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By A. C. Ter-Oganesyants, N. N. Anisimova, G. P. Kotukhova, G. N. Dylko

The process utilized at Norilsk Nickel Polar Circle Division for treating slimes from the electrorefining of copper and nickel was developed in the late nineteen fifties and has survived without any fundamental changes. This technology is a combination of pyro and hydrometallurgical operations to produce PGM concentrates that are sent away for refining. The characteristic feature of the current technology is multiple-stage, extended cycle treatment with significant incomplete production, low labour and automation efficiency and poor hygiene and sanitary conditions. To eliminate all negative aspects mentioned above, specialists of Norilsk Nickel Polar Circle Division have developed a new hydrometallurgical process for treating electrolytic slimes. The main steps of the flow sheet developed are autoclave leaching of the slimes and electrochemical opening-up of a cake from autoclave leaching. The implementation of the new process will allow Norilsk Nickel Polar Circle Division to shorten the process cycle 4-5-fold thus reducing the volume of incomplete production, considerably increase labour efficiency, simultaneously improving working conditions, upgrade the final concentrate, reducing costs and increasing PGM recovery during refining and, ensure higher security of precious metals by employing automated processes and vacuum sealed units.

Jan 1, 2004

By B. Meddings, O. J. I. Evans

"This paper is mainly concerned with the present and probable future role of hydrometallurgy in the production of base metals.The economic and technological bases of the hydro-metallurgical plants built and operative in the mid-fifties are compared to those in production in the mid-sixties. The trends observed are extrapolated and some estimates made concerning the probable size and type of hydrometallurgical plants which will be operative in the mid-seventies.The impact of emerging socio-economic factors such as pollution control and the market demand for specialized metal products which favour hydrometallurgical recovery processes are also discussed."

Jan 1, 1971

By S. S. Rahman, A. Gholami, M. A. Aghighi

"This paper provides a foundation for studying the growth of fractures in presence of other discontinuities and different anisotropies of low permeable hydrocarbon formations and helps to improve the design strategies for multistage fracturing.The multistage fracturing technology has recently been used to exploit low permeable hydrocarbon reservoirs. However, the mechanism of hydraulic fractures interaction and the impact of local heterogeneities on ultimate trajectory of the growing hydraulic fractures are not yet understood in depth. A fully coupled poroelastic Finite Element based model is developed to investigate the mixed mode propagation behaviour of growing hydraulic fractures. This model takes advantage of an explicit representation of the fracture which enables us to take the effects of rock and fluid related parameters into account. Moreover, impact of fracture geometry and leak-off phenomenon is investigated. The refined mesh around the crack provides the added advantage of more detailed stress distribution, pore pressure change and back stress in the vicinity of the fracture and in particular at the fracture tip. The potential deviation propensity of the fractures is evaluated based on the fundamental rule that fractures propagate perpendicular to the direction of the minimum horizontal stress.This study shows that pressurization of transverse hydraulic fractures results in the reorientation of local principal stresses, particularly in vicinity of fracture tips. Variation of flow patterns clearly influences the evolution of shear stress around the fracture tips which will potentially lead to mixed-mode I and II fracturing and consequently, fracture deviation. The presence of local heterogeneities such as preexisting fissures and/or fractures is a main source of such pore pressure induced stress redistribution and reorientation and potential deviation of hydraulic fractures.Most existing models ignore or simplify the effect of pore pressure/stress coupling as well as the fracture geometry and fluid flow within the fracture. Also, the fluid leak-off from the hydraulic fracture into the formation, which is a controlling factor in fracture growth, is often considered using analytical models. Taking advantage of a fully coupled porelastic model along with an explicitly discretized fracture, this study provides a more realistic insight into the complex fracture propagation processes of multistage fracturing operations particularly in presence of reservoir geo-mechanical complexities."

Jan 1, 2015

By Buse Florian

This paper presents the specific features of the large-scale production and transportation systems (LSPTS), describing the main notions and characteristics of the LSPTS elements. A methodologically unitary approach of the formulation, formalization and solution of the problems regarding the planning of the LSPTS structure development is offered, based on the system description by the aggregation-decomposition method, as weil as on the complex of interreloted models for the planning optimization. The paper describes the characteristics of the complex of dynamic models for investments, utilized in solving the planning problems of the LSPTS structure development.

