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By A. V. Golovanov, A. V. Mihailova

"NPO RIVS employs complex approach to engineering and design of the new facilities in close cooperation of Mining, Research, Hydrometallurgy, Design, Construction, Power Supply, Automation, Production and other departments. General Design Contractor (and then General Contractor) is directly involved in geological exploration, engineering surveys, floatability studies, feasibility study of process solutions and construction options. It delivers greenfield project and guarantee its efficient performance in future. Shiralgin is a small gold and copper deposit, gold average grade is 4.7 g/t. RIVS departments have studied ore floatability, developed process procedures for design and performed pilot testing. Construction of integrated plant including ore crushing and grinding, flotation and hydrometallurgy units with Dore gold production of 5 000 thousand tons ore per year (66.7 t/h) is recognized as economically viable. The technology used of separate dry stockpiling of flotation tailings and cyanidation tailings. Water circuit for concentration and hydrometallurgy is separated, too. Process design was performed based on BIM software like Autodesk Revit, Civil 3D, Rocscience slide using process procedures developed by RIVS Research units. Engineers provided modeling of primary crushing unit, coarse ore storage, main building (including grinding, flotation, thickening, filtration, loading, hydrometallurgy), tailings thickening unit, building for reagent storage and conditioning, tailings pond for dry stockpiling of flotation tailings and cyanidation tailings, sedimentation ponds, laboratories, infrastructure including Administration building and camp. Payback period is 3.5 years. 3D model of facility is currently stored at the State Agency of Geology and Mineral Resources affiliated to the Government of the Kyrgyz Republic.INTRODUCTION The Kyrgyz Republic has substantial potential of mineral resources including gold ores. Mining industry actively develops and involves international investors. Inventory includes 42 deposits (Figure 1) that have reserves of 616.4 t [1] of gold. The Kyrgyz Republic takes the third place in gold mining among CIS countries after Russia and Uzbekistan by producing up to 20 t annually."

Jan 1, 2018

By M. Pischtschan, S. Belz, M. Perrucci

In High Pressure Grinding Rolls (HPGR), the material grinding takes place between the fixed and floating rollers. In this regard, the rollers start to wear over a period of time, which is impacted by for e.g.: ore characteristics, operating pressure, feed material size and non-uniform feed presentation across the roller width. HPGR operational experiences have shown that the rollers do not wear at the same rate. This differential wear rate over time leads to differences in the tangential speeds of the rollers, causing an uneven gap between the fixed and floating rollers in relation to the material. This unwanted but extremely common situation results in a less effective grinding process due to the fact that the slip between rollers is not optimal. As the rollers wear profile increases, the roller with smaller diameter starts to wear further, deteriorating the comminution efficiency up to a point where operators have to stop the HPGR to replace the rollers. Since the wear rate of the rollers is not equal, the replacement of the same cannot be properly planned so that their life-time are fully utilized. In this paper, a dynamic load share control with the use of ABB’s variable speed drive system is proposed, which provides the possibility to the HPGR operator to impact the roller wear in such a way that it equalizes the wear rate to a certain extent and extends the roller life time. Called RollXtend™, this solution includes a load share factor which can be parameterized based on the wear measurement performed manually during maintenance procedure. Additionally, this paper describes an automated load sharing concept based on a non-invasive wear measurement method. The partial results of the technology trial in a copper/gold mine are presented, which aimed at detecting stud damage and estimating the real rollers profile throughout their life time. The final objective of the pilot project was reduce the amount of planned and unplanned downtimes of the HPGR by increasing the rollers life time and avoiding catastrophic stud damages.

