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By M. C. Bluteau, G. P. Demopoulos

Arsenic reports in the effluents of many non-ferrous metallurgical operations. The production of scorodite, a crystalline ferric arsenate, is considered as an attractive option for the fixation of arsenic from aqueous effluents. However, scorodite solubility and long-term stability in the pH region of interest for tailings disposal have not been thoroughly investigated. In this study the long-term stability of scorodite in the pH 5 to 9 region and the mechanism of scorodite dissolution were studied. Construction of eh-pH diagrams indicated that scorodite stability is highly dependant on the nature (stability) of co-existing iron-hydroxide/oxyhydroxide. It was also found that when scorodite dissolves, a ferrihydrite phase having very small particles size (nano-scale) forms and that the growth and crystallization of this material are delayed by the presence of arsenate even under accelerated (75°C) ageing conditions. Around neutral pH and ambiant temperature (22°C) scorodite seems to reach an equilibrium with ferrihydrite after 48 weeks yielding soluble arsenic concentrations < 5 ppm.

Jan 1, 2004

By James R. Yeager, Eric L. Hoffman, John R. Clark

"Abstract -This paper describes fire assaying and ‘high tech’ alternatives for gold analysis, including advantages and disadvantages of each method. These ‘high tech’ methods include INAA (instrumental neutron activation), aqua regia digestion/AA (atomic absorption), GFAA (graphite furnaceatomic absorption) or ICP/MS (inductively coupled plasma emission mass spectrometry) and a combination of cyanidation with AA, GFAA or ICP/MS methods.Fire assay remains the stalwart among analytical methods for gold but, even with its multiple analytical finishes, is not fool-proof for recovering 100% of the gold present. Consumers of assays should not blindly trust the assay results without consideration of quality control data. Laboratories can and do make mistakes. Some of these can be easily discovered if you do your own due diligence. All these measures should ensure that gold analysis values from successive campaigns and from different laboratories meet acceptable levels of accuracy and precision, and can be correlated together, particularly when they occur in neighboring holes. This is essential just as much for prospect evaluation as for project feasibility."

Jan 1, 1998

By K. L. Eastwood

The ISA PROCESSTM cathode plate is characterised by its copper coated suspension bar, coupled with a blade employing austenitic stainless steel alloy 316L. The blade material has become the mainstay of the technology and has been closely copied by competing cathode designs. Improvement to the cathode plate design remains a key area for research, and ongoing developments by Xstrata Technology&apos;s ISA PROCESSTM have recently been commercialised. Two such developments are the ISA Cathode BRTM and ISA 2000 AB Cathode. The ISA BR cathode is a lower resistance cathode that has proven to enhance operating efficiencies. The AB cathode was designed to improve stripping inefficiencies in the ISA 2000 technology. These developments have now had time to mature and their long term performance will be discussed. Rising material costs and the desire to extend the operating boundaries of the standard 316L cathode plate has triggered a number of significant advances. These involve the use of different stainless steels as alternatives in some operational situations. The technical aspects and results of commercial trials on this development will also be discussed in this paper.

Jan 1, 2007

By Owen Owens, W. P. Armstrong

The process of arriving at the size and grade of: (a) a newly-discovered body of mineralization, (b) a potential ore resource, (c) an orebody proposed for mining, or (d) the ore reserves in a mine, requires fundamental geological, and geometrical determinations as well as physical and chemical analyses. This paper outlines geological and geometrical features considered critical, in the authors&apos; experience, in realistic reserve determination. These are discussed under the headings "The Four Cs". They include the Character, type or nature of the mineralization; the Continuity of various types of mineralization in the deposit; various key concerns in the Calculation besides the mathematics; and the Classification section which refers to basic considerations in classifying a mineral estimate. It is suggested that the responsibility for the calculation of a Resource or Reserve should be that of a geologist experienced in the ore type under review. Further, it should be the responsibility of the board of directors of the company owning the deposit to ensure that a sufficiently experienced person is chosen to carry out the process.

