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By A. C. Stevenson

"There are many critical application issues that affect all AC drives, but there are several that are absolutely mandatory for pulse width modulated (PWM) AC drives. If these rules are not followed, the drive system will have insulation, bearing EMI or noise problems. Pulse Width Output VoltageFigure 1 shows the output current of a typical pulse width modulated (PWM) drive. This is, of course, not a clean sine wave thus will have a lot of very significant harmonics. In fact, the harmonic spectrum is directly related to multiples of the carrier switching frequency plus side bands related to the basic output frequency. A typical spectrum for a PWM source bridge switching at 5 kHz is shown in Figure 2. Notice that the spectrum has multiples of the 5 kHz switching frequency and the number of side bands gets larger as the harmonic number increases.IGBT Switching TransientsWhenever we have PWM inverter switching, voltage transients are formed that propagate (usually at about half the speed of light) down the power cables to the motor just like in a radio frequency transmission line. If we do not terminate these transmission lines (motor cables) properly, the voltage pulses will be reflected when they reach the motor end and will be transiently increased up to twice their original amplitude.This transient voltage rise, shown in Figure 3, is important for three reasons:1. Insulation Voltage Stress — Higher voltage stress in the motor connecting cables and motor insulation will lead to a shorter insulation lifetime. If any of the voltage transient peaks exceed the insulation corona discharge level (partial discharge level), the insulation will gradually degrade with each voltage pulse. When it has been sufficiently degraded, it will then fail.Most new “inverter rated” motors have triple layer insulation which has a 1600 to 2000 volt partial discharge level. This will make them suitable to withstand the double voltage peak transient from a 600 volt inverter. It is wise to make sure of this fact, since a “standard” induction motor will only withstand about 1200 volts. Use of a standard motor in this application would shorten its life drastically. This can sometimes be as little as a matter of hours."

Jan 1, 2000

By R. L. Bruening, R. M. Izatt, N. E. Izatt, S. R. Izatt

"Molecular Recognition Technology (MRT) is a simplified, green chemistry process with applications in selective separations of Ni(II), Co(II), and platinum group metals in primary ore beneficiation processes and secondary recovery operations from spent products, scrap, and environmental waste solutions. Simplification in MRT processes is achieved by non-use of solvents, reduced space requirements, and a simple separation system involving columns packed with metal-selective SuperLig® resins. Minimal waste is generated and metal recovery is achieved at 99% levels from g L-1 to <mg L-1 concentrations. MRT systems are attractive technologically and economically compared with solvent extraction, ion exchange, and precipitation separation processes. Commercial examples of MRT use include removal of impurity metals Cd, Cu, Ni. Fe, and Pb to mg L-1 or lower concentration levels from Co streams to produce battery-grade Co. Highly purified Co is required for optimal function of lithium ion rechargeable batteries and superalloys associated with aerospace and gas turbine operations. Impurity metals are recovered for reuse or proper disposal rather than being discarded to landfill. Green chemistry processes, such as MRT, are needed in metal separations going forward into the 21st century to achieve global metal sustainability in processing of native ore and treatment of secondary sources.INTRODUCTION Maximizing efficiencies of metal separations and optimizing metal recovery rates during separation processes are important goals on the road to achieving metal sustainability. Achievement of these goals is consistent with stated principles of green engineering (O'Connor, Zimmerman, Anastas, & Plata, 2016) and green chemistry (Anastas & Eghbali, 2010). Molecular Recognition Technology (MRT) separation processes using SuperLig® resins have a 25-year record of performing competitive, commercial metal separations with metal recovery rates approaching 100% (Izatt, Izatt, Izatt, Krakowiak, & Bruening, 2017). SuperLig® resins are characterized by high selectivities for specific metals over concentration ranges from g L-1 to mg L-1 or lower. MRT systems use no solvents and are simple in design and operation resulting in reduced capital and operating expenses."