Oct 1, 2009

By L. Nastac, Y. Xuan

"The metal-matrix-nano-composite (MMNCs) in this research work consists of an A356 alloy matrix reinforced with 1.0 wt. % SiC 50 nm diameter nanoparticles that can be dispersed within the molten alloy matrix via ultrasonic stirring technology (UST) and induction melting and stirring processing. The necessary ultrasonic parameters to achieve the essential cavitation for adequate degassing and refining of the A356 alloy as well as the optimum fluid flow characteristics for uniform dispersion of the nanoparticles into the A356 alloy matrix have been investigated in this study by using computational fluid dynamics (CFD) modeling with a magneto-hydro-dynamics (MHD) model and an UST cavitation model.The MHD model accounts for turbulent fluid flow, heat transfer and solidification, electromagnetic field as well as the complex interactions between the solidifying alloy and nanoparticles by using ANSYS Maxwell and ANSYS Fluent Dense Discrete Phase Model (DDPM) and a particle engulfment and pushing (PEP) model.INTRODUCTIONAluminum matrix nanocomposites can offer outstanding properties, including low density, high specific strength, high specific stiffness, excellent wear resistance and controllable expansion coefficient, which make them attractive for numerous applications in aerospace, automobile, and military industries field (Bozic, 2010, De Cicco, 2009, Elshalakany, 2014, Goh, 2006, Jia, 2013 and 2015, Liu, 2014, Reihani, 2006, and Su, 2010).As shown in literatures (Aki, 1999 and Mussert, 2002), it is highly advantageous to use nano-sized ceramic particles to produce metal matrix nano-composites (MMNCs) since similar ductility and higher strength with the metal matrix can be achieved. Currently, there are several fabrication methods of MMNCs, including mechanical alloying with high energy milling (Chen, 1997) , ball milling (Filho, 2003), nano-sintering (Groza, 1999), spray deposition, electrical plating, sol-gel synthesis, laser deposition, etc. The mixing of nano-sized ceramic particles is normally lengthy, expensive, and energy consuming.Ultrasonic Stirring Technology (UST) has been extensively used in purifying, degassing, and refinement of metallic melt (Jian, 2005, Khalifa, 2008, Eskin, 2002, Xu, 2004, and Meek, 2006) mainly because introducing the ultrasonic energy into a liquid will induce nonlinear effects such as cavitation and acoustic streaming. SiC nanoparticles are widely used as reinforcement particles due to their relatively good thermal and chemical stability. Ultrasonic vibration can improve the wettability between the reinforced nanoparticles and the metal matrix (Lan, 2004, Cao, 2008, and Yan, 2011), which will assist to distribute the nanoparticles more uniformly into the metal matrix. Ultrasonic cavitation in liquids causes high speed liquid jets of up to 1000 km/h. Such jets press liquid at high pressure between the particles and separate them from each other (Hielscher, 2005)."

Jan 1, 2016

By F. W. Wellmer

"This paper discusses the changing nature of reserve/consumption ratios, using data from Canadian operations and focussing particularly on copper.IntroductionStudies in world metal consumption and world metal reserves are done regularly by the U.S. Bureau of Mines, the German Federal Institute of Geosciences and Raw Materials, and other institutions. Formerly, on the basis of these data, the following figures were calculated:• a static lifetime of reserves-reserves at year end divided by the consumption of the previous year;• a semidynamic lifetime of reserves-reserves at year assumed constant growth rate.These figures were severely criticized because they were purely theoretical and did not consider the availability of the raw materials.Recent practice is to calculate reserve/consumption ratios (R/C ratios) for periods(1) or for different years(2,3) and to interpret the trend. For base metals, these R/C ratios are increasing (Table 1). This had led to the conclusion that today the relative availability of base metal reserves has increased as compared to 10 or 15 years ago(4,5) As there are normally numerous deposits for each commodity, the anticipated production rates of deposits are irrelevant to this conclusion as long as the statistical distribution of possible production rates does not change significantly.The above conclusion is only justified if the quality and the nature of the data base remain the same. This is certainly the case for the consumption data. It is also assumed for the quality of the reserve figures, which usually take into account only proven and probable reserves. For the nature of the reserve figures, however, this does not seem to be true.Undoubtedly, the reserves increased in absolute terms between 1966 and 1978. To put the absolute reserve figures into perspective, it is common, as said above, to compare them with the mine production, which increased in the free world between 1966 and 1978; e.g. for copper by 40%, for Pb by 17% and for zinc by 36%. However, the reserves are also influenced by other factors, such as average size of the mines, changes in the grade of the mined ore, price-to-cost relationships and the like.The purpose of this paper is to examine the nature of the reserve figures in more detail. Because the completeness of mining data published in Canada is rather exceptional, Canadian .data serve as an example and it is assumed that the conclusions can be extrapolated to other mining countries or at least to those with free market systems."

