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By O. Zach, K. Gamweger

"The Process of gas purging in molten Aluminium has been an industrial practise for many years. The melting of alloying elements and their rapid distribution in the bath is very important. To improve the mixing and homogenisation process, at RHI NON FERROUS METALS ENGENEERING GMBH a lot of CFD calculations were done. The so developed new ""purging program"" was tested at Alumino Catalan S.A., Spain. The results of the testtrials were very satisfactory and corresponds very well with the calculated data."

Jan 1, 2004

By D. Naden, D. J. King

"The high capital and operating cost of liquid-solid separation circuits in hydrometallurgical plants has led to an increased focus on the use of in-pulp systems for metals recovery in order to eliminate the need for solids washing and to reduce the need for liquid-solid separation.Carbon-in-pulp (CIP) has now been accepted in Canada and around the world as the leading process for recovery of gold and silver, replacing the Merrill-Crowe process and thus removing the need for CCD thickeners or belt and drum filters. The overall design of conventional CIP adsorption circuits was established in the late 1970s and it has remained substantially unchanged until now. Most of the development work since 'hen has been concentrated on improving methods of separating pulp and carbon and on reducing carbon losses during transportation and agitation.Resin-in-pulp (RIP) has been used for many years in uranium mills in the USA. However, most of the plants were built in the 1960°s and RIP was only chosen when liquid-solid separation of leach pulps proved very difficult. The plants are far from ideal as they have high resin losses and high maintenance costs. Consequently, there is room for improvement.Davy McKee has taken a fresh look at the engineering development of in-pulp contactors leading to a fundamental redesign of the adsorption units. The improved in-pulp technology uses a modification of the proven air-swept screen techno1ogy together with a new technique of process operation. The new contactor operates at high pulp throughput rates with high concentrations of carbon or resin in the recovery stages, resulting in a significant reduction in the contactor size over conventional design. As a result of this reduction in the size of the contactor by up to 80%, significant savings can be made in equipment and building costs. In addition, the plant 1s easier to operate than a conventional CIP plant."

Jan 1, 1987

By Esteban M. Domic

"T.L. Leaching ProcessCommercial PerformanceSociedad Minera Pudahuel Ltda. (SMP) has been innovating in the copper producing field with the commercial application of the Thin Layer (T .L.) leaching process in its two operating division s: Lo Aguirre and La Cascada. Since November 1980, SMP' s Lo Aguirre Division has been producing high-purity copper cathodes at a nominal rate of about 16,500 metric tonnes / year, by mean s of the new route of T.L. leaching, followed by solvent extraction and electrowinning (TLlSX/EW). This has been the first commercial application on T .L. technology in the world, and the only commercial application in Chile for solvent extraction and electrowinning.By mid -1980, SMP acquired Sagasca Mining Co., renaming it as La Cascad a Division. The existing vat leaching facilities were modified to apply T.L. in the same old vats. The existing scrap iron cementation recovery circuit was kept running for the continuing production of copper precipitates. The modifications in the leaching circuit allowed shorter treatment cycles with a lower acid consumption and consequently, copper product ion increased from a previous historical high of 12,000-13,000 metric tonnes /year to a new level of about 22,000 metric tonnes/ year . These changes have been in operation since March 1981.T.L. Leaching commercial performance, both at Lo Aguirre (TL / SX /EW) and at La Cascada (TL/cementation), has been presented in several recent publications. Real operating parameters and process requirement s were reviewed in detail. A breakdown for TL / SX/ EW economics was also published based on Lo Aguirre' s performance during 1982(41."