Jan 1, 2018

By Rasool Hejazi

The feed to Chadurmalu iron ore concentrator plant is a mixture of magnetite and haematite iron ore with a Fe/FeO ratio of about 8. The feed to plant, after grinding via wet SAG mill, is pre-separated by wet low intensity magnetic separator. Magnetic product is conducted to magnetite processing circuit for producing magnetite concentrate, and nonmagnetic product is directed to haematite processing circuit. Due to surface oxidization of magnetite particles and a decrease in magnetic attraction properties, significant amount of these particles are misled to tailing which results in decreasing the efficiency of haematite processing circuit. This problem can be remedied by using magnetic drum separator with more magnetic intensity and/or gradient. In this paper, the replacement of LIMS separators with wet medium intensity magnetic separators with a field intensity of 3800 gauss on drum surface (MIMS) have been suggested and considered as the most suitable solution to prevent the loss of magnetite particles. The results of carried out investigations with replacement of drum separators in industrial scale, showed that utilizing MIMS in magnetite processing circuit resulted in increasing final concentrate weight recovery on average by 2.59%, without any adverse effect on the concentrate quality; decreasing the magnetite content in the feed to high gradient magnetic separator (HGMS) by about 3.5%; decreasing the feed to floatation part by about 7% and consequently decreasing consumption of chemical reagents; increasing Fe/FeO ratio of the feed to plant. Keywords: iron ore, medium intensity magnetic separator, haematite, Chadurmalu

Sep 1, 2012

By J. W. Ahn

Calcined calcium oxide from limestone is hydrated to manufacture calcium hydroxide, and then precipitated calcium carbonate is synthesized from calcium hydroxide. Precipitated calcium carbonate of various morphologies is obtained by controlled conditions of each step and characteristics of limestone, calcium oxide and calcium hydroxide. Especially characteristics of calcium hydroxide have the most influence on morphology of precipitated calcium carbonate character. In this study, therefore, it is investigated the specific surface area of calcium hydroxide and morphology of precipitated calcium carbonate according to hydration temperature. Calcium hydroxide hydrated at high initial temperature has larger particle size than that hydrated at low initial temperature. And formation yield of aragonite precipitated calcium carbonate has improved by using calcium hydroxide had larger particle size (hydrated at high initial temperature).

Jan 1, 2014

By Yuri Yemelianov, Stanislav Balikov, Alexander Epiforov, Andrey Boldyrev, Andrey Bogorodsky

"Test work was carried out using copper gold-bearing flotation concentrate with 6.85%Cu, 14.30%Fe, 20.70%S and 2.34%As. Gold and silver grade in the concentrate is 54.6 g/t and 92 g/t, respectively. Gold and copper are valuable components in the concentrate. Gold is partially associated with pyrite and fahlores. Copper in the concentrate can be found as tennantite (Cu12As4S13). The 71% of gold from the flotation concentrate is recoverable by cyanidation with simultaneous cyanide consumption in the amount of 96 kg/t. The major reason of refractoriness is that gold is fine encapsulated into sulfides and the presence of cyanicide-copper. The concentrate ground as much as 95% minus 10 µm was treated using low-temperature POX at the temperature of 100±5°C, L:S ratio of 5:1 and the process time of 1-5 hours. Residual sulfide sulfur in the cake is 2.28% which is 89% sulfide oxidation. The highest copper recovery to POX solution is 91%. It was found that gold recovery to cyanide solution is 85-94% during alkaline pre-treatment of POX cakes followed by cyanidation. In this case, cyanide and lime consumption is 75-90 kg/t and 120 kg/t, respectively. In order to recover precious metals from POX cakes leaching using sodium sulfite was carried out. Test work was conducted at varied reagent concentration, L:S ratio and leaching time. Gold and silver recovery achieved was 85-95% and 59-63%, respectively."

