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By P. T. O'Kane

"INTRODUCTION Wright Engineers Limited is active and has extensive experience in the design of pressure oxidation plants for the treatment of refractory gold ore and concentrate. In addition to the Mercur oxidation facility, similar projects undertaken during the last few years include the 3000 ton per day acid oxidation plant for the Getchell Mine, Nevada, a concentrate treatment autoclave for Asamera in 1984 and a feasibility study of a 50-tons per day autoclave plant for Consolidated Professor's Duport property in Ontario. The Equity Silver antimony and arsenic precipitation autoclaves, and the low pressure autoclaves at Key Lake Uranium in Northern Saskatchewan were also engineered by Wright in recent years.In August 1986, Wright was retained by Barrick Resources (U.S.A.) Inc. to add a 750 tpd pressure oxidation circuit to the existing mill at their Mercur Gold Mine, Utah. This paper describes this facility and outlines the start up in the spring of 1988 and subsequent successful operation. MERCUR OPERATION The Barrick Mercur Gold Mine is located at the south end of the Oquirrh Mountains in Tooele County, Utah. The carbon-in-leach (CIL) process plant camnenced operation in 1983 with a design throughput of 3000 tpd and has since been expanded to handle rrore than 5000 tpd. 'IWo ore types are mined, an oxide ore and a refractory ore, which is by Barrick's definition ""an ore from which less than 60% gold extraction is achieved by a standard CIL amenability test."" Typical of many sulphidic/carbonaceous ores, the refractory gold does not respond well to the cyanidation process. As a result, refractory ore has been stockpiled since the start of mining. As of June 1987, Mercur had about 570,000 tons of refractory ore stockpiled and 5.7 million tons of proven and probable reserves, grading 0.06 oz/t including approximately 3.5 million tons of tailings from the previous operation grading 0.55 oz/t. In 1986, Barrick decided to build a 750 ton per day pressure oxidation plant to process these ores. The process, for which a patent was granted, comprises pressure oxidation of the sulphides in an alkaline environment. It was developed in 1981 but was set aside in preference of a CIL plant treating only oxide ores by the previous owner of the property, Getty Oil. This process is capable of increasing gold recovery from the refractory ore from as low as 35% by conventional CIL processing to more than 85%. In 1986 Wright Engineers was engaged to undertake a feasibility study based on batch testing. This lead to a decision by Barrick Mercur later that year to build the commercial pressure oxidation plant. Wright was awarded the contract for engineering, procurement, construction managernent and commissioning in March 1987. The plant was mechanically complete in January 28, 1988, and was in operation by February 1988."

Jan 1, 1989

By Robert B. Parsons

"Canada's mining industry has reason to celebrate the federal government's budget which was tabled on February 26, 1986. The budget contains an important proposal to improve the flowthrough share rules by effectively eliminating the investor's liability to third parties. This proposed rule change and other important budget proposals are the subject of this month's edition of Tax Notes. IntroductionWhile Finance Minister Michael Wilson's February 26, 1986 budget received a mixed reaction from business and labour leaders, the budget was mainly ""good news"" for the mining industry. A long-standing bugaboo in the flow-through share rules will be cleared up, a permanent set of rules will be installed for the tax treatment of Northern allowances, and limited partnerships will apparently be able to continue to serve a useful role in financing exploration programs. Flow-Through SharesThe present rules which apply to an investment in flow-through shares are structured in such a way that the relevant Canadian exploration expense (""CEE"") must be incurred by the investor, and not by the issuing corporation. Obviously, in the case of most flow-through share issues, this requirement that the investor incur the CEE poses a practical problem-the investor typically does not have the expertise or organization to incur the CEE. As a result, an integral part of most flowthrough arrangements is an agreement whereby the investor appoints another party (usually the issuing corporation) as his agent to spend the flow-through funds on CEE on his behalf. Although the issuing corporation might consequently be the party which actually spends the flow-through share funds on CEE, nevertheless the legal structure is such that the investor is the ""principal"" who is incurring the CEE. As such, the investor is legally responsible for any third-party claims with respect to the exploration program. Third-party liability might arise, for example, in the case of property damage, personal injury, environmental infractions, and so on."