Jan 1, 1986

By R. Tipman

"In 25 years, processing of tar sand progressed from two small pilot plants to two major commercial operations owned by Syncrude and Suncor. These plants mine tar sand and extract the bitumen which is then converted into a synthetic crude oil. Considerable research on extraction of bitumen from tar sand has been undertaken by these two companies as well as other major oil producing companies, private individuals, universities and the federal and provincial governments. These studies have produced a number of alternate processing schemes which have yet to be commercialized. The producing companies are focusing their efforts on achieving increased processing efficiency, which includes improved bitumen recovery, reduced unit cost, energy conservation, and equipment reliability. In this review, the Syncrude process and examples of new process developments will be briefly described. IntroductionTwenty-five years ago, tar sand processing was limited to two pilot plants owned by Cities Service Athabasca Ltd., and Great Canadian Oil Sands. Earnest Manning was Premier of Alberta and was inviting proposals for the construction of a commercial tar sands plant. The invitations called for a much larger operation than those which had been undertaken in the past. All of the previous attempts at commercial operations up to 1960's had failed, largely because of a poor technical understanding of the process requirements, lack of suitable equipment, and lack of adequate capital. The previous record was not good. The pending new large scale plant was based on improved but not proven technology and equipment, which were developed from the pilot plant studies. In addition, the surplus of conventional oil in Alberta and low world oil prices were factors reducing the need for such a plant."

Jan 1, 1987

By F. P. Hassani, J. F. Boily, A. M. O. Mohamed, M. Hossein

The optimal geochemical parameters required to form ellringite in a lime-remediated site have been investigated with the use of thermodynamic modelling. The speciation of sulphate and 10 metals analyzed in samples of a mine tailing from northern Quebec was calculated with a computer model. The model also includes calcium, which would result from the addition of lime to the system. Two speciation calculations were done. The first one is a hypothetical speciation before the onset of precipitation and was used to devise the stability fields of minerals susceptible of forming in high pHs. The stability fields were determined by building activity ratio diagrams with sulphate, aluminum and calcium species concentrations for pHs ranging from 4 to 14. The investigation was carried out for a 25°C solution with an ionic strength less than 0.12. Thermodynamics predict that an optimal stability field for ettringite in the mine tailing samples containing 10-3 mol/L SO4-2,10-2 mol/L of AI(OH)4 requires at least 10-2mol/L of Ca+2 and a pH larger than 11.6. The sulphate contents of the mine tailing samples, however, limit the precipitation of ettringite and monosulphate could be an end-precipitate. The second speciation is in equilibrium with precipitates and provides information on the speciation of the residual metals. If ellringite could be precipitated as a stable form, it could serve as a sorptive agent for residual metals, and, due to its binding properties, consolidate tailings.

Jan 1, 1995

By J. Drozdiak

In this paper we present the results of preliminary investigations into the applicability of new laboratory scale tests for the prediction of operating gap and specific throughput in high pressure grinding rolls (HPGR). The work is a part of the CAMIRO HPGR research program being conducted at the University of British Columbia, which aims to develop a suite of small-scale tests and procedures for the selection and sizing of HPGRs. A focus of the presented study is to test sample types in terms of their terra-mechanics based characteristics and relate them to specific throughput and gap results from pilot HPGR testing on the same samples.

Jan 1, 2012

By M. Feinendegen, Ph. Siebert, C. Clauser, K. Willbrand, M. Ziegler

"Three institutes of RWTH Aachen University collaborate on laboratory tests and numerical simulations of hydraulically driven fractures in igneous rocks. The project´s target is to enhance the understanding of hydraulic induced fractures for deep geothermal energy exploration. Based on the idea of creating new discrete fractures in hot dry rock (HDR) reservoirs, the current project stage deals with this process on a laboratory scale. Especially for this purpose, a new testing facility has been developed and laboratory tests are performed to verify a hydraulic fracture propagation code based on the extended finite element method (XFEM). The testing facility enables us to initiate and propagate fractures in large samples of dense rock under triaxial confining pressures and to monitor the fracture propagation by extensive measurements. This contribution gives a short introduction to the project‘s background and mainly focusses on the test facility, the experimental procedure and exemplary results.INTRODUCTIONThe most efficient technique to increase the permeability of subsurface rock is to initiate and open fractures by applying hydraulic pressure from a packed borehole-section and to inject fluid into these fractures to propagate them. Since its first use in petro industries to enhance the production of wells in natural gas and oil reservoirs, the interest in targeted creation of hydraulic fractures has increased exponentially. As the key technology to the extraction of unconventional gas from shale, hydraulic fracturing (HF) became a major topic in a heated public debate. Based on the fact that a fracture tends to propagate in a direction perpendicular to the minimal principal stress, hydraulic fracturing has become an established tool for estimating geological stress states in almost any depth. Enhanced geothermal systems (EGS) in HDR reservoirs use engineered fractures as a heat exchanging system for a cycling fluid driving a power plant."