Jan 1, 2014

By Ashish Kumar

High grade ore deposits in the world are fast depleting and the valuables in the low-grade ores are finely disseminated. The feed grade to flotation circuit is also declining. Attainment of suitable grind is preferred, which inevitably creates more fines of the gangue minerals to interfere with the flotation process because of the undue competition between the fines and the valuables for the collector ion adsorption. Besides the use of polymeric or long chain hydrocarbon depressants for the gangue mineral, microbial induced flotation also has potential to float minerals selectively. Thiobacillus ferroxidans and Thiobacillus thiooxidans adhere on the minerals to modify its surface properties and affect the minerals flotation acting as depressants. Hindustan Zinc has conducted laboratory studies to understand the adhesion of microorganism on the mineral surfaces and its impact on the selective flotation. The experiments were further designed to reduce consumption of depressing reagents for graphitic carbon, pyrite, and galena. Preliminary studies reveal that desired quality of concentrate can be achieved with reasonable recovery. Keywords: thiobacillus thioxidans, thiobacillus ferroxidans, bioflotation, microbial induced flotation

Sep 1, 2012

By Xubo Chen, Zhiqiang Hu, Zhijian Sun, Gaoyun Zhou

"The research aimed at developing an efficient and environmental frother,which was applied in the flotation of sulfide ores. The flotation properties of an efficient frother and pine oil have been studied relatively by flotation tests of lead and zinc sulfide ores. At the same time, the biodegradability of two kinds of frother has been studied by the method of biological respiratory curve. The test results show that the flotation properties of new frother are superior to pine oil such as flotation rate, dosage etc. and its biodegradability is superior to pine oil. INTRODUCTION Frother is a kind of important agent in flotation reagents.In practice, the criterion of the foaming performance of the frother is what is high and low according to flotation indexes. The difference of different minerals and flotation technologies has great influence on the foaming performance of frother, and it is very important to choose the corresponding frother. The type, dosage and selectivity of frother in flotation process must be considered carefully. In today's society, environmental protection and ecological protection are becoming more and more important, and the environmental and ecological damage from mine development has aroused increasingly more attention. The use of mine agents has promoted the development of mineral resources, greatly improves the recovering utilization of mineral resources, at the same time, the production and use of mine reagents also inevitably bring about pollution, and result some influence or damage in the ecological environment.The frother is a common kind of reagent in the flotation process of the concentrator. In many cases, the waste water in the concentrator can not be let out in the natural water because the higher content of the frother in the waste water results in higher index of COD.This will inevitably increase the cost of waste water treatment in the mine.Therefore, the choice of frother should not only consider its influence on the flotation index, but also consider its influence on environmental protection. Waste water treatment is a way to solve the waste water pollution, but it needs to cost a lot of fund, manpower and material resources.And the development of high efficiency pollution-free reagent is a good way to reduce the production cost of mining enterprises and reduce the environmental pollution."

Jan 1, 2018

By S. S. Yu

In this paper, the producing process of using V2O3 as raw material to obtain vanadium nitride was analyzed through the means of thermodynamic. The analysis shows that conversion follows the principle of reduction step by step in the conversion process of V2O3. The temperature of the reaction system has prominent influence on the nitrogen content of products, and the reaction is very sensitive to temperature. As raising temperature, the fine grain structure of the nitrides is more evident, and the grain size of nitrides increases. At 1703K, the nitrogen content of the products tended to be constant after soaking over 3 hours.