Jan 1, 1993

A series of small scale tests have been conducted to evaluate the effect of micro-fracture development, imposed by blasting, on the material properties of the rock as well as its resistance to crushing and grinding. The uniaxial compressive strength, tensile strength, Poisson?s ratio, P-wave, Swave velocity, point load test index, crushing and grinding work indices were evaluated for samples without any blasting load and for samples which had received a variety of blast loads ranging from a single impact with low strength detonating cord, to combination of impacts at different times and significant impacts with powder factors close to those used in practical blasts. It was shown that the rock mechanics parameters change even at low impacts, suggesting easier crushing of the rock. Damage values appear to be affected by timing as stress wave superposition affects the damage process. Fragmentation is achieved at higher impact levels while work index modification of the fragments is also observed when high powder factors are used, suggesting improvements in grinding.

May 1, 2003

By T. Junne, L. Eltrop, S. Moreno-Leiva, J. Haas, W. Kracht

The energy systems of the future will be highly renewable. The flexibility that is consequently required can be provided with many options, the main ones being energy storage, transmission reinforcement, and demand side management. The role of the latter is explored for the copper industry, using the scheduling of maintenance services as an example of Solar-Paced Design - the coupling of energy demand with solar resource availability. We used a linear energy optimization model to define the minimum-cost configuration for a fully renewable energy system of a copper concentration plant under different scenarios for the scheduling of maintenance services. For the case we studied, (total) costs were 4% lower when the maintenance was scheduled in winter. We expect that exploring the potential of such Solar-Paced Design in the copper industry will allow new potentials for a more cost-effective full renewable energy supply of this critical industry. INTRODUCTION The mitigation of climate change requires a worldwide transformation of the energy system by the significant expansion of renewable energies and the electrification of various sectors and processes (Teske et al., 2015)(International Energy Agency IEA, 2018). Moreover, considering the decreasing costs of renewable energy technologies and the intensive use required to deliver the goals in the Paris Agreement, we can expect to have highly renewable energy systems in the near future. However, to rebuild and expand our energy systems, we need certain materials, including copper. Also, energy systems based on renewables are more copper-intensive than conventional ones (Kleijn, van der Voet, Kramer, van Oers, & van der Giesen, 2011). The mineral industry, in turn, needs clean energy to achieve a better environmental performance (e.g. solar energy for copper production (Moreno-Leiva et al., 2017)) and to avoid negative secondary effects induced by the strong expansion of clean technologies. But there is something else the minerals industry can offer in this bi-directional relation with energy systems.

Jan 1, 2019

By R. E. Whitehead

"Abstract - Biotite from aplite that appears to have crystallized simultaneously with disseminated Cu-Mo mineralization at MacLeod Lake in northern Quebec yields K-Ar dates in the range 2032 ± 44 Ma to 2097 ± 47 Ma. The mean value, 2065 Ma, is some 400 Ma younger than the 2485 ± 64 Ma date obtained from a hornblende concentrate separated from a granodiorite sill that is spatially, but apparently not genetically, associated with the disseminated Cu-Mo deposit. The mean biotite date of 2065 Ma at MacLeod Lake, a K-Ar date of 2055 Ma reported from an area 50 km east of MacLeod Lake and published dates of about 2000 Ma for galenas from the Chibougamau Cu-Au ores, suggest a widespread thermal and mineralization event, in that part of the Superior Province east of James Bay, that differs from the common late Archean mineralization that is related to volcanism and metamorphic-intrusive activity.Sommaire - Les datations au K-Ar sur des biotites qui auraient cristallise en même temps que la minéralisation disséminée en Cu et Mo dans une aplite mise en place au Lac MacLeod, au nord du Québec, s&apos;échelonnent entre 2032 ± 44 Ma et 2097 ± 47 Ma. La datation moyenne, soit 2065 Ma, est d&apos;environ 400 Ma plus récente que la datation obtenue pour un concentre de hornblende extrait d&apos;un filon-couche de granodiorite qui est spatialement mais ne serait pas génétiquement associée à la minéralisation disséminée en Cu et Mo. La datation moyenne de la minéralisation au Lac MacLeod, soit 2065 Ma, la dataion au K-Ar à 2055 Ma citée pour une région à 50 km à l&apos;est du Lac MacLeod, de même que les datations d&apos;environ 2000 Ma établies pour des galènes qui se trouvent dans le minerai aurifère et cuprifère à Chibougamau, suggèrent un phénomène thermique répandu qui aurait produit la minéralisation dans cette région à l&apos;est de la Baie James, dans la province du lac Supérieur. Ce phénomène serait diffèrent de celui qui aurait produit la minéralisation répandue d’âge archéen tardif qui elle serait associée à l’activité volcanique et à l‘activité intrusive accompagnée de métamorphisme."

