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By William W. Shilts

"In carrying out a geotechnical survey of a proposed gas pipeline route from the Arctic Islands south to Longlac, Ontario, the Polar Gas Consortium contracted the drilling of several hundred 2- to 2D-m-deep boreholes in drift and bedrock. Samples from these holes were made available to the Geological Survey of Canada, where they were subjected to stratigraphic and trace-element geochemical analyses. The geochemical characteristics of the clay and sand-sized heavy mineral fractions of till samples from these boreholes have been summarized in a series of geochemical profiles.From the proposed pipeline terminus at Longlac northward to the vicinity of God's River in Manitoba, tills contain significant amounts of Paleozoic carbonate rocks and Proterozoic sedimentary rocks derived from the Hudson Bay basin and lowlands. Within this section, two sites were enriched in base metals, indicating the possibility of local mineralization of possible economic interest.From God's River northward to Seal River, Manitoba, no evidence of local mineralization was noted. The heavy mineral fractions of the tills are universally enriched in Mn-rich siderite thought to originate on or in the Paleozoic section of the Hudson Bay lowlands.From Seal River northward to Thelon River, near Baker Lake, tills contain only components originating west of the Hudson Bay sedimentary basin. Near the Keewatin-Manitoba border, all till is enriched in uranium, which probably originates in the ""young"" porphyritic granites underlying much of the region, and produces a distinctive airborne radiometric anomaly.At the Thelon River, multiple till sections are variously enriched in Cr, Ni, U, Cu and Mo in the vicinity of a distinctive aeromagnetic anomaly.From Thelon River northward, several coincident zones of chromium and uranium enrichment are found where the line of boreholes crosses east-west-striking belts of volcanic, ultramafic and sedimentary rocks of the Prince Albert Group.The results of this study indicate that till tends to have characteristic element associations or concentrations over each of several broad regions along the pipeline route. These are related both to large-scale bedrock associations and to largescale effects of glacial dispersal. In addition, the samples, collected more or less at random with respect to local bedrock geology, have intersected several small-scale geochemical anomalies that appear to be related to zones of mineralization of possible economic interest."

Jan 1, 1980

By A. Bowles

The process of accumulative roll bonding (ARB) has been applied to wrought magnesium alloy AZ31. Accumulative roll bonding results in severe plastic deformation of sheet material. In AZ31, this process leads to the refinement of the microstructure by dynamic recrystallization. The refinement of the microstructure results in an improvement in mechanical properties with potential for producing materials for superplastic forming. In this work AZ31 was bonded with up to 64 layers and the potential of roll cladding with aluminium was also investigated. The development of microstructure and the mechanical properties are reported here.

Jan 1, 2006

Operating CIP/CIL gold recovery plants in the arid regions of Western Australia face unique challenges due to water and ore quality issues. The presence of cations of Mg, Fe and Cu metals in water supplies and leached sulphide ores can have considerable effect on plant consumption of lime and cyanide, due to pH buffering and complexation effects. Reagent costs are critical to many of these operations. In this paper, computational modelling is used to analyse a number of process options to mitigate such issues. This requires careful consideration of the chemistry of the process system, and the ability to predict accurately the response of speciation and precipitation reactions to changing process conditions. The Mg-Fe-Cu-CN-H20 system is specifically modelled in this application. The Gibbs Free Energy Minimisation thermodynamic framework has been selected to model equilibrium phenomena. Furthermore, this approach has been extended to the process flowsheet level, incorporating multiple unit operations and recycle streams in a steady-state mass balance model. The Gibbs equilibrium composition module of HSC Chemistry software has been successfully integrated into the commercial flowsheeting package SysCAD. Consideration of the Gibbs Energy Minimisation capabilities of other flowsheeting packages has also been given. This approach has been successful in simulating the aqueous process chemistry typical of such plants. It has resulted in a predictive capability where equilibrium states respond appropriately to process changes. Potential cost savings may be identified by examining alternative process conditions to minimise overall reagent consumption.This methodology may be extended to other hydrometallurgical plants where issues of solution ideality, temperature and other equilibrium processes are sufficiently understood.

