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During heap leaching of secondary copper sulphide ores operated at low heap temperatures and high levels of leach solution salinity, copper recovery is usually unsatisfactory, due to a slow chemical and bacteriological leaching of the covellite minerals either formed from leaching of chalcocite or naturally occurring in ores. A laboratory test program was conducted to investigate the effect of leach solution temperature in the range of 20 to 50°C on copper extraction during stirred reactor, bottle roll, and short column leaching of fresh or heap leached secondary copper sulphide ores. It was demonstrated that increasing heap temperature is an effective approach for improving recovery of copper from secondary copper sulphide ores. A review of the technologies available for heating heap leach solution or decreasing solution salinity to improve copper recovery from secondary sulphide ore indicates that an integration of copper concentrate pressure leaching with heap leaching is potentially a cost-effective approach. A copper flotation concentrate sample was tested through pressure oxidation with the use of heap leach solutions of varying strengths for the repulping of the concentrate in order to examine its effect on pressure oxidation performance. The test results indicate that use of heap leach solution of high salinity in the pressure oxidation process does not cause a negative impact on the process performance for copper extraction, sulphide oxidation, and recovery of gold (if present) from pressure leach residue, and has additional advantages of removing the bacterially inhibitory aluminum from heap leach solution and generating more acid and ferric iron in the pregnant leach solution. A flowsheet configuration for full integration of the copper concentrate pressure oxidation with heap leaching of secondary copper sulphide ore is proposed and discussed.

Jan 1, 2014

By Etienne S. Bieler

Mr. Chairman, Ladies and Gentlemen, I come to you tonight distinctly as a physicist, not as a geologist or a mining man. My experience in applied geophysics has been short, and I do not doubt that many of you have a much larger acquaintance: with the subject than I have. A little over a year ago, the firm of Alderson, MacKay & Armstrong decided to investigate the possibility of developing a new method of electrical prospecting suitable to our northern Quebec and northern Ontario conditions, and asked me to take up the work. A preliminary survey of existing literature convinced me that the field of induction methods was most promising. I wish to give you some account of the work carried on last summer in the Rouyn district in this connection with the very able assistance of Mr. H. G. I. Watson. Geophysical methods of prospecting can be divided generally into four classes: magnetic, electrical, gravitational, and seismic. Each class depends on the existence of a definite property in which the valuable mineral to be discovered differs materially from the surrounding rocks. In the four classes, the property will be, respectively, magnetic permeability, electrical conductivity, density, and elasticity. By far the largest differences occur in the case of electrical conductivity, where it is not rare to find ratios of the order of several millions, or even billions, between ores, sulphide ores especially, and the surrounding rock. Hence the sensitiveness and delicacy of electrical methods. Of these four classes, only two, the electrical and the magnetic methods, have been put to extensive practical use in the discovery of metallic ores. The other two classes are important mainly in connection with oil detection.

Jan 1, 1928

By P. A. Riveros, R. Molnar, F. J. Baša

"An acidification circuit was installed and operated at the Agnico-Eagle Silver Division refinery in Cobalt, Ontario, for treating ~300 m3 of a concentrated cyanide waste solution with the purpose of recovering its cyanide and metal values. The acidification circuit was designed from parameters determined experimentally at CANMET. Available refinery equipment was assembled according to a flowsheet developed by Agnico-Eagle Mines. The process produced a regenerated cyanide solution containing >15 g/L of free cyanide, which was used for leaching gold ore at another Agnico- Eagle operation. It was estimated that the value of the recovered cyanide offset the treatment cost. BackgroundThe Silver Division of Agnico-Eagle Mines needed an economic and effective method for disposing of ~300 m3 of a concentrated cyanide waste solution that had remained in the plant after the operation was shut down in 1989. As a result of extensive recycling and evaporation, the solution had become practically saturated with metals, cyanide, thiocyanate, sulphate and other components, and was, therefore, an environmental liability for the company. A partial analysis of the solution is presented in Table 1. Initially, the use of cyanide destruction methods was considered by Agnico-Eagle, but the estimates indicated a considerable cost with no credits to be gained. A research project carried out by CANMET showed that a simple procedure consisting of acidification, filtration and reneutralization was the most attractive option, because it enabled the recovery of a substantial portion of the cyanide. Furthermore, the metals would be recovered in the form of a solid precipitate. The research showed that conventional AVR was not applicable because of excessive cyanide degradation and low HCN volatilization obtained with this particular solution (Riveros et al., 1996). This paper describes the procedure used to treat the concentrated cyanide waste solution and the operating practices of the large-scale acidification circuit run at the Agnico-Eagle refinery."