Jan 1, 2015

By Matthew Russell, Bobby Randhawa, Leopoldo Mariscal Samaniego, Jose A. Puente, D. Brosig, Paykan Safe

The La Caridad copper smelter, located in Nacozari, Mexico, have started a multi-year plan to reduce sulfur dioxide and particulate matter emissions into the environment. In 2014 the smelter completed a voluntary plant-wide SO2 process emissions inventory as part of the smelter’s proactive environmental stewardship policy. In turn, this triggered the development of several environmental projects to alleviate these emissions. A strategy consisting of improved capture efficiency of the sources with greatest impact has been followed to maximize cost-effectiveness. The reduction of secondary emissions from the Teniente Converter, as well as of primary and secondary emissions from the Peirce-Smith Converters have been key areas of priority. Additionally, a new system to capture and recover particulate matter from the Anode Refining Furnaces off-gas is also in the process of being implemented. This paper presents an overview of the work developed behind this effort and the smelter’s vision towards a greener future. INTRODUCTION The La Caridad copper smelter is owned and operated by Metalurgica de Cobre S.A. de C.V. (a subsidiary of Grupo Mexico). Currently, the smelter has a production capacity of 300,000 tonnes of anodic copper per year. The smelter is coupled with a 300,000 t/y electrolytic refinery. Other by-products (such as precious metals and sulfuric acid) are also generated as part of an integrated process. The original smelter started operating in 1986 with one Furukawa concentrate dryer, one Outokumpu Flash Smelting Furnace (FSF), two slag cleaning electric furnaces (SCFs), three Peirce-Smith Converters (PSCs), two Anode Refining Furnaces (ARFs) and one casting wheel. In 1997, a plant expansion project was concluded with the installation of one steam dryer, one Modified Teniente Converter (MTC), one additional ARF, one additional casting wheel, and the electrolytic refinery [1]. Over the years, the smelter management has implemented numerous environmental projects to alleviate SO2 and particulate matter (PM) emissions. The smelter process gas handling system captures the process gases from the FSF, MTC, and the three PSCs. The process gases are cleaned and conditioned and sent to the two acid plants. The first acid plant (with a capacity of 226,000 Nm3/h, wet basis) was commissioned in 1988 to process the FSF and PSC off-gases. A second acid plant (with a capacity of 195,000 Nm3/h, wet basis) was commissioned as part of the smelter expansion project [1]. The PSCs also have a secondary gas handling system with a dedicated baghouse and stack. The Furukawa dryer off-gas reports to a dedicated electrostatic precipitator (ESP) for dedusting before venting via a local stack. Process gas from the two SCFs, along with hygiene ventilation from various sources inside the smelter (including matte and slag tapping hoods from the FSF) report to a baghouse-based gas handling system and vent to atmosphere via a local stack. The original ARFs do not have an off-gas handling system, however, each ARF has a post- combustion chamber which naturally vents the process gases to the atmosphere via a dedicated stack.

Jan 1, 2019

By Stephen G. Hardcastle

Worldwide, metal mines are going deeper. For example in Canada there are six such mechanized mines planning production at 3000m (10,000?). Working at such depths challenges all aspects of mining including the provision of ventilation to supply an equitable working climate for personnel and machinery. This paper explores the overall challenges of supplying ventilation in Canada?s deepest mines and how the volumes required could be minimized. This is essential because it must be remembered that ventilation and refrigeration are not only costly items to supply, but the magnitude of their cost is also very sensitive to the volume supplied. For ventilation this is obvious because of the cubic relationship between volume and cost. In deep mines, the main function of ventilation is the removal of heat transferred from the strata and generated by the mining machinery, and the air volumes supplied are designed accordingly. The second consideration is the removal of other pollutants that could be harmful to humans such as diesel and explosive fumes. However, the need for ventilation at its present design levels could be reduced. This paper discusses the implications of such technologies as: teleremote mining and alternatives to diesel equipment on the magnitude of the volume supplied; ventilation-on-demand which recognizes ventilation as a costly and limited resource; plus other aspects, such as the benefits of controlled recirculation, local cooling, and heat rejection back to the strata to gain further advantage from new developments. Furthermore, this paper advances the need to be able to design ventilation systems more cost effectively and how such new advances as process simulators can be used in conjunction with ventilation simulators to explore the diverse options that could affect the air volumes required and provide more realistic economic data upon which to base design decisions.