Jan 1, 1981

By J. A. E. Bell

"Inco has shifted part of its traditional extractive research effort at its J..Roy Gordon Research Laboratory in Mississauga toward new, value-added products. Most of the effort is being expended on new Ni powders for batteries and new Ni-coated products which will be produced in Inco's carbonyl nickel refineries. New products under development are Ni-coated powders, Ni-coated fibres and ultra-fine Ni powders. Other new products for advanced material applications include controlled expansion composites, NiGOLD strip, Thermal barrier coatings on Inco alloys, and plasma coatings.Research and Corporate Strategic ThrustsThe newest strategic thru st of the company is to increase the value of the primary metal products. These new products are to be in addition to any new alloys or downstream alloy fabrication.Historically Inco has had the highest research expenditures in the extractive metallurgy field in North America. This has resulted in many new processes including flash smelting , matte separation, fluid bed roasting, pressure carbonyl refining and cobalt electrowinning which have contributed to establishing Inco as the lowest cost nickel producer. The recession of the 1980s caused a restructuring of Inco research and corporate goals .As shown in Figure I, from 1975-1982, i.e. pre-recession, Inco spent around 33 million dollars per year on research. Some 48070 of that sum was spent in Corporate Laboratories in Sterling Forest in the United States and in the United Kingdom , mostly on alloy associated research. A further 10% was spent on alloy research at the alloy production facilities in Hunting- ton, West Virginia, and Birmingham and Hereford in the United Kingdom. On extractive research, 13% was spent by process technology groups at the plant s, 20% at the pilot plants in Port Colborne and 9% at the J. Roy Gordon Research laboratory.The relative research expenditures (Fig. 2) have decreased so that today they are at the same level as 1975-80. The research as a per cent of sales has been cut from 2.2% to 1.2% of normalized sales. A normalized sale price of $4.00/lb Ni was used in the 1988 figures. This was partly achieved by closing Corporate Laboratories. Most of the essential alloy research was moved to producing plants and total alloy research is now 27%.A new thrust initiated in the 80s was mining research which now accounts for 20% of research expenditures. Over a period of the past five years this research has doubled the mining productivity in Inco. The pilot plant expenditures have been cut in half. One entire research station at Port Colborne was converted into a platinum group metals intermediate refinery. The decrease in pilot plant expenditures has been compensated by full scale plant trials devoted to the S02 abatement program at Sudbury."

Jan 1, 1990

By J. Satur

In copper mineral processing, pyrite coexisting with copper sulfide minerals like chalcopyrite is separated by flotation as tailings and its oxidation in tailing dams causes the formation of acid mine drainage. This paper proposes carriermicroencapsulation (CME) as a new method for suppressing pyrite flotability, as well as its oxidation. In this method, an organic carrier combined with Ti is used to form a thin Ti02 layer on pyrite, which gives a hydrophilic property and acts as a protective coating against oxidation. To form the coating, a ground pyrite sample was treated with Ti-catechol complex solution under various conditions. Bubble pick-up experiments and flotation experiments showed that the treatment of pyrite with Ticatechol complex changed the hydrophobic nature of pyrite into hydrophilic even in the presence of xanthate as a flotation collector. Oxidation testing of the CME-treated pyrite by 0.02 kmol m-3 HN03 showed that Fe release was suppressed by the CME treatment with respect to the control. This is assumed to be due to the formation of Ti02 coating on the pyrite surface. The effect of CME treatment on chalcopyrite wettability is also discussed.