Jan 1, 1998

"IntroductionThe Chairman, in his speech to this body last year in Montreal, stated that the Dominion Coal Board looked to and depended upon the Bureau of Statistics for statistical material, and the Bureau does collect and publish monthly and annual data on coal. It may therefore be asked why an officer of the Dominion Coal Board should prepare and give a talk on statistics.I would explain that it has been our experience in the Board that, since the supply and consumption of coal in Canada is subject to a seasonal ebb and flow, it can be more profitably studied on the basis of a twelve-month period ending on March 31st than of a calendar year, since the end of March does represent a fairly stable end point in this ebb and flow. The figures are not prepared or published by the Bureau on that basis and it has therefore been thought that a presentation on this fiscal-year period would be of interest. The Bureau of Statistics has agreed that this may be valuable and all the data here presented are based on the reports secured from various sources by the Mining, Metallurgical and Chemical Division, Dominion Bureau of Statistics. The only contribution by either myself or the staff of the Dominion Coal Board has been the tabulation in a different twelve month period, and the comments upon the picture presented.It should be noted that the data for the month of March, 1950, are not available in all cases and consequently the figures for that year contain an estimate for this month."

Jan 1, 1950

By T. P. Weldum, W. Conger

"These studies address the relationship between mill media sizing and its grinding efficiency. Starting with the results from a review of the literature, the issues of initial media sizing for a new ball milling circuit, and then optimal media sizing for an existing milling operation, were studied. The Functional Performance parameters “Mill Grinding Efficiency” and cumulative “Mill Grinding Rates” from both plant and test-scale equipment were used, and provide valuable new insight into this topic. A plant media sizing diagnostic tool is presented, as are newly developed testing equipment and evaluation methods, and recent case studies.REVIEW OF MEDIA SIZING LITERATURE For a plant metallurgist to answer the question “How can I maximize plant profit by manipulating this grinding circuit variable?” she must know what effect the variable has on grinding circuit efficiency. Despite the significant cost of grinding media and its potential effect on production capacity, the ‘best’ media sizing remains ill-defined for any given ball mill circuit in the industry today. The underlying reasons for this will be discussed. But the importance of this issue drove Metcom and its industrial partners to take on the challenge of how to engineer the ball charge for an existing grinding circuit. In the absence of any proven method, the first step was a review of the literature. Sponsored by Cleveland-Cliffs, Inc., a broad review of the literature was undertaken, producing “The Effect of Media Sizing on Ball Milling Efficiency” (McIvor, 1997). Among hundreds of publications that were reviewed that discuss the topics of media sizing or wear, forty-five were studied in detail. These were grouped into: plant experiences; laboratory and pilot plant investigations; media wear studies; population balance modeling studies; and general papers on ball milling which included the topic of media sizing. The reader is encouraged to refer to that review. The findings remain unchanged, although some relevant papers have been written since (e.g. Staples et al, 1997; Banasi et al, 1999; Orford et al, 2006; LaMarsh, 2015). The main findings of the review were as follows:"