Jan 1, 2005

By Marc C. Bétournay

"Surface crown pillars, acting to safely protect underground workers and operations from surface elements, are recognized, herein, as distinct from conventional deeper underground pillars. Moreover, because of the variation in mining and geological conditions that exist from mine site to mine site, each case is viewed as unique. A review of numerous case studies and existing literature indicates that there is little general information or systematic problem-solving approach associated with them.A design process, not unlike that of other engineering disciplines, is presented to correct these deficiencies. As part of its purpose, it will inform operators of the key elements required for design and will address the problems of these appendages. The design, while taking into consideration possible surface crown pillar settings and inherent characteristics, is founded on a step-by-step procedure starting with site investigations through to monitoring or pillar recovery. The process is flexible, in that it incorporates decision making and changes in mining strategy. The purpose of each step is explained and each step is extensively described in terms of the required equipment and methods for field work, analysis and support measures. Analytical formulae and studies from several fields directly applicable to surface crown pillars are also given. Recommendations for future research studies are presented."

Jan 1, 1987

By M. E. Holter

"Five main lignite seams occur in the Tertiary Ravenscrag Formation in the Eastevan area, at depths of 100 feet or less. They are named, in ascending order: the Boundary, Estevan, Souris, Roche Percee and Short Creek seams. A total sequence of approximately 250 feet is represented by the coal beds and interstratified clays, silts and sands. Strata dip to the southeast at 25 feet per mile or less and trike northeast. Large areas underlain by coal seams at shallow depths are delineated. Reserve calculations are dependent on detailed information on seam thicknesses and feasible stripmining depths. The stratigraphically higher seams are thinner on the average than lower seams and this, together with the increase in elastic size fractions in higher strata, suggests a retreat of a Tertiary marine margin to the south during the closing depositional history of coal seams and associated strata."

Jan 1, 1972

By J. F. Liu, L. Chen, C. P. Wang

"Calcite-cemented joints abound in the rock masses of Beishan area, which is the most potential area for the high-level radioactive waste (HLW) disposal of China. The mechanical properties of Beishan granite containing a calcite-cemented joint with a dip angle of 82° was investigated under uniaxial compression and the acoustic emission (AE) characteristics were also studied in this paper. Compared to intact granite, the calcite-cemented joint caused a decrease more than 50% in uniaxial compressive strength and a decrease more than 90% in shear strength. The Young’s modulus was also decreased, while the circumferential deformation of jointed granite was sharply increased. The AE monitoring system successfully recorded the process of micro-crack development and the results indicated that the risk of rock-burst could be reduced due to the appearance of calcite-cemented joint.INTRODUCTIONThe properties of jointed rocks differ considerably from that of intact rock. Due to the difficulties in specimen preparation, analogue experiments with artificially prefabricated fractures are often used to study the mechanical behavior of jointed rock (Chen et al. 2012; Kulatilake et al. 2001; Singh et al. 2001). However, natural joints are not quite similar to the artificial fractures and it is necessary to investigate the mechanical behavior of jointed rocks. Xie et al. 2011 studied the mechanical properties of marbles with natural joints by uniaxial compression tests and found that the uniaxial compressive strength of jointed rock is greatly decreased. With the unaxial compression tests, Jacobsson 2005, 2007 tested the intact and jointed granites, which were taken from the potential site for high-level radioactive waste (HLW) disposal of Sweden. However, no significant difference in strength or modulus was found. The above research results are inconsistent and it indicates the complexity of the mechanical properties of natural joints."