Jan 1, 1986

By P. Hickey

"The object of this paper is to describe how the Iron Ore Company of Canada develops its management personnel. It will elaborate on the practical application of Supervisory Training and Management Development.Why are Supervisory Training and Management Development important? The answer has been the subject of many textbooks. Dr. Ken Blanchard, author and consultant, addressed this issue concisely when he said that effective managers and organizations must do two things, ""get results and develop people"". lPeople development at IOC is best illustrated through its supervisory training and management development programs. For the past twenty-five years IOC has been recognized as an industry leader in the training field. Periodic studies have played their role in establishing and maintaining this distinction. For example, in 1974, the company decided to review and up-date all its training programs. At this time, it established its own Task Force on Training and this resulted in the development of many of our present programs. Today, Supervisory Training (i.e. for first and second level management) at the Carol Project in the Labrador City area consists of various programs including: New Foreman Induction, Foreman Entrance School, Basic Management Skills, Management II, and Effective Presentations."

Jan 1, 1983

By Laura Prati

Gold-on-carbon catalysts resulted very active and selective in liquid phase oxidation [1, 2, 3] and during past studies we established that activity is ruled by two factors: particle dimension and gold exposure on the carbon surface [4]. These two parameters are also connected to the nature of activated carbon where the chemical nature of the surface oxygenated groups probably plays an important role [5]. Our studies, focused on the design of an active gold-on-carbon catalyst for liquid phase application, were aimed, operating a fine tuning of all the parameters involved in determining activity, to optimize gold-on-carbon preparation, keeping in mind that gold particle activity increases with decreasing particle size and increasing gold exposure. Gold sol immobilisation represents a versatile methodology in preparing gold catalysts [6]: throughout this work we used as sol stabilizing agent, the N-dodecil-N,N-dimethyl-3-amino-1-propan sulphonate (SB), that provides both sterical and electrostatic stabilisation, a condition we already demonstrated necessary to preserve particle dimension when carbon is used as the support [6]. We generated different gold sols by varying the relative amount of reagents (HAuCl4, SB, NaBH4), the type of alkali and the temperature of the gold precursor reduction. Moreover, as we had recently evidenced that there is also a carbon effect [5], we employed only one active carbon to immobilize the sols.

Oct 1, 2003

By Elizabeth Gardiner

Tailings and water management facilities are integral components of mine and mill operations. They must be managed for the long term to ensure that safe and environmentally responsible stewardship is achieved. The Mining Association of Canada (MAC) has developed and published two manuals to provide guidance to mining companies on sound practices for the safe and environmentally responsible management of tailings facilities: ???A Guide to the Management of Tailings Facilities; and ???Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. The Guides were designed to help companies develop and implement tailings management systems that include environmental and safety criteria, to improve the consistency of application of sound engineering and management principles to tailings and water management facilities through their full life cycle, and to demonstrate this to regulators and the public.

May 1, 2003

By Jean-François Lessard

The performance of rock pass systems has a significant contribution to the economics of underground mines. Operational concerns include hang-ups due to arching of material, blockage and degradation of the rock pass. This papers presents the preliminary results of a comprehensive rock pass database on the engineering and operation of rock pass systems in Quebec underground mines.

May 1, 2002

By S. Dicarlo

"In late 1985, B-zone ore was first processed through the Eldor Mines mill at Rabbit Lake. Extensive modifications had been completed in order to mill this ore. In-plant process development was initiated to tune up the new circuits and concentrated on leaching, solvent extraction, impurity and uranium precipitation and tailing and effluent treatment. This process development effort and the results are described.INTRODUCTIONEldor Mines, a division of Eldorado Resources Limited, operates the Rabbit lake mine-mill complex at Collins Bay on the western shore of Wollaston Lake in northeastern Saskatchewan.The first orebody was discovered in 1968 by Gulf Minerals Canada Limited below a small body of water named Rabbit Lake. Ore from the Rabbit Lake (RL) deposit was first processed through the new mill in June, 1975, with depletion scheduled over the next ten years. Continued exploration in the area led to the discovery of four orebodies in the vicinity of Collins Bay: A-zone (1971), B-zone (1977), D-zone (1978) and Eagle Point (1980). Collins Bay is about ten kilometres from the mill facility.In 1982, Gulf Minerals was acquired by Eldorado Nuclear Ltd., who continued the development effort to bring the B-zone deposit into production. The RL pit was mined out in May, 1984 with stockpiled ore providing mill feed until startup on B-zone ore, which was scheduled for November, 1985."

