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By Shahram Tafazoli

This article presents a novel technology for sensing the size of rocks after blasting in hard rock mines. Blast engineers require rock size statistics to carefully adjust the blasting parameters. The rock fragmentation requirements vary depending on the ore type and crusher specifications. The most popular statistical parameters in the industry are the so-called P numbers (e.g., P80 and P100). A machine vision based system is introduced here for automatic image collection and fragmentation analysis of the material right inside the bucket or dipper of mining shovels. A heavy-duty camera provides the required imaging data to an embedded computer mounted inside the cab. A custom machine vision software continuously analyzes the captured bucket images and stores the suitable ones in local storage which are then fed to a Desktop software for automatic fragmentation analysis. This technology has been developed by Motion Metrics International and is commercially available as FragMetrics?.

May 1, 2009

By Les Johnston

_ BACKGROUND - About EPCOR - Genesee Generating Station - Phase 3 Expansion _ TECHNOLOGY SELECTION - Selection Criteria - Combustion Options - Flue Gas Emission Control Options _ STAKEHOLDER VIEWS _ PROJECT STATUS _ EPCOR is an integrated utility company for water, gas, electricity and technology services. _ EPCOR has about 1.6 million customers in Alberta, Ontario, Manitoba, BC, and the U.S. Pacific Northwest. _ EPCOR Generation Inc. operates three power stations in Alberta which were in operation before deregulation, including the coal-fired Genesee Generating Station. _ EPCOR Power Development Corporation owns generating stations in Alberta, BC and Washington State and will be building the Genesee Phase 3 expansion.

May 1, 2002

By M. Neven, R. A. Steane, E. Lam

"The Key Lake uranium mill is located in Northern Saskatchewan. It treats a high grade, complex uranium and metal sulphide ore. The plant and process are in many respects unique, because commercial treatment of this type of uranium ore had never been done before. The process and engineering design was based on extensive laboratory test results. A pilot plant testing stage was omitted because of confidence in the test results and time constraints to bring the plant into production.The bench scale testwork on exploration drill core samples along with preparation of the feasibility study and environmental impact statement were carried out between 1976 and 1979. The contract for detailed engineering was awarded to Wright Engineers of Vancouver in late 1980 and in August of 1981 following a public inquiry, approval to proceed with construction was granted.Construction began immediately, and during the winter the foundations for many of the plant buildings were poured and by the beginning of the following winter the buildings had been erected and installation of equipment began. Despite a six month construction worker strike in 1982, the crushing plant started up in June of 1983 and ore processing commenced in October of that year, approximately 3 months behind the original schedule.This paper describes the mill design and compares the expected performance, with the operating experience. Emphasis is directed towards flowsheet and equipment changes made since start-up, operational difficulties encountered and further improvements envisaged. Auxiliary systems are only discussed where they directly affect mill operation."

Jan 1, 1986

By K. Nasrallah

"The Dumont deposit is a large (1,179 Mt proven and probable reserve) low grade (0.27% nickel), nickel sulphide project located in the Abitibi region 25km west of Amos, Quebec. Royal Nickel Corporation acquired the project in 2007 and has since taken the project from a scoping study in 2010 through to completing the feasibility study in July 2013.The Dumont deposit in a nickel deposit with the recoverable nickel contained in three minerals; pentlandite, haezlewoodite and awaruite. The minerals are recovered by a combination of flotation and magnetic separation. Over the course of the studies many flowsheet design decisions and changes were made. This paper outlines an overview of the project, flowsheet design including the comminution circuit, desliming and awaruite recovery. The overall resulting flowsheet that was used for the feasibility study is then presented along with the confirmatory locked cycle testing that showed the feasibility design basis was able to produce the predicted concentrate grade and recovery.IntroductionRoyal Nickel Corporation (RNC) is a mineral resource company headquartered in Toronto, Canada, primarily focused on the exploration, evaluation, development and acquisition of base metal and platinum group metal properties. RNC's principal asset is the Dumont Nickel project (Dumont project) located in the established Abitibi mining camp, 25 km northwest of Amos, Quebec. RNC acquired a 100% interest in the Dumont property in 2007. The mineral claims covering the Dumont deposit are currently held 98% by RNC and 2% by Ressources Québec.The Dumont project is located in the province of Quebec in the municipalities of Launay and Trécesson approximately 25 km by road northwest of the city of Amos, 60 km northeast of the industrial and mining city of Rouyn-Noranda and 70 km northwest of the city of Val d’Or."