Jan 1, 2015

By G. Kolosay, J. Rajala, G. Deschênes, A. Romanov

ABSTRACT: The Kupol project, located in Far East Russia, treats a high-grade, free-milling ore containing 25.5 g/t Au, 298.3 g/t Ag, and 0.5% pyrite,with a P70of 53 microns. Most of the gold occurs as elec-trum and the silver is predominantly present in the forms of acanthite, stephanite, pyrargyrite, andproustite. The mill reached the design throughput of 3,000 tpd six months after start-up. AKnelson con-centratorrecovers10.4% gold and 0.5% silver. Leaching (14.5 hours pre-treatment and 116 hours cyanidation)of gravity tailings is performed with the CANMET Enhanced Leach Process (CELP),using only 490 ppm NaCN (cyanide consumption of 1.1 kg/t). The precious metals are recovered by counter-current decantation and the Merrill-Crowe process. Calcium hypochlorite destroyscyanide and thiocyanate. Overall, gold and silver recoveries for 2008 were 95.4% and 85.6%,respectively (2.8% and7.5% higher than targets). In the first eight months of 2009, gold and silver recoveries were 95.0% and82.6%, respectively. By August 2009, the mill processed 1.42 million tons of ore with production of 1.1 million ounces of gold and 11.3 million ounces of silver. CELP performance was not affected by changes in feed grade and ore mineralogy. Additional modifications to the leaching strategy allowed further reduction in cyanide consumption and effluent treatment costs.

Jan 1, 2011

By G. Mousavian, R. Bagheri, N. Dalili

Polypropylene (PP) and its composites have an increasing use in automobile and domestic industries. Since the published results on strain rate effect on yield behavior do not match, and there is a high attention paid for effect of nanometeric fillers on deformation behavior of composites, in this research the strain rate effect on yield behavior of PP and the effect of nanometeric fillers on deformation behavior of PP have been studied. Microscopic observations and tensile tests in different strain rates on neat PP samples and on samples filled with 5, 10 and 15 %wt have been used. A dramatic change in behavior for the modulus and post-yield slope curves when the strain rate is between 0.0433-0.05 s-1 has been observed. Microscopic observations on PP indicate a change in deformation mechanism from shear yield to crazing at the same strain rate that the change in behavior of curves occurs. It has been observed that in PP nanocomposites with higher amount of calcium carbonate, fracture in early stages of deformation occurs in lower strain rates. In other words for a fixed stain rate there is a critical filler percentage such that if the filler percentage is higher then early-stage fracture will occur. Similarly for a fixed filler percentage there is a critical strain rate and in higher strain rates early fracture will occur. The critical stain rate will decrease as the filler percentage increases and vice versa.

Jan 1, 2006

By H. F. Naldrett

"AbstractAt the end of May, 1950, Imperial Oil, Limited, had completed a total of 192 D-3 wells in the Leduc-Woodbend field, 62 of which lost circulation in the D-3 zone for periods ranging from two hours to fifty days. The majority of the remaining wells •lost some mud without actual loss of returns. In addition, independent operators completed 69 D-3 wells, of which 9 lost circulation. Included among the latter is the now well known Atlantic No. 3 well, which blew wild out of control for seven months. The well was finally brought under control through two directionally drilled wells, but not before the derrick fell and the well caught fire. Practically all known filler materials have been used in attempt3 to prevent or regain loss of circulation, but none has been successful, except in minor cases. Ordinary sawdust has come to be the most commonly used filler material and is added to the mud before the D-3 zone is contacted. In cases of serious loss of circulation, the on1y successful method of getting returns has been the use of a series of small cement plugs.IntroductionThe Leduc field is twenty miles southwest of Edmonton, Alberta. Geologically, it is on the east limb of the Alberta syncline, in the homoclinal belt. The main productive zones are in the Upper Devonian formation and are known locally as the D-2 zone and D-3 zone, respectively (see Figure 1).The D-3 zone is a dolomitized reef with fair average porosity and permeability, and shows considerable evidence of vertical fracturing. Porosity is mainly due to moderately uniform development of vugs which are interconnected by small crevices. However, the formation is known to be, locally, extremely vuggy and in places cavernous. These latter conditions create very serious drilling problems due to the hazard of loss of circulation, particularly in the gas cap, which has a maximum thickness of 200 feet. The D-3 zone is contacted at an average depth of 5,300 feet."

Jan 1, 1950

By M. M. Holgate

"Porosity neutron deflection scales can be derived more easily by cumulative correlation than by the conventional method of plotting corresponding points on a graph. The micro-log can be used as a porosity datum for the neutron log by transforming the permeability cut-off it shows to a porosity cut-off by a permeability-porosity function obtained from core analysis. Porosity footage values calculated in this manner from the neutron log are within 20 per cent of core analysis values."