Jan 1, 2017

Barrick Gold Corporation is the gold industry leader, with 25 operating mines and a pipeline of large, long-life projects located across five continents, in addition to large land positions on some of the most prolific mineral districts. Barrick&apos;s high level of commitment to sustainable economic development and environmental stewardship was recognized by Dow Jones Sustainability Index (DJSI) - World, for the third consecutive year in 2010. The potential for adverse environmental effects from acid rock drainage (ARD) and metals leaching (ML) and their financial implications for Barrick are key considerations in our environmental assessment and business development processes. Barrick&apos;s membership in the International Network for Acid Prevention (INAP) reflects the importance of these issues to our business. INAP&apos;s development of the Global Acid Rock Drainage (GARD) Guide (a best practices guide for acid rock drainage prevention) provides Barrick with an important tool to assist in the assessment of environmental and financial risks from ARD and ML associated with our planned and ongoing mining operations (INAP, 2009). In this paper we will discuss how Barrick incorporates the GARDGuide and its principles for ARD and ML prediction and prevention in our business development processes and the management of our operations. The GARDGuide serves as a key reference for our project environmental assessments and as a common link between our projects and operations management, consulting specialists, permitting and regulatory authorities and the public. We will discuss how the GARDGuide is being "syndicated" throughout Barrick as a standard of practice and present a case study of how it was used in a recent Barrick Business Development Project.

Jan 1, 2011

By W. C. Whittaker

Introduction When one thinks of a coal stripping deposit, the picture that usually comes to mind is that of a more or less flat seam from two to twenty feet in thickness overlain by ten to fifty feet of overburden, in suitable ratio for economic operation. This is the usual type of stripping deposit and is quite a common occurrence in various parts of the prairie provinces. Rather unusual types of coal stripping deposits are being presently worked as open-cut mines by Sterling Collieries, Limited, and the Co al Valley Mining Company, Limited, at Miles 47 and 48 on the Alberta Coal Branch, some 150 miles south west of Edmonton. These deposits are of interest chiefly because they represent turned-up and greatly thickened sections of the Mynheer seam, and as such they present their own problems, peculiar to the commercial exploitation of a seam of this type. The area in which these deposits occur was originally owned by the Pacific Pass Collieries, whose operations, however, were confined to under-ground mining at Lovett, some eight miles to the southeast. It was not until l918 that the value of these deposits was realized, when the Company now known as Sterling Collieries, Limited, opened their pit at Mile 47. At the inception of the work, coal was loaded directly into the railway cars by men using wheelbarrows. In 1920, a tipple was built, after which the coal was loaded by steam shovel into mine cars, hauled by steam dinkeys, and loaded over the tipple into railway cars. In 1922, the Coal Valley Mining Company entered the field at Mile 48, with an entirely mechanical equipment, and at the present rime these two are the only stripping properties in Alberta using mechanical equipment both for the removal of overburden and the loading of the coal. These Companies have operated continuously since that time, and have to date mined and shipped 4,000,000 tons of coal, and moved some 5,255,000 cubic yards of stripping. The present annual coal output for the two mines is about 240,000 tons.

Jan 1, 1935

By J. S. Roper

"IntroductionSNOW LAKE is situated in northern Manitoba at latitude 54° 55 and longitude 100°, 400 miles northwesterly of Winnipeg, 80 miles northeast of The Pas, 80 miles east of Flin Flon. A 38-mile road from Wekusko, on the Hudson's Bay railway, serves the community.The mine is located in and close to the southern edge of the Precambrian Shield in typical low-relief muskeg and lake country.The Howe Sound Exploration Company, Limited optioned the property from Nor Acme Gold Mines, Limited, after preliminary diamond drilling had outlined two orebodies of low-grade arsenical gold ore.Following the examination and study of geological data and of 50,000 feet of diamond-drill core, and metallurgical tests made during 1942 to 1945, a decision was made to develop the mine and build a 2 ,000-ton mill concurrently. This development has been described by G. C. Lipsey in a paper entitled The Development of a Mining Operation from Diamond-Drill Data which was published in the August. 1952, issue of Mining Engineering.Geological Features of the OrebodiesThe orebodies at Snow Lake occur in volcanic rocks of acid to basic composition and, to a lesser extent, in intrusive hornblendite. The hornblendite is a massive, uniform, .coarse-textured rock except in the immediate vicinity of the ore zone, where it becomes sheared and carbonatized. The acid volcanics have been converted to quartz-garnet-biotite gneiss, and the basic volcanics to amphibolite gneiss. Orebodies have been formed by the replacement of all three rock types."