Jan 1, 2014

By John A. Rumball, Martin R. Houchin

"For gold leaching of oxide ores, the optimum cyanide : oxygen ratio is approximately 106 mg/L NaCN : 10 mg/L O2 (6.9:1 by mole). In sulphide ores, galvanic coupling of the gold with the electrically conductive sulphides significantly increases this ratio such that leaching may occur in a relatively low dissolved oxygen (DO) environment.RESULTS AND DISCUSSIONGold leaching in a carbon in pulp (CIP) and carbon in leach (CIL) circuit is driven by the supply of cyanide and oxygen, as described by Elsner’s equation (1):• 4Au + 8CN- + O2 + 2H2O ? 4Au(CN)2 - + 4OH- (1)Equation 1 suggests that the ideal molar cyanide : oxygen ratio should be 8:1, or 122.5 mg/L NaCN to 10 mg/L of DO. It is generally accepted however, that oxygen is not completely reduced to hydroxide at the gold surface, and that equation (2) better represents the gold leaching reaction (Marsden and House, 1992):• 4Au + 8CN- + 2O2 + H2O ? 4Au(CN)2 - + 2OH- + H2O2 (2)Additionally, since gold leaching is limited by either the diffusion of cyanide or oxygen to the gold surface (Habashi, 1993), then the relative diffusion rates of cyanide and oxygen must also be taken into account. Marsden and House (1992) suggest that the ideal molar cyanide : oxygen ratio is 6:1, while a more recent investigation using laboratory and plant observations (Heath and Rumball, 1998) suggested a molar ratio of 6.9:1.In practice, although a cyanide : oxygen mole ratio of 6.9:1 applies to some circuits, there are many instances when this is not the case.In sulphide ores, galvanic coupling of the gold with the electrically conductive sulphides significantly increases this ratio. Galvanically connected sulphides, and possibly carbon, provide a large surface area for oxygen reduction. As the cathode surface area increases, the oxygen concentration required to sustain the same rate of gold oxidation decreases proportionately.Galvanically connected particles may be composite particles, however they may simply be liberated sulphides in the same suspension as the gold. Particle collisions within a slurry are sufficient to provide momentary galvanic connection (Greet, 1995)."

Jan 1, 2003

By V. M. Mankov, O. V. Zamyatin

"Fine free gold at a size of minus 250-100 µm can be effectively recovered from mineral materials (buried clay placers, saprolites, gold-bearing aggregates, technogenic sands etc.), or MM, using some developed and implemented in practice cost-effective basic technological schemes of MM processing at every stage: exploration, main concentration processes, upgrading of gravity concentrates etc. Such technologies are based on mineral materials composition, different content of fine gold mass fractions, and include improved two-stage sluicing technology, jigging technology, advanced technology and integrated technology. The main operation principle of the given technologies is gravity concentration. They provide recovery of fine gold of any size from MM, including gold finer than 100 µm, using concentration systems and plants with a capacity of 1-2 and up to 100-200 m3 per hour. Selection of a cost-effective technology depends on its technical and economic viability regarding to mineral material composition, optimum performance and concentration rate. The developed technologies of mineral materials concentration establish a balance between technological, technical and economic factors, and ensure profitable development of deposits containing free gold and characterized by a complex composition of concentrating material. Free gold recovery with these systems increases by 2.0-2.5 times for gold particles at a size of minus 250+100 µm and 10-30 times for gold particles of minus 100 µm, compared to conventional sluicing systems. The Irgiredmet Institute has developed and supplies primary concentrate washing machines for upgrading gravity concentrates of up to 100 mm in size, with a capacity of 1.0-5.0 m3/h, fitted with various production equipment including pyro- and hydrometallurgical systems. Additionally, the Irgiredmet Institute develops and manufactures systems of mechanized processing of geological and technological samples (UOMP; registered design certificate No.27505, Russia) designed for complete recovery of free gold in the process of geological samples handling and decreasing of a human factor influence. A system includes a package of technologically associated disintegration, classification and concentration equipment with some “know-how” elements that provide effective recovery of fine gold at the exploration stage. A number of Irgiredmet’s patented technologies and systems (patents of the Russian Federation) have no equivalents in the field of mineral processing and provide designing of technologically practical and cost-effective flowsheets that offer higher recovery of gold of different sizes (fine gold), at every stage of processing of mineral materials including basic concentration processes, upgrading and exploration etc."

Jan 1, 2018

By Hong Nguen Vu, Pavla Ovcarí, Peter Fecko, Barbara Tora

The aim of this paper is to evaluate the suitability of a coal sample from the mine Jaworzno (Poland)- locality for bacterial leaching. Laboratory research used a pure bacterial culture of Thiobacillus ferrooxidans. The results showed that bacterial leaching was effective, with a one month leaching time, when 65% of total sulphur and 85% of pyritic sulphur was leached. The paper describes changes to the pyrite during and after bacterial leaching.