May 1, 2003

By C. Groccia

As the search for new ore bodies drives mines to be developed at greater depths, the associated high stress environments present challenges for rock support design. Excavations in highly stressed brittle rock are often subject to large volume increases due to rock failure, a phenomenon known as rock mass bulking, which can result in significant wall convergence. Support systems need to be designed to minimize the amount of bulking and to accommodate large wall convergences. In order to design such a support system, empirical guidelines are often used to predict the amount of bulking. However, the empirical guidelines that are currently available are based on a limited number of case studies and consider few input parameters, which may result in an inaccurate bulking assessment. This paper describes methods of collecting quantitative field data at Creighton mine in Canada to better understand rock mass bulking and to further develop the empirical guidelines for bulking assessment for tunnels in highly stressed grounds. Measuring

Aug 1, 2013

By J. Font

New approaches for the fire refining process of blister copper have been carried out at the Codelco Norte Smelter. These have been mainly focused on modification and improvement of the process configuration based in fluid-dynamic and metallurgical studies of the oxidation and impurity treatment stages. This paper presents the results of the laboratory simulations and industrial tests performed in the 250 t anode furnace, evaluating two different process configurations: ? Bottom Bath Agitation System in the vessel during the oxidation stage, ? Dual Flux Injection System during the impurity treatment stage. The results show the possibilities of effective removal of high content of sulfur from the melt during the oxidation stage by using the bottom bath agitation. The use of the dual injection system demonstrated the significant improvement in the removal efficiency of impurities. Cu2007

Jan 1, 2007

By Julia Pflieger, Manfred Russ, Johannes Gediga

This paper shall show an economic feasible approach to implement Greenhouse Gas (GHG) reduction measures into the mining and metallurgy industry. The goal to improve energy consumption is directly linked to the reduction of GHG emissions and therefore directly in correlation with the economic viability. A baseline scenario of the considered reference system and of the respective reference year has to be defined, mapped and analysed. In a second step an analysis of the same operation using available and prospected Best Available Technology (BAT) processes is carried out to generate a basis for a benchmark system. The identified reduction potentials are reported and the GHG emission reductions are put into relation to the investment cost of the new process technologies / process adaption to be implemented. This economic feasibility calculation is necessary to realise a cost efficient GHG reduction roadmap implementation into the company's business operations. The GHG reduction roadmap is developed using ratios between GHG reduction and investment / operating cost to get an indication for a sequence for implementing carbon emission reductions measures.