Jan 1, 1955

By W. B. Burchall

Introduction In presenting this paper the author wishes to state that the opinions here given represent only his personal views. A general survey of the subject has been attempted, but such deductions as may have been drawn are not necessarily endorsed by the Company with which he is associated. The aeroplane as an instrument of transport is yet a novelty, for it is only twenty-five years since man first flew. This statement, by itself, may be very deceptive, for compared with the steam locomotive or even the auto-mobile, this infant in industry has made some remarkable showings. The &apos;actual performance&apos; speed-curve of aircraft plotted over a ten-year period is rising faster than the &apos;expectancy&apos; speed-curve of 1924 indicated, and it should be noted that, today, the possibilities of 600 miles per hour provoke less scepticism than did the prophecies of 400 miles per hour only a decade ago. Commencing with the remarkable achievement of raising one man into the air, aircraft with an all-up weight of 14 tons are now in daily use on the British airways, and recently a non-stop flight of 5,340 miles was accomplished in an aeroplane, without refuelling. More true than ever is the statement that the records of yesterday are commonplace tomorrow, for new ideas are today seized on and exploited to the utmost once the period of scepticism and doubt has been overcome. In fact, so many new ideas have been brought forward, during the past few years, and applied successfully in our economic life, that one may well ask if today we are not a little too impatient, too exacting in demands, forgetting that real worth-while progress -is attained by no short-cuts.

Jan 1, 1933

By D. K. Sarkar, J. Perron, J. D. Brassard

"Nearly perfect spherical shaped water drops rolling-off from the surface of lotus leaf is one of the beauties of nature. This kind of surface is called superhydrophobic, since the water does not like it. Physically, a superhydrophobic surface provides a contact angle (CA) of water over 150°. The combinations of both mico-nanostructure topography as well as low surface energy are essential to have such high CA on a surface. Nano-micro structured superhydrophobic surfaces have been developed in different methods. (i) Monodispersed fluorinated silica nanoparticles have been synthetized via Stöber Sol-Gel process and deposited on various surfaces, such as aluminium or glass, to obtain transparent superhydrophobic thin films. (ii) Similarly, zinc stearate nanocomposite coating has been fabricated by spray process on the same substrates. These thin films are found mechanically robust with drag reduction of coefficient 16% lower than as-received surfaces. (iii) By electrodepositing pure zinc on steel surfaces and further coating it with diluted room-temperature vulcanized silicone rubber, the surface become superhydrophobic. This superhydrophobic surface protects the steel against corrosion by increasing the polarization resistance from 1.5 k? on steel to 44.4 k?. This coating also reduced the ice adhesion on the steel surface 6.3 times as compared to bare steel substrates. Globally, these superhydrophobic surfaces have tremendous applications against corrosion reductions, drag reductions and ice adhesion reductions.INTRODUCTIONSuperhydrophobic coatings are increasingly attractive to the industry and academia due to their unique self-cleaning properties as a result of their water repelling characteristics. Fabrication of superhydrophobic coating is an inspiration from nature as water is seen to repel on many natural surfaces such as those of the lotus leaves, butterfly wings, water striders’ legs, and so on (Gao & Jiang, 2004; J. Huang, Wang & Wang, 2006; Neinhuis & Barthlott, 1997; Zheng, Gao & Jiang, 2007). This non-wetting phenomenon is well understood on lotus leaves, shown on the Figure 1 (a), and it is considered as the basis of the studies of superhydrophobicity. The existence of this binary structure on the surface of the lotus leaves allows a large amount of air entrapment and consequently reduces the contact area of water on it and the presence of low surface energy waxy components with reduced affinity to water together leads to the superhydrophobic properties. The phenomenon is shown on Figure 1 (b). Cassie and Baxter (Cassie & Baxter, 1944) as well as Wenzel (Wenzel, 1936) proposed two mathematical models to explain the wetting phenomena on rough surfaces that leads to superhydrophobic properties. By definition, superhydrophobic surfaces are characterized by a water contact angle value = 150° with the rolling off of water drops from the surfaces (Sarkar & Saleema, 2010). Superhydrophobic surfaces find tremendous importance in the technological world where it can applied in domains such as anti-corrosion, anti-biofouling, electrowetting, icephobic and even in drag reductions (Bushnell & Moore, 1991; Cao, Jones, Sikka, Wu & Gao, 2009; Carlborg & van der Wijngaart, 2010; Carré & Mittal, 2009; Y. Huang, Sarkar & Chen, 2010a; R. Karmouch, Coude, Abel & Ross, 2009). However, the most important challenge faced by industries is their feasibility large scale in an effective an economical manner."