Jan 1, 1960

"Option pricing is used in finance for valuing options to buy (or sell) shares at some future date because it provides a convenient framework for quantifying values subject to uncertainty. As one of the main sources of uncertainty in mining is the price (sales) of the metal, this approach can also be used for valuing mining projects.The first part of this paper reviews options and option pricing; the second part presents the approach developed by Brennan and Schwartz (1985) for using option pricing to value natural resources. Several applications of this methodology have been published; these are described. From a mining point of view, the assumptions made by Brennan and Schwartz are too simplistic. The weaknesses are discussed with a view to improving an apparently promising new way of assessing the value of projects. IntroductionThe collapse of the British merchant banking group, Barings, has highlighted the risks that can be incurred by speculators and arbitragers in the futures and options markets. But this negative attention on futures and options should not make us forget their positive aspects. They can provide producers and consumers of metals with more predictable sales prices. The introduction of the new traded average price options, TAPOS, by the London Metal Exchange in January 1997 is a response to this need. Equally important, the theory that the finance industry has developed for valuing options provides an interesting framework for valuing mineral projects as well. While this paper was being revised, the South African gold mining house, JCI, announced that it was using a methodology based on option pricing for valuing the mineral rights to deeplevel gold resources (see Box 1)."

Jan 1, 1997

By C. Moctezuma

Since the start up of the IMMSA electrolytic zinc refinery in 1982, the dissolved iron coming from the acid attack of the ferrites has been precipitated by the jarosite process. At the beginning of operations, sodium jarosite was produced; however, the plant was converted to ammonium jarosite in 1990. The final storage of the residue is on the company&apos;s property adjacent to the plant, over the natural surface of the land. Before the construction of the refinery, several studies were done in order to evaluate the characteristics of the ground, such as, permeability, underground water localization, etc. The results showed that the site was adequate for the storage of this kind of material. For several years, the jarosite residue was filtered on rotary drum filters and was sent as a pulp to the storage area for settling. The water from the storage pond was recycled to the re-pulp tank for the jarosite residue. These filters were replaced in 1999 by an automated filter press. Since then, the jarosite residue has had a lower water content, and the zinc recovery improved. At present, a second filter press for the jarosite circuit is in the acquisition process to diminish the soluble zinc content in the residue from the present value of 2% to < 1% Zn.

Jan 1, 2006

By E. A. Roux

As the first mine-to-metal zinc operation utilising atmospheric leaching, solvent extraction and electrowinning, Skorpion Zinc faces unique challenges and opportunities. One of these challenges is found in the solvent extraction circuit, in which di-ethylhexyl phosphoric acid (D2EHPA) is used as the organic extractant. Although D2EHPA is an excellent extractant for zinc, it suffers from the co-extraction of ferric iron, which is produced during leaching and by the corrosion of the grinding media. This situation is partially mitigated by iron precipitation in the neutralisation step prior to solvent extraction. Unfortunately, some ferric iron still reports to the solvent extraction process. This leads to a slow build up of iron in the organic phase. Chemical stripping is used to maintain the Fe concentration at an acceptable level. In this paper, the efficiency of the iron removal process is discussed.

Jan 1, 2006

By M. B. Mansur, A. S. Guimarães, A. J. M. Santanilla, D. C. R. Espinosa, J. A. S. Tenório, R. A. Pini

The separation of Ni and Co from sulphate medium containing Mn, Mg, Cu and Ca was carried out by solvent extraction. The object of this study was to investigate the synergistic effect using phosphinic acid (Cyanex 272) and carboxylic acid (Versatic 10) and their mixtures in kerosene. The extraction percent of each metal ion was found to increase with increasing pH and extractant concentration. Co was preferentially extracted over Ni under the same extraction conditions. The separation factors of Ni/Co increased with the use of the synergistic systems investigated.