Jan 1, 2007

By J. van Deventer

Volatile gold prices in the face of rising costs for mining and refining is causing the mines to look for new ways to reduce costs and increase recoveries. This task is complicated by the fact that the gold in hereto unexploited reserves is associated with increasingly complex ores - either preg-robbing, refractory, associated with high concentrations of copper, or all of the above. Ion exchange resins can play a significant role in this quest for improvement. Although ion exchange resins have been used in Former Soviet Union (FSU) countries for the recovery of gold for many decades, it is still not widely used in the Western World. Synthetically manufactured ion exchange resins can be tailor-made to suit the chemical and mechanical characteristics of a specific application. As such, ion exchange resins can be used in a variety of solution matrices (e.g. cyanide, thiosulphate and acid), and process designs (recovery from clear liquor after solid-liquid separation or directly from the leached pulp). In this paper, a number of applications are discussed along with a review of recent developments in ion exchange technology.

Jan 1, 2014

By G. H. Agnew

When water floods are initiated after gas-oil ratios have increased, the transition period from the start of injection until" the gas-oil ratios are returned to the solution gas-oil ratio may be important for either economic or technical reasons. The transition period is longest, and consequently most critical in water floods where injection is equal to withdrawals. This paper describes a theoretical basis for predicting the behavior of such a system and outlines a procedure for making the necessary calculations. The calculation procedure is illustrated for two actual cases: a line drive water flood and a five spot water flood. In each case there is a reasonable similarity between the actual and calculated performance.

Jan 1, 1960

By M. Epiney, A. Ghahreman, R. Kim1and

"Pre-oxidation and cyanide leaching behavior of gold in the presence of sulfide minerals were reviewed, focused on the effects of oxygen injection in the gold leaching process. Generally, pre-oxidation and gold leaching kinetics from iron sulfide refractory minerals, such as pyrite, pyrrhotite, marcasite, pentlandite and arsenopyrite, can be enhanced with higher dissolved oxygen (DO) concentration. However, most of copper sulfide minerals dissolved well both in water and cyanide solutions, and copper from the minerals consumed DO and cyanide to oxidize and leach. Only in the presence of chalcopyrite, gold leaching was effectively occurred with increasing DO. However, chalcocite and covellite severely retarded gold leaching. Stibnite, an antimony mineral, formed a passive film on the gold surface under any DO conditions, and it slowed gold leaching. This impeding effect can be alleviated by leaching at low pH or adding lead salt. Using oxygen and lead together can make synergistic effect in oxidation of sulfide minerals and can enhance gold extraction. Depending on the mineralogical characteristics of the ore, the optimum DO and lead concentrations can be optimized. However, lead can cause environmental problems, and so its dosage should be minimized or eliminated by substituting it with oxygen injection.INTRODUCTIONGold ores containing sulfide minerals are becoming more significant as high grade gold oxide deposits are continuously becoming difficult to find. In light of this situation, to produce more gold, recovery methods from refractory gold ore containing various sulfide minerals should be investigated. Generally, sulfide minerals have impeding effects on gold leaching: formation of a passive film on the gold surface, high consumption of chemicalssuch as cyanide and oxygenduring leaching, reduction of gold cyanide by sulfide ions, etc. (Senanayake, 2008). Therefore, sulfides must be properly treated for better gold recovery. Pre-oxidation of sulfide minerals by injecting pure oxygen can decrease the impeding effects in gold leaching. Prior to cyanidation, sulfide minerals can be oxidized to metal hydroxide and sulfate form, which consume negligible cyanide in the following cyanidation circuit (Bodnaras et al., 1993). Moreover, gold cyanidation can be enhanced by increasing concentration of the dissolved oxygen (DO). In general, the optimum concentration ratio of [CN-]/[O2] is calculated as 6, but it goes higher in the real system (Marsden &House, 2006), which means that the reaction is typically controlled by DO concentration."