Jan 1, 2016

By A. H. Marquis

Since the start-up of its first Direct Reduction Module in April 1973, S1DBEC has produced over 2 million tons of prereduced iron. During this period, SIDBEC has acquired comprehensive experience in the operation of the direct reduction process and at the same time has learned to recognize the characteristics that the oxide should have to constitute an adequate feed for the process. A comparison is made as to the design and operation of the two direct reduction units now operating at Contrecoeur, Que. A description is given of a method of evaluation of a direct reduction unit, which takes into account the main process variable sand which permits comparison ofthe results on a daily basis. The paper defines the characteristics that the iron oxide and the prereduced iron pellets must have to meet the specific requirements of the direct reduction and the electric arc furnace processes. A simple model makes possible a rapid evaluation of the technical and economic effect related to the use of a given raw material. Finally, the paper outlines the advantages of prereduced iron in the steelmaking process and on the quality of the steel products.

Jan 1, 1979

By A. Taylor, J. Shelegey, H. Sullivan, J. Doucet

"Historically, performance at Vale’s Clarabelle Mill was measured by Mill throughput and Mill recovery. After the economic collapse in 2008, a series of reviews were performed to drive improvements in business efficiency. These identified that product quality (e.g., concentrate grade, variability in concentrate grade) had a profound impact on downstream processes and suggested that improved control of these parameters would generate the greatest value for the customer (the Copper Cliff Smelter) and the company (Vale). Consequently, a movement was initiated to transform the Mill operating philosophy to consider customer needs as paramount. Systems and strategies used to drive the transformation are described. In 2011, an unexpected furnace failure resulted in decreased capacity at the Copper Cliff Smelter. In response, a two-stage change in production strategy was developed at Clarabelle. The first stage was to modify the ore blend feeding Clarabelle so that the concentrate grade could be significantly increased with minimal impact on recovery. The second stage was a circuit modification to ensure the elevated concentrate grade could be sustained. Execution of the first stage was complete five days after the failure and the second stage was complete within 10 weeks. Steps involved in each stage are outlined and the overall benefits are presented.INTRODUCTION Clarabelle Mill is located in Copper Cliff, Ontario, Canada (approximately 350 km north of Toronto). The Mill treats copper (Cu) and nickel (Ni) sulphide ores. The primary diluents are pyrrhotite (Po) and non sulphide gangue rock (Rk). The process description of the circuits at Clarabelle is documented in the paper by Taylor, Doucet, Blanchette, Barrette & Lawson (2012) in this Proceedings and will not be repeated. The Mill treats ore containing Cu, Ni and platinum group elements (PGE’s) and produces two concentrates; a Cu concentrate and a bulk Cu/ Ni Concentrate (referred to as nickel concentrate). The Cu concentrate is sold to market while the Ni concentrate is thickened at the Mill and pumped to Vale’s smelter complex in Copper Cliff Ontario for further processing. Since commissioning in 1971, Clarabelle Mill has undergone many circuit changes to suit the changing needs and wants of our customers, both internal and external. The Mill processes ores of varying quality, based on mineralogy and size and until 2009 the Mill daily performance was primarily based on throughput. The second key performance indicator (KPI) of “good” or “bad” performance was quality of the concentrate and third; Mill metal recoveries. There were other plant level KPIs such as flotation feed grind size, slurry densities and mass flows to the separation circuit, but for the most part each day was good or bad depending on how many tons were processed through the Mill."

