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By Richard J. Haslinger, C. Mark Rebagliati, James L. Oliver

Abstract - Exploration at the Specogna gold deposit has identified a geological resource of 65.0 Mt grading 1.63 g/t Au, which equates to 3 million ounces of contained gold. This resource is hosted in a low-sulfidation epithermal deposit of Miocene age that is localized along the northwesterlytrending Sandspit fault. The fault has juxtaposed Late Cretaceous mudstone of the Haida Formation to the west, with Late Tertiary coarse clastic sediments and lesser andesitic volcanic rocks of the Skonun Formation to the east. A plagioclase porphyritic dacite dike intrudes the Haida mudstone and Skonun sediments along the fault. Gold mineralization, in hydrothermal breccias, veins and stockworks developed mainly in Skonun sediments and dacite. These are formed in an 800 m long zone that roughly parallels the Sandspit fault. The gold zone is funnel-shaped in cross-section, approximately 300 m wide at surface, 220 m above sea level, and narrows to approximately 50 m, at sea level. The deposit lies within an elongate zone of moderate to intense hydrothermal alteration that, at surface, extends over a known area of approximately 2 km2. Its western extent is bounded by the Sandspit fault. There is an asymmetric alteration zonation, with a core of silicic-potassic (adularia) and smectite-illite clay alteration that is bounded to the east by argillic alteration. Similar zoning defined by the distribution of metals reflects the position of the main feeder conduit. Mineralization of altered wallrock is dominated by 1% to 4% auriferous pyrite and marcasite. Gold and silver occur as electrum; individual silver minerals have not been identified. Other sulfides are rare, and are identified only microscopically. The mineral suite is typical of low-sulfidation epithermal systems. Gold occurs in early, multi-phase, variably bladed and banded quartz veins and breccias, which are cut by barren, single phase, drusy quartz veins.

Jan 1, 1998

By M. G. Mena, M. S. Mena-Junio

Silver (Ag) filler is the most attractive choice among all the conductive fillers of die attach materials for the attachment of silicon devices because of its balanced properties and relatively low cost. However, a major problem of silver is that it electrochemically migrates in the presence of moisture and applied bias. In microelectronic devices, silver migration can occur between adjacent conductors/electrodes, which leads to the formation of dendrites and eventually results in short-circuit failure. In order to assess the reliability of these conductive fillers, an investigation for two types of Agfilled die attach materials was done using the water drop test at room temperature and using a 1000 hour temperature-humidity-bias (THB) test under 85 ºC and 85% RH conditions. Four different bias/voltages and six different electrode distance spacing were used. Both dendrite and cloud/lace-like growths were observed as a result of the electrochemical migration of silver, Water drop test results revealed that increasing the applied bias/voltage and decreasing electrode spacing causes migration to occur faster, thus resulting into shorter time to fail (TTF). It was also observed that the growth rate of the dendrites from the cathode increased linearly as the dendrite approached the anode, probably due to a combination of increased ion availability and electric field. A minimum applied bias of 3 volts was required for migration to occur in Epoxy A as compared to 2 volts for Epoxy C. The higher migration voltage requirement for Epoxy A was attributed to the higher volume resistivity of the said epoxy. In addition to the minimum voltage requirement, it was observed that a minimum electric field of about 1 volt/mm is required for migration to occur. The 1000 hour THB testing did not result into any failures. It is surmised that the presence of condensed moisture is another requirement for migration. Such condition is not present during the THB testing.