Jan 1, 2016

By M. Pearson, J. Irvine, L. Mercer, P. Lauzon

Severe service ball valve performance has a direct impact on the mechanical availability of high pressure oxidation and leach plants. The primary function of these valves is to isolate the autoclave for maintenance. Valve failure has historically contributed significantly to the maintenance downtime of these process plants. An understanding of the root causes of valve failures is the first step in increasing the reliability of the severe service ball valves. A rigorous failure analysis practice has been developed by Hatch for investigating refractory failures in furnaces and kilns based on Kepner-Tregoe methodology. The method has also been modified for valve failure analysis. From a root-cause failure tree analysis of each of the valve components, a list of all potential valve failure mechanisms was developed for ranking and evaluation, along with recommendations for further valve development. The purpose of this paper is to present the reader with the modified Kepner-Tregoe method and examples of this analysis.

Jan 1, 2004

By Unknown

Diesel locomotives for underground haulage have been used in coal mines in Continental Europe for twenty-five years or more. In Great Britain, it was not until 1935 that permission was granted to use them in gassy coal mines, but since that time they have been employed in increasing numbers both in gassy and non-gassy coal mines and in metal mines. Their use underground in coal mines in the United States is still prohibited and the same was the case in Canada until 1946, when permission was granted to operate a Diesel underground in the Adanac mine of West Canadian Collieries, Limited, at Bellevue, Alberta. The locomotive used here is a 50 h.p. Hunslet Mark II. More recently, a 100 h.p. Diesel was placed in operation for underground haulage at No. 18 Colliery of the Dominion Steel and Coal Corporation, in the Sydney coalfield, N. S. Thus, on this continent, Canada has been a pioneer in the use of these locomotives underground in coal mines and there is no doubt that more and more of them will be employed as time goes on. We feel, therefore, that the following notes concerning their design and performance, which we have received from the High Commissioner for the United Kingdom, will be of interest to our members.

Jan 1, 1949

By K. R. Nichol

The author points out that corrosion works 24 hours a day, every day. It is an economic reality that the cost of corrosion is inevitable and that its cost should be incurred in the least expensive way. An economic evaluation technique to properly assess its relative impact is the Discounted Cash Flow Method. Various remedial and corrosion control measures are available and these, when coupled with a planned corrosion control program, help reduce the cost of corrosion.