Jan 1, 2012

By J. A. Finch

"Much progress has been made over the last several years in the ability to measure flotation cell hydrodynamic parameters in both the laboratory and plant. These techniques have allowed fundamental research to proceed to determine the effects that frother chemistry has on the main hydrodynamic parameters (gas hold up, bubble size) as well as on the amount of froth generation and water content of froth. A research program was begun that brought together a team consisting of private companies and a University with expertise in hydrodynamic characterization (McGill), flotation reagent applications (Flottec) and chemical synthesis (Sasol N.A.) with the purpose of characterizing frother chemistries with two goals in mind: Determine which frother chemistry can provide optimized cell hydrodynamics; and, create new frother chemistries with specific hydrodynamic properties.This paper describes the key steps that were taken that led to the development of new frother chemistry for use in flotation.The first step was the characterization of the major frother chemical families in a two phase system. The parameters measured were gas hold up, bubble size, froth height and water carrying rate at different concentrations and gas velocities.Analysis of the data indicated that definite patterns existed between frother chemistry and hydrodynamics and showed that frothers could be grouped into classes. More importantly, by modifying known frothers through chemical reaction it was shown that these frothers could be moved from one class to another. As a result of this better understanding of the interdependence of hydrodynamic and chemical properties, a new frother chemistry was proposed that was predicted to perform similarly to MIBC.The new frother was synthesized and hydrodynamic testing confirmed that the chemical performed similar to MIBC. Laboratory flotation tests were conducted on two different ore types that also confirmed the similar performance of the new chemical and MIBC. Subsequently, the new product was placed on a plant for a short period of time. The results showed that the product was an excellent frother but increased the flotation rate slightly more than MIBC at the same addition rate.Further research showed that the new frother chemistry was a family of products. By changing the reaction the resultant products could be made to be slightly weaker or stronger than MIBC but that this chemistry cannot provide hydrodynamic/froth characteristics similar to strong frothers like glycols and glycol ethers. Further work is planned to conduct longer plant trials to confirm the efficacy of this new frother family."

Jan 1, 2007

By J. E. Scott, L. M. Heaman, R. A. Creaser, G. S. Salazar

"Schaft Creek is a calc-alkaline porphyry Cu-Mo-(Au) deposit located in northwestern British Columbia. The deposit formed in a volcanic arc setting, likely on a back-arc rifted continental fragment. It is hosted by Late Triassic basaltic to andesitic volcanic rocks of the Stuhini Group (Stikine Terrane), and is associated with porphyritic granodiorite dikes emanating from the nearby Hickman batholith. The age of the Hickman batholith is approximately constrained here by a composite U-Pb zircon date of 222.1 ± 9.6 Ma, which is in broad agreement with a well-constrained age for mineralization at Schaft Creek of 222.0 ± 0.8 Ma (Re-Os molybdenite). The deposit is in most respects typical of calc-alkaline porphyry systems, but displays silica-poor sericite-chlorite alteration in mafic country rocks in place of classic phyllic altera¬tion. The deposit comprises three distinct, but related, zones: the northern Paramount zone, the Main zone, and the West Breccia zone. Two phases of mineralization are observed. The first phase occurs as hydro-thermal veins and breccias, and minor disseminations. It consists of bornite, chalcopyrite, molybdenite, and pyrite with potassic and sericite-chlorite alteration. The second phase is minor and consists of veins of molybdenite ± specularite, as well as Cu-Pb-Zn sulfide veins without any significant corresponding alteration. Extensive structural modification has affected the deposit both during and after its formation.Schaft Creek est un gîte porphyrique de Cu-Mo-(Au) calco-alkalin situé dans le nord-ouest de la Colombie Britannique. Ce gîte s’est formé dans environnement d’arc volcanique, probablement situé sur un fragment continental bordé par un bassin d’arrière-arc. Le gîte est encaissé par les roches volcaniques basaltiques à andésitiques du Groupe de Stuhini (Terrane de Stikine) d’âge Triasique tardif, et est associé à des dykes de granodiorite porphyrique provenant du batholithe de Hickman avoisinant. L’âge du batholithe de Hickman est estimé par un âge U-Pb composite sur zircon de 222.1 ± 9.6 Ma, lequel est grossièrement en accord avec l’âge de la minéralisation de Schaft Creek, estimé a 222.0 ± 0.8 Ma (Re-Os sur molybdénite).Ce gisement, bien qu’à plusieurs égards typique des systèmes porphyriques calco-alcalins, présente une altération en séricite-chlorite pauvre en silice dans l’encaissant mafique a la place de l’altération phyllique classique. Ce gîte comprend trois zones distinctes bien que connexes : la zone Paramount au Nord, la zone Principale et la zone West Breccia. Deux phases de minéralisation sont observées. La première phase se présente sous forme de veines et de brèches hydrothermales ainsi qu’en disséminations mineures et consiste en bornite, en chalcopyrite, en molybdénite et en pyrite avec une altération potassique et en séricite-chlorite. La seconde phase est mineure et consiste en veines de molybdénite ± spécularite ainsi qu’en veines de sulfures de Cu-Pb-Zn sans association à une altération particulière. Le gisement a été profondément modifié par la déformation a la fois durant et après sa formation."