Jan 1, 1988

By Zolfan F. Oszter

As exploration for new mineral deposits advances farther into the Canadian North, the more the design engineer is faced with the problems of cold weather conditions. This is especially true when designing belt conveyor systems for open-pit operations where the temperature in the winter may go to -40°F or below. Problems with the mechanical components and also with the belting will arise, which in turn may reduce the availability of the system. This paper outlines the problems encountered during cold weather operation and what precautionary measures must be taken into consideration in the design of equipment, as well as in the selection of materials, in order to ensure a system which will maintain production. THE conveying of ore and waste in the pit or to the processing plant poses problems during cold weather, when temperatures may drop to -4o?F or be-low. Troubles with the mechanical components, the belting or the supporting structure may arise, and this, in turn, will reduce the availability of the conveying system.

Jan 1, 1965

By Paul J. Bourassa

Alin de pourvoir aux besoins d'hébergement des quel¬ques 1600 employes qui travailleront dans toutes les spheres opérationnelles de l'exploitation du gisement du Mont-Wright, ainsi que de leurs families, Quebec Cartier a dû, avec l'aide de conseillers reconnus, et /a participation de ses employes résidant a Gagnon, étudier tour les nouveaux établissements résidentiels nordiques des dernières années tout au Canada qui dans lee pays scandinaves afin d'être en position de coneepter une agglomeration moderne répondant a toes les besoins de see future résidants. Les pre¬miers residants ont pu passer Noel 1972, et maintenant les logements prévus et construits sont °coupes a 92%.

Jan 1, 1977

By Dean McDonald

The Committee Bay Greenstone Belt extends over 300km and is one of the largest unexplored greenstone belts in North America with excellent gold and diamond potential. Committee Bay Resources Limited holds over 550,000 acres of land with prospective geology in the Committee Bay area southwest of Melville Peninsula, Nunavut. Committee Bay is a typical Archean greenstone belt comparable to the Yellowknife, Red Lake, Kirkland Lake and other prolific gold belts. Drilling during 2003 at Committee Bay resulted in: 1) the discovery of high-grade gold-bearing quartz veins with silicification and sulphidation at Three Bluffs, and 2) the continuation of high-grade gold mineralization in the hinge area of the iron formation at Inuk. Gold mineralization at Three Bluffs is identified in iron formation and adjacent sediments and has been traced by drilling for over 700m. The Three Bluffs iron formation is open to depth and along strike where is has been traced on surface for over 6km. In January 2004 Committee Bay and joint venture partner Gold Field?s announced a $7.1 million exploration program for the Committee Bay project in 2004. A total of 8,000m in exploration drilling has been approved for the expansion of the Three Bluffs to the resource stage and drilling of at least five new target areas. Additional mapping, sampling and geophysics will be used to identify new gold targets along the very prospective Committee Bay belt.