Jan 1, 1992

By V. Cvetkovic, L. Zou, L. Jing

"Sorption process plays a significant role for solute retardation in rock fractures. In this paper, for the aim to investigate the effect of sorption on solute transport in a single rough fracture, a 2D model of representative single rock fracture was built and its roughness was statistically characterized based on the measured data of rock surface topography by laser scanning. A Finite Volume Method (FVM) code was developed to solve the Navier-Stokes (NS) equations and transport equation for numerical modelling the process of fluid flow and solute transport in the rock fracture model. Two groups of simulations were conducted: with and without the consideration of the sorption process with different average flow velocities. The results show that the surface roughness increased the complexities of flow fields, and the non-linear sorption process plays a significant role in the retardation of solute transport through rock fractures. The sorption process caused an obvious lagging time in both the solute concentration fields (plumes) and corresponding breakthrough curves. This lagging time increases with the distance from the inlet boundary, and relatively decreases with the increase of mean velocities. INTRODUCTIONFluid flow and solute transport in fractured rocks is an important research topic for performance and risk assessments for rock engineering projects concerning geo-environment safety, such as radioactive waste disposal, mining, geothermal extraction, reservoir engineering and other contaminant transport processes in geosphere (Berkowitz 2002).The solute transport in the rock fractures mainly involve the advection, surface sorption, matrix diffusion, dispersion, radioactive decay and chemical reactions, governed by general transport equations (e.g. Bodin et al., 2003). Among these transport phenomena, the sorption on the fracture walls can alter solute migration between the fractures, and play an important role in natural retention of solute transport (Weber et al., 1991; Wels et al., 1998; Kumar 2007; Dai et al., 2012). The aim of this study is to investigate the effect of sorption on the solute transport in a single rock fracture with rough surfaces. More complex transport processes, such as matrix diffusion, dispersions, radioactive decay and chemical reactions, are not included in this study."

Jan 1, 2015

By Kiran B. Chaudhuri, Michael Koch, Jorg Lema Patino

"Stricter pollution regulations together with other factors have stimulated interest in the modernization of the traditional sinter - blast-furnace lead operation. In this context, direct smelting methods have again come into prominence. Consequently, the Kivcet Lead Smelting Process, which belongs to this group, has attracted the attention of the lead producers of the world. The Kivcet Process offers the advantage that lead and zinc can be simultaneously recovered in a single furnace unit. KHD Humboldt Wedag A G, Koln, Federal Republic of Germany, has signed a contract with the Sociedad Complejo Metalurgico de Karachipampa of Bolivia for the delivery of a turn-key Kivcet plant, which is expected to be the first plant of its kind in commercial operation. This paper describes the design and expected operating data of the plant."

Jan 1, 1980

Introduction ?MT involves the measurement of naturally occurring magnetic and electric field oscillations. ?The ratio of E/H (wave impedance) is measured as a function of frequency to give resistivitydepth information. ?The ratio of vertical and horizontal magnetic fields (tipper) gives information about the location of (channeled) current systems.

May 1, 2008

By John O. Marsden

Technology development and innovation has played a crucial role in the copper industry throughout history. The effective development and implementation of new technologies allows mankind to produce copper at progressively lower cost of production at a given feed grade and mineral type. This progress serves to counteract cost escalation over time and, depending on the magnitude of the cost benefit, allows ore cut off grades to be reduced thereby improving the availability, accessibility and utilization of mineral resources. The development of step change technologies that can offer >$0.15/lb total cost benefits provides a significant opportunity for producers to achieve competitive advantage, but it has been argued that rapid dissemination of technology makes such competitive advantage unsustainable over time. This paper presents the results of a recent study that evaluates a number of historical and emerging step change technology case studies in the copper industry and quantifies the associated cost benefits for users, the impact on the production cost curve, and the duration of such cost benefits for various categories of implementers: first mover, fast follower, conservative followers and laggards. The results provide a compelling case for major, mid-tier and emerging copper producers to invest in technology development initiatives if they wish to achieve and sustain competitive advantage over the long term. INTRODUCTION AND BACKGROUND A key issue for mining companies is how much time, effort and cost to spend on research and technology development (R&TD). The economic drivers for technology development and implementation are poorly understood in our industry and the business case is clouded by some notable and well-publicized failures (McNulty, 1998). Mining companies are in business to deliver financial returns to investors. This means delivering short term results on a quarter-by-quarter reporting basis as well as sustaining and growing the company to retain and reward a sustainable longer term investor base. The cyclical nature of the commodity metal markets makes it challenging to maintain investment in research and step change technology development: Mining companies must manage through the highs and the lows of price cycles, typically ranging from 5-15 years in length. The discounted cash flow approach to investment evaluation results in weak financial justification for R&TD expenditures. A clear and compelling rationale to support longer term investment in research and step change technology implementation is required.