Jan 1, 2003

By M. Saghaeian, R. Hejazi, L. Hosseini, M. Zare

Difference between plant feed specifications in practice and design feed is a problem that most of processing plants face during operating and commissioning. This topic has led to inappropriate operating and necessitates repeating the basic tests on new feed. Gol-E-Gohar fourth concentrate line with a capacity of 2 MTPY, located in Kerman province, is the first iron concentrate plant in Iran in which High Pressure Grinding Roll (HPGR) technology has been applied. Plant&apos;s feed consists of 30% AG mills pebbles of lines 1-3 and 70% run of mine crushed ore whose Fe=51%, Fe/FeO=2.5, S=1.7% and work index=15 kWh/t. Desired concentrate has Fe>68% and S<0.7%. After the plant construction and operation commencement, providing design feed was not possible due to the crushing unit`s not being complete, therefore the plant was fed by AG mills pebbles. For predicting optimal conditions of the plant and investigating the possibility of improving the current concentrate specifications, sampling from the new feed and laboratory and pilot tests was performed again. Studies showed that new feed has Fe=41%, Fe/FeO=3.5, work index=17 kWh/t. Results of laboratory tests with Davis tube device and pilot tests run using magnetic separators with simulating the plant`s circuit showed that with current feed, achievable recovery in industrial scale would be 75.52% which compared to plant&apos;s recovery in studied period (75.94%) shows that plant operated in optimal conditions. To improve the current concentrate specifications (Fe=66%, S=1.03%, Ferec=75.94%) and for achieving desired concentrate, samples were reground to four fractions with k100= 300, 212, 100, 45 and Davis tube tests were performed on each of the samples separately. Results showed that the fraction whose k100=212 µm or k80=200 µm has respective Fe and S grades of 68.27% and 0.681% which are consistent with the desired concentrate.

Jan 1, 2014

By Kazutoshi Haga, Batnasan Altansukh, Atsushi Shibayama

Results of flotation process combined with atmospheric leaching and high pressure leaching for recovery of copper from low-grade silicate-copper ore have been presented in this study. The low-grade copper ore contains a small amount of copper (0.42 mass %), iron (4.6 mass %), and silicon (38.3 mass%) and among many other metals (Al, Ca, K, Mg, Na, Ti and S). The main mineralogical constituents of the copper ore are calcium aluminosilicate (Ca(Al2Si2O8), amesite (Mg2Al2SiO5(OH)4) and gypsum (CaSO4×H2O), and quartz (SiO2) as resulted from the alteration of an igneous rock. This study has shown that about 92 % of copper can be recovered with a maximum copper grade of 4.2 mass% in a froth after 15 minutes of flotation at pH 8.5 when used potassium amyl xanthate as a collector, MIBC and Dow-froth 250 as frothers and calcium hydroxide as a pH adjuster. The images of bubbles in the cell during flotation process were recorded using a high-speed camera. The froth concentrate with average copper grade of 2.0 mass% was further processed by atmospheric leaching with a solution of sulphuric acid and hydrochloric acid, respectively and high pressure leaching with sulphuric acid solution. As a result, leaching rate of copper reached about 60 % in an atmospheric leaching with sulphuric and hydrochloric acid respectively, whereas the rate can reach more than 70 % by autoclave leaching at high pressure under the controlled condition. A process to recover of copper from its low-grade ore can be developed by optimization of flotation combined with acid leaching.