Jan 1, 2018

By G. Beckstead, L. F. Sawatsky, R. Nutbrown, D. Long, G. Gould

"This paper presents a case study for optimizing water management at Gregg River Coal Mine located near Hinton, Alberta. The optimization study was derived based on a review and assessment of existing management practices and plans for future operation and final reclamation. A proactive water management strategy was developed to assist mine staff in adopting a rational, environmentally sound, and economical approach to water management. A plan was developed to provide for safe operation, self-sustaining operation, low maintenance, minimum negative environmental impacts, and anticipation of future needs for existing and future operations. A plan for final reclamation drainage was developed including establishment of effective, sustainable, and maintenance-free water management systems. The study demonstrated the importance and benefits of a proactive approach for integrated mine water management. This approach is recommended for other similar mine operations because it will improve environmental compliance and reduce costs of water management. IntroductionGregg River Resources Ltd. (GRRL) operates an open pit coal mine on the eastern slopes of the Rocky Mountains, located about 45 km south of Hinton, Alberta. GRRL opened the mine in 1982 and expects to continue operations after Year 2000. GRRL has progressively reclaimed the disturbed area and expects to complete mine-land reclamation shortly after mining in the area is complete. The existing disturbed area and reclaimed area covers approximately 9.5 km2 and will expand to about 10.5 km2 upon mine closure.Like other coal mines in the mountainous areas of Alberta and British Columbia, the GRRL coal mine is subject to highly variable temperatures and moisture conditions. Average monthly precipitation varies from a low of 12.6 mm in January to a high of 113.0 mm in August, based on the precipitation record at the mine site since 1982. Despite the relatively high rainfall during the spring and summer months, excess water problems during rainfall events are quickly replaced by water deficit conditions during periodic droughts. Surface runoff varies from near zero in the winter to a mean annual monthly maximum of 78 mm during the month of June. The mean annual surface water yield is 345 mm."

Jan 1, 1997

By S. Power Warren

Introduction It is generally conceded by flotation men that the condition at the surface of a particle of mineral or gangue is the most important factor controlling its behaviour in a flotation cell. Much research work has been devoted to the study of the forces that are active at the surface of the particle and of the effect of the surrounding solution upon these forces. Study of the relationship between mineral or gangue particles and gas bubbles indicates that, in the main at least, flotation is a physical phenomenon. The important factor, that of mineral-gas-bubble attachment, is unquestionably physical; however, modifications may be effected by chemical means, whereby the nature either of the surface of the particle or of the surrounding solution may be changed. For example, the coating of lead sulphide that forms on lead-carbonate ore particles when sodium sulphide is added greatly aids the flotation of the carbonate particles. Without going into the question as to why, under certain surface conditions, mineral particles will attach themselves to gas bubbles whereas under other conditions they will remain unaffected, it may be stated that there are three general conditions in a flotation pulp which control the attachment of the particle and the gas bubble.

Jan 1, 1933

By C. H. B. Leitch

"The Bralorne-Pioneer deposit produced more gold than any other deposit in British Columbia over its 70 years of operation (130 kg or 4 million oz of Au, from 7 million tonnes of 18 glt ore). Mineralization is related to a suite of late Cretaceous albitite dykes of 85 to 90 Ma age. It thus occurred long after and is genetically unrelated to the Early Permian (275 Ma) Bralorne diorite and soda granite.The major veins strike about 110 degrees and dip north at 70 degrees, with slickensides plunging 45 degrees east that indicate last movement was reverse. Major ore shoots in the veins occupy somewhat less than 20% of the vein and plunge steeply west, roughly perpendicular to the slickensides. The structures that contain the veins probably formed at around 95 to 90 Ma during a strike-slip episode with easterly directed maximum compression.Disseminated pyrite, pyrrhotite, and minor chalcopyrite occur within envelopes up to several metres from the veins. Arsenopyrite is confined to vein selvages. Local sphalerite and galena appear to correlate with gold-rich portions of the veins. Traces of tetrahedrite and stibnite have been observed but tellurides have not. Gold is found principally as thin smeared flakes of the native metal in the black sulphidic septae of the strongly ribboned veins. Hydrothermal alteration envelopes around the veins grade outwards from intensely foliated quartz - ankerite - sercite (±fuchsite) to less sheared calcite - chlorite - albite to unsheared epidote -calcite.Open-space vein filling textures found in the deep (mesothermal) environment at Bralorne can be explained by a fault- valve model. High-angle reverse faults may have acted as fluid-pressure activated valves on geopressured reservoirs, causing large cyclic fluctuations in fluid pressure that promoted mineral deposition in an episodic fashion . The faults that were mineralized were reactivated sub-vertical former strike slip faults, oriented at a high angle to the northeast-directed stress in a compressive regime."