Jan 1, 2019

By Adriana Ramirez, Bradford C. Wesstrom, Blanca Olave

The Freeport McMoRan El Paso Copper Refinery optimizes electrolyte quality using a number of systems. The facility controls copper, arsenic, antimony and bismuth using electro-winning cells within the Tank House and Nickel Carbonate Plant Liberator Circuit (NCP). The NCP manages sulfuric acid content utilizing recycled electrolyte in the slimes autoclave as well as operation of the Acid Purification Unit, APU. The El Paso Refinery removes common sulfates using metal hydrolysis with sodium carbonate. Finally, a Mechanical Vapor Recompression, (MVR), at the water recovery plant removes sodium sulfate generated by the NCP. This paper will provide a summary of these operations. INTRODUCTION In the mid 1920’s Nichols Copper Company, in Laurel Hill, New York, recognized the need for a modern copper refining facility in the southwest. Because of the many railroad heads, affordable power and abundant labor supply, and the close proximity to regional copper smelters in Mexico, Arizona, and New Mexico, El Paso became the ideal location. In December 1928, ground was broken for the joint venture refinery between the Nichols Copper Company, Phelps Dodge, and the Calumet and Arizona Mining Company. In September 1930, Nichols Copper Company became a part of Phelps Dodge Corporation after a stock exchange. In July 1938, Nichols Division officially became Phelps Dodge Refining Corporation. In March 2007, Freeport McMoRan Copper & Gold acquired Phelps Dodge. Water is a precious commodity in the desert southwest, making conservation of this natural resource an important goal for the El Paso Operations. In the 1980’s, work on the treatment of slimes was improved through the use of pressure leaching of the refinery slimes using an autoclave. Due to the high tellurium content in the leached slimes solution, it was crucial to implement a method for its removal before the solution returns to the tank house electrolyte. A copper telluride cementation operation was installed for tellurium recovery and the ability for the recycle of the leachate and wash water to the refinery electrolyte. In October of 1997, ground was broken for the construction of the water recovery plant using an MVR to reuse process water, reducing water consumption by 25%. In 2002, electrolyte purification was further improved with the installation of an Acid Purification Unit, (APU) (Sheedy, Pajunen, & Wesstrom, 2007). The APU recycles 90% of the acids (both sulfuric and arsenic acids) back to the tank house electrolyte. The solution that passes through the APU is treated with soda ash to precipitate metals out of solution as carbonates and generates a sodium sulfate solution. This sodium sulfate solution is easily processed in the new water recovery plant, where the majority of the water recycles back into the plant as pure condensate. In 2012, the power plant at the refinery upgraded its Reverse Osmosis System to provide RO water to the tankhouse. This insured that the refinery would not have to bleed electrolyte for metals contained in well water such as: calcium, magnesium, iron and sodium chloride.

Jan 1, 2019

By M. Lytle

"The Corbin area of southeastern British Columbia has been a coal mining area since 1908. Byron Creek Collieries Ltd. Has operated its Coal Mountain Mine in this area from 1974 until the present. In February 1981, this company was purchased by Esso Resources Canada Ltd.Coal Mountain is structurally complex and standard computer algorithms are not applicable to model the overturned synclinal structures and faulted bedding surfaces. This paper discusses two approaches used by Esso Resources staff to model the geology of Coal Mountain.The first approach projects digitized cross-section data along trend to develop a large data base which correctly approximates the shape of the structure. The spatial orientation of the structure is corrected by merging the generated data set with drill-hole data. The second approach uses digitized cross-section and bench-plan geology to generate a block model of the coal reserve.HistoryThe Coal Mountain Mine, also known as the Corbin Mine of Byron Creek Collieries Ltd. is located 24 kilometres south of Highway 3 in southeastern B.C.In 1905, two American businessmen recognized the coal potential of the area during a horseback tour. The two businessmen, D.C. Corbin and E.J. Roberts, formed the Corbin Coal and Coke Co. to mine and market coal from their newly acquired 6075 hectares of coal licenses. By 1908, the town of Corbin was under construction, a 22.4-km rail spur was constructed from the mine to the main CPR line and the first underground mine began to produce coal. An open-pit operation was also developed at the 1828-metre elevation using a steam shovel loading into rail cars. The company operated continuously until 1935, when a lengthy strike forced suspension of operations.In 1943, the Consolidated Mining and Smelting Company Ltd. (now known as Cominco Ltd.) operated two surface mines to produce coal for its smelters at Kimberley and Trail, B.C. This operation ceased in 1948."