Jan 1, 1973

"Ore deposits containing rare earth elements normally contain small amounts of the radioactive elements thorium (Th) and/or uranium (U). These are the naturally-occurring isotopes U238, U235, and Th232 (and associated decay-series daughter products) that are ubiquitous in nature, and that contribute a small percentage of the natural background radiation exposure encountered by humans. The presence of these radioactive materials in the ore deposit creates potential hazards to human health and the environment that must be dealt with properly in the mining, processing, and refining of the ores, as well as management of waste streams and residues. This paper presents an overview of the environmental and safety issues associated with U and Th, with particular emphasis on rare earth mining, processing, and refining projects; the regulatory approaches followed to ensure that rare earth deposits are developed, operated, closed, and decommissioned safely; and the development of information during the project predevelopment work and permitting processes that feed into the design, operation, and closure of tailings impoundments and milling/separation/refining facilities. Case studies will be presented subject to the availability of relevant public information. INTRODUCTIONNearly all ore deposits containing economically-recoverable rare earth minerals also contain small amounts of the radioactive isotopes for the elements thorium (Th) and/or uranium (U) and their associated radioactive decay products. Therefore, the handling and management of these materials in mining and mineral processing operations must be performed so that workers and the environment are protected from harm from Th and/or U (and their radioactive decay products), just as they must be protected from any other potentially harmful constituents present in the ore or introduced in processing. Examples of these might include ores with high sulfide content, which may pose a risk of acid rock drainage, or chemicals used in ore processing and metals production.The purpose of this paper is to present information on how rare earth mining and processing projects with ores containing Th and/or U can be developed, operated, and decommissioned safely according to applicable regulations intended to protect worker health & safety and the environment.It should be noted that some countries are considering developing Th as a feedstock for producing nuclear energy, which could have some effect on future development of rare earth ore deposits. To avoid confusion, that issue is not discussed in this paper."

Jan 1, 2012

By H. Sato, Y. Sato, T. Ooishi, K. Sakamoto

"Sumitomo Metal Mining Co., Ltd.(SMM)'s Niihama Nickel Refinery(NNR) produces high quality Nickel cathode, Cobaltcathode and other by-products using hydrometallurgical refining process called “MCLE”(Matte Chlorine Leach and Electro-Winning). In 2005,NNR started to use nickel and cobalt mixed sulfide (MS) produced by one of the SMM’s subsidiaries Coral Bay Nickel Corporation(CBNC)’s HPAL plant in Philippines, although its main and the only raw material until then was nickel matte. With start-up of the second HPAL plant at Taganito in 2013, NNR expanded its production capacity of nickel cathode from 41,000 to 65,000 tpa and finally achieved its target in 2015 by producing 65,980 tpa. SMM developed the technologies to improve poor reactivity of MS and installed new facilities to cope with increased Cobalt and Sulfur production at that time. This paper describes the technical approach to increase MS treatment with high efficiency.INTRODUCTIONThe Sumitomo Metal Mining Co., Ltd.(SMM)Niihama Nickel Refinery(NNR) produces Nickel cathode, Cobalt cathode and other by-products using Matte Chlorine Leach and Electro-Winning (MCLE) process technology. SMM uses nickel matte and nickel & cobalt mixed sulfide (MS) as raw materials for the MCLE process. Table 1 shows typical composition of these raw materials. Nickel matte had been only raw material until 2005, and with start-up of Coral Bay Nickel Corporation (CBNC) operation in the Republic of the Philippines, MS became major part of it. In 2009, when CBNC doubled its production capacity, NNR also expanded its plant capacity of electrolytic nickel from 36ktpa to 41ktpa, keeping an eye on the possibility of 65ktpa with oncoming SMM’s second HPAL in Philippines. Poor reactivity of MS was the prime concern at that time because our intention was to increase production with MS. Nickel extraction rate deteriorated with increasing usage ratio of MS in raw materials. To keep high nickel extraction rate under high ratio of MS, NNR developed a new leaching technology. Another concern arising from treatment of MS was Cobalt and Sulfur contents that are much more than those of nickel matte as shown in Table 1.NNR introduced new technology of solvent extraction process as to Co/Ni separation process in order to keep cost competitiveness instead of the conventional cobalt oxidation–neutralizing method. As to sulfur products, new sulfur productive facility was installed to improve the exposure to sulfur dust and the hot working conditions for workers. As a result of process development and installation of new facilities against the problem with MSusage,65 ktpa production was achieved in 2015."