Jan 1, 2017

By Neil Schofield

"The Pine Creek gold mineralization is associated with saddle reefs and quartz and quartz sulphide veining within the Enterprise Anticline. The anticlinal structure is complex and the mineralization was considered prior to development to be dominantly strata controlled. Gold grades vary up to 160 gin 1.5 m core samples with coefficients of variation in excess of three.The estimation of ore reserves for such a deposit must account for both the geological complexity and the extreme variability of gold grade.This paper describes the structural and variogram analysis of the gold grades and demonstrates the importance of incorporating the geological model in such an analysis. Variogram interpretation is greatly improved and greater insights into the finer geological structure areprovided. Part 2ofthis work presents the application of multigaussian kriging to reserve estimation for deposits with highly variable grade and which consequently demand highly selective mining operations. IntroductionThe Enterprise Gold Mine is situated some 220 km southeast of Darwin in Australia's tropical north. Gold is believed to have been discovered there in 1869 during the construction of the overland telegraph line.From 1894to 1915, some 75 000 ounces of gold were produced from 121 000 tonnes mined mainly by Chinese leaseholders. From 1906 to 1915, government-sponsored drilling led to the sinking of the Enterprise Shaft to 79 m and several drives were developed. Mining ceased because of war.Since late 1980, Goldfields Exploration Pty. Ltd. had explored on several mining tenements near Pine Creek under joint venture with the title holders, Enterprise Mines NL. This work culminated in the development of the current mine which opened on October 29, 1985.Feasibility studies to determine the economic viability of mining were based on ore reserves generated by project geologists using a sectional polygonal approach tuned to the interpreted geological control of the mineralization.The study motivating this two-part paper covers are-estimation of the recoverable reserve s using the geostatistical approach of multigaussian kriging developed at Stanford University, (Verly, 1984)."

Jan 1, 1988

By L. A. Wolff

"Second only to profitability (but not always), productivity is the most sought after measurement for any operation. Whether it is in mining, manufacturing, construction, etc. managers always strive to know how productive various plants are. Even the Federal Government publishes, on a monthly basis, the nation's factory productivity.Just what is productivity and how is it measured? This is an important topic that needs definition. There could be as many definitions as there are people who use it. In the mining industry, the problems of defining productivity would be analogous to the definition of equipment availability. Each mine uses its own definition to suit its needs. Webster's Dictionary primary definition for productivity is ""the quality or state of being productive,"" with productive defined as ""yielding or furnishing results"". This is a definition open to a broad spectrum of interpretation. A discussion of how productivity is currently used in the mining industry and an introduction to a potentially different approach to its measurement and meaning is outlined in this paper.Defining ProductivityTypically, mining companies track several productivity measurements. These are partial measurements and can include the following: tons per specific equipment class per hour, tons per man-hour, and tons per shift. None of these, however, track the over -all performance of an operation, that is, a unit of output per unit of input.For a mining operation, output can be defined as the ore for mill processing. Input includes the required components of production to get to the first step of processing.The Wesbter's Dictionary definition exposes a major fault with the popular conception of productivity. The critical issue of accountability is not addressed. Anyone can produce, but how effectively and efficiently are resources used? Quantifying an inclusive measurement is difficult. Statistics referring to an increase in productivity are often published. For example, the statement, ""gold productivity has increased by 10%"" has many potentially dangerous interpretations. One must ask, what does this statistic really mean? Did gold companies produce 10%” more gold? Were less manpower or equipment required to produce an equivalent amount of gold? Did ore grades increase resulting in more ounces of gold produced, etc. Obviously, production and productivity can have similar implied applications and meanings, but also two different, distinct meanings.To mitigate a problem like this, a standard needs to be developed within the mining industry. Because of varying ore grade, changing waste to ore ratios, different mining methods, etc. all of which have a direct impact on mining, development of a standard is difficult. Kendrick(1) discusses the use of Total Factor Productivity as a productivity measurement. Summarized, the total factor productivity measure is an indication of the change in efficiency in the use of basic labour and capital factors associated with an operation.This measurement has little meaning when calculated at a given point in time. It should be an on-going calculation, tracking an operation over a period of time, to evaluate trends. These trends can be used to determine if an operation's productivity is what it should be, and alert management to potential problems before they become major and adversely affect an operation."