Jan 1, 1982

By Ken Woloschuk

??Owners?Perspective ??Owners?Challenges ??EcoNomics?Delivery Model ??Projects ??Project Outcomes ??Questions ??Balancing the triple bottom line initiative: ?shareholders expectations of economic costs and benefit; ?stakeholders expectations of social and environmental costs and benefits; ?deciding what is sustainable and which design alternatives are the most sustainable. ?? Delivering required project outcomes

May 1, 2008

By WM. G. Heeley

This paper will describe the experience gained and explain the deductions made from the phenomenon of the great squeeze which occurred at Brule Mines. The first indication of the commencement of the squeeze was the breaking of posts on the high-side rib of the slope. At first we thought this was due to a lateral pressure only, and we renewed the broken posts with new ones, the result being that the new posts also were soon broken. A noticeable bending and breaking of the collars occurred, with a corresponding reduction in the height of the haulage slope. These symptoms were also evident on the counter above the slope, indicating that the trouble was of an exceptional nature. In the meantime, we had concentrated a large force of repair men, renewing broken timbers and brushing the roof and floor, but in spite of all our efforts we could not overtake the damage being done. Our next problem was to find the cause of this trouble. We were in a new basin of coal (No. 2) which had only been opened a few months, as we had worked the previous four years in another basin (No. 3) where no such trouble as this had ever been encountered. Naturally our first thought concerned the adequacy of the size of the pillars. We had worked in the No. 3 south basin for the previous four years. without any such experience, with 60-feet pillars between slope and counters; whereas we had established 100-foot pillars in the No. 2 south basin between the slopes and counters with an 80-foot pillar between counter and first line of cross-cuts, and 100-foot pillars between the breasts.

Jan 1, 1924

By Donald S. Cameron

By dispersing gold in high surface area form supported on metal oxides, its inert character can be transformed to make economical, effective catalysts. Gold has already been demonstrated in a number of fuel cell applications such as gas phase catalysts, electro-catalysts, and electrical connectors. In this paper, the various types of fuel cell systems are reviewed, and several opportunities for gold identified. Low temperature fuel cells, including alkaline and solid polymer electrolyte types rely on high surface area platinum group metal catalysts which are highly susceptible to poisoning by low concentrations of carbon monoxide in the fuel supply. Hydrogen is frequently obtained by steam reforming hydrocarbons, followed by the water gas shift (WGS) reaction. A promising initial use for supported gold catalysts is in catalysing this WGS reaction. Research has shown that gold supported on iron oxide (Au/a-Fe2O3 ) WGS catalysts are more active than the current commercial copper oxide / zinc oxide catalysts, and effective at temperatures as low as 120oC. Products from reformer/ water gas shift reactors can be further purified by removing traces of carbon monoxide. If a small proportion of oxygen is introduced into the fuel gas stream, carbon monoxide can be preferentially oxidized to carbon dioxide even in the presence of hydrogen. Gold nanoparticle catalysts on iron oxide support (Au/a-Fe2O3 ) have exhibited higher activity than commercially available platinum on alumina (Pt/?- Al2O3 ) preferential oxidation catalysts. The low temperature of this reaction may make it feasible to incorporate these catalysts within the fuel cell itself. Proton exchange fuel cells provide several possible applications for catalytically active gold and its alloys. Carbon supported platinum group metals would benefit greatly from improved electrical conductivity if gold replaced some or all of the carbon support material. As electrode current densities are raised, electrical resistance constitutes an increasing proportion of voltage losses within the fuel cell. Dramatic reductions in cell stack voltage losses have already been demonstrated by reducing inter-cell contact resistance using gold plating. The low temperature oxidation properties of gold catalysts have been investigated in controlling gaseous emissions from direct methanol fuel cells, and gold also provides essential catalysis in building direct borohydride oxidation fuel cells. The prospect of a range of other applications for gold in fuel cells to contribute useful improvements in corrosion resistance and conductivity is assessed. Globally, fuel cells have been developed for a wide range of applications including stationary generators, cars and buses, industrial vehicles and small portable power supplies, each of which represents a substantial market. Hence there are likely to be many and varied opportunities for gold catalysts to contribute to the performance and economics of the systems being commercialized.