Jan 1, 2017

By W. G. Campbell

"The region discussed comprises approximately eight million acres spreading across the Arctic Circle in Yukon and North West Territories.Encouraged by four years of surface geological and geophysical work, which strongly suggested that suit-able conditions existed for the entrapment of oil and gas, a decision was reached to drill. In due course two holes were drilled; Eagle Plains No. 1 drilled to 9589 in 1957-8 and Western Minerals Chance No. 1 spudded in 1959 is being deepened this year.Thick sections of sedimentary rocks occur on both sides of the Richardson Mountains, however, most of our activities have been concentrated to date on the west side in the Eagle Plains basin. Here are found stratigraphic units ranging from Precambrian to Tertiary age. The drilling of the two exploratory wells proved the presence of these strata at depth and have confirmed the presence of promising structures. A geological cross-section across Eagle Plains presents an interpretation of these conditions.Physical and engineering aspects of exploration in the northern Yukon and North West Territories are de-pendent largely upon seasons and transportation. Reconnaissance gravity and surface geologic mapping by air presents no serious problems. However, seismic operations on the ground are greatly affected by the season, presence of permafrost and mobility of equipment.The actual drilling of the hole may well be the simple part of a wildcat undertaking once equipment and supplies are on location. Over-all planning, assembling supplies, transporting equipment and personnel seems to be the real job. Serious consideration must be given to per-ma-frost effect in the drilling pro-gram and on surface installations as well.Programming for -the various exploration activities should be under-taken well in advance of the actual doing. Considerable extra costs may be the results of crash programs. Costs are high, and the rewards uncertain. Economic evaluation is based •on the long term outlook."

Jan 1, 1960

By Ian Ewart, Trevor Bergfeldt, Gourab Satapathy, Ajay Patel

"Conventional electrowinning (EW) of nickel from sulfate electrolytes is complicated by several factors including the requirement for a diaphragm cell to separate the anolyte and catholyte and the need to minimize nickel mist emissions. Developed and commercialized by emewCorporation, this novel process electrowins high purity nickel cathode (99.5%) from copper refinery bleed streams using the proprietary emew vortex EW technology. The emew nickel process incorporates high flow rate in an enclosed cylindrical EW cell operating at high current densities that overcomes the challenges of conventional nickel EW and completely eliminates the risk of nickel mist emissions. The tubular cathodes are easily harvested and mitigate the effect of plating stresses inherent in nickel EW. The present paper describes the emew nickel process and its most recent application to copper refinery bleed streams at full-scale.INTRODUCTION To meet the stringent demand of customers, nickel producers are giving prime importance to production of high purity nickel cathodes. The major challenge for refineries is to improve cathode quality and appearance despite fluctuating electrolyte impurity levels. The basis of achieving good quality cathode includes the control of electrolyte impurities and consistency of specific process conditions. The commercial operation of emew nickel technology has been successfully implemented and has demonstrated the ability to produce high quality nickel cathode from refinery bleeds. This paper emphasizes the importance of upstream impurity removal to achieve the required nickel emew feed composition by evaluating the benefits of using selective precipitation as a purification scheme with the aim of improving the overall nickel recovery while ensuring suitable nickel concentration in the advanced electrolyte is achieved. Nickel electrowinning is similar to other electrowinning processes that employ insoluble metal anodes & cathodes. It requires the passage of direct current between two electrodes that are immersed in a conductive, aqueous solution of nickel salts. For the recovery of nickel from solution, the most common methods are electrowinning and hydrogen reduction. Electrowinning usually occurs from sulfate, chloride or mixed sulfate/chloride electrolytes. In sulfate electrolytes, nickel electrowinning cells are normally designed to achieve specific criteria as outlined below (Robinson & Tuppa, 2002):"

