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By Afshin Sadri, Wai Lai Ying, Brycklin Wilson, Zoe Coull

"Although there have been great steps forward to integrate corrosion engineering into operations, there is still an underlying tendency for maintenance tasks to be performed in a reactive manner. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify leading indicators of failures. Prevention is generally less costly than repairs; moreover, when paired with appropriate monitoring techniques, intervention of corrosion protection can be more effectively timed and based on more accurate data. Hatch asset reliability studies show nearly 80% of defects are introduced through operations and maintenance. Therefore, proactive corrosion management can provide the necessary feedback to optimize operations and maintenance strategies preventing costly corrosion losses. Understanding corrosion risks gives a clear picture of the benefits of a proactive approach to asset performance. Monitoring techniques (Non-Destructive Testing, field testing, sampling, etc.) by nature are a more effective means of improving maintenance efforts and preventing corrosion losses than other methods (RCA, FMECA). This paper will outline the importance of proactive corrosion management and demonstrate its benefits through industry examples.INTRODUCTION Over the past few decades, with the growth of technology and awareness of sustainable development many studies have shown the benefits of a proactive approach to maintenance strategies. However, in practice there is still an underlying tendency for maintenance tasks to be performed in a “reactive manner”. This is especially true when strategies focus on lagging indicators such as visual inspections, RCA (root-cause analysis), and FMECA (failure mode, effects and criticality analysis). This trend to “reactive maintenance” can be avoided by utilizing more inspection and monitoring methods to identify defects and leading indicators to failures."

Jan 1, 2017

By H. M. Lewis

The current status of the international zinc market is summarized, and a supply /demand outlook is presented for the next five years. A number of technical problems facing the industry are outlined. Introduction ZINC has sometimes been called the unknown metal. Considering that on a world basis it ranks third among non-ferrous metals in production and consumption, zinc retains a certain modesty. It has no distinctive colour like copper, lacks the low density of aluminum or magnesium and is not always easy to identify as a product. The 'spangle' of galvanized steel is probably zinc's most distinguishing feature. The purpose of this article is to develop an over-all review of zinc. Starting with the current position of the metal, the major factors that will shape its future will be described so that an assessment of the outlook for zinc can be made.

Jan 1, 1978

By A. J. MacEachen

"LIKE ALL OTHER NOVA SCOTIANS, I have been thrilled during the past few years with the growing evidence that substantial reserves of oil and gas are being discovered off the Atlantic coast of Canada. There are those in this province who believe that large-scale commercial production is just around the corner, and that when it starts Nova Scotia will begin to float on a sea of royalties. These overly optimistic people, of whom I am not one, are convinced that with the first barrel of oil shipped to market, Nova Scotia can forget its financial problems while its people take on the luxurious lifestyle of the shieks of Kuwait or Saudi Arabia. You and I know, however, that even though offshore oil and gas may turn out to be the greatest gift nature has ever bestowed on Eastern Canada, it may take some considerable time before the reserves can be accurately assessed, before the industry can become fully operational, and before the benefits of production can be translated into royalties and tax revenue, improved public services, new industrial facilities and more jobs. While it is premature for the ordinary Nova Scotian to take on the habit of buying expensive cigars and lighting them with ten-dollar bills, it is not too early for him to insist that governments and industry plan intensively and well for the beneficial exploitation of undersea resources."

Jan 1, 1973

By N. M. Soonawala

Detailed regional geophysical and geochemical surveys, ground surveys and drilling were undertaken to follow-up the federal-provincial Uranium Reconnaissance Program (URP) over the 27,OOO-km2 Kasmere-Munroe area in northwestern Manitoba. An analysis of the URP data showed a fair correlation between the regional airborne radiometric results and lake-bottom geochemical results, both of which also correlated with the regional geology. More detailed surveys defined anomalies with greater precision within the broad zones outlined by the URP. The ground follow-up indicated that URP anomalies can be caused by varying degrees of uranium concentration in the rocks. Mineralization of interest was found in leucogranites at several locations within the survey area. Anomalous uranium concentrations were also found in coarse pegmatites and Hudsonian granitic intrusions. It can be concluded that large-scale regional surveys can be followed up in relatively short periods of time to yield meaningful results if a properly planned exploration sequence is employed, each stage of which successively narrows the area of interest.