Jan 1, 2014

Éléonore Project Highlights Éléonoreis a multi-million ounce, high grade gold discovery in Québec Currently at the advanced exploration and engineering studies stage Excellent potential for expansion Underground mine with potential for small open pit Excellent infrastructure including road and high quality/low cost electricity within 70 km Les Mines Opinaca Ltée, a 100% subsidiary company of Goldcorp, was created to manage and operate the Éléonore Project

May 1, 2007

By H. Aaltonen, T. G. Robinson, M. Morimitsu

"The energy required to plate pure zinc can be the most significant operating cost for an operator in the production of electrolytic zinc. This paper reports on developments on low energy Outotec coated titanium anode process technology with fully amorphous coatings, MSA®, and its application to brownfield zinc electrowinning operations around the world. This technology aims to reduce the operating cost and increase productivity for zinc producers.INTRODUCTIONZinc electrowinning is an energy-intensive process using more than 3,000 kWh/t of electric energy [1-4], and the reduction of the energy consumption is one of the key issues. The high energy consumption is due to a high cell voltage during electrolysis, which is mainly caused by a high overpotential of oxygen evolution reaction on lead alloy anodes which have been widely used in commercial zinc electrowinning processes. The overpotential of oxygen evolution is 0.6 V or more and which is approximately 4 times higher on average than that of the cathodic reaction (zinc deposition) [3,4]. Therefore, the reduction of oxygen overpotential is significant to reduce the electric energy consumption, and this will become more significant with increasing demand in metal production and rising energy costs.Oxide coated titanium anodes have been widely investigated for the oxygen evolution anodes in order to replace the lead alloy anodes [5-9], because it is known that the oxygen overpotential strongly depends on the material and structure of the anode. The most typical example of such anodes is an IrO2-Ta2O5 coated titanium anode, which is usually prepared at thermal decomposition of a precursor solution containing metal salts at 450 oC or more and obtained mixed oxide coating consists of crystalline IrO2 and amorphous Ta2O5. On the other hand, one of the authors of this paper, Professor Morimitsu, Doshisha University in Japan, has developed a novel oxide coated titanium anode, MSA® [10-25]. The most specialized point of MSA® is that the catalytic coatings are prepared at low thermal decomposition temperature and amorphous IrO2 or RuO2 is contained as the components in the coatings. Such amorphous coatings have high catalytic activity for oxygen evolution compared to lead alloy or crystalline coatings. Outotec acquired the international specialized MSA® patent licensing rights from Doshisha University and has produced and commercialized the amorphous oxide coated titanium anodes. These anodes have already been utilized mainly in copper electrowinning plants worldwide and have demonstrated a significant voltage reduction, a cost-efficiency, and a long lifetime. This novel technology is also effective to zinc electrowinning process, thus this paper presents the characterization and performance of amorphous IrO2-Ta2O5 coated titanium anodes and amorphous RuO2-Ta2O5 coated titanium anodes for oxygen evolution in zinc electrowinning."

Jan 1, 2016

By W. W. Bake

INTRODUCTION IN IN JUNE, 1943, the main pillars of the Beattie Mine glory hole failed, allowing over a million yards of wet clay and debris to flow into the mine, completely filling all workings to within seventy feet of the 3rd level. The resulting Job of clearing these workings and rehabilitating the mine represents a unique and hazardous operation, seldom, if ever, previously encountered in Canadian mining. The purpose of this paper is to describe one phase of this operation -that of cleaning and rehabilitating the mine from the 6th to the 9th level -to outline briefly the events which led up to this work and to describe the techniques and costs involved. It will be noted that such costs, methods, and performance figures as are dealt with in this paper refer only to work in the internal shaft and adjoining workings from the 6th to the 9th level, previous work having been done under other supervision and management. The Beattie mine is in Duparquet township, northwestern Quebec, twenty miles northwest of the town of Noranda and twenty-three miles southeast of the town of La Sarre. The mine and the town of Duparquet, which it?supports, are accessible by highway from Noranda throughout the year. Production at the Beattie mine began in May, 1933, and up to June, 1943, twenty-one million dollars in gold and silver had been recovered from five and a half million tons of ore.

