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By Hans Lundberg

The magnetometer which was developed during the war for detecting submarines has proven exceedingly valuable in outlining deep-seated structures in oil exploration, and will be useful also to geologists in outlining regional structural features in the Precambrian. Our magnetometer has been developed to outline local and detail structures. 1 am quite sure that all geophysicists and geologists would agree with me that, in ore prospecting, it is important to obtain as much detailed information as possible. We know that, as we ascend from the ground and get away from the magnetic ore-bearing structures and orebodies, the magnetic intensity decreases rapidly, but, worse than that, we lose the details even faster. Figure l shows two strong, very sharp, magnetic 'highs' over two orebodies which, as our distance increases, rapidly merge into one fairly broad, moderately strong anomaly. If we drilled on this maximum, we would not encounter any of the orebodies. Therefore, we should fly the airborne magnetometer as close to the ground as possible in order to duplicate the results of the magnetic ground surveys. The first chance to accomplish this came with the helicopter, which is an exceedingly maneuverable aircraft. It can be landed in a cleared space not much more than fifty feet square. With floats, it can be landed anywhere, even in a swamp, on thin ice, or on soft snow. It can stand still in the air, hovering over a given point. It can ascend and descend vertically, fly sideways and even backwards, at the will of the pilot. It flies forward at any speed up to l00 miles an hour. The helicopter can be taken to any desired position at a given time. It can fly at any useful altitude from a few feet to several thousand feet above the ground. It can fly very close to the ground with safety. In bare areas, the survey flight may be performed a few feet above the ground. In forested areas, however, the flights, to clear the trees, must be made at l00 to 150 feet. To mark out a certain point, a small parachute-like marker may be draped over a tree or laid on the ground. This can be done from the helicopter without touching the ground.

Jan 1, 1947

By L. S. Trenholme

"Belleterre Quebec Mines, Limited, is a subsidiary of Mcintyre Porcupine Mines, Limited. The property is in Guillet township, Quebec, 45 miles due east of Haileybury, Ontario. It is accessible by 72 miles of gravelled road from New Liskeard, Ontario (Fig. 1).Gold production at the property commenced in 1936 and to March 31st, 1945, had exceeded $9,000,000. For the past 3 years the milling rate has averaged 325 tons a day and the gold recovery about $14 a ton.GENERAL GEOLOGYThe rocks of the district consist of Keewatin-like volcanics conformably overlain by Timiskaming-like sediments. Together they form the remnant of an easterly plunging anticline engulfed by granite (Fig. 2). The pregranite intrusives consist of diorite, gabbro, and ultrabasic rocks, occurring as dykes, sills, and irregular stocks. Dykes of porphyry and lamprophyre presumably related to the batholithic intrusive are common in this area. The veins of quartz are also probably derived from the batholithic intrusives. A few dykes of Keweenawan-type diabase have been observed."

Jan 1, 1954

By T. Lamb, T. Aston

"The Gays River Mine is located within a complex hydrological regime and underground mining environment. Early in the mine history, the operation was' affected by an inability to control mine water inflows. More recently, the reopened mine operation had been unable to maintain consistent drainage of groundwater to the mine workings and sustain low groundwater levels.In 1992, a series of investigations were completed, which in part Were funded under the Canada-Nova Scotia Mineral Development Agreement. The studies undertaken included: hydrochemical and drainhole well screen assessments, an air photo study of sinkhole features, numerical modelling studies and a major piezometer installation and overburden soil study. The results indicate that the water draining to the underground workings is comprised of two distinct components: precipitation over the drawdown cone catchment area and seepage from the nearby Gays River. In addition, a third ""balance"" component was' also found, which represents uncertainties in the areal extent of the drawdown cone and river seepage components.After outlining the history of the groundwater problems experienced at the Gays River Mine, this paper examines the various studies undertaken during 1991-1992 and concludes that control of groundwater levels in the mine area is achievable. A number of recommendations are also proposed for future study ."