Jan 1, 1979

By Hulbert A. Lee

"A REVIEW OF MINERAL DISCOVERIES IN CANADA, and in particular the Canadian Shield, using the physical aspects of overburden reveals a trend in the art of exploration. At an early time of exploration (1847-1954), float and heavy clasts were used successfully to find ore deposits with little knowledge of Quaternary environments. At a later time (1955 to present) , use of Quaternary rock-units for sampling have made possible tracing indicator trains of float, heavy clasts and other ore-type clasts to the source bedrock. The basal till of retreat ice is now recognized as a1l favourable sampling environment and as such has been used to successfully discover hidden orebodies. The esker massive gravel is beginning to be recognized as a favourable environment and use of it has met with technical success. An understanding of those changes that have taken place during the transportation of the material and after its deposition is essential to proper sampling and treatment of the samples from the basal till and the esker massive gravel. Use of float and heavy clasts in search of orebodies is continuing in present-day exploration on the Shield. Lessons learned from it are being incorporated into exploration using favourable Quaternary rock-units for sampling. Hence, both subjects have a need for review and are discussed in this paper."

Jan 1, 1971

By J. Mrozowski, R. Kurowski, A. Chmielarz, Z. Szolomicki

PbSO4 is a commonly encountered component of the materials used in lead recycling (e.g. battery paste) and in by-products of metallurgical processes (e.g. residues from zinc hydrometallurgy, dust from copper smelting). Smelting of battery paste results in SO2 emission and in generation of significant amounts of hazardous ‘white slag’. Those adverse phenomena can be eliminated by removal of sulphur from the paste. Lead-bearing by-product materials are of polymetallic character with usually low Pb content, which makes lead recovery technologically difficult and uneconomic. However it can be successfully achieved by extraction of lead sulphate from solid phase with triethylenetetramine (TETA) water solutions. That compound has capability for selective solvation of a whole lead sulphate molecule. Virtually pure lead carbonate can be precipitated by means of saturation of lead-loaded aqueous TETA solution with carbon dioxide, and complete regeneration of the extractant is achieved by fixing of sulphate ion into gypsum through operation of calcium hydroxide suspension. The paper presents results of the lab and pilot scale studies into process of battery paste desulphurisation and recovery of lead from the residue of zinc calcine leaching.

Jan 1, 2014

By D. F. Sangster, P. J. Hood, G. A. Gross

"Some results are presented of an integrated geological and geophysical study of Precambrian magnetite-quartz iron-formation in the Kapiko Iron Range north of Nakina, Ontario. Detailed geological and topographical mapping was carried out in conjunction with detailed geophysical investigations such as vertical magnetic field, vertical magnetic gradient, hammer seismic, horizontal-loop electromagnetic and magnetic susceptibility surveys. In addition, oriented drill cores were obtained for magnetic polarization studies.Vertical-force magnetic anomalies within individual rock units showed a strong positive correlation with topographic relief. Moreover, magnetic intensity was found not to be quantitatively proportional to the magnetite content in the rocks, due to the presence of high remanent magnetization of the magnetite. Also, the remanent polarization direction was sub parallel to the plunge of the fold structure and mineral lineation in associated rocks.Vertical magnetic gradient measurements were found to be more accurate in locating buried contacts between magnetite-quartz iron-formation and country rock than the vertical magnetic force data.An in-situ magnetic susceptibility meter was used to measure the magnetite content of iron-formation, and the measurements were subsequently compared with vertical-force magnetic results.The results of the EM survey were inconclusive; some magnetite-rich zones produced anomalies in the out-of-phase component. whereas others did not. The reasons for such inconsistencies are not yet apparent.Longitudinal seismic wave velocities measured parallel to the bedding in magnetite-quartz iron-formation ranged from 10,600 ft/sec. to 14,500 ft/sec. The seismic velocity appears to increase with an increase in deformation of the rocks."