Jan 1, 1951

By G. F. Doggett

In describing accounting methods at Lake Shore Mines, it is the intention of the writer to limit the discussion to the principal features of the system used in securing cost figures and other statistics. The subject can be conveniently treated under the following divisions: (1) Time-keeping and Labour Distribution (2) Supplies: Handling and Distribution (3) Method of Assembling Data for Cost Purposes (4) Details of Operating Costs Time-Keeping and Labour Distribution After a new employee has gone through the routine of being &apos;hired on&apos;, he is assigned an employment number corresponding with the group applying to his occupation. This is for identification purposes in the plant and time office. He is also given an individual serial number, the use of which will be refer-red to later. On entering and leaving the plant, each employee passes through the clock room adjoining the time office, where he registers the time in and out on time recorders, on the clock card (Figure 1) bearing his name and number. It is the duty each morning of the time clerk to extend the hours worked by each employee, as indicated by the clock for the previous day, and at the end of the half-month period the total hours are multiplied by the rate and entered in the space provided for total wages at the bottom of the card.

Jan 1, 1935

By M. Reda

Erosion corrosion is acceleration in the rate of corrosion attack in metal due to the relative motion of a corrosive fluid and a metal surface [1]. The increased turbulence caused by pitting on the internal surfaces of a tube can result in rapidly increasing erosion rates and eventually a leak [2]. Engineers and scientists in different disciplines have worked for many years on methods of complete protection from flow induced corrosion or partially reducing corrosion of this type, and they have proposed or applied different countermeasures [2]. The accident at the Surry-2 nuclear power plant (USA) and other similar incidents have once again disturbed the scientific-technical community. This has forced the plant operating personnel and the management to undertake wide-ranging measures in order to discover on time, assess, and monitor such cases. In these extreme cases, protective coating and even metallic bulk material coating (the substrate itself) may suffer considerably from mechanically induced damage [2]. At high velocities, the "leaching out" dissolution reaction of particular, for example, steel elements at the solid-liquid interface become the rate determining step. One practical example for the difference between erosion corrosion and flow induced corrosion is the famous steam eruption from a Japanese [3, 4] nuclear power plant cooling system at the pressurized water reactor (PWR), turbine and in the condenser-steam generator connecting pipe. The rupture occurred in the carbon steel pipe connecting the condenser and steam generator. The damage occurred in the easily eroded/corroded carbon steel at a vulnerable location downstream of an orifice plate, In general, when there is significant reduction in pipe thickness through erosion/corrosion, distinctive patterns are visible, but those patterns were not observed in this case, Thus one can speculate that another phenomenon is possibly controlling, Fluid flow within pipes reduces the pipe thickness leading to an eventual rupture, The thickness reduction mechanism is erosion/corrosion, One example is "cavitations corrosion", Erosion and corrosion occur at the same time, and it is difficult to determine which one is dominant, Therefore, the term, "erosion/corrosion," is used [5]. In the atomic energy field, the terms "Flow Accelerated Corrosion" and "Flow Induced Corrosion" are also used. It is the purpose here to show that during flow induced corrosion a different mechanism may possibly be operating and in some cases it can be different from the well known erosion corrosion. Another example is fretting failures in early Canadian nuclear steam generators which was thought to be due to excessive vibration caused by high.

Jan 1, 2010

By Ralph W. Edie

"IntroductionTHIS PAPER presents some analyses of diabases from a number of metallogenic provinces in Canada and the United States. It is intended as a contribution to the literature on the genesis of mineral deposits associated with diabase.As it has been in the past, opinion today on the origin of the cobaltnickel- native silver and associated pitchblende type of deposit is sharply divided. Some geologists hold that this type of deposit is in some way genetically related to intrusive diabase; others are of the opinion that the deposits are related to granite. The controversy, like others of a similar nature, probably will not be settled satisfactorily for many years to come, •but in the meantime it is recognized that, with respect to most deposits of the type referred to, altogether too few facts are known for accurate conclusions on genesis to be drawn. To contribute in a small way to factual data on this whole .problem, the writer analyzed diabase from several districts in Canada in which deposits of the aforementioned type occur. For comparative purposes, the copper, cobalt, and nickel content of diabase from Cornwall, Pennsylvania, and of norite from the Sudbury basin of Ontario, was also determined.Insofar as is known, none of the analytical work undertaken had been previously carried out."

Jan 1, 1953