Jan 1, 1993

By Peter Harben

"This paper discusses the benefits of industrial minerals, their sources of supply, price and marketing trends, and their increasing use as substitute materials and ""strategic"" minerals. IntroductionKaolin finds have yet to spark the kind of frenzy associated with the 1849 California gold rush; no dolomite deposit has ever gained the notoriety of the Comstock Lode; and few industrial minerals are counted among the currently fashionable list of "" strategic mineral s"". Nevertheless, the glamorous zhine associated with metals may be somewhat superficial; further digging provides perhaps the real foundation of modern society - industrial minerals.They are often tagged as common, everyday materials that are simply dug out of the ground, crushed and hauled to a local point of consumption. Although this description is accurate in the case of road aggregates, sand and gravel, and the like, there are many exceptions to this rule. The term industrial minerals is rather nebulous, covering as it does the mundane and esoteric, the chemically active and the refractory, the $2 and the $10m-a-ton product. All of these minerals influence every facet of modern life from fertilizers to fire retardants, ceramics to cars, construction to clothes, and toothpaste to tennis courts. Their usefulness is well illustrated by the variety of industries they serve; the main ones are listed in Table 1. It is now time to dismiss the notion of non-metallics as the ""third world"" of natural resources business after the metallic and energy products by dispelling some of the myths regarding abundance, variety and value of the group's sixty-plus products."

Jan 1, 1982

By Liu Liching, Yan Hongjiu

"In China, the electromagnetic induction initiating system f or blasting engineering has been greatly developed in recent years. With this system, the total number of detonators that may be blasted in each round has been increased from 420 to 940 as a result of the invention of a powerful exploder, and the length of leg wires of a detonator has reached 12 metres. These developments make the new system suitable for blasting engineering of medium scale. Another attractive feature of this system is a set of testing instruments which have been invented that enable a final check of the system to be made before firing as in normal electric blasting. This paper reports on these developments.IntroductionThe initiating system for blasting explosives is one of the key factors to the success of blasting engineering, along with the progress of explosives and blasting technology. Today, we have initiating systems which may be divided into two groups: electric and non-electric. The earliest initiating system was non-electric. Many mines, as well as many projects where rock excavation was involved, were blasting non-electrically before the new nonelectric initiating system came into use in the 1970s. Electric and non-electric initiating systems are the two main initiating systems which are now being widely used, each having its advantages and disadvantages. In electric blasting, the blasting supplies and the blasting circuit can be checked before it is used or fired and, therefore, is regarded to be more reliable. In many large-scale blasting engineering where reliability of the initiation is of great concern, a checkable initiating system is preferable. The electric initiating system is not considered to be as safe as the non-electric initiating system due to its inability to choose proper ignition energy. Therefore, a non-electrical initiating system would be preferable where a hazard of stray currents or static electric energy exists. At this stage of development, one would say it would be advantageous to develop a new initiating system."

Jan 1, 1988

By R. C. Beard

"The Ontario Ministry of Natural Resources has recently initiated several incentive programs to encourage and facilitate the development of new mines in northwestern Ontario. Some are privatized out to consultants and contractors. The status of three of these programs will be reviewed in this paper.IntroductionOne of the main objectives of the Mineral Resources Group of the Ontario Ministry of Natural Resources is to encourage and assist mineral exploration and the development of new mines in the Province. Programs to accomplish this objective are largely carried out through two Branches in the main office (in Toronto), the Mineral Resources Branch and the Ontario Geological Survey, and also a number of regional field offices scattered across Ontario.The function of the Mineral Resources Branch is to identify and administer effective policies that will ensure maximum benefits to the Province from mineral resource extraction.One of the most important factors in ensuring effective exploration in the Province is the availability of a good geosciences data base from which to work. It is the responsibility of the Ontario Geological Survey to develop and continually update this data base, providing, to both the public and private sector, an inventory and analysis of the geology and mineral deposits of the Province.The main functions of the regional field offices are to provide technical data and advice to exploration companies and prospectors, to encourage and assist exploration, and to provide information and general assistance to producing and developing properties to facilitate resource development and extraction. This is accomplished through the offices of the mineral resource coordinators and resident geologists. In northwestern Ontario, these field offices are located at Thunder Bay, Kenora, Red Lake and Sioux Lookout.To accomplish their objectives, the Ontario Geological Survey and the regional field offices carry out regular, ongoing geoscience and other mineral resource programs, under their base funding."