Jan 1, 2008

By Fabien Miller

Automation technologies are increasingly envisaged to improve underground mining productivity. However, the technologies need to be used and adopted gradually in order to get the best benefits. This paper presents the technical and operational aspects of autoguided production vehicles at Brunswick Mine. During 2001 Noranda?s Brunswick Mine has successfully commissioned an automated haulage zone where two optically guided trucks transport ore from a remotely operated chute to two orepasses. Operational advantages include increased system capacity and enhanced safety and comfort for the operator. The data obtained up to now indicate that the system can operate reliably in mine production

May 1, 2002

By Ross Nairn

"Tulawaka Mine is a joint venture between Pangea Minerals Limited 70% (a wholly-owned subsidiary of Barrick Gold Corporation) and Northern Mining 30%. Tulawaka Mine is located in North West of Tanzania in the Lake Victoria Goldfields. Tulawaka Mine is scheduled to process 360,000 tonnes per year at an average 11.5 g/t head grade over a 4 year mine life.The Tulawaka Process Plant uses single stage crushing, single stage SAG milling, gravity, intensive leach of gravity concentrates, CIL, Zadra desorption and cyanide detoxification to process the ore. Gold recovery exceeds (or is expected to) 95%.The Process Plant was designed and constructed under the supervision of Ausenco Engineering of Australia. Site works commenced in January 2004, Process Plant construction commenced in July 2004 and the first ore was presented to the Process Plant 26th February 2005. The first gold was poured on 15th March 2005. All construction contractors were demobilized from site 7th April 2005. Major achievements have been 3.4 million hrs LTI free during construction and operation to date, training of the Tanzanian workforce at Bulyanhulu Mine prior to commissioning, a succession plan to replace expatriate personnel with Tanzanian staff and significant over performance of the Process Plant against design.INTRODUCTIONTulawaka Mine is situated approximately 160 km south west of Mwanza in the western Lake Victoria Goldfields District of north western Tanzania. The property is held under a joint venture between Pangea Goldfields Inc (70%), a wholly owned subsidiary of Barrick Gold Corporation, and Explorations Minieres Du Nord Ltée (30%). A location map showing the position of the operation in Tanzania is shown in Figure 1.Mine site staff at Tulawaka comprises a combination of Tanzanian and Expatriate personnel. All Pangea personnel live on site and commute to their place of residence for their R&R on a 9 weeks on 4 weeks off roster."

Jan 1, 2006

By Brad Thrall

"Viceroy Resource Corporation of Vancouver, B.C. has recently developed the Brewery Creek Mine, an open pit heap leach gold mine 55km East of Dawson City in Yukon, Canada. Mineable reserves are 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797000oz) of gold. Ore processing employs the heap leach technology using run of mine ore. 1996 highlights included construction of 158,000 m2 of leach pad, placing 1.9 million tonnes of ore at a grade of 1.46 gpt on to the leach pad, construction and successful commissioning of the ADR plant, and pouring of the first gold bar on November 15th.Permitting this mine has drawn significant attention because the heap leach technology, while proven in other jurisdictions, has not been used in Yukon where winter site temperatures routinely reach -45 C for extended periods.IntroductionFollowing a comprehensive governmental and public review of the proposed project, a Class A Yukon Water license was issued in August, 1995. Construction started in 1995 and leaching commenced in October 1996. The Brewery Creek Mine is in Yukon, the home of the Klondike Gold Rush nearly 100 years ago. This is the only part of Canada not glaciated in the Wisconsin advance so there is oxide ore resulting from about 80,000 years of weathering -unique in Canada. Discontinuous permafrost is present on site and has required special consideration in the design. Winter temperatures dip below minus 50 C, demanding an approach to mining and leaching that is different than in more temperate climates.Project DescriptionThe mine comprises 8 shallow, largely oxidized gold deposits along a 7km corridor. An 8 year mining program will extract 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797,000 oz) of gold. The strip ratio will be 1.35: 1. Overall gold recovery is projected at 78%. There will be 2.3 million tonnes of ore placed on the pad annually, with an average of 2.57 tonnes (83, 000 oz) of gold recovered per year. Because of the cold winters, the mine will operate approximately 210 days per year, while the leaching process will operate on a year round basis. Run of mine ore is placed on the heap 150 days per year. The recovery process utilizes conventional sodium cyanide leaching , carbon adsorption, caustic desorption, and on-site smelting. Peak employment during mining is 145 and winter staff is reduced to 45."