Jan 1, 1990

By J. Shibata, N. Murayama, H. Yamamoto

As one of effective usages of wastes discharged in the non-ferrous metal industry, the syntheses of AlPO4-5 and hydrotalcite were carried out using aluminium dross as a raw material. AlPO4-5 is an aluminium phosphate condensate with properties of zeolitic materials and large pore size. Hydrotalcite is an inorganic anion exchanger and has a layered structure of complex hydroxide. They were synthesized in an autoclave at high temperature and pressure. Various physical properties such as crystal structure, surface texture, and specific surface area were measured. AlPO4-5 can be synthesized from aluminium dross under hydrothermal conditions at 180°C-200°C, and 3h. At the same time, AlPO4-34 and non-porous AlPO4 were also formed as by-products. The crystals of AlPO4-5 have a hexagonal structure. Lt is desirable to heat the reaction product at around 550 °C to remove tri-ethyl amine. The specific surface areas of the reaction product before and after heat treatment at 550°C were 17.9m2/g and 358m2/g, respectively. Hydrotalcite can be obtained by a co-precipitation method from the aluminium dross and waste MgCl2 solution discharged in the aluminium regeneration process. Small amounts of SiO2, Al2O3, and Fe2O3 remain in the reaction product as an impurity component. The interlayer distance of the obtained reaction product is about 0.3 nm. Hydrotalcite changes to Mg-Al oxide during calcination at 500 °C for 3h, and then hydrotalcite is formed again by a rehydration operation. The physical properties of the reaction products obtained from the wastes were very similar to those from fresh reagents.

Jan 1, 2004

By S. Kursunoglu

The aim of this study was to investigate the effectiveness of Ascorbic (C6H8O6) Acid (AA), Activated Carbon (AC) and Guar Meal (C6H12O6) (GM) as a reductant for the simultaneous complete dissolution of zinc (Zn) and manganese (Mn) from a spent and mixed Zinc-Carbon (Zn-C) and alkaline battery powders in sulphuric acid (H2SO4) leaching. AA was tested previously as a reductant by other researchers while AC and GM were tested as a reductant for the first time in battery recycling. The effects of H2SO4 concentration, AA/AC/GM dosages, reaction temperature and leaching time on the Zn and Mn dissolutions were investigated according to 2k full factorial experimental design and Central Composite Design (CCD) technique; then, a simple optimization study was carried out for comparing the reductants. The optimum reductive acid leaching conditions for AA were determined at 3 hours leaching time, 70°C leaching temperature, 0.5M H2SO4 concentration, 13 g/L AA dosage, 1/20 g/mL solid/liquid (S/L) ratio and 200 rpm stirring speed. Under these conditions, the dissolution efficiencies were 99.9% for Zn and 99.3% for Mn. The best reductive acid leaching conditions for AC were determined at 3h leaching time, 80oC leaching temperature, 1M H2SO4 concentration, 3 g/L AC dosage and 400 rpm mixing speed. Under above conditions, Zn and Mn dissolutions were not complete. At 2M H2SO4 concentration, 10 g GM dosage, 700C leaching temperature, 200 rpm stirring speed, 1/20 g/mL solid/liquid (S/L) ratio and 3 hours leaching time, full dissolution of both Zn and Mn was achieved. As a result, three different reductants were evaluated in this study for complete simultaneous Zn and Mn dissolutions. This paper also compared present test results with previous spent battery recycling studies for Zn and Mn dissolutions. Full valuable metals dissolutions from spent batteries were achieved at low H2SO4 concentrations with AA and high concentrations with GM. Selective precipitations of Zn and Mn from acid solutions were carried out using NaOH and KOH. Using 3M NaOH as precipitating agent at room temperature and at pH 8; 95.4% of Zn and at pH 10; 93.7% of Mn were precipitated from the leach solution. Under the same conditions, using 3 M KOH at pH 8; 91.6% of Zn and at pH 10, 96.4% of Mn were precipitated. Based on the experimental results obtained, an appropriate flow sheet was proposed to recover both Zn and Mn.