Jan 1, 1982

By M. Fall

The progressive depletion of ore available at shallow depths in several underground mines around the world means that underground mining operations would increasingly be carried out at greater depths and therefore at higher temperatures. However, our understanding of the effect of hot temperatures on the response (mechanical, economical, environmental) of cemented paste backfill (CPB) is still limited. Hence, an extensive laboratory investigation was conducted to study the performance of young and aged CPB, in response to deep mine temperatures. Several CPB samples with different compositions, cured at different temperatures (20 to 50°C) and different times (7 to 160 days) were tested regarding their mechanical properties, economical performance (binder consumption) and microstructural properties. The results show that hot temperatures significantly affect the performance properties of CPB at young and advanced ages. An increase in the curing temperature leads to a considerable improvement of the rate of gain of CPB strength and also to a significant increase of the strength of CPBs studied. CBP samples cured at hot temperatures show lower binder consumption and finer pore structure. Results of this study could serve as background information for the development of optimal mine backfill design procedures.

May 1, 2007

By G. J. Hutchins

Precision surface mining is gaining traction in the iron ore, copper, iodine, limestone, bauxite, coal and gypsum markets. In this paper, we first address the possible improvements of a surface miner control using GPS techniques. An application in an iron ore mine in Western Australia is presented. The second item addressed is improvements of a new drum driving technique for a 100 ton surface miner. This technique involves installing a slow speed hydrostatic motor directly on the cutting drum rather than driving the drum through chain and sprockets. Details of the performance of this direct-drive versus the chain-drive are detailed. In addition to the 100 ton machine, we also present a 200 ton surface miner. This larger machine has 1600 hp (894.8 kg), and has been successfully introduced into a large iron ore mine in Western Australia. Performance of the 200 ton surface mining machine in various rock hardnesses is detailed. Some comments on the cost effectiveness of using a built-in loader versus loading with wheel loaders are included.

Aug 1, 2013

By K. C. Corin, M. S. Manono, J. G. Wiese

Depressants play a crucial role in the flotation of PGM bearing ores as they prevent naturally floatable gangue (NFG) from reporting to the concentrate. This action is regarded as critically important because less dilution of the concentrate means lower costs for downstream processes. However, abnormal water conditions (such as high concentrations of ions) in the flotation system can modify the selectivity of these depressants. It is well known that the existence of selected electrolytes in water can alter the behaviour of some polysaccharide depressants by enhancing their adsorption onto gangue minerals and thereby prevent naturally floatable gangue from moving into the froth phase. Concurrently these same electrolytes may enhance frothability, owing to their stabilising effect on the bubbles within the system. Plant water at various ionic strengths was investigated against depressant type and dosage in order to understand electrolyte-depressant interactive effects during the flotation of a Merensky ore, using entrainment, rate of NFG recovery, and total gangue recovery as proxies. The study showed that the rate of NFG recovery per unit mass of water decreased with increasing ionic strength at all dosages, however the total amount of gangue reporting to the concentrate increased with increasing ionic strength at all depressant dosages. Thus, this paper attempts to consider the effects of both ionic strength and depressant dosage as individual factors within flotation. It further looks to investigate whether any interactive effects exists between these two factors when considered simultaneously.