Jan 1, 1966

By P. Marcotte, G. LeBlanc, S. Ouellette, J. Boutin

"To characterize noise and vibration sources of different types of mining equipment used in underground mining, the authors performed a study in eight Quebec mines on 28 pieces of equipment. This paper presents the procedure followed to select the equipment to be evaluated, and the low-cost acquisition system developed to perform multichannel time-domain data acquisition in harsh environments. It also presents the results obtained for the noise level produced by the equipment and for handarm and whole-body vibration exposures.RÉSUMÉ Dans le but de caractériser les sources de bruits et de vibrations de divers équipements miniers utilisés sous terre, les auteurs ont étudié 28 équipements dans huit mines du Québec. L’article présente la procédure suivie pour choisir les équipements à évaluer ainsi qu’un système multicanal à faible coût développé pour acquérir des données dans des environnements difficiles. Il présente aussi les résultats obtenus pour les niveaux de bruit produit par les équipements et pour les expositions main-bras et du corps entier aux vibrations."

Jan 1, 2015

By J. E. Dutrizac, Alba Sunyer

The factors affecting the precipitation of arsenic-free alunite (KAl3(SO4)2(OH)6) were investigated in a series of laboratory experiments. Although the amount of alunite precipitated increased with increasing retention time, temperature, solution pH and the concentrations of Al(SO4)1.5 or K2SO4, the composition of the products remained nearly constant. The preferred conditions identified for the precipitation of arsenic-free alunite were then used to assess the behaviour As(III) and As(V) during alunite precipitation at 98°C. Increasing additions of As(III), as NaAsO2 or As2O3, resulted in a slight increase in the amount of precipitate formed at pH 2.80. However, X-ray diffraction analysis showed all the precipitates to be alunite, and <0.2% As(III) was detected in the products. In contrast, increasing additions of As(V), as KH2AsO4 or As2O5, resulted in significant increases in the amount of precipitate formed at pH 2.80 or 3.00. Furthermore, the arsenate (AsO43-) contents of the precipitates increased up to 15%, and the sulphate contents decreased, as the As(V) concentration of the synthesis solution increased from 0 to 9 g/L. X-ray diffraction analysis of the products detected only alunite, but there was a progressive expansion of the alunite cell with increasing arsenate content. The implication is that arsenate substitutes for sulphate in the alunite structure. Preliminary observations on the environmental stability of the arsenate-bearing alunite using the TCLP protocol gave solubilities <0.4 mg/L from a precipitate containing 8.5% AsO4 and 7.8 mg/L from a product containing 19.5% AsO4. Thus, it appears that alunites containing less than -10% AsO4 would be an acceptable vehicle for the disposal of arsenic from hydrometallurgical processing solutions.

Jan 1, 2011

By Robert G. Boutilier

So far, most social performance monitoring systems have not gone beyond listing the impacts on various stakeholders. Executives have had to rely on intuition to devise interventions that would improve the impacts. This paper describes a survey process, known as the Stakeholder 360 (S360), which eliminates much of the guesswork. The paper reviews key studies showing that raising the levels of communication, trust, and common vision among stakeholders leads to the acquisition of the resources needed to improve the socio-economic situation. Therefore, the Stakeholder 360 measures the levels of these three factors in the relationships between a company and its stakeholders, and among the stakeholders themselves. In a validation study at a gold mine in rural Papua New Guinea, the S360 produced a socio-political ?roadmap? that showed management and stakeholders alike which relationships need more communication, trust, or common goals/vision. Management used the findings to create alliances that helped the government move forward on a regulatory regime for the mine closure. The community used the findings to focus its planning for life after the closure. An S360 survey conducted six months later revealed a decline in dependence on the mine and an overall increase in levels of mutual understanding.