May 1, 2004

By Alan D. Akerman

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

May 1, 2002

By Ernie Doell, Trung Nguyen

"In early 1995 Cluff Mining commissioned a newly constructed high density tailings thickener at its Cluff Lake uranium mill. The 85 ft diameter high density thickener is one of the first of its kind in North America, and incorporates the novel paste technology in its design to produce densified (in the range of 60 -65% solids) mill tailings suitable for stable deposition in the tailings management area. This paper discusses the impetus behind the installation of such an unconventional thickener, and the many trying experiences in making it operational.IntroductionCluff Mining, a wholly owned subsidiary of Cogema Resources Inc., is the operator of a uranium mine and mill complex at Cluff Lake which is located in northern Saskatchewan. Since 1980, the company has developed and mined out several different ore bodies within the Cluff Lake region for the production of uranium concentrates, commonly known as yellow cake. Based on the known ore reserves, the Cluff Lake operations are projected to last till the early 2000's.Tailings from the Cluff Lake mill have been discharged to a tailings management area consisting of a tailings pond and two facilities for primary and secondary treatment systems. The tailings pond has an impervious bentonite lined dam, and it is divided into a solids and a liquids holding areas. Until the beginning of 1995, the mill tailings were discharged in two separate lines to the solids pond; one line carried the slurry residue of 45-50% solids (w/w) from the CCD circuit, and the other discharged raffinate tails containing less than 1 % (w/w) gypsum precipitate. Supernatant in the solids pond is treated in the primary treatment system prior to discharging to the liquids pond. Figure 1 shows the site plan of Cluff Lake tailings management area.It has been estimated that by the end of 1995 the solids pond would be filled to about 60% of its design capacity, and probably would be full before the year 2000. Therefore, Cluff Mining had to consider a more efficient tailings disposal method that could extend the service life of the existing Cluff Lake tailings management area. A high density tailings thickener was believed to be the most practical and economical system for tailings disposal at Cluff Lake mine."

Jan 1, 1996

By Frank Cappuccitti, James A. Finch, Stéphanie Gélinas

"A colorimetric technique, originally developed for methyl iso butyl carbinol (MIBC) based on the Komarowsky reaction, has been extended to a wide range of common mineral flotation frothers. The procedure, which is briefly described, is shown suited to on-site determinations in a campaign at Kennecott Utah Copper Copperton Concentrator (Rio Tinto). Some observations are described, including: frother (MIBC) concentration evolution down a bank, frother distribution between pulp and froth phases, and loss of frother over time due to adsorption on certain minerals. A possible interference with a fuel oil addition was overcome. MIBC in recycle water was also measured.The ability to monitor frother easily will help interpret gas dispersion behaviour and should permit further optimization of flotation cell hydrodynamics and chemistry. The capability to directly measure should help optimize the type, amount and location of frother addition, and to assess frother recycled with reclaim process water.INTRODUCTIONOwing to the lack of analytical methods, the task of determining frother concentration in plant flotation circuits is not routinely performed. Industrial sites seldom outsource analyses that are both costly and inconvenient, due to the necessity of shipping freeze-dried samples to remote testing facilities. A more direct colorimetric method has recently been demonstrated for the laboratory characterization of common industrial frothers (Gélinas and Finch, 2004). The approach, based on the Komarowsky reaction (Penniman et al., 1936; Coles et al., 1942; Duke, 1947), was previously described by Parkhomovski et al. (1976) for methyl iso butyl carbinol (MIBC). The reaction involves the interaction of the OH group of a higher alcohol, concentrated sulphuric acid, and salicylaldehyde, to yield coloured solutions with intensities that can be analyzed by UV-visible spectrophotometry."

Jan 1, 2005

By L. J. Vincze

The high cost of constructing mineral processing plants in remote locations warrants a close examination of the alternatives available for reducing the amount of on-site construction work. Among the alternatives are portable process plants, modular design and barge mounted plants. Each alternative has certain advantages as well as limitations depending upon specific conditions. On the basis of practical experience and engineering analysis, the paper examines the potential benefits to be realized by these techniques and summarizes the conditions required to obtain them. The potential savings indicated by such studies should encourage consideration of innovative design features for new plants located in remote areas.