Jan 1, 2016

By W. A. Crosby, W. K. Smith, K. L. McDonald

"IntroductionThis paper describes how the introduction of two blasting techniques and the resuItant development of new dragline digging methods have increased the productivity of single- and double-seam dragline operations at the Rietspruit opencast mine.LocationRietspruit , one of South Africa's largest opencast strip mines, is situated some 11 5 kilometres east of Johannesburg in the Witbank coal field.BusinessRietspruit is a joint venture between Transvaal Consolidate d Land and Exploration Company (T.C.L.) and Shell, South Africa. Rietspruit is administered and managed by Rand Mines, the Mining division of Barlow Rand, transportation and marketing being the responsibility of Shell. The total saleable coal product, approximately 5,5 million tons per annum, is exported via Richards Bay.Presplitting and Throw BlastingPresplitting was initially introduced in September 1980, as a means of dewatering t he overburden and mid burden to facilitate the use of dry-mix explosives a s opposed to slurry explosives.The utilization of the throw blasting technique arose as a direct result of observed ground movement after the successful introduction of presplitting. The first trials commenced in March 1981 on the double-seam operation. The methods, economics and resulting advantages are fully described elsewhere. A brief description follows.Method of PresplittingAfter determining the desired presplit line, 250-mm holes are drilled to top of coal at 4-m to 6-m intervals, dependent on the competency of the rock overlying the coal. A single 60-kg charge of slurry explosives is located at the bottom of each hole, no tamping is used and all the holes are detonated simultaneously. The results are a competent, straight, vertical highwall. This enables accurate control of the first row of blast holes closest to the highwall, which is a prime requisite for successful throw blasting."

Jan 1, 1983

By Douglas A. Sloan

"Recently, a number of major mining companies seemed unable to find a president from within the industry, and were searching outside the industry. From this, one could conclude that managers within the industry are either not being prepared or are not preparing themselves for presidential responsibility. Opinions were sought from a number of senior executives, to attempt to define the skills a prospective president should acquire and what actions a company could take or that a prospective president could take to acquire these skills.This paper contains summaries of the opinions obtained, along with the author's comments. The paper also describes the actions some companies are taking and the actions that an aspiring president can take to prepare himself for corporate management.IntroductionA manager is promoted up the management ladder when the manager's superiors believe that he is capable of handling a more senior position. Normally, the manager acquires this credibility by outstanding performance in his current management post, whether it be in a junior management (supervisory) or in a vice-presidential capacity.In most instances, the skills required for promotion can be acquired in the current position or, at worst, the abilities exhibited in a candidate's current role will convince his superiors that the necessary expertise for the more senior position can be acquired on-the-job. This is particularly the case when the new skills are felt to be an extrapolation of the old skills.However, in the case of appointment to presidential rank, there appears to be a need for new expertise which often is not acquired in normal management progression or, at least, boards of directors of some mining companies seem to believe this to be the case. The objective of this paper is to attempt to define the new skills that should be acquired by a manager who aspires to be the president, and to describe what actions might be taken by him to acquire them."

Jan 1, 1982

By David M. Parkes, George E. Davies

"Mathematically, the proposed formula is: ""Human Effectiveness + Technological Improvement = Success in the Nineties"". A brief review is made of geology, level of technology, management and labour situations, and range of production costs in coal producing countries. This comparison shows keen competition for Canadian coals, especially from the People's Republic of China, South Africa and Australia. Domestic competition comes from nuclear energy, hydro-electric generation, natural gas (if permitted) and eastern United States coal.The huge increase in the size and power of surface mining equipment in the last forty years led to modern large-scale open pit mining. While conventional truck and shovel operations will continue to be widely used, more continuous mining and conveying systems will be installed as pits become deeper and haul distances longer. Computer systems will become more sophisticated and their applications more widespread, leading to higher productivity and closer control of all operations and equipment performances and to partial or complete automation of certain operations.The underground revival will be driven by a new generation of mining people, cooperating to produce over 3 million t/y from 300 m longwall faces retreating over 3 km resulting in mine productivities of over 40 tonnes per man shift, as is already achieved in several mines throughout the world. Continuous operation using on-line control system will assist in consistent production with availabilities over 75%."