May 1, 2002

By K. Szczesny

This paper considers the integration of uncertain real-time logistics data for reactive construction scheduling. In order to manage a construction project efficiently, an accurate schedule representing the current project progress is inevitable. The quality and up-to-dateness of such a schedule depends on the availability of real-time data. Typically, real-time logistics data contain information about the availability of material, equipment and personnel as well as delivery dates and site conditions. The accuracy and inherent uncertainty depends on the location where the real-time data was acquired. Currently, the integration of such data into a construction schedule is a very time-consuming, manual and, thus, errorprone process. Therefore, this paper proposes a methodology that enables an automatic integration of such uncertain data into construction schedules. By integrating uncertainties into the existing schedule their impacts on the construction work can be evaluated. For this, discrete event simulation is applied. In order to model uncertain input parameters for simulation models this methodology applies the fuzzy sets theory. In combination with alpha-cut sampling technique, discrete model input parameters are obtained. By applying reactive scheduling with several discrete event simulation experiments, the results can be used to modify construction schedules according to agreed timeframes and costs. In order to demonstrate and validate the presented approach an example is conducted.

Aug 1, 2013

By H. R. Banks

SHORTLY after the commencement of operations at the Sullivan concentrator, the use of a pilot table was instituted in order to present a visual control of various products by showing the amount of galena still present in the tailing from several stages of flotation. Among the products so treated, the final tailing was later included. It was sratifying to note that very little free galena was escaping, but a fine streak o a whitish mineral appeared at the concentrate zone. This mineral was identified as cassiterite. The amount was small and the newly recognized component in an already complex ore was considered primarily as of academic interest. However, the problem of recovering a usable metal was intriguing and, as opportunity presented itself in temporary lulls in research on Sullivan and other ores, the concentration of tin was a useful &apos;bit of knitting&apos; to go on with. It was recognized from the start that the bulk of the mill tailing would have to be floated and the residue subjected to gravity treatment. Since one of the predominating features of Sullivan concentration operation has been the necessity of fine grinding, the problem of gravity concentration was thereby intensified. Several batch runs were made, and sufficient pulp was treated to produce about one ton of final tin concentrate assaying 67 percent tin. The overall recovery was under 30 percent and the estimated profit at full tonnage was only marginal. Testing was resumed several years later, when the price of tin again appeared attractive, in an attempt to develop a more compact plant with better recovery of tin. The weakness of the original plan of concentration was the large number of tables required to treat a feed so low in tin.

Jan 1, 1941

By Nur Hossain

Analysis of Linear Elastic Fracture Mechanics (LEFM) parameters via the Virtual Crack Closure Technique (VCCT) has been obtained for SENT specimens of AM6OB magnesium alloy. It is found that the ratio of initial crack length to initial monotonic plastic zone size is one of the critical factors in establishing the limit of using LEFM concepts. If this ratio is below a certain limit (i.e. when crack lengths are small in comparison to the plastic zone size), loss of similitude stress intensity factor range would occur. This ratio, therefore describes the limit below which the use of LEFM would no longer be admissible. In this study, the above limit was established for AM6OB magnesium alloy. In addition, fatigue crack propagation tests were conducted to ascertain the fatigue response of the alloy and determination of the coefficients of Paris model.

Jan 1, 2010

By J. S. Vanderploeg

I WILL begin this presentation by citing the annual per capita use of copper in Canada. This is best calculated by taking refinery domestic sales, plus imports of the products of foreign fabricating mills (very little refinery copper is imported), and deducting the exports of Canadian mills. No attempt has been made to estimate the copper content of imports or exports of machinery, motors, etc., but the trade balance here is probably against Canada. In any event, we find that, though varying somewhat since the war, the estimated yearly per capita figure has reached a high of 18 pounds. This is practically on a par with the United States. The rest of the world uses an average of about 2 pounds per capita, yearly, though this includes some countries, such as Sweden, Germany and England, which consume much better than average quantities. It looks, therefore, as if the Canadian copper industry has not (as has been generally charged) been asleep after all.