Jan 1, 1990

By Staff

This paper contains an outline of the history of the Sullivan mine, now owned and operated by the Consolidated Mining & Smelting Company of Canada, Ltd.; some account of the various methods by which the ore has been treated in efforts to solve the metallurgical problems which its complex character presents, and, finally, to give, as concisely as possible, an outline of the present mining and metallurgical practice along with a description of the mining and milling plant at Kimberley and the smelter and refineries at Trail, in British Columbia. EARLY HISTORY In May, 1892, Pat Sullivan, John Cleaver and Mike Holland left the Coeur d'Alene country, in the State of Idaho, to seek their fortunes in the Kootenay lake district in British Columbia. They were aided in their venture by James Cronin, afterwards locator and owner of the St. Eugene mine at Moyie. Two months later the party broke up, Sullivan and Cleaver crossing the mountains from Crawford bay on Kootenay lake to the head waters of the St. Mary's river, the course of which they followed down to Fort Steele. Here they found a good deal of excitement about the North Star mine, and, joined by "Ed." Smith, who was familiar with this part of the country, they determined to return and prospect in its vicinity.

Jan 1, 1924

By R. M. Kleine

In the fall of 1968, Sheridan Geophysics leased the Renzy Mine property 50 miles northwest of the town of Maniwaki, Quebec. A 500-tpd flotation mill was dismantled at Belleterre, Quebec, trucked into the mine over a winter road and re-erected during extreme winter conditions. Approximately one billion gallons of water were removed from Renzy lake to expose the orebody. A 3,000-hp diesel generating plant and a self-supporting community were set up during the early part of 1969. This was a remark-able achievement considering that most of the work, including the pouring of foundations and the draining of the lake, had to be done during the winter months. Despite this, the project was completed ahead of schedule and one million dollars below budget. The mill is now treating an average of 800 tpd.

Jan 1, 1970

By J. G. Bennett

Coal consumption has increased globally by 57% over the last ten years. Underground mining typically provides coal of the highest calorific value and accounts for the greatest proportion of production. Despite a negative environmental image and indeed impact, this industry appears likely to thrive on the global scale for many years to come. Such mining consumes large amounts of electricity with implications for carbon dioxide emission at power plants and emits substantial quantities of the powerful greenhouse gas methane. In response to this significant carbon footprint, the European Union has funded research to examine the potential for a range of improvement technologies in a project entitled Low Carbon Mine Site Energy Initiatives (LOWCARB). Coal properties related to seams and mines, together with longwall characteristics, provide the basis for research into modelling optimally efficient methane drainage with a view to assisting mining as well as maximising electricity generation at surface and hence oxidation of the methane. Possible systems for the oxidation of very low concentration methane in ventilation air, which contributes the greatest greenhouse gas impact due to the volumes emitted, have been studied and modelled. Simulation and investigation of intelligent optimisation of electricity demand patterns provide the basis for reducing the demand peaks at mines and hence the cost and ultimately the carbon footprint of a mine, while specific investigations have been undertaken into ventilation efficiency at an unusually challenging mine and simulation of mine water pumping in order to develop an innovative method to monitor pumping systems efficiency. For post-mining use, the potential of disused shafts for compressed air energy storage to improve the operation of future electricity grids with high renewable energy penetration by reducing peak generation capacity requirements has been studied. While underground coal mining will always by definition be related to a significant carbon footprint, this paper provides an overview of a set of initiatives that can make a positive environmental impact while controlling costs across a huge global industry.