Jan 1, 1997

By P. Radziszewski

"The comminution energy curve is a profoundly simple graphical technique that displays detailed operating efficiency information for industrial comminution processes. The database underlying the methodology has recently more than doubled, to now contain a substantial fraction of the international comminution output (1.7 billion tonnes of rock per year) across more than 8 major commodities. This increase has deepened the analytical capabilities and effectiveness for assessing comminution circuit performance in relation to comparable operating mines. This paper will explore how the energy curve methodology can be used to examine the ability of stirred mill technologies to increase efficiency.Specifically, this paper explores how the energy curves methodology can be used to present energy efficiency gains achieved at three mines employing a stirred mill technology under different duties. The first of these cases studies was conducted by Rosa (2014) who compared the performance of two ball mills operating in parallel with a Vertimill in the regrinding circuit at the Samarco Iron project in South East Brazil. The Vertimill was found to achieve the same product specification while consuming 40% less energy. Brissette (2010) investigated the impact of grinding media on the performance of both ball mills and Vertimills. The energy savings achieved varied from 10% to 40% for the ball mills and 30% to 60% for the Vertimills. Lastly, Bergerman (2012) investigated the operating conditions of the Sossego regrind circuit from 2006 to 2011 against design specifications and laboratory testing. The operating work index of this circuit varied from 5.2 kWh/t to 44 kWh/t over this 5 year period. The full suite of energy curves"

Jan 1, 2016

By Brian Hart, Hong Zhong, Liuyin Xia, Kyle Douglas

"The application of hydroxamic acid as flotation collectors is fast becoming of significant interest for the selective flotation of oxide minerals along with upgrading oxidised based metal ores and minerals. In the hydroxamate molecule, both O and N atoms in the -CONHOH group are identified as coordination atoms in many complexes and their characteristic structure determines the strength of the chelation complex between the hydroxamate and metal ion. The chelating performance of hydroxamates with transition metals including Cu, Ni, Zn, Fe, Cr, Mn and Co, the alkaline-earth metals (Be, Ca) and heavy metal (Pb) has been studied. Cytec has developed and patented a range of alkyl hydroxamates as flotation collectors for oxidised base metal sulphides, metal oxide minerals and precious metals. This paper introduces two new structures of hydroxamate collectors (Cyclohexyl and 4-tert-butylbenzoyl hydroxamates) and evaluates their characteristics relative to alkyl and benzoyl hydroxamates. Laboratory small-scale flotation tests were conducted with ilmenite and wolframite. The use of 4-tert-butyl benzoyl hydroxamate resulted in a best flotation performance for ilmenite. A relatively low cyclohexyl hydroxamate dosage was required in the flotation of wolframite to obtain comparable results to the alkyl and benzoyl hydroxamates. It is also shown a significantly improved flotation performance with 4-tertbutyl benzoyl hydroxamate in the flotation of ilmenite plant ore in comparison to the oleic acid or fatty acid collectors typically used for ilmenite flotation.INTRODUCTIONHydroxamic acid has been reported as an effective collector in small-scale flotation tests for a wide variety of oxide minerals and ores including copper (Lee et al., 1998, Lee et al., 2009), iron (Quast, 2000), tin (Sreenivas and Padmanabhan, 2002; Wu and Zhu, 2006), tungsten (Marinakis and Kelsall, 1987; Xia et al.,2004), and rare earth metal minerals (Ren et al., 1997; Pradip and Fuerstenau, 1991; Assis et al., 1996; Pavez et al., 1996; Zheng et al., 1996; Chen et al.,2005).As part of our previous research project, a selected suite of hydroxamic acid collectors including fatty, aromatic and modified hydroxamates (naphthoyl, cyclohexyl, benzoyl, octyl, 4-tert-butyl benzoyl, salicylic hydroxamates) were tested in order to examine their potential for recovery and selectivity of rare earth minerals. In these tests it was shown that the flotation performance with the hydroxamate collectors was significantly better than the phosphoric acid collectors on no slimes removed samples (Brian, et al., 2014; Liuyin, et al., 2014 and unpublished internal technical reports). Furthermore the tests revealed that for most of the hydroxamate reagents tested, their dosage requirements to achieve recoveries at the same levels was less than that for the phosphoric acid collectors. Recovery of both La and Ce was significantly better for the salicylic hydroxamate and that Nb, Y and Zr recovery were favoured by the octyl and benzoyl hydroxamates (Brian, et al., 2014; Liuyin, et al., 2014). Comparison among the hydroxamate collectors showed that the flotation and recovery performance of cyclohexyl (CHH) and 4-tert-butyl benzoyl (TBH) was not as good as the other hydroxamates for rare earth recovery."