Aug 1, 2013

By J. E. Quinn, S. Wolstencrof, K. H. Soldenhoff

Ion Exchange (IX) using Strong Base Anion Exchange (SBA) resins is conventionally used to purify uranium from sulfuric acid pregnant leach solutions (PLS), particularly when uranium grades are relatively low. However, the presence of chloride in the PLS interferes negatively with conventional SBA based IX processes, by reducing the uranium loading on the resin. Chloride can be present in the PLS due to the use of saline bore or seawater in leaching, or chloride containing leach/IX reagents. ANSTO has been examining strategies to combat this problem for several years. ANSTO previously reported that a recently developed high-capacity SBA resin was capable of extracting uranium efficiently from saline leach liquors produced at Boss Resources’ Honeymoon in-situ recovery mine in South Australia. The resin was tested successfully in a 2017 Field Leach Trial carried out onsite in the existing wellfield area. While the piloting was extremely promising, the elution was more challenging, with eluate tenors limited to 2 g/L U3O8 using NaCl. This is due to the resin’s strong affinity for the uranium complex, which makes it difficult to elute efficiently by standard methods. In this paper, we describe a novel elution process developed for strong base resins that significantly improves upon conventional methods. The process, developed by ANSTO, is based upon conversion of the extracted uranyl sulfate species to uranyl carbonate, followed by elution with sodium chloride. The loading and elution process was demonstrated in continuous locked-cycle piloting conducted at ANSTO in 2019. The results were excellent, with eluate tenors of 8–9 g/L U3O8 achieved from Honeymoon PLS containing 50 mg/L U3O8, with very little transfer of impurities. In subsequent test work, the eluate was shown to be amenable to uranium peroxide precipitation. The results represent a huge step forward for the purification of uranium from saline leach liquors.

Jan 1, 2020

By V. Casaletto, L. Widdifield

"Equipment capable of higher production requires more sophisticated maintenance programs. Reduction in fleet size through use of modern technology requires higher utilization and greater availability.Caterpillar's maintenance control system program will display the capabilities of computer technology in a maintenance environment. Utilizing such resources will provide increased availability, lower inventory requirements, fewer last minute disasters, and lower cost per ton for maintenance. High production from premium quality equipment can only be realized by good planning and care, executed by maintenance and operating personnel acting cooperatively.IntroductionAccurate information is the key to accurate decision making. In today' s competitive industry, mines' teeter on the brink between profit and loss. Their survival will be predicated on their ability to retrieve, analyze, and formulate accurate information regarding the operating costs of mobile equipment. This paper deals with the impact of managing equipment operating costs and introduces a computerized control system designed for monitoring and controlling these costs.Caterpillar has produced several computerized modelling programs designed at taking the guesswork out of equipment selection and management. The most basic of these is Equipment Investment Analysis (E.LA.). This model compares two or more alternatives over the projected life of the machine. It deals with comparisons in the owning and operating costs of equipment, as well as, their productivity over a specified period of time.In order for a computer model to be credible as a decision making tool, it must be simple to use and the results measurable and accountable . Caterpillar has introduced several computer models to assist the industry in selecting and managing an equipment fleet. These programs allow the user to predict and monitor the operating costs and production capability of mobile equipment. They are often used in the machine selection process to select equipment which best suits a mine's long-term cost per tonne objectives. After the optimum selection is made, Caterpillar's Maintenance Control System provides an efficient management tool to monitor and verify the data used in the selection model."