Aug 1, 2013

By A. Eslami

When producing high grade mattes in smelter plants, copper losses in the slag are inevitable. Hence, the recovery of copper from slag has been the focus of many research projects, copper flotation being a widely used process. In the Khatoonabad converter, 200 t/d of slag are presently produced with a grade of 2.3% Cu. Assuming a 85% recovery by flotation, about 3.9 t/d copper could be produced, which is of prime importance economically. In the present work, a sample of this slag was crushed and ground in the laboratory to liberate the copper-bearing minerals. Following mineralogical studies, optimum laboratory flotation parameters were obtained, resulting in 90.27 % recovery and 9.42% of copper grade for the rougher stage. At pilot scale, a pulp of 28% solids was floated at ph 10.5 using 40 git of Z6, 25 git of R407 and 20 git of MIBC and A65. A recovery of 83.52% was obtained for a concentrate grade of 28.36% Cu. In the rougher cells, the feed consisted of particles 94% finer than 74 microns whereas in the cleaning stage, particles were 95% finer than 44 microns. Based on the obtained results, the Sarcheshmeh Khatoonabad converter slag is presently being fed to the Chargonbad flotation plant, where a concentrate of 32% copper at 86% recovery is being produced.

Jan 1, 2007

By C. A. Young, H-H. Huang, L. G. Twidwell

Equilibrium calculational software programs can be effectively utilized to model important parameters in aqueous and aqueous/solid systems, e.g., activity or concentration, solubility, temperature, solution pH, solution potential, and ligand complexation. In this regard, the calculational program ST ABCAL will be demonstrated. Illustrative examples for the creation of diagrams such as potential-pH, and activity or concentration-pH will be presented to demonstrate the fundamentals in real hydrometallurgical systems. Speciation, titration and mixing will be used to simulate or predict operational processes. Berkeley Pit water from a flooded abandoned copper open-pit mine will be used to illustrate the modeling process. According to analytical results the water contains about 20 important constituents. In addition to measured potential and dissolved oxygen, there are two distinctive oxidation/reduction couples. Concentration and other experimental parameters are seldom matched to each other and 12 different conditions have been identified. Water for each condition must be speciated in order to find the best-fit model. The STABCAL program will be used for the modeling calculations and the implication of the water chemistry to defining treatment opportunities will be discussed.

Jan 1, 2005

By Nick Vayenas, Ming Cai, Hongbin Zhang Lorrie Fava, Enrique Acuña

"A hybrid methodology is proposed to improve the accuracy of Diesel Particulate Matter (DPM) concentrations simulated in a ventilation network model by using Computational Fluid Dynamics (CFD). DPM, as a primary concern for underground hard-rock mines, has been studied in two dominant numerical models, ventilation network solvers and computational fluid dynamics. Ventilation network solvers are efficient, but they are not able to provide three-dimensional DPM concentration contours and only accept area-average DPM data as input. CFD simulations are time-consuming, but generating DPM concentration results with high accuracy. Besides, both monitoring points and planes can be created in a CFD model, which can take both point data and area-average DPM data as input. The hybrid methodology is intended to combine the advantages of the two by using the CFD results to update the network model results at key locations. A field study was conducted in a dead-end heading in an underground gold mine in the United States. Real-time DPM monitors were used to collect data. A CFD model and a network model were built for the experiment area. The CFD model was calibrated to the experimental data. In the study presented here, results from a calibrated CFD model are converted to equivalent diesel emission rates in the ventilation network model at a shared outlet. The hybrid methodology is used to provide better input for the network model. INTRODUCTION Mine ventilation system is one of the most important parts for an underground mine. It not only provides fresh air to the personnel but also helps clear the contaminants generated from the diesel-powered equipment. For most underground metal and non-metal mines, diesel particulate matter is the main contaminant. It is also the focus of this paper."