Jan 1, 1962

By J. B. Evans

"NORMALLY the duties of the exploration engineer and geologist cover the initial, and possibly, the most important phase of mining property evaluation; that phase being the presentation of an opinion of the property's ore reserve potential in terms of tonnage and grade. The prime objective of this pa-per is to outline one method of bridging the wide gap that lies between a know ledge of a property' s tonnage and grade potential and an appreciation of the value of that property in dollars and cents.THE PRESENTATION OF PROPERTY EVALUATIONThe engineer engaged on a mining property evaluation, regardless of whether he be an independent consultant, or a company employee, has as his goal, the presentation of his appreciation of the property's potential value or worth within terms of reference acceptable to his principal.To furnish a complete evaluation report, the evaluator must firstly study all aspects pertaining to the particular property under consideration, then present his appreciation of the property's worth in some tangible form. The ultimate presentation is one giving a Present Value of the pro pert y in terms of monetary exchange. Such an idealistic presentation is not always possible; typical preventives being -insufficient reliable information, limited time, Jack of ability and absence of definite direction."

Jan 1, 1960

By Peter Richards, Alexander Lewis-Gray, Mark Davies, Nicholas Katsikaros

"Gekko Systems developed the Gekko Resin Exchange Column (G-REX) in order to optimise the recovery of gold in complex leach-to-electrowinning processes, as an intermediate step using a highly gold-selective resin to isolate contaminant metals. The AuRIX®100 resin produced by Purolite is licensed exclusively to Gekko, with the G-REX column designed specifically for this resin (Lewis-Gray et al, 2015). Operational experience has been gained at the CGT Ballarat Gold Plant in near continuous operation since 2008, treating unclarified concentrate leach solution. The extension of the technology to higher throughputs and more complex chemistry is discussed.Aurix®100 ResinAuRIX®100 resin is a cross-linked polystyrene alkaline resin developed by Henkel (Virnig et al, 1996). The resin beads are off-white in colour, spherical, with a nominal size of 100% +600µm. This resin is highly selective for gold and silver over many metals, by way of extracting precious metal cyanide complexes from leach solutions with a pH less than 11.5. The higher end of the pH scale produces best selectivity according to the order of preference: Au > Ag > Hg > Zn > Ni > Cu > Co > Fe. Purolite produces the resin and Gekko Systems maintains licensing of AuRIX®100 resin for use in its G-REX column as part of its unique suite of gravity gold handling equipment.Significant cost savings over carbon-in-solution (CIS) systems are realised with AURIX®100 resin, of around 4% to 12% in capital savings and 27% to 40% in operating costs (Virnig et al, 2004). Allied to this is that AuRIX®100 resin is not susceptible to fouling, that is, the resin does not load with inorganic salts or organic compounds which would affect the loading and extraction of precious metals. To counter any potential for fouling by inorganic salts, in service a dilute acid wash is carried out periodically on the resin to unblock resin pores."

Jan 1, 2016

A line of nine self-aspirating W emco cells, part of the Rougher circuit at Division Salvador, Codelco Chile, was retrofitted to allow operation with forced air. Each cell could be operated self-aspirated or with compressed air supplied through a 4-inch line equipped with a mass flow meter. Gas dispersion was characterized for the two modes of operation. Metallurgical performance was compared under self-aspirated conditions and with different gas profiles under forced air conditions. Cell characterization demonstrated that with forced-air the cells could not evenly distribute air across the cell volume. Bubble size increased with gas velocity, as expected, with no difference between self-aspirated and forced-air operation. A systematic increase in bubble size down the bank was found. Cumulative bubble surface area flux down the bank showed no major differences between surveys. However, grade-recovery curves revealed that the highest recoveries were invariably obtained with forced air operation. Plotting concentrate mass recovery vs. enrichment ratio showed that the line performance could be controlled over a wider range when forced air was used.