Jan 1, 2010

By Bruce K. McKnight

"The new H-W orebody was evaluated by considering its production at three technically feasible rates. Capital and operating costs were estimated f or each rate and production sequences were established using mining cutoff limits generated by an ore value algorithm. The viability of the project was then examined by conducting economic and financial analyses of each of the three production cases under various world economic scenarios. These analyses employing standard profitability measures demonstrated all three cases would be economically viable; the production case which maximized the Net Present Value of the project was the one selected for development and production.IntroductionWestmin Resources Limited and its predecessor company, Western Mines Ltd., has been continuously carrying out mining operations near Myra Falls in Central Vancouver Island since December 1966. The mining operation, whose current production rate is approximately 830 tonnes / day (t/d), based on ore derived from the Myra and Lynx Mines, produces copper, lead and zinc concentrates which contain significant quantities of gold and silver in addition to the base metals.In the late 1970s, with Lynx and Myra ore reserves slipping to unacceptably low levels, a major increase in mine-site exploration was initiated, with outside geological staff brought in to complement the efforts of the mine's geological staff. By the end of 1979, this program had resulted in the discovery of a significant new orebody on a deeper horizon some 300 metres below the one which hosts the Lynx and Myra deposits. Throughout the period 1980-1982, major drilling was carried out to evaluate the new H-W deposit and by the end of 1982, drill-indicated mineral inventory for the deposit compared with Myra, Lynx and Price ore reserves was as shown in Table I. During this same three-year period, a major development and evaluation program was underway comprising environmental monitoring and control programs, shaft sinking test mining, bulk sampling and mill testing, rock mechanics studies and preparation of the Stage I and II reports for the multidisciplinary Environmental Land Use Committee (ELUC).As a result of the preliminary engineering work and exploration drilling, it became rapidly apparent that the H-W deposit could support a considerably higher production rate than the current one. Accordingly, engineering studies including scheduling of development and production as well as capital and operating cost estimates, were focused on three possible production rates: 1350, 1800 and 2700 t/d. Our task was to select the optimum one of these three rates."

Jan 1, 1987

By J. Lu, M. Mohammadi, C. Pelletier, B. Wassink

Chemical reduction of selenate by chromous ions is proposed as a novel method to remove selenate from sulfate-bearing solutions Chromous ions were generated by electrochemical reduction of chromic ions using an electrochemical cell. The investigation was conducted in sulfate medium and under various concentrations of chromous ions (0.0062 to 0.05M), pH 1 to 2.2 and temperature 10 to 60°C. Selenate ions were rapidly reduced by chromous ions to hydrogen selenide. The overall reaction at a chromous/selenate molar ratio of 8 or higher can be expressed by the following reaction. At an initial chromous/selenate molar ratio below 8, the products are hydrogen selenide and elemental selenium. At a lower chromous/selenate molar ratio and pH, more elemental selenium and less hydrogen selenide are produced. The reduction kinetics is controlled by both chromous ion and hydrogen ions concentrations. The reaction rate is first order with respect to selenate, hydrogen ion and chromous ion concentrations. It was found that the selenate reduction rate with chromous is independent of the concentration of sulfate present in the solution. The general rate equation was proposed and the rate constant was calculated as k= 0.38 M-2s-1. An activation energy of 58.7 kJ/mol was obtained in the temperature range from 10 to 50°C. Nearly 100% of selenate can be reduced to H2Se from solution containing 17 ppm selenate in less than 30 minutes at pH 2.2 and 60°C. Various strategies have been tested to remove the produced H2Se from solution. INTRODUCTION Selenium in nature is mostly associated with metal sulfide minerals such as copper, iron, zinc, and lead sulfides (Zingaro & Cooper, 1974). The extraction of metals from ores has the potential for selenium contamination of ground and surface water which can pose an environmental and health concern. Therefore, selenium contamination in the receiving environment is a key issue for many industries (specifically copper industry) and the treatment of wastewater contaminated with selenium is a growing challenge. The effective removal of selenium from contaminated water is very important to support sustainability in the copper industry and the other industries with selenium pollution issues.