Jan 1, 2012

By Sylvie Lévesque, Cory Hennessey, Daniel Amariei

"In the iron ore industry, fine particles recovery is an important concern in terms of process performance and production costs. Continuous efforts are thus devoted to increase the efficiency in handling these fines.The Reflux Classifier (RC) is a relatively new technology that is mainly used in the coal and industrial minerals industries. The operating principle of this system is based on three mechanisms: hindered settling, autogenous dense medium and lamella settling. A preliminary evaluation of the Reflux Classifier technology for the beneficiation of iron ore fines was formerly done at the pilot scale using a RCTM300 unit. The good results obtained, using iron ore fines from screened spiral stream, made this technology very attractive for the iron industry. However, the high capacity of the RCTM300 unit (1–3 t/h), makes it unsuitable for R&D purposes. Thus, a smaller unit, the RCTM100, was assessed to validate the performances obtained with the RCTM300.This paper summarizes the performances obtained with the RCTM100. The challenges of the scale-down related to the adaptability of this technology to the iron ore industry are also presented. The results are compared to the RCTM300 performances, as well as benchmarked against sink-float tests. The metallurgical results on feed and products issued after the test work with the RCTM100 unit are supported by mineralogical characterization using a Mineral Liberation Analyzer.INTRODUCTIONFine particles recovery by physical separation means is a historical concern (Holland-Batt, 1992; Peukert and Wadenpohl, 2001; Srivastavaa et al., 2001; Majumder et al., 2003). Attempts to improve fine particle recovery at the laboratory, pilot and industrial scales adopting different strategies with traditional equipment or assessing new promising devices such as the MGS (multi-gravity separator), the Kelsey jig, the Yang jig, etc. (Kim, 2002; Goudreau, 2008; Kerr, 2012) have yielded variable success."

Jan 1, 2016

By J. De Geoffroy, T. K. Wignall

The paper describes a statistical method based on regression and classification analysis which is designed to assist exploration management in the selection of prospecting areas and drilling targets in regional programs. The classification is based on three criteria which are formulated from sets of relevant geological, geophysical and geochemical factors: (a) regression estimates of expected ore values, (b) Bayesian probabilities of success and (c) expected utility payoffs. The advantages of the method are: (a) rational and unbiased ratings for areas or targets in a manner consistent with management's goals; (b) calculation of probabilities of success and confidence intervals for the ratings, and (c) rapid and accurate handling of a large amount of data by computer programs.

Jan 1, 1970

By H. C. Cooke

"This paper has reference in a general way to the region extending from the north shore of lake Buron to the northern limit of the elliptical-shaped area generally known as the Sudbury Basin, and more especially to the district lying south of the Basin (Fig. 3). Attention is concentrated mainly on the structure of the district and, as space does not permit of much geological description, it is assumed that the reader has some knowledge of the general geology. The accompanying table outlines the sequence of the rock formations according to the most recent available information; for further details the interested reader may consult the publications of the various authors mentioned in the paper.STRUCTURE OF THE SEDIMENTARY ROCKS SOUTH OF THE SUDBURY IRRUPTIVEThe rocks south of the Sudbury irruptive, excluding certain intrusives, are, in order from north to south:(1) A band of basic lavas.(2) A band of well-bedded greywackes and quartzites, long termed the McKim greywacke.(3) The Copper Cliff formation, with McKim greywacke' both to the north and south.(4) The Ramsay Lake conglomerate.(5) A thick quartzite formation.All these rocks strike approximately east-northeast, dip steeply south, and generally face south, though there are local exceptions."

Jan 1, 1954

By M. Thérien, M. Rémillard

"Data from two industrial plants are treated by mass balance package BILMAT. The first application concerned a base metals/precious metals (PM) producer and the second, implementation of a hydrocyclone for the recovery of iron chips in the granite industry. Also LOTUS 123 software can easily be adapted for laboratory test mass balances using an IBM-PC computer. INTRODUCTIONThe present paper deals with two different BILMAT program applications. The first application concerns a copper-zinc-gol d-sil Yer producer based in North-western Quebec and the second, concerns the iriplementation of a hydrocyclone for the recovery of iron chips in Quebec granite company.Afterwards, we deal with some LOTUS 123 software applications for laboratory test mass balances using an IBM-PC.1. Base metal and P.M. producerNoranda Inc, Mattagami division, which operates mines in North Western Quebec, produces copper and zinc concentrates from a sulphide ore. Small amounts of gold (0,34 g/t) and silver (20 g/tl are present. At the time of the study, only 30% of the silver content was recovered in the copper concentrate. The main objective of this study is, to evaluate the metallurgical behaviour of silver in the flotation circuits, to increase its recovery in the copper concentrate and therefore to improve its final economic value. It is then worthwhile to identify the silver bearing minerals and to determine the critical flotation stages where they are lost. The methodology proposed is based on the coupling of a mineralogical study and a detailed mass balance ca1cu1ation in the flotation circuit performed using the BILMAT mass balance package (1, 2, 3).The results are discussed with respect to the distribution of silver in the circuit. The recoveries obtained at the various separation stages for the minerals present in the ore are also discussed."