Jan 1, 1992

By Michael Moser, Brighty Dutta, David Dreisinger

"Molybdenum is widely used in the industries as an alloying element in the manufacture of steels and super alloys. The widespread use of the element encourages a growing need to develop extraction processes for recovery from both primary and secondary sources. The Solvay Group has developed a solvent extraction reagent named CYANEX®600 for the recovery of molybdenum from acidic solutions originating from both low grade (e.g. copper solvent extraction raffinates, smelter dusts and slags) and high grade (molybdenite) molybdenum sources. CYANEX®600 is a purified form of CYANEX®272 with the active component bis(2,4,4- trimethylpentyl)phosphinic acid. The extraction behavior of CYANEX®600 towards molybdenum in sulphuric acid medium was evaluated. The uptake of molybdenum increased with the increase in concentration of CYANEX®600. The approximate stoichiometry of the extracted complex was: Mo: CYANEX®600 = 1:2. Efficient back-extraction could be achieved with 0.1 M disodium EDTA and 0.1 M (NH4)2CO3, thus providing the option of recyclability of the extractant. The detailed back-extraction studies are currently under progress to find out the possible option for complete transfer of Mo(VI) to the aqueous phase so that high purity Mo salts could be precipitated from the molybdate solutions.INTRODUCTION Molybdenum (Mo) is one of the world’s valuable metals and is highly sought after by researchers due to its versatile mechanical, thermal, chemical properties. Swedish scientist Carl Wilhelm Scheele demonstrated molybdenite to be a mineral sulfide in 1778. Peter Hjelm successfully isolated dark metal powder from the mineral sulphide and named it as ‘Molybdenum’ in 1782 (Gupta, 1992). Molybdenum is a refractory metal of silver gray appearance and is an important alloying element used in the manufacture of steels and super alloys. Molybdenum compounds are widely used in formulation of catalysts (Gupta, 1992). Molybdenum occurs in nature only in chemical combination with other elements. Several molybdenum bearing minerals have been identified, but the only one of commercial significance is molybdenite (MoS2). As molybdenum is a strategic metal for the industrial sector, its widespread use acts as a factor for depletion of the natural resources. Hence, there is growing need to develop extraction procedures for its recovery from both primary and secondary sources. United States, China, Chile, Canada, Peru, and Mexico are listed as the main producers by the U.S. Geological Survey, 2016 (U.S. Geological Survey, Mineral Commodity Summaries, January 2016)."

Jan 1, 2017

By Fidelis T. Suorineni

HydraboltTM is a Swellex-type dowel support element developed and manufactured by New Concept Mining in South Africa. Like Swellex, the HydraboltTM is a folded tube which can be inserted into a larger diameter hole without pushing. It is then activated by injection of high pressure water which inflates the folded tube to intimate contact with the walls of the borehole at a set pressure, normally 25 MPa. Unlike Swellex however, the set water pressure at the end of the inflation is maintained throughout the life of the dowel. An integral non-return valve makes this possible. The HydraboltTM is being investigated as a possible stress change measuring cell. This paper presents the results of closed form solutions, numerical modeling and laboratory test to date. Preliminary results indicate that the HydraboltTM can be used as a stress change monitoring cell in addition to its conventional role as a rock mass reinforcing element. If successful, the HydraboltTM will supplement microseismic monitoring systems in rockburst-prone ground conditions where they will give quantitative stress change data for both mine design model calibrations and means for proactive safety measures.

Oct 1, 2010

By A. F. Banks

"Potash processing in Canada commenced on a commercial scale in 1962. Over the last 25 years it has grown into a world-class industry with many advances in processing technology. As it is a relatively young industry, many more advances can be expected. Unlike much of the mineral production in Canada, potash is sold as a range of finished products. The processing involves potash recovery and finishing in about equal amounts in terms of the effort of processing. Environmental concerns are not insignificant and are being treated uniquely in some areas. Research and development efforts, while not carried out on a large scale, are attacking industry problems on a wide front.THE INDUSTRYThe Canadian potash industry has 12 producing mines, 10 in Saskatchewan and 2 in New Brunswick. The total productive capacity of the industry is 18,300,000 tonnes of products per year. At capacity, the industry 1•ill process the equivalent of about 53,000,000 tonnes of ore per year. Plants range in size from 8,000 tonnes to 24,000 tonnes of feed per operating day. In product terms this is from 2,500 to 3,500 tonnes of products per day.Of the 12 mines, 11 are conventional underground mining operations with potash recovery principally by flotation supplemented by crystallization and one is a solution mine where mining is achieved by dissolving the potash and salt in underground caverns and then treating the solution in an evaporator/ crystallizer circuit. In all plants there is commonality of unit operation in the product screening and compaction sections. There are three principal ores being treated in the conventional plants. These may be characterized in general terms as follows:"

Jan 1, 1987