Jan 1, 2019

By W. C. Zhu, C. H. Wei, L. L. Niu

With an increase of mining depth, a series of mining-induced hazards such as rockburst, coal and gas outburst, roof collapse, and water burst are getting more serious and more frequent. The intrinsic mechanism responsible for the occurrence of mining-induced hazards is the damage and unstable failure of rockmass or coal seam. The most distinct difference between deep and shallow levels is the so-called three ‘high’ (H3) conditions, i.e. high geo-stress, high fluid pressure and high geo-temperature. Therefore, the response of rock or coal to the deep mining operation is a phenomenon involving thermal (T), hydraulic (H), and mechanical (M) processes. Most importantly, mining excavation may vary the rock stress condition greatly, which may be a key factor to trigger the mining-induced hazards such as rockburst. In this regard, it is of great significance to clarify the damage and failure mechanism of rock and coal under coupled THM conditions, in order to clarify the rock failure mechanism responsible for the occurrence of mining-induced hazards. Thereafter, the mining-induced hazards cannot be predicted with confidence by considering each process independently. Of course, the requirement to include coupling of these processes depends on the specifics of the mining-induced hazards under consideration. For example, the water inrush is considered as a coupled hydro-mechanical (HM) process, in which the unstable failure of rockmass occurs under the combined contribution of geo-stress and water pressure. As for the coal mining at depth, in addition to high geo-stress and gas pressure in coal seam, the high geo-thermal condition that may greatly change the adsorption / desorption of gas and gas flow should be taken into account. Firstly, a general-purpose mathematical model for rock damage and failure process under coupled THM conditions is formulated based on damage mechanics principle, and it is solved by finite element method (FEM). In this model, the deformation and damage of rock, fluid flow and thermal transfer in rock would interact with each other, one process affects and initiation and progress of another. Then, the model is used to predict the mining-induced water outburst, where it is simulated as coupled hydro-mechanical (HM) problems. Based on the numerical simulation, the dimension of water-proof pillar is designed. Finally, the gas drainage from deep coal seam is numerically evaluated, where the coupled coal-gas interaction considering the effect of gas adsorption/desorption, gas flow in coal seam and geo-stress and geotemperature, is comprehensively taken into account. The proposed model could be used for clarifying the mechanism of mining-induced hazards in deep-level mining.

Jan 1, 2015

By R. P. van Hille, N. Mooruth

Remediation of acid rock drainage (ARD) was performed within a linear flow channel reactor (LFCR) via a floating sulphur biofilm (FSB). A full sulphur species material balance was conducted in order to characterize the sulphide oxidation. The reactor was able to achieve an 82% and 93% conversion of sulphide with a hydraulic residence time of 2 and 5 days respectively. 92% and 55.5% of the converted sulphide reported to the biofilm as sulphur for the 2 and 5 day residence times respectively. The mass transport limitations within the biofilm were identified via a dissolved oxygen gradient profiling system.

Jan 1, 2011

By W. F. Baker

Location and History God's lake is in the northeastern part of Manitoba, about 400 miles northeast of Winnipeg, or about 250 miles due north of Red lake, Ontario. The lake is quite large, having an overall length of 54 miles and a maximum width of 18 miles. There are numerous islands in the lake, the largest of these, known as Elk island, being about 15 miles long and 3 miles wide in the widest part. The accompanying map (Figure 1) shows the location of God's lake and of the mine. The God's Lake area has long been regarded as promising country for the prospector, but, due to its inaccessibility, practically no prospecting was done prior to 1927. In the years 1927-1931, inclusive, a few prospectors visited the area, but no discoveries were made. In 1932, Bob Jowsey and Archie McDonald entered the area from Island lake. They first prospected in the vicinity of Knife lake, which is immediately south of the main part of God's lake, and then moved on to the latter lake, heading for the north shore of Elk island. The first afternoon on God's Lake, when looking for a place to camp on the north shore of what is now known as Jowsey island, Jowsey discovered a quartz porphyry dyke which was cut by a number of gold-bearing bluish quartz stringers. On the strength of this discovery, he and McDonald began at once to stake the Reno group of claims. Rumours of the discovery brought in other prospectors, and other groups of claims were staked to the east, along the north shore of Elk island. A second discovery was soon made by Dan McCrea on his Gold Standard claims, three and a half miles to the east of the original discovery. Staking still continued to the east, along the north shore of Elk island, and Bob Brown and Harvey McKenzie staked the Akers group on a discovery approximately two miles east of McCrea's discovery. Through the efforts of Jowsey, the Reno, Rand, Elk, and Cona groups, belonging to the original syndicate for which Jowsey and McDonald staked, were combined with the Gold Standard, Greenstone, and Akers groups, and the Company known as God's Lake Gold Mines, Limited, was formed. Several additional groups of claims were later taken over by the Company and a considerable area of adjoining ground was staked to round-out the property.