Jan 1, 1987

By J. J. Barakso, C. Tarnocai

This paper outlines a method of testing for the mercury content of rocks, soils and plants. Techniques of sample collecting are described and the analytical procedures outlined. Examples are given of mercury determinations in two known mineralized areas in British Columbia - Copper Mountain Mines and Pacific Nickel Mines.

Jan 1, 1970

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 Denis Yaychuk, Gary Billingsley

The economic eva luation of a mineral property or mining venture should include the quantification of ri k as part of the analy is. The re ults of such an analysis provide the decision-makers not only with the most likely financial outcome and the probability of achieving that or any other outcome. but al o with a ranki ng of the relative impact of all the ri sk factors. These type of resu lts offer more complete information for investment and technical deci ions than the traditional cash flow/ ensitivity analysis. In addi tion. by attempting to quantify ri sk. the personnel providing the va ri able input are forced to take a much clo e r look at the data involved, and are fo rced to work together. the reby increa ing substantially the awa reness of the impact their work and others· work has on th e outcome of the analysis.

Jan 1, 1986

By M. S. Badollet, W. C. Streib

"AbstractA commercial method .has been developed for controlling the texture of chrysotile asbestos fibers so that they may possess properties comparable with natural sem1-harsh fibers for use in wet •processes.The physical properties of the soft, silky and slimy fibers are partially altered by a flash-heating process which removes a portion of the molecular water.The heat-treated fibers show an improvement in filterability, an increase in bulk, absorption, and surface area and better electrical properties, such as volume resistivity.IntroductionCHRYSOTILE ASBESTOS fibers are found in nature having varying degrees of texture, referred to as soft, semi-harsh, and harsh. Fibers of each type of texture have inherent characteristics which directly affect their usefulness to industry. Visual differences are apparent under a microscope where it is seen that the soft-textured fibers have a silky, serpentine or wavy appearance, whereas the harsh-textured fibers are coarser and spicular. Semi-harsh fibers, of course, have properties intermediate between these extremes.Fankuchen and Schneider ( l) have shown by the use of low-angle X-ray scattering that the diameter of the harsh type of chrysotile fiber is somewhat greater than tha of the soft variety. Surface area measurements on various chrysotiles of different textures tend to confirm their findings. By nitrogen adsorption methods, it was found that the surface areas of soft types of chrysotile asbestos are approximately 23M2 / g whereas for the harsh types they are as low as 11M2/g."

Jan 1, 1955

By C. H. Attwood

Introduction In presenting this paper on the water-power resources of the Province of Manitoba, it was considered that a brief resume of the power resources of Canada, of the power already developed, and its utilization in the industries 9f the country, would be of particular interest in showing the rapid progress that has already been made. Amongst Canada's national assets, water power occupies a foremost place because of the facilities it provides for the development of her other great natural resources. The rapid development of the mining, pulp and paper, and general manufacturing industries, and the concomitant growth in urbanization, with its numerous demands for domestic, commercial, and municipal service power, have combined to stimulate hydraulic development to a point surpassing even the most sanguine predictions of a few years ago. With the bringing into operation during 1928 of hydraulic turbines aggregating over 550,300 h.p., and of a further 378,400 h.p. in 1929, Canada's total hydraulic development at the end of 1929 amounted to over 5,700,000 h.p., and in this year, 1930, the active construction in hydro-electric plants throughout the country totals in excess of 1,600,000 h .p.