Oct 1, 2003

By André Chagnon, Héroux. Yvon

"Résumé - Cette étude porte sur l&apos;altération de la matière organique et des argiles dans les boues carbonatés dévoniennes du facies ""F&apos; de la Formation de Pine Point et ses équivalents stratigraphiques la Formation d&apos;Evie et l&apos;unité bitumineuse de la base de la Fonnation de Hom River. La matière organique se compose principalement de bituré solide et de quelques fragments de fossiles (organaclastes). La majorité des échantillons ne renfement que de l&apos;illite et des inter-stratifiées illite/smectite.Si on compare les températures d&apos;homogénéisation (Th = 100°C) des inclusions fluides de la sphalérite et des dolomites associées a la minéralisation aux températures estimées à partir de la réflectance de la collinite (84°C à 117°C), l&apos;on ne peut pas conclure à la présence d&apos;une anomalie thermique dans le district minier de Pine Point. De plus, la réflectance des organoclastes n&apos;est pas plus élevée dans le district minier de Pine Point que dans les localités plus éloignées des gites. L&apos;analyse des minéraux argileux conduit à la même conclusion: aucune anomalie thermique n&apos;est décelable dans les unités échantillonnées à l&apos;intérieur du district minier de Pine Point quelque soit l&apos;indicateur utilisé.La kaolinite et la matière organique altérée, affichant des valeurs anomales de sa réflectance, se trouve essentiellement en présence de soufre et de sulfures. Cela suggère une origine authigène de la kaolinite et une altération de la matière organique reliées au phénomènes de minéralisation.Abstract - The alteration of organic matter and clays is studied in the Devonian Pine Point Formation carbonate muds, ""F"" facies, and its lateral equivalents the Evie Formation and the bituminous unit at the base of the Hom River Formation. The organic matter is mainly composed of solid bitumen with few fossil fragments (organoclasts). Most samples contain only illite and mixed layer illite/smectite.If we compare the Th (100°C) from fluid inclusions of sphalerite and dolomites associated with mineralization to the temperatures calculated from the reflectance (Ro) of the collinite (84°C to 117°C), we cannot detect a thermal anomaly in the Pine Point mining district. This result is based on the reflectance values of organoclasts from the mining district that are not higher than those reflectance values measured on organic matter (OM) away from the ore deposit. A similar conclusion is reached from the clay study: none of the parameters used allow us to identify a thermal anomaly in the samples from the mining district.The kaolinite and the altered OM showing anomalous Ro values mainly occur with sulfides and sulfur. This association suggests an authigenic origin for the kaolinite and an alteration of the OM due to the mineralization events."

Jan 1, 1994

By Jacob Wood, Robert Matusewicz

The Outotec® Ausmelt Top Submerged Lance (TSL) Process has achieved widespread commercial acceptance over the past 40 years for the processing of copper, nickel, lead, tin, zinc and precious metal bearing feeds. The continual development and evolution of the technology during this period has resulted in a more intense smelting process with higher energy efficiency and lower operating costs. More recently, considerable effort has been invested in decarbonisation of the process through improvements such as increased oxygen usage, dry feed injection and use of low-carbon auxiliary fuels. This paper covers a number of these recent advances to the technology and highlights their impacts on energy consumption and CO2 emissions for a range of non-ferrous smelting flowsheets. INTRODUCTION Relentless demand for improvements in the profitability, safety and environmental performance of non-ferrous smelting plants has driven a continual development and evolution of processing technologies in this industry. In response to these demands, a number of bath smelting technologies have emerged over the past 40 years and have been implemented for the treatment of primary and secondary feedstocks. The Outotec® Ausmelt Top Submerged Lance (TSL) Process (henceforth Ausmelt Process) is one such bath smelting technology which has been widely adopted in a large number of greenfield projects and brownfield plant modernisations (Wood & Hughes, 2016). Emissions of CO2 from the production of non-ferrous metals represent approximately 4-5% of global totals (Rankin, 2012), comparable with the almost 10% attributed to iron and steel production. Despite significant improvements in the energy efficiency of modern smelting technologies (Coursol, Mackey, Kapusta & Cardona Valencia, 2015), primarily through increased oxygen usage, further innovation and development is still required to address their reliance on fossil fuels such as coke and coal. Transformation of the non-ferrous smelting industry to low-carbon technologies and process flowsheets is lagging behind the power and transport sectors, which have witnessed significant growth in clean/renewable energy technologies to reduce CO2 emissions and address the issue of anthropogenic climate change (IRENA, 2018; IEA, 2018).