Jan 1, 1980

By André Chagnon, Michel Malo, Benoît Dubé, Chantal Pelchat

"Abstract- In the southern Gaspé Appalachians, gold mineralization is spatially associated with the Acadian dextral strike-slip Grand Pabos-Restigouche fault system. Two different structurally-controlled gold prospects, the Lac Arsenault and the Saint-André-de-Ristigouche, are described to unravel the genesis of gold mineralization in this part of the Canadian Appalachians.At the Lac Arsenault gold prospect, gold mineralization consists of Au-As-Pb-Zn-Cu-(Ag) polymetallic fault-filled quartz veins with laminated textures emplaced in brittle-ductile sinistral X shear fractures. Mineralized veins are hosted by Middle Ordovician graywacke of the Arsenault Formation, belonging to the Dunnage Zone, the Early Paleozoic oceanic domain of the Appalachians. Terrigeneous rocks of the Arsenault are regionally metamorphosed at the lower greenshist facies and the mineralized veins are included in a zone of Fe-carbonate alteration.The Sb-Au-As mineralization of the Saint-André-de-Ristigouche gold prospect, in the southwestern Gaspé area, comprises extension veins in the extension direction emplaced in brittle conditions. Mineralized veins are hosted by calcilutite and laminated silty and argillaceous limestone of the Early Silurian part of the White Head Formation, which belongs to the Gaspé Belt, the Middle Paleozoic successor basin in the Gaspé Appalachians. Metamorphic grade of the White Head Formation in the southwestern Gaspé area is very low, but the gold mineralization is included in a zone of hydrothermal propylitic alteration which includes two Cu-skarn mineral occurrences. The Lac Arsenault gold prospect has many characteristics of "greenstone-hosted quartz-carbonate vein" deposits whereas the southwestern Gaspé area, which includes the Saint-André-de- Ristigouche gold prospect, shows affinities with the geological setting of sediment-hosted gold deposits (Carlin-like deposits). The two gold prospects are controlled by the Grand Pabos- Restigouche fault system but they were not emplaced at the same level in the crust. Acadian strikeslip fauting played a major role in their respective genesis in providing channelways for ore-bearing fluids. The recognition of the analogy of the geological setting of the southwestern Gaspé area with that of Carlin-like mineralization gives new ideas for exploration in the area and elsewhere in the Appalachians.Résumé - Dans le sud des Appalaches de la Gaspésie, on trouve des minéralisations aurifères spatialement associées au système de failles de coulissage dextre acadien de Grand Pabos-Restigouche. Deux indices très différents, Lac Arsenault et Saint-André-de-Ristigouche, sont décrits pour évaluer la genèse des minéralisations aurifères à contrôle structural de cette partie des Appalaches canadiennes. Au Lac Arsenault, la minéralisation aurifère comprend des veines polymétalliques à Au-As-Pb- Zn-Cu-(Ag) en remplissage de failles. Ces veines à texture laminaire se retrouvent dans des zones de cisaillement fragiles-ductiles senestres de type X. Les veines minéralisées sont encaissées dans les grauwackes d’âge Ordovicien moyen de la Formation d’Arsenault appartenant à la zone de Dunnage, le domaine océanique du Paléozoïque précoce des Appalaches canadiennes. Les roches terrigènes de l’Arsenault sont métamorphisées régionalement au faciès inférieur des schistes verts et les veines aurifères sont dans de larges zones d’altération dolomitique (Fe-carbonate).Dans le sud-ouest de la Gaspésie, la minéralisation à Sb-Au-As de Saint-André-de-Ristigouche est dans des veines d’extension comprises dans la direction d’extension et mises en place dans des conditions de déformation fragile. Les veines minéralisées sont encaissées dans les calcaires argileux et les calcilutites de la partie silurienne de la Formation de White Head qui appartient à la ceinture de Gaspé, le bassin successeur du Paléozoïque moyen des Appalaches de la Gaspésie. Le degré métamorphique des roches du White Head est très bas, mais"