Jan 1, 1991

By Randy Billing, J. Fraser Wilson

"IntroductionThe job of designing and implementing effective environmental management sounds like what one executive, assuming responsibility for a very sick organization with lots of potential described as, ""an insurmountable opportunity"".Effective environmental management is an opportunity, no doubt. Its an unusual, if not unique opportunity. Insurmountable? Maybe not! Indeed, in the authors' experience, the keys to unlocking this opportunity are not in new or complicated technicalities; they are in the existing strengths and successful experience that one has in managing other complex and exacting management issues.To begin, it is necessary to understand what these issues of sustainable development mean to business. What is the nature of this opportunity? What makes it look unsurmountable?New Games: New RulesLawyers have described some of the new rules companies are facing and there is a new game being played; a game characterized by unique challenges.Take two, for example: • The ecological problems to be faced are Mother Nature's business, the political solutions required are our business. This combination of natural problems and political solutions requires the development of new management mechanisms, to bridge the gaps among us, as individuals, as professions, as interest groups and so on; indeed, even as countries;• and gaps there are : about as many gaps as the people involved : many of them with new and changing expectations, often mutually exclusive and not negotiable.The challenge of these relationships and communications among so many different interests is one of the keys to effective environmental management.Like any game, this one has rules and they are new, too. These rules are evident not just in new legislation - tough legislation with draconian penalties; they are also evident in new and exacting business policies, value driven and just as unforgiving of poor performance. Senior management of many companies are speaking about the role of enlightened corporate policies and how important it is for everyone involved that these policies drive and reflect business practices. Absence of day to- day behaviour which evidences the words in action, the policy on the wall of a corporate office or published in an Annual Report is first evidence for the prosecution , not the defence.The challenge of practical policies is another key to effective environmental management.This is a new game, with new rules: the challenge of change."

Jan 1, 1991

By N. Saracoglu, R. H. Wallis, J. E. Betz, F. L. Jagodits, B. R. Krause

"Geophysical test surveys were conducted with various methods (EM, lP, gravity and magnetic) over the McClean uranium deposits of the Canadian Oxy- lnco Joint Venture. The result s were assessed to judge the contribution each method might make toward further discoveries of graphite-associated uranium occurrences.The best drill targets have proven to be discontinuities in graphitic conductors and locations where the tatter are intersected by fracture zones in the Athabasca. The tests demonstrated that the preferred combination of geophysical survey s is horizontal loop EM to locate graphitic conductors in the basement and VLF-EM to locate the fractures.IntroductionThe discoveries of the McClean North and South uranium deposit s (Fig. 1) are essentially geophysical successes resulting from drilling MaxMin delineations of INPUT airborne electromagnetic responses (Saracoglu et al., 1983). After the initial discovery in 1979, various geophysical methods, techniques and instruments were employed to test their effectiveness in this environment and to guide exploration for other deposit s of a similar nature in the remainder of the 260 km2 property.The McClean uranium deposits lie below 150 m to 180 m of overburden and Athabasca Group. Radioactive signatures might be expected; however, the Athabasca Group acts as a barrier to radioactive emanations. Fortunately, the uranium mineralization is associated with graphite in the crystalline basement. Prior drilling of ground electromagnetic anomalies confirmed that EM surveys could locate and out line basement graphitic conductors. However, as there were many anomalies, most of which could not reasonably be expected to be associated with uranium , there was need to identify additional parameters, related to mineralization, which could be detected geophysically and used to narrow the search."