Jan 1, 2019

By P. Latostenmaa, T. Veneranta, J. Järvi, E. J. Peuraniemi

Boliden Harjavalta has operated a copper flash smelter since 1949 thus the smelter celebrates 70th anniversary of flash smelting in 2019. This paper shortly describes the historical perspective of the smelter and gives an update of the current operational issues and process modifications made during the recent years. The plant has carried out several major investments lately providing a firm view on the future. A new landfill area for the final slag was commissioned in 2018. A modernization of the concentrate storage area, a new acid plant and a debottlenecking project of the smelting line have been recently commissioned. At the same time, the tankhouse capacity will be expanded. This paper focuses on smelter modernizations. INTRODUCTION Boliden is a metal company operating mainly in northern Europe with core competencies in the fields of exploration, mining, smelting and metal recycling. Boliden Harjavalta, located in Finland, is part of the Smelters Business area of the Boliden Group and operates a copper and nickel smelter with related sulphuric acid plant in Harjavalta, and a copper refinery in Pori. As a short historical review, Harjavalta’s history may be dated back to the year 1910 when the Outokumpu ore body in eastern Finland was discovered. By the end of 1913, a copper mine was in operation and a copper plant based on Hybinette process was ready for commissioning. Due to difficulties in metal recoveries and throughput the Hybinette process was permanently shut down in 1929, and 100% of the mining production was sold as concentrate abroad. As the mine production increased steadily, a decision of a new smelter was made in early 30’s. In 1936 Outokumpu’s copper smelter based on electric smelting was commissioned in Imatra. The smelter was dismantled and transferred to Harjavalta during the final stages of the Second World War. The copper refinery started in Pori already in 1941 and the first copper anodes were cast in Harjavalta in 1945. First sulphuric acid plant started operation in 1947. Due to the post-war shortage of electrical energy, the plant metallurgists initiated a major development work to start exploiting the latent heat of concentrates. Thus, the flash smelting method was developed in Harjavalta and commissioned in 1949. Ten years later, flash smelting was also applied for nickel concentrates. Table 1 summarizes major historical and technical milestones of Harjavalta. The history of flash smelting is described in details in another paper of this conference (Jåfs et al., 2019).

Jan 1, 2019

By Nawshad Haque, Leanne Smith, Hal Aral, Joseph Cho, Warren Bruckard

"Water availability is one of the principal parameters in determining the feasibility of mining projects in arid and semi-arid regions. The volumetric water footprint (VWF) of a conceptual model of a copper flotation plant was found to be 2.45 kL/t Cu ore, compared with an actual measurement reported in the literature of 2.72 kL/t Cu ore. The flowsheet considered included mineral processing stages such as crushing, screening, grinding, classification, separation, flotation, thickening and filtration. The effect of a number of variables on the VWF was evaluated, including solid/liquid ratio, feed mass flowrate, ore loss, water loss, moisture content of ore, ore grade and water recycling. The use of seawater with recycling provided the most environmental and economic advantage among several scenarios evaluated. The study assumed a price of $1/kL freshwater, $4/kL for transport over a 200 km distance at 2,000 m altitude and $4/kL for water treatment. The water related cost of the desalinated seawater use scenario was A$493/t Cu concentrate, while the water related costs of fresh water and blended water scenarios were A$308/t and A$268/t Cu concentrate, respectively. The water related cost (fresh water scenario) accounted for 44% to 49% of the entire mining and processing costs that included drilling, blasting, loading, hauling, crushing, grinding and concentrating. The total overall cost was A$435/t Cu concentrate for the seawater with recycling, compared to A$451/t Cu concentrate for the fresh water with recycling case.INTRODUCTIONReducing the water footprint (WFP) by utilising alternative water sources has been a focus of mining projects due to increasing concerns about water scarcity and growing energy costs. The global mining industry can expect to experience fresh water shortages in the future, and saline or hyper-saline water may be the only available water source to process minerals in arid regions. Extensive studies on alternative water sources (e.g. seawater, desalinated seawater, blended water) and the reuse of process water have recently been conducted (Moreno, Aral, Cuevas, Monardes, Adaro, Norgate & Bruckard, 2011; Aral, Mead, Cuevas, Davey & Bruckard, 2010). Such studies provide sustainable and economic strategies for mines and concentrators in the arid or semi-arid regions of the world such as in Chile, Peru, Indonesia, and Portugal. More work, however, is needed to confirm water consumption data for different base metal flowsheets and use this data to develop water models that can lead to reduced WFPs and more sustainable water usage in the mining industry."