Jan 1, 1998

By Rita Michael

"The Marmara Ironworks was not the earliest ironworks in Ontario, but it was distinguished from other early works in a number of ways. It was established on an ambitious scale as a self-sufficient and, for the time, sophisticated community. In effect it was an iron plantation on the scale and scope of those at Hopewell, Pennsylvania and Saugus, Massachusetts(1). It was, besides, the only one of the few early ironworks in Upper Canada which operated almost to the end of the nineteenth century, albeit in fits and starts, and which used magnetic ores rather than bog iron ores (limonite). Furthermore it is the only works which has produced archaeological interest over a number of years. The ironworks is on the east bank of the Crowe River near Highway 7, on Lots 7 and 8, Concession 4, Marmara Township, Hastings County, Ontario. It is the property of the Village of Marmara, and the extant remains encompass about 2. 5 acres of the original 2000 or so which made up the original grant. The mineral riches of the Canadian Shield had been known since the days of the Jesuit missionary-explorers. A consortium headed by Alexander Henry and the Duke of Gloucester planned to exploit the copper near Sault Ste. Marie during the last part of the eighteenth century, but nothing came of the venture(2). This attempt may have grown out of Lord Dorchester's suggestion that private enterprise be encouraged in order that the iron ore which ""abounds"" in Canada might be exploited(3). John Graves Simcoe, the first Lieutenant Governor of Upper Canada was also anxious to see iron working develop. Simcoe was eager to encourage many enterprises, among which ""the development of iron mines""(4) - Governor Gore had been approached by John Mason for help with his ironworks in Norfolk County (5). Three Americans had applied for permission and support to erect an ironworks on the Gananoque River at the falls to become known as Furnace Falls. They were granted 1000 acres of land in fee simple to encourage their endeavor(6). Sir Peregrine Maitland, only a few months after taking up his duties as Lieutenant Governor in 1818, intended to visit the ""bed of iron ore on the Crow River"" (7) - Maitland was to provide a good deal of support, both moral and substantive, to Charles Hayes when he came to Canada in 1820."

Jan 1, 1999

By D. M. Doyle

"A study of the various components contributing to energy costs and their relationships to generally trended operating data, such as tonnage, operating costs, etc. over progressively shorter time periods provides information for an energy audit. A study of annual data gives some insight into the importance of various energy components. As the time frame of the study 11rogresses through monthly, daily and finally, into quarter hourly data, the variations become more evident and most important, strategies develop to minimize energy costs. The results of an audit conducted during the summer of 1978 at Wesfrob Mines are reported to illustrate this important phase, prerequisite to a meaningful energy cost avoidance program.The balance of the paper deals with the energy conservation program at Falconbridge Nickel Mines Sudbury Operations, the material and control equipment, the commitment, the new energy accounting practices and lastly, the policies. Examples of successful energy conservation endeavors include automatic peal electrical load control, waste heat recovery from mine air and compressor cooling water, energy reductions resulting from lower building temperatures and curtailmen: of idling loads. The use of pulse meters to measure the flow of gas, steam, compressed air and electrical energy, with their signals interfaced to process computers, allows monthly, daily and if necessary, immediate reporting of energy and energy per unit of production information. The program so reported at Falconbridge’s Sudbury Operations is credited with an annual cost avoidance of .9 million dollars in a 14.0 million dollar annual energy account."

Jan 1, 1979

By J. F. Archibald

This paper reviews the formation of the Canadian Mining Education Council (CMEC) and its terms of reference. CMEC considers that Canada?s mining schools represent a distinct competitive advantage to the Canadian Mining Industry. The core objective of CMEC is to reinforce the links between the constituent schools and their individual Industry Advisory Committees. The latter traditionally provide the schools with a great deal of guidance on a range of planning issues, including recruitment, curriculum, research and infrastructure. Beyond those bounds CMEC intends to improve its ability to network with the industry and government. It is concerned overall with the objective to raise the quality and level of its educational and research contributions to meet the needs of industry and society.