Jan 1, 1930

By D. Markwart, B. Volk

Anode effects are a phenomenon of the aluminium electrolysis process which produce potent greenhouse gases called PFCs (CF4, C2F6). With concerns surrounding global warming, and increasing regulation of GHG emissions, anode effects have become a significant sustainability issue for aluminium producers. In modem smelters, sophisticated computer control and automated alumina feeding systems allow for very tight control of the alumina concentration in the electrolyte and thus very low anode effect frequencies. Older smelters, however, do not have these systems and must either invest heavily to obtain them, or find other, innovative ways to reduce anode effect frequency. This paper will present the integrated approach to anode effect reduction used in the Vertical Stud Soderberg (VSS) potlines at Kitimat Works. Through an innovative combination of simplified signal analysis, modified alumina feed control logic, anode effect prediction, and anode effect prevention using a pager based communication system, Kitimat W arks has been able to make significant reductions to its anode effect frequency.

Jan 1, 2006

By L. B. Hale

"Introduction This paper will discuss the current operations of Westar Mining Ltd. and give a brief history of the company and of the Crowsnest Pass area. Westar is an integrated company involved in mining, processing and marketing coal from its mines in southeastern British Columbia and shipping coal from Westshore Terminals at Roberts Bank, located just south of Vancouver, B.C. It is two-thirds owned by the B.C. Resources Investment Corporation and one-third owned by the Mitsubishi Corporation of Japan and a consortium of Japanese coal consumers. Operations in southeast British Columbia consist of four coal mines and two processing facilities (Fig. 1). The Elkview Coal Processing Plant near Sparwood, B.C. receives its raw coal from Balmer operations (Harmer open pit), Balmer South (Panel 6) an underground hydraulic mine, and Balmer North an underground room-and-pillar mine. The fourth mine, Greenhills, an open-pit operation, is located near Elkford, B.C. and has its own processing plant. The Balmer mining and processing complex is the largest metallurgical coal facility in Canada producing up to 7 .5 million tonnes of clean coal per year. The Greenhills operation, completed in mid-1983, has a capacity of 2.8 million tonnes. The high-grade metallurgical and thermal coal produced is primarily for export markets. The major customers are Japan, Korea, Brazil, Pakistan, Chile and Taiwan.Our coal and that produced by other mines in Alberta and British Columbia is shipped to the international markets through Westshore Terminals Ltd., a wholly-owned subsidiary. Westshore will have an annual capacity of 22 million tonnes of coal and accommodate ships of up to 250,000 dead weight tonnes by 1984 when its current expansion program is completed."

Jan 1, 1985

By R. Bainbridge

THE cinnabar deposits of the Consolidated Mining and Smelting Company's Pinchi Lake property, situated near Fort St. James, B.C., were discovered and reported on by a Dominion Government geological party in 1937. Claims were staked by a group of local prospectors and, later, the Consolidated Mining and Smelting Company of Canada, Limited, took an option on the property. By the fall of 1939, exploration work had indicated ore of commercial quantity and grade, and laboratory tests had shown that standard methods of reduction, namely, roasting of the ore, followed by condensation of the mercury vapour produced, would result in satisfactory recovery. In June, 1940, construction of a 50-ton unit arranged for wood firing was completed and operation commenced. The installation consisted of a 46 in. by 60 ft. rotary kiln (see Figure 1) followed by a 14-in. Sirocco cyclone, a cast-iron condenser unit, and a 1,700 c.f.m. fan, exhausting to a stack. Other equipment included a 9 in. by 18 in. Denver jaw crusher with the necessary bins and feeders. As the need for mercury was urgent, because of war requirements, construction of a duplicate unit was begun almost immediately. This first extension started operation in January, 1941, and the plant was then capable of treating about 150 tons of ore daily.

Jan 1, 1945

By S. Nafisi

Permanent mould casting may be regarded as a near net shape manufacturing process where simple to very complex shaped engineering components are fabricated with high degree of precision in a metallic mould, In this group, High Pressure Die Casting (HPDC), have attracted more attention because of its production rate, where both liquid and semisolid metals (SSM) can be cast with high degree of precision and versatility. The SEED process, Swirled Enthalpy Equilibration Device, the new process for semi solid metals slurry production route, consists of two steps: The initial step involves extracting specified amount of heat from the molten metal to generate liquid-solid slurry, i.e, mushy structure, followed by drainage of remaining liquid to produce a compact free standing feedstock for rheocasting operation. In this paper, microstructural evolution during the process and some initial casting results of automotive components an also reported.