Jan 1, 2015

By B. Benmokrane, G. Ballivy

"RésuméLe mécanisme de transfert des charges et le processus de décohésion le long des scellements d'ancrages scelles dans des massifs rocheux sous des charges de tensionnement peut être examine par instrumentation de l'ancrage à l'aide de jauges de déformation. Dans ce contexte il est présente ici les résultats d'une étude, en vraie grandeur sur chantier, ayant porte, d'une part sur des essais d'arrachement conventionnels et d'autre part sur des essais déflagrée barres d'ancrages instrumentées et scellées à l'aide d'un coulis de ciment dans un massif rocheux sain et compètent. Les résultats décrits ici, particulièrement les profits de contraintes de cisaillement le long de l'ancrage, obtenus à partir des valeurs de déformations relevées sur les jauges, ont permis de préciser le niveau de chargement correspondant à la décohésion initiale du coulis de scellement, d 'examiner l'effet de la décohésion sur la distribution des contraintes et de caractériser le fluage du système barre d'ancrage/coulis de scellement.ABSTRACTThe load transfer mechanism and the debonding process along grouted rock anchor, subjected to tention loads, can be examined through the instrumentation of the anchor with the aid of strain gauges. In this context, the resultsof a full-scale site investigation including classical pull out tests and creep tests are presented in this paper. These tests were performed on instrumented bars which were cement grouted in a competent rock mass. Results presented in this paper concern, among others, shear stress pro/ties along the grouted anchors which were determined from strain values obtained from the strain gauges. These results have been used to: (1) predict the load level corresponding to initial debonding of the grout; (2) study the effect of debonding on shearstress distribution along the anchor; and (3) characterize the creep behavior of the bar anchor/cement grout system."

Jan 1, 1991

By Zbigniew J. Hladysz

A Deep Underground Science and Engineering Laboratory (DUSEL) is being planned at the site of the former Homestake Gold Mine in Lead, South Dakota, under the sponsorship of the US National Science Foundation (NSF) in cooperation with the US Department of Energy (DOE). This national facility will host a variety of multidisciplinary science and engineering experiments including physics experiments that require shielding from cosmogenic radiation. Geotechnical mapping was performed in 2010 in large excavations of the Davis Campus at the 4850 Level of the former Homestake Mine. LIDAR mapping included laser scanning using a red light laser scanner and 288 Mpixels 360° still camera. The resulting vector map with the photographs digitally draped over the model, was used to create an accurate, virtual model of the excavations. For model verification, the laser scanning was accompanied by surveying and manual mapping of the geology and rock structure. The immediate use of the model was to perform structural analysis and interpretation of geology needed for the design of the DUSEL?s super large excavations. The second round of scanning, after the application of shotcrete to the excavations walls, will be used as a technical blueprint to assess the effectiveness of shotcrete application.

May 1, 2011

By G. P. Holmes

"IntroductionThe copper-molybdenum property of Brenda Mines Ltd. is located 18 miles north west of Peachland in the Okanagan Valley of the Southern Central interior of British Columbia. The actual site is 50 miles north of the international boundary and 150 air miles east of Vancouver at an elevation of 5000 feet above sea level. The earliest written mention of the prospect is found in the Geological Survey of Canada, Memoir No. 243, issued in 1947 by Dr. H.M.A. Rice. In 1954 the area was staked by a prospector, Bob Bechtel, who interested Bern Brynelsen of Noranda Exploration in examining the claims. A joint Noranda - Kennecott program resulted but since the grades were so low the property was not taken up until in 1964 a re-examination by Chapman, Wood and Griswold produced recommendations leading to the construction of the Brenda Mine as it is today.The rounded, timber covered mountains of the area are composed of the tuffs, argillites and limestones of the Upper Triassic Nicola Group, which is intruded by a Jurassic quartz diorite, called the Brenda stock0 The actual orebody occurs in a strongly fractured zone within the Brenda stock, approximately 1500 feet from the contact with the Nicola group0 The ore minerals, .chalcopyrite and molybdenite, associated with pyrite and magnetite of lesser importance, occur as fillings within the fractures 0 The grade of the ore decreases outwards from a central higher grade core and in January 1971 total reserves were estimated at 165 million tons assaying 0,182% Copper and 0,049% Mo."