Jan 1, 2017

By W. W. Heywood

"IntroductionCIRCULAR structures on the Arctic islands were first noticed early after World War II. During the indexing of the 1950 Royal Canadian Air Force photographs their occurrence was brought to the attention of the Geological Survey of Canada by Mr. W. B. Waugh, Surveyor General. As a result, I. C. Brown ( 195l) of the Geological Survey of Canada studied the air photographs of these structures and discussed theories that might explain their origin. The author, as a member of the Geological Survey of Canada, spent several months in 1952 and 1953 in reconnaissance study of the geology of Ellef Ringnes island, using the Isachsen meteorological station as a base. Twelve days in the summer of 1953 were spent mapping the Isachsen dome and adjacent areas. The Isachsen dome, one of several similar structures occurring on Ellef Ringnes island, is situated 35 miles southeast of the meteorological station.PhysiographyEllef Ringnes island is a mature, stream dissected plain having an average elevation of about 400 feet. The surface of the plain is undulating with a relief of about 150 feet; only a few of the numerous streams that form a dendritic drainage pattern have eroded valleys this deep. Long, low, cuesta escarpments cross' the plain, which is underlain by sedimentary rocks of Lower Cretaceous and possibly younger age. The sedimentary strata have a low regional dip to the southeast; exceptions are found in the vicinity of the domes, where the strata are up-turned, and in the plateau region, northeast of Deer bay, where they are flat lying. The plateau, which is underlain in large part by basalt, is deeply dissected and has an average elevation of 1,000 feet."

Jan 1, 1955

By W. S. Szolga, M. Moser, M. D. Soderstrom, L. Cohen

"CYANEX® 272 is a phosphinic acid-based solvent extraction reagent used commercially since the early 80’s to recover and purify cobalt from sulfate solutions. Historically, the design of CYANEX 272 circuits has involved the selection of an optimal pH profile during pilot-scale testing using mixbox pH control. The desired pH profile is required to be carefully controlled in the same manner during commercial operation. To assist operators in the design and optimization of their circuits, Solvay developed CYANEX 272-specific solvent extraction modeling software, which has enabled determination of the ideal pH profile and staging configuration. Solvay’s recent advances in modeling capabilities have allowed the simulation of circuits without direct mixbox pH control. Modeling has indicated that circuits operated without direct pH control can achieve the desired metal separation while simplifying the commercial operation significantly. This paper reviews a number of potential circuit configurations for the use of CYANEX 272 and demonstrates the separations achievable under the right design and operational conditions, some of which have historically been considered too difficult.INTRODUCTION CYANEX® 272 is a phosphinic-acid based reagent designed specifically for the separation of cobalt from nickel by solvent extraction from weakly acidic sulfate solutions (Rickelton, Robertson, & Burley, 1982; Rickelton, Flett, & West, 1984; Rickelton & Nucciarone, 1997). Following commercial introduction in the 1980’s, CYANEX 272 has been used in a number of hydrometallurgical flowsheets for cobalt purification and/or recovery. CYANEX 272 metal extraction occurs by means of a cation exchange mechanism. Extraction of a divalent metal ion M2+ is represented by the following equation where RH represents the CYANEX 272 ligand and MR2 represents the ligand-metal complex."