May 1, 2002

By Thomas H. Heine

"The Rabbit Lake uranium deposit is located at 58° 11’00”N.. 103°42'36""W., close to the west side of Wollaston Lake, and approximately 800 km north of Saskatoon. The orebody is hosted by Aphebian Wollaston Group rocks, initially deposited as a series of shallow-water marine sediments consisting, in part, of carbonates and possible saliferous petites. Metamorphism during the Hudsonian Orogeny, peaking at about 1850 Ma, recrystallized the sediments to upper amphibolite grade paragneisses. This was accompanied by partial anatexis. The waning stages of Hudsonian orogenesis appear to be marked by minor granitic intrusive activity.The post-Hudsonian period was marked by a long interval of physical and chemical erosion, resulting in the unroofing of the Wollaston metamorphic complex. The entire region underwent extensive lateritic weathering under tropical to subtropical conditions. Carbonates were especially vulnerable and, in the Rabbit Lake area, suffered extensive solutioning with accompanying formation of collapse breccias. Old zones of weakness also underwent periodic reactivation.It was during this period that uranium was leached from the surrounding meta-sediments by oxidizing meteoric waters, and transported into the karsted and fractured rocks of the Rabbit Lake doline.Athabasca Group sediments eventually covered the deposit, their diagenesis taking place at about 200 °C and 900 bars. This allowed the partial to complete recrystallization of the initial mineralization, resulting in a minimum age of 1281 ± 11 Major ""first""-generation pitchblende. Periodic fault/fracture reactivation modified the hydrologic regime within the deposit, resulting in episodic mobilization and recrystallization of pitchblende and other uraniferous species. This is clearly shown in the open pit at the present time: uranium is being mobilized and recrystallized on damp pit walls as bayleyite and liebigite due to the modification of the hydrologic system by mining activities.The uranium mineralization occurs mainly as fracture fillings, coatings, and impregnations within breccia zones and intensely altered metasediments. Lesser mineralization is intimately associated with phyllosilicates which form the matrix of a carbonate-col/apse mega-breccia. The primary ore mineral is pitchblende, consisting of five generations, and from which a large suite of secondary uraniferous minerals have formed. On a gross scale the metal content of this deposit appears to be simple, consisting almost exclusively of U, but minor Ni, As, Cu, Se, Fe and Co are also present. The eastern limit of the mineralization is defined by a vertically-dipping microgranite dyke - breccia complex, containing high-grade uranium values. The orebody is truncated to the west and at depth by the Rabbit Lake reverse fault. Minor mineralization occurs as fracture fillings in unaltered plagioclasite in the footwall of the ore body. Precipitation of uranium from solution could have taken place by a number of processes. A mobile reductant (methane, carbon dioxide, etc.) may have been generated from graphite present in some of the host rocks of the orebody. Sulphides are also a common accessory and may have aided in the formation of a reducing environment. Phyllosilicates may have acted as adsorbants for uranium, allowing for its fixation. This metal has also been incorporated into the phyllosilicates themselves."

Jan 1, 1986

By I. Jackman

"Gold is present in different forms and associations in different ores. Flotation is used to recover gold and minerals associated with gold, but the applicability and type of flotation vary. The purpose of flotation in a gold recovery plant is largely dependent on the mineralogical association of the gold, and environmental and economic considerations. In this paper, the role of flotation in the recovery of gold is reviewed. The paper will describe examples of gold recovery by flotation including flotation of native gold, gold associated with sulphides including specifically copper sulphides, gold associated with tellurides, gold ores containing carbonaceous material and gold contained in tailings.INTRODUCTIONFlotation is widely used in the recovery of gold. However, the objectives and the mode of application are quite variable dependent on the type of ore, the gold association(s), other metal values, marketing considerations and environmental requirements. In this paper, a range of different applications of flotation incorporated in the recovery of gold are discussed. The reasons for each particular application are outlined and metallurgical results are presented.The mineralogy of the ore and the gold associations are fundamental influences on gold recovery. The use of flotation to concentrate gold is dictated by the mineralogy of the ore and gold. The fundamental factors are mineral/gold size, liberation size, association of the gold and type of gangue minerals or other valuable minerals. Gold can exhibit a range of sizes in a host from relatively large size (+50 µ) to refractory size (1 µ and sub-micron size). Similarly, the gold can occur in a number of phases in the same host. For example, the gold was present as petzite (AgAu telluride), calaverite (AuTe2) and native gold in a gold telluride ore and each of these minerals was associated with the pyrite host.Understanding the gold mineralogy and association is important in establishing the correct process route. The gold mineralogy is established by good mineralogy, use of diagnostic tools such as diagnostic leaching and assay by size fraction analyses and basic metallurgical testwork."

Jan 1, 1995