Jan 1, 2016

By Errol Ladner

The application of large-diameter bore holes in underground operations at Heath Steele was first tried in February, 1975. Since that time, 90,000 feet of 6-l/2-inch holes have been drilled, primarily in open blasthole stoping, for a total of 1.4 million tons, 37% of underground production. This paper deals with a review of drilling with conventional percussion longhole drills, a practice which is still utilized at Heath Steele, and the changeover to accommodate the use of larger blastholes in underground operations. The discussion will include layouts for 2-inch-diameter blasthole stope blocks, 6-inch-diameter stope blocks, trials for I. T.H. (in-the-hole) stope rooms, and drill pat/ems, drilling and performance. The complexity involved in the development, drilling and blasting of 2-inch blastholes is overcome by the over-all simplicity of drilling and blasting in I. T.H. stopes. This has made the practice of open blasthole stoping more economical and efficient. The future indicates an increase in the company's I. T.H. program. Investigations are being undertaken regarding longer holes to decrease development costs. A VCR stope is also being developed for trial.

Jan 1, 1979

By A. Atrafi, L. Barroilhet

The top size of particles in the flotation of potash ores, which can be as large as 4 mm, exceeds by far the top size in other flotation plants. It is then understandable that while long chain amines are used in the flotation of fine fractions (below 0.8 mm) of potash ores the coarse particle flotation also requires an extender oil. While new and very promising fluidized-bed flotation machines (e.g. HydroFloat) constitute a significant development in the flotation of coarse particles, in the area of extender oils, as reviewed in 2007 by Strathdee, Gotts and McEachern, there have been no new developments to replace the industry standard asphaltene-based carcinogenic extenders. This situation first of all results from the experimental problems that arise when water-soluble minerals like sylvite are to be tested in saturated brine. Both oils and longchain amines are water/brine insoluble. The oil with the amine dissolved in it can however be emulsified and then used as an extender oil. Such oil droplets must wet KCl particles and the emulsion must be stable to avoid handling problems. In this paper we test the use of the phase inversion technique as a method of studying wettability of KCl particles by the oil in saturated brine, and the effect of amine dissolved in this oil on the wettability. The results show that this relatively simple technique can be used to characterize the wettability of fine KCl particles by the tested oil and to determine the effect of added amine on it, and so it can be useful in selecting proper extender oils.

Jan 1, 2016

By Maria Skyllas-Kazacos

The All-Vanadium Redox Flow Battery that was pioneered and has been developed at the University of New South Wales (UNSW) in Sydney since the mid-1980s is currently regarded as one of the most attractive energy storage systems for large-scale implementation in a wide range of grid-connected and offgrid applications. Several companies are now manufacturing and installing MW-scale VFBs in applications ranging from renewable energy storage, load-levelling, emergency back-up power and power arbitrage. The full-scale uptake of the VRB in commercial energy storage systems however, is heavily dependent on the availability and cost of vanadium used in the VRB electrolyte. Cost is also a function of purity requirements and although there is little scientific evidence on the effect of impurities on the VRB life and performance, VRB developers continue to demand high purity vanadium at considerable cost. This paper will provide a brief overview of the current understanding of electrolyte impurities on VRB performance together with an economic analysis of the impact of vanadium prices on overall VRB capital and levelised costs for a range of applications.

Jan 1, 2014

By C. J. Kerr

"A recent information sheet from the Mining Health and Safety Branch of the Ontario Ministry of Labour was sent to all Ministry inspectors and engineers. The subject title was' 'Two Brakes on a Hoist Carrying Persons"" and it quotes mining regulation 699, sub-section 206(i):No hoist shall be used for the transporting of persons unless it has a braking system consisting of at least two sets of mechanical brakes to stop and hold the drum for the shaft conveyance transporting the persons.The intent of the regulation is that each of these brakes is to be set so that, individually, they can safely stop the drum carrying persons and also hold the drum without movement with the maximum manload.This can be achieved in the following ways: Single Drum Hoist-one brake on each side of the drum, one brake on the drum, one brake on the pinion shaft, where disc brakes are used two separate disc brake assemblies on the disc. Double Drum Hoist, brakes on companion drum can serve as backup brake only pinion brake with one drum unclutched.Friction Hoist, one brake on each side of drum As new hoists can be manufactured easily with a two-brake system, attention will be focused on retrofitting pinion brakes to older hoists.A brake mounted on a pinion shaft is designed purely as an emergency brake in the event of main brake failure , controls malfunction, and power loss."

Jan 1, 1989