Jan 1, 2019

By Szilvia Szabo, Jozsef Paulovics, Ljudmilla Bokanyi

"Waste recycling is one of the most important challenges of the XXI century. The recycling of wastes is closely related to and bases on the mineral processing. Many mineral processing techniques and equipment are applied in this field. The principles of the characterisation of wastes and design of technologies is rather similar to the classic mineral processing. Nevertheless, the diversity of the wastes and their complex composition and properties, as well as their environmental impact requires a special approach.Solar elements have sandwich structure of glass substrate and cover, as well as a very thin semiconductor layer. CdTe semi-conductor can be recycled by flotation. Within the RESOLVED (LIFE European Framework) R&D project on the recycling of solar elements the surface properties of pure CdTe semiconductor and pure glass were investigated by the measurements of zeta-potential using Zeta PALS Brookhaven instrument at University of Miskolc. Applied surfactants were: potassium ethyl xanthate; the anionic oxhydryl Aero Promoter 825 or Flotinor SM 35; the cationic Armoflote 43 or Armoflote 64, as well as Hostaflot LET (dithiophosphoric acid diethyl ester) and Hostaflot M91 (mercaptobenothiazole). The tested electrolyte was sodium-silicate. Zeta-measurements were carried out in full pH-range. Interfacial interactions were detected and interpreted. The basic results were verified by the flotation kinetic tests.Finally, the flotation technological experiments were carried out at a semi-technical scale using the real obsolete solar elements. The particle size at the liberation degree of 98% was as fine as below 5 µm. A special flotation cell providing the generation and distribution of very fine air bubbles was built. The pre-concentrate for the manufacturing of the test solar module was performed and transported to the BAM Institute (Berlin), the principal co-ordinator of the Project, and then further to the First Solar (USA) where a new panel was manufactured using recycled semi-conductor."

Jan 1, 2016

"An atmospheric process for the synthesis of scorodite(DMSP®)has beendeveloped,in which ferrous ions were oxidized by oxygen gas in the presence of pentavalent arsenic ions. Under optimum conditions, the synthesized scorodite (FeAsO4?2H2O) was well crystallizedand the crystals were faceted; the particle sizes were as large as 15 to 20 µm. In thisstudy, iron (II) sulfate heptahydrate (FeSO4·7H2O), arsenic (V) acid (60mass%H3AsO4) solution, and distilled water were used to prepare the original experimental solution (700 ml), in which the contents of Fe(II) and As(V) were 55.9 g/L and 50.0 g/L, respectively. The effects of various synthesis conditions, such as the type of oxidizing gas (oxygen or air), gas injectionrate, temperature, and the initial pH of the solution, on the size and shape of the scorodite particles wereinvestigated. From the experimental results, the changes in the shape of the scorodite particles wereclarified for each synthesis condition.INTRODUCTIONDOWA has developed a processfor synthesizing well-crystallized scorodite (FeAsO4•2H2O). Theprocess is named andtrademarked as DMSP® (Fujita et al., 2008; Fujita et al., 2008; Fujita et al., 2009; Fujita et al., 2009; Fujita et al., 2009, Kubo et al., 2010). In this process, oxygen gas is injectedinto a sulfuric acid solution containing large amountsof As(V) and Fe(II). Facetedscorodite crystals as large as 15–20 µm weregeneratedthrough the pre-formation of a gel-like precursor. However, it is known that the synthesized scorodite particles become smaller and more aggregatedwhen the synthesis conditionsdeviate from the optimumconditions.In this study, the effects of various synthesis conditions, such as the type of oxidizing gas (oxygen or air), gas flowrate, temperature, and initial pH of the solution, on the size and shape of the scorodite particles were investigated. The experimental resultsclarified the changes in the shape of the scorodite particles for each synthesis condition."

Jan 1, 2016