Jan 1, 1986

By E. Wright

"INTRODUCTIONThe Ruttan Mine is located twenty-two km east of Leaf Rapids in northwestern Manitoba. The copper-zinc exhalative massive sulphide deposit is comprised of a series of individual and interconnected en echelon lenses which strike east 20 degrees north and dip south 70 degrees. The mine has been owned and operated by the Hudson Bay Mining & Smelting Company since July 1987. Sherritt Gordon Mines Limited began mining the orebody in 1973 from an open pit, but production has been entirely from underground since 1980. HistoryDuring the progression from open pit to underground mining, it was recognized that manual methods of ore reserve calculation were inadequate for responding to changing metal prices and evaluating alternative mine plans. The mine planning system that was developed is described in the paper, ""Computerization of Ore Reserves and Mine Planning Functions at Ruttan Mine"", presented by B.C.W. Haystead at the 1984CIM Annual General Meeting. At that time, programs for core logging, diamond drill hole plotting, grade interpolation, ore outline digitizing, and reporting had been developed by the Systems Department for use on Sherritt's UNIVAC 1100 mainframe computer. Telecommunications linked terminals at the Ruttan coreshack and office to the UNIVAC in Fort Saskatchewan, Alberta. The same mine planning system was also used at a second property.Operation of the mine planning system was expensive, and it was evident that increased use required a costly upgrading of the UNIVAC in order to maintain an acceptable service level to all users. The system was re-evaluated,' and it was concluded that: core logging was not easily adaptable to a new property, nor flexible enough for exploration; plotting, grade interpolation, and digitizing required considerable manual effort; and that the UNIVAC operating system was difficult to learn.It was recommended that a study should determine if: core logging could be redesigned and/or implemented on a microcomputer; interactive graphics be used to reduce the effort for functions requiring visual interpretation; and the creation of input processors would assist users in setting up parameters for guiding the programs."

Jan 1, 1989

By Lorne Roberts

"This paper describes: how Falconbridge's fire protection system meets the needs of the Lockerby Mine; why the system was chosen over other alternatives; how it is unique, but can be applied to any underground situation; details of the system; how it was installed; the role of a fire protection company; and general considerations when choosing afire-suppresant system.IntroductionIn May 1981, after about three years of searching for the best fire protection system for the re-opened Lockerby nickel mine at Whitefish, near Sudbury, Ontario, Falconbridge Nickel Mines Ltd. installed an AFFF type of fire suppression system. It was designed and supplied by the Fire Protection Systems Division of Levitt -Safety Ltd.The system protects against loss of life, equipment and/or production, and it complies with legislation should fire occur in a fuel storage area and/or scooptram garage and service bay at any or all of the three levels near Shaft No.2.About 18 months after Levitt-Safety began working with Falconbridge, the system was designed and installed at a cost considerably less than that which would be incurred if fire damage caused the loss of two days of production.The fire protection system, which overcomes a limited water supply, is a self-contained balanced pressure proportioning system. It senses the flow and automatically determines the correct concentration of foam to water. It is triggered by a release mechanism which operates a bank of nitrogen cylinders, which in turn pressurize a pressure vessel to expel the foam concentrate and water from the tanks. This solution is piped to sprinkler heads in the specific area."

Jan 1, 1982

By R. B. Allen, E. E. N. Smith, B. C. MacDonald

"LocationTHE MAIN PROPERTY and townsite of Eldorado Mining & Refining, Limited, Beaverlodge Operation, is on the north shore. of Beaverlodge lake, •about seven miles north of the deserted town of Goldfields on lake Athabasca, and four hundred and ninety air-miles equidistant from Prince Albert, Saskatchewan, and Edmonton, Alberta. Both Eldorado Airlines •and Canadian Pacific Airlines maintain scheduled flights from Edmonton to the 4,000-foot airstrip on the north boundary of the Company property. Bi-weekly flights are made by Saskatchewan Government Airways from Prince Albert. Men and priority freight are flown by Company aircraft direct from Edmonton. From June to-September, when the waterways .are ice-free, freight is carried by barge from the •railhead at McMurray, Alberta, down the Athabasca river to Chipewyan, and across lake Athabasca to• Bushell, the terminal on Black bay, lake Athabasca, a total distance of 265 miles.The Eldorado Operation has been connected by a 12-mile, all-weather highway to Bushell. Where the highway crosses the park-land along the Fredette river, the townsite, Uranium, is under construction to provide services to the uranium-producing district. Spur roads have been built to the Ace, Fay, Eagle, •and Martin mines of the Eldorado operation, and to the properties of Pitch-Ore Uranium Mines, Ltd., and Rix Athabasca Uranium Mines, Ltd."