Jan 1, 1935

By A. A. de Gast, R. B. James

"The metal content of ore blocks can be calculated by the use of many different methods. These methods range in sophistication from manual calculation to computer. oriented techniques. In this case a cubic polynomial regression model is developed to depict the grade distribution of an orebody. Mine production, in stope dimensions, is then simulated on a computer to predict the output of metal content. The volume, grade and variance of the grade are estimated by triple integration and matrix algebra. A case study shows reasonable agreement between the results from the mathematical model and the mine geologists' estimate of production and ore reserve grade and tonnage."

Jan 1, 1972

By F. M. Doyle, G. Sidhu, A. J. Dussault, A. Raygani

There is a growing demand for rare earth metals for use in high strength permanent magnets, most notably Nd2Fe14B. Rare earth metals are extremely reactive, with reduction potentials around -2.5V SHE, and are conventionally produced by molten salt electrolysis. The current work was done to investigate an earlier report of electrodeposition of a neodymium ferroalloy from aqueous solution, to determine whether this approach could be an environmentally and economically competitive commercial approach for producing feedstock for permanent magnets. Such a process would be analogous thermodynamically to the Castner- Kellner process, in which aqueous sodium chloride brine is electrolyzed in cells with mercury cathodes. Metallic sodium forms an alloy (amalgam) at the cathode, thereby lowering the activity of the metallic sodium significantly below unity and making the reduction potential of sodium significantly less negative than the standard reduction potential. Here we report the effects of Nd/Fe ratio in the electrolyte, current density, temperature and two different complexing agents, glycine and cysteine, on the composition and morphology of the electrodeposits, along with current efficiency. The energy needed to produce neodymium as Nd:Fe alloys by aqueous electrodeposition was compared with values estimated for production by molten salt electrolysis and the thermodynamic energy requirement.

Jan 1, 2014

By Celine Y. Zhang, Chloe J. Feng, Charles Q. Jia, Donald W. Kirk

Oil sands petroleum coke (OSPC) is a by-product of coking - a high-temperature process that converts the mined bitumen to the synthetic crude oil (SCO). For every barrel of the SCO produced, about 20 kg of OSPC are generated. Over 70 million metric tons of OSPC have been produced and stockpiled as a result of the development of oil sands industry in the past few decades. Unlike conventional petroleum coke, OSPC has uniquely high impurity contents, particularly sulphur (~ 7 wt%) and metals (e.g. vanadium at ~0.15 wt%), which has hindered its large-scale applications as a solid fuel. Vanadium is a valuable metal that is widely used as an alloy for strengthening steels. The stockpiled OSPC contains about 100,000 tons of vanadium, while the world’s production in 2013 was only 75,600 tons. At the current price of $25US/kg, the OSPC-bound vanadium represents a total value of $2.5 billion US dollars. In this work, we investigate the technical feasibility of extracting vanadium from OSPC. The work focuses on the characterization of vanadium in OSPC and the conditions for effective extraction of vanadium from the OSPC.

Jan 1, 2015