Jan 1, 2017

By D. P. Goodall

THE development of the oil and gas resources of Western Canada is not, as many suppose, a new industry. For more than half a century an intensive search for these valuable products of nature extended from near the western edge of the Precambrian Shield to the Pacific coast, and from the International boundary north to the Arctic circle. The chief centre of interest to the oil prospector has, however, always lain in that region lying east of the first range of the Rocky mountains and confined largely within the boundaries of the Province of Alberta. Although there are many geological problems yet to be worked out in this Province, the oil-well driller has helped in no small way in determining sub-surface conditions and distribution of rock formations. The chief geological conditions as they affect the drilling of wells are generally re-cognized, and for this purpose the Province may be partitioned into three main divisions: first, the disturbed belt or foothills region extending along the eastern edge of the Rocky mountains; second, the Alberta geosyncline, a broad trough lying to the east of and parallel to the disturbed belt and from which the formations rise eastward to level off and form, third, the plains ? ? region, extending over the rest of the Province. A relatively small area in the northeastern part of the Province is underlain with Precambrian rocks and may be excluded from this classification, as it is of no interest to the oil prospector. The foothills, or disturbed belt, has presented the greatest difficulty to drilling, though it has produced the largest yield of oil within the Province to date. Within the foothills belt, the rock formations consist largely of hard shales interspersed with layers of abrasive sandstones, which wear out drilling bits at an alarming rate. The strata, in most flaces, dip steeply and are cut by numerous thrust faults. Although some o the faults have great displacements, their presence may easily be overlooked or the extent of the fault misinterpreted. Many a prospect well has been located on what appeared to be a suitable geological structure only to find, after drilling through a normal succession of rocks for 4,000 feet or more, that the drill had passed through a major fault plane to a younger formation than that in which drilling was started. Only a repetition of formations already drilled could be expected at greater depths.

Jan 1, 1942

By Bruce A. McFarlane

"I WOULD LIKE TO SAY how honoured I am that I have been invited to participate in this panel discussion. I have taken the liberty of narrowing my topic somewhat so that instead of speaking on the Sociology of Professions as a whole I will speak on one aspect of it, that is, on Manpower Problems in the Minerals industry of Canada, with some reference to a new social role for the professionals engaged in this industry. This probably means that I will be encroaching on areas covered or to be covered by other speakers, but I hope that when I do so I will do so from a slightly different vantage point. That is, from a sociological perspective rather than from a historical, industrial, business or professional perspective. I plan to divide my discussion into three areas, namely: (i) problems of ownership and control; (ii) environmental problems; and (iii) manpower and recruitment problems. I do not plan nor am I able to provide clear-cut solutions to the various problems I raise under these three headings. Rather, I hope that my discussion of the problems may form the basis for an extended discussion here and elsewhere. Because of the limitations of time, I will only briefly discuss the first two problem areas noted above – (i) ownership and control and (ii) environmental problems - and I plan to concentrate on the manpower issue."

Jan 1, 1972

By Alessandro Navarra, Amir Arash Rafiei, Kristian Waters

Mathematical programming (MP) is fundamental to systems engineering and operations management, but has not been widely adopted by mineral processors. The current paper presents an interdisciplinary approach, using MP to incorporate basic notions of mass balancing into an optimization framework. The optimization is typically related to economic profitability. Two- and three-product formulas are extended to give formal descriptions of alternate modes of operation, and a global representation of the concentrator. At this global level, the framework may assist plant managers to make tactical decisions based on incoming feed data. The MP framework is demonstrated through sample calculations describing a lead-zinc concentrator.

Jan 1, 2015

By A. J. Paul Laprairie

The process for which it is to be used is too often the only consideration in the design of a vessel. A de-sign allowing for practical manufacture and erection, as well as for proper maintenance, can often give over-all economies. Most platework in-stalled today is of welded construction. Therefore, metallurgical control is important in its manufacture. Also, because many concentrating and re-fining processes tend to be corrosive, the subject of protective coatings as a part of the manufacturing process is extremely important. The plant de-signer should know how to evaluate and specify controls for the metallurgy and for the coatings. Mining operations are becoming more sophisticated in the field of mechanical engineering. More and more emphasis is being given to preventive maintenance. The first step in any maintenance program, however, is good inspection service. This paper will suggest methods for the inspection of platework, and outline methods for repair and replacement.

Jan 1, 1963