Jan 1, 1954

By S. Esmaeili

The yield strength model developed by Esmaeili, Lloyd and Poole [1] has been adapted to model isothermal aging in Cu-containing AA6xxx alloys, with (a) a moderate and (b) a very low Cu content in the solution-treated, as-quenched, condition, Isothermal calorimetry has been used to analyze the kinetics of precipitation in these alloys, While the kinetic parameters for the low Cu alloy has been derived from the present experiments, the previously determined kinetic parameters for the high Cu alloy AA6111 has been used to model the precipitation kinetics in the moderate Cu alloy. The age hardening responses of both alloys have been well predicted by the model.

Jan 1, 2005

The mixer that is commonly encountered in hydro metallurgical operations consists of a single turbine and tank combination. However, it would be advantageous to examine some common solvent extraction mixing systems in the light of the fundamentals of chemical reactor design. The basic concepts of reactor design are commonly used in the chemical industry, and it should not be too difficult to apply them to solvent extraction. The factors that affect the engineering design of a reactor are: the reacting system; the type of reaction; and the configuration of the reactor. The reaction system in solvent extraction consists of a heterogeneous liquid phase, involving two immiscible liquids. It is essential f or the process that the reactor product can be separated efficiently in the subsequent settler. The type of reaction in solvent extraction system may be quite complex, and the picture is complicated by the presence of competing and side reactions. The reactors themselves have been generally continuous stirred tanks, and the nature of the mixer-settler makes it unlikely that the pumping mixer can be dispensed with. However, it appears that there should be some definite advantages to a system of stirred reactors in series. The kinetic experiments which are carried out should have the definition of optimum reaction conditions as one of their goals. The data obtained from these experiments must also be applicable to the design of reaction equipment. Reactor selection and design is often a unique problem for each chemical process, and does not lend itself to a systematic general approach. However, the application of chemical and physical principles to mixer design in solvent extraction should result in practical, more efficient plants.

Jan 1, 1979

By Francis Dakubo, Courtney Young, Avimanyu Das

"Hydrometallurgy of copper ores typically involve acid leaching followed by solvent extraction and electrowinning (SX/EW). EW is the final purification stage in which a voltage is applied across two electrodes causing the copper ions to reduce and deposit on the cathode. Applied voltages are near 2 volts with current densities around 300 amps/m2. In this study, research was undertaken to decrease the energy consumed in the EW process. To do this, various cell designs were constructed and tested in which a membrane was used to separate the cathode and anode compartments with concentrated solution from SX serving as catholyte and raffinate from SX serving as anolyte. Therefore, copper in the concentrated solution would be deposited on the cathode while ferrous in the raffinate would be oxidized to ferric at the anode. Because it is assumed that ferric acid leaching is used, resulting ferric would be recycled to the leaching process. A positive side effect of the envisioned process would be the elimination of oxygen evolution at the anode and thus the prevention of acid-misting. After a cell design was selected, it was used to test a number of variables: flowrate, concentration, temperature, ion-exchange membrane, and applied voltage. Following experiments in which variable ranges were determined, statistical modeling was conducted using STATEASE software. Optimal results indicate the voltage can be decreased to 1.5-1.7 volts with current densities of 300-400 amps/m2. Significant reduction in the energy consumption was accomplished by reducing the applied voltage. Furthermore, current efficiencies and copper production rates was increased by application of the membrane.INTRODUCTIONLeaching of copper ores is achieved using mostly sulfuric acid. The copper pregnant solution is contacted with an organic solvent or resin adsorbent which picks up copper ions as in Equation 1:"

Jan 1, 2016