Jan 1, 1972

By D. M. Doyle

"The Strathcona Concentrator operations, the application of control systems in the crushing, flotation and tailing fill sections, and current and future computer control concepts are described in this paper.The computer has been used for reporting and monitoring roles and operating the on-stream analyzer since start up of the mill in 1968, while over the past twenty months, it has been used for process control. The systems which have been developed include:1. The blending of pentlandite concentrate with pyrrhotite concentrate to produce a special product of constant nickel analysis.2. The blending of cement with tailing fill to produce backfill of consistent cement content.3. The supervisory control of xanthate, frother and pH to the flotation circuits to maintain the nickel copper concentrate grade within narrow limits.IntroductionThe Strathcona Concentrator is currently treating 7,200 tons per day of an ore which contains nickel associated with the minerals pentlandite (28 -32% Ni) and pyrrhotite (0.3 -1.0% Ni). The ratio of the nickel minerals varies from 4 to 15 parts of pyrrhotite to 1 part of pentlandite over the orebody. The production of a high grade concentrate re4uires the separation of this small quantity of .oentlandite from the much greater proportion of pyrrhotite and gangue and is complicated by the presence of two pyrrhotite minerals differing in nickel content, floatability and magnetic susceptibility."

Jan 1, 1974

By E. W. J. Thornton

During the past six or seven years extensive research has been performed on ore samples procured at the Bruns1,vick Tin Mines which is located in the south-west corner of New Brunswi.ck. This property was originally staked by Mount Pleasant Mines and they did considerable metallurgical and geological work on a small copper, zinc and tin deposit. In 1969, the property was obtained by the Sullivan Mining Group and after much geological and diamond drilling work, an entirely separate ore body \Vas located two miles south of the previous workings. The major economic metals in this ore zone are tungsten, bismuth and molybdenite, but many other metals exist as well. As the ore contains a host of different mineral species, it can be seen that considerable time WRS required to develop a practical flow sheet.

Jan 1, 1977

By Paul Hosford, Tim Haldane

"The paper describes the fast-track development of the project from feasibility study through to detailed design and construction, highlighting the process adaptations for handling sticky ore and water management in a tropical environment, and subsequent commissioning and operating experience of the mine. The paper discusses the geological setting, the environmental and socioeconomic considerations in developing and operating a mining operation in an underdeveloped country and the logistical challenges involved in bringing a large capital investment into Central America.INTRODUCTIONGlamis Gold Ltd. acquired the San Martin project in Honduras as a result of its merger with Mar-West Resources in late 1998. Despite the prevailing low gold price environment at the time of acquisition, Glamis anticipated rapid development of the San Martin project due to the quality of the deposit and other positive factors.Following favorable exploration and permitting activities in the first half of 1999, Glamis prepared a Feasibility study. In October 1999, Glamis decided to proceed with the development of the project and selected Hatch to provide the engineering, procurement and construction management services for the project. The San Martin project was in full-scale commercial operation approximately 14 months after the receipt of Board approval, and by July 2001 the San Martin project was operating at approximately 150% of its feasibility design capacity."

Jan 1, 2002

By J. J. Bouillon

"Located in the northwestern portion of the Abitibi greenstone belt, Les Mines Selbaie is a copper-zinc (silver and gold) producer. Felsic tuffs host three are zones. Composed of sulphide veins and breccias, they are not exhalative massive sulphide deposits, except, probably, for the massive pyrite (fragments and lenses) localized close to the top of the volcanic sequence.The total of all (mineable and mined) ore in the three zones presently outlined on the property, is of the order of 29.9 x 106 tonnes with average grade of 0.63 g/t Au, 37.02 g/t Ag, 1.21% Cu, 1.91% Zn.The ore reserve calculations and the daily production procedures are computerized to various degrees. The data handling process is highly computerized.Various geophysical methods are, and have in the past, been successfully used on the property. The ""mise-à-la-masse"" surveys were used to perform the geological interpretation of an underground deposit (A-2 zone). Presently the PULSE-EM surveys are performed in all surface and underground exploration drill holes."

Jan 1, 1990