B and the 18 vein systems."

Jan 1, 1982