Jan 1, 2005

By H S. Ellis

Flow studies have been conducted on nickel-water suspensions in a 1in.-diam., 42-ft.-long transparent lab-oratory pipeline at concentrations of up to 25 per cent, by volume, and slurry velocities of up to 15 ft/sec. The average size of the nickel powder was approximately 150 mesh (106J.L). Three flow regime were noted. At the highest velocities, i.e., above 10 ft/;sec., where the concentration distribution through the vertical diameter was most uniform, pressure gradients could be correlated with the Durand-Condolios equation (7,8). An intermediate region, i.e., from 7 ft/sec. to10 ft/sec., could be distinguished, the lower velocity limit being that at which nickel particles began to deposit. This region was also marked by decreasing pressure gradients, for a given concentration, as the velocity was reduced. The upper velocity limit in this region was also uniquely defined in that the friction factor for any nickel concentration was the same as that for water. In the third regime, below about 7 ft/sec

Jan 1, 1963

By C. E. Smith, R. J. Inglis, M. I. Brittan, J. H. Schoeman

"AbstractA number of plant-scale cyanidation tests were carried out in an attempt to uncover the causes of fluctuations in gold recovery efficiency. Computer analysis of the results verified that the treatment of reclaimed waste rock material along with normal run-of-mine ore was having an adverse effect on metallurgical efficiency. Mineralogical examinations showed that the free gold particles in the dump material were heavily tarnished or coated (predominantly by hydrated iron oxide), accounting for the lower recoveries. The indications were that the effect could be counteracted somewhat by using higher than normal cyanide and lime reagent concentrations and adequate leaching times. Analysis of the results showed further that leach pulp density was an important operating parameter affecting extraction efficiency. A variable activation energy leaching model provided an extremely good characterization of individual batch leach runs.IntroductionFLUCTUATING METALLURGICAL EFFICIENCY at the gold concentrator of the S.A. Land and Exploration Company Limited (""Sallies"") prompted some plant-scale cyanide leach studies in an endeavour to uncover the causes of the variations in gold recovery."

Jan 1, 1977

By L. W. Vollmer

Introduction During the past three years at least fifty strings of 9% nickel steel tubing have exhibited excellent resistance .to the variably severe corrosive conditions typical of many of the sweet condensate wells in Mississippi, Louisiana, and Texas. This experience, and the characteristically outstanding performance of other ?nickel alloy steels under hydrogen sulphide corrosive conditions, dictated the selection of 9% nickel steel tubing for the second well drilled in the sour condensate Pincher Creek field of southwestern Alberta. The damaging effects of the Pincher Creek reservoir fluids on well equipment had been manifested in the discovery well by the rapid and not yet fully understood failure of API Grade N-80 tubing, stainless steel wire lines, and alloy steel fishing tools. Two very unexpected failures in the 9% nickel steel tubing, after only six days of service in production tests, instigated an extensive and continuing investigation to ascertain the probable cause of failure. This discussion presents some of the results obtained thus far which cast a little light on the perplexing behaviour of steels in hydrogen sulphide environments in general, and in sour condensate wells in particular. History of Tubing Failures Walter Marr well No. 1, in which the 9% nickel steel tubing failures occurred, produces from the Madison lime at the depth interval approximately 12,200 to 12,750 feet. The gas-oil ratio is about 26,000 and the gas contains 10.2 per cent hydrogen sulphide and 6.3 per cent carbon dioxide by volume.

Jan 1, 1952

By R. L. Bishops

This paper discusses some of the materials, processes and systems used in motor insulation. Among the materials mentioned are epoxies, polyesters, mica paper composites and wire enamels. Two processes developed to take advantage of the special characteristics of two of these materials are described, and how these materials are used in several new insulation systems now on the market is discussed. Finally, future trends in motor insulation are outlined.

Jan 1, 1969

By H. W. Wevers

This paper is the result of an intensive literature search and practical study of the problems experienced by a mining company with the frame cracking of their large-tonnage haulage trucks. It explains the advantages of particular HSLA steels for applications in the welded structures of such equipment. Examples of existing welds in truck frames are analyzed. Modern fatigue models and linear elastic fracture mechanics techniques are explained.

Jan 1, 1978