Jan 1, 2007

By M. Hames, K. Larmour-Ship, B. Grinbaum, E. Buchalter, R. Hackl, B. Wassink

Sodium cyanide continues to be the lixiviant of choice for gold dissolution. Many gold ore-bodies contain a significant amount of cyanide-soluble copper which increases the cost of processing due to high cyanide consumption and high cyanide destruction and disposal costs. Several cyanide destruction processes are in use today, however, there are just a few cyanide recovery plants operating. A solvent extraction process to recover cyanide has been developed which utilizes the organophosphorous extractants Cyanex 923, di-butyl-butyl-phosphonate (DBBP) or tri-n-butyl phosphate (TBP) in Bateman Pulsed Columns. Copper cyanide species are first converted to hydrogen cyanide (HCN) by acidification, with or without sulfide addition. HCN is extracted by the organic and stripped using a suitable base (eg. NaOH) resulting in a high strength cyanide solution (eg. NaCN) for recycle to the gold recovery process. Continuous pilot plant testwork on HCN extraction using a 40 mm diameter Bateman Pulsed Column demonstrated a cyanide recovery of greater than 99% with final levels of cyanide in solution of less than 10 ppm. These results illustrate the potential of this technology to recycle cyanide and to detoxify final effluent streams.

Jan 1, 2005

By George R. Pratt

Although the title of this paper focuses attention to the Winnipeg coal market the following remarks should be considered applicable not only to conditions in Winnipeg but to the whole western coal industry. Technical descriptions of coal and coal-burning have been omitted. These details are already covered in other numerous publications. In discussing a market the first consideration must be the product which is required to be sold. The class, quality and price at the point of origin must be taken into account and therefore this feature will be discussed before proceeding to outline conditions in the Winnipeg local market. The writer thinks of coal as a manufactured article, not, as it is generally considered, a fuel to be dug from the ground and dumped into the consumer&apos;s bin. The work of manufacturing must be considered in detail:- 1. Consider first the coal as it is in the ground: (a) What is its fuel value? (b) Where is its market? © With what will it be in competition? 2. Consider secondly: (a) What it will cost to mine the coal. (b) What has to be done to prepare the coal for market after it is mined. This must be considered in conjunction with the answer to question 1 ©. 3. Thirdly, consider the method of business to be adopted by the producer:- (a) Is it proposed to build a market on price? Or (b) On quality?

Jan 1, 1925

By M. Cai

A practical simple method is proposed to estimate the tensile strength (st) of strong brittle rocks from the strength ratio of R= sc/st = 8 sc/sci, where sc is the uniaxial compressive strength and sci is the crack initiation stress in an uniaxial compression test. 8 is the Griffith strength ratio and the term sc/sci accounts for the difference of crack growth or propagation in tension and compression in uniaxial compression tests. sci can be reliably obtained from volumetric strain measurement or acoustic emission (AE) monitoring. With the strength ratio R determined, the tensile strength can be indirectly obtained from the result of uniaxial compression tests. In addition, a practical estimate of the Hoek-Brown strength parameter mi is presented and it is suggested that mi = 12 sc/sci can be applied to strong, brittle rocks in high confinement zone and mi = 8 sc/sci can be applied to low confinement to tension zones. It is found that the predicted tensile strengths and Hoek-Brown strength parameter mi using this method are in good agreement with test data. The rock strength parameters like st and mi, which require specialty tests such as direct tensile (or Brazilian) and triaxial compression tests for their determination, can be reasonably estimated from uniaxial compression tests.

May 1, 2009