Jan 1, 2014

By R. D. Alorro

Melting has become a popular pre-treatment method for municipal solid waste (MSW) incineration residues in Japan. Although the method is effective in stabilizing the hazardous organic sub-stances such as dioxin, it concentrates the heavy metals such as Zn, Pb, Cu, and Cd in a newly formed fly ash (melting fly ash). Melting fly ash is classified as a hazardous waste because of the leaching potential of these heavy metals in landfill environment. Extraction and recovery of these metals seem to be more environmentally and economically attractive than disposing the material to landfill after immobilization process. This study proposes a Carrier-in-Pulp (CIP) method as a new hydrometallurgical route to reject and recover heavy metals from fly ash. In this method, a carrier material which recovers the extracted metals is added simultaneously with fly ash to leaching solutions and is harvested from the pulp by physical separation method like magnetic separation or sieving. To demonstrate the effect of CIP method, shaking flask experiments were conducted under various conditions using NaCl solution as lixiviant and iron powder or granular activated carbon as carrier materials. In the CIP method using iron powder, more than 97 wt% of Pb and Zn were extracted from the ash to the solution phase. However, the iron powder which was harvested from the pulp by magnetic separation, recovered only Pb (more than 94%) through cementation, leaving behind Zn ions in the solution phase. Due to this problem, granular activated carbon (GAC) was considered as an alternative carrier material. Single- and multi-metal adsorption experiments using granular activated carbon were conducted as a preliminary study. Around 85% Pb and 88% Zn were recovered by GAC in the single-metal adsorption experiment, while 60% Pb and 70% Zn in the multi-metal experiment. These results showed that activated carbon was superior to the iron powder since it was able to recover both Pb and Zn through adsorption. The leaching test conducted on the residue after the CIP-Fe treatment revealed that the solubilisation of Pb was successfully suppressed to meet landfilling guidelines.

Jan 1, 2014

By Xiaodong Jia, Williams. Richard A.

This paper describes the recent developments, arising from research at Leeds, in the computer modelling of packing of complex shaped particles and prediction of physical properties of the structures represented by the packing. The computer model DigiPac, is capable of packing particles of any shapes and sizes in a container of arbitrary geometry. The ability to predict packing structure of real particle shapes and to compute directly some structure-dependent physical properties (such as liquid permeability, mechanical strength/ stability, compaction and sintering, dissolution and leaching, etc.) is obviously highly desirable and has significant potential in industrial applications. Examples are presented relating to the packing of granular materials.

Jan 1, 2003

By Yizhong Yuan, Dao Li, Nannan Xue, Tao Liu, Yimin Zhang

A new multi-stage counter-current circulation leaching process for extracting vanadium from stone coal was proposed, and the main factors on multi-stage counter-current circulation acid leaching process were investigated. The results show that the vanadium recovery could reach 86% under the conditions of sulfuric acid concentration of 4 M, liquid to solid ratio of 2 mL/g, temperature of 95 °C, reaction time of 60 min, mean particle size of 125 µm and circulation acid leaching stage of three. The losses of vanadium in acid leaching solution appeared during the four-stage acid leaching process. The strong adsorption performance of new formed KAl(SO4)2(H2O)12 crystal was main reason.

Jan 1, 2014

By H. Koca, D. O. Aksoy, S. Koca

"In this work, modelling of galena flotation from a disseminated Pb-Zn ore containing 0,83 % Pb was investigated. In the flotation experiments, collector type and amount, frother type and amount, particle size, pH and flotation time were kept constant while solid ratio and depressant dosage were varied. The varied parameters are described with a mathematical model by using statistical design method. Central Composite Design method which is one of the principle response surface methodologies was used in statistical design and analysis of experimental results and process modelling. Two quadratic mathematical models were developed for Pb grade and Pb recovery. Analysis of variance showed that models obtained for Pb grade and Pb recovery were found to be statistically significant in 95 % confidence level. Predicted vs actual values of Pb grade and Pb recovery were also given in graphically. It was found that predicted values represent approximately 96 % and 94 % of actual Pb grade and Pb recovery, respectively. The high values of R-square (R2) indicate that the models developed for two response variables are powerful. INTRODUCTION Lead and zinc metals are widely used in electrical, mechanical, military, metallurgical, chemical, light and medical industries. Sulfide ores are the main resources for lead and zinc minerals (Luo et al., 2016). Froth flotation is the main beneficiation method to achieve lead and zinc sulfide minerals separation. There are two basic approaches to obtain lead and zinc separation by flotation. First, flotation of lead sulphide is carried out and zinc sulphide and gangue minerals are depressed by various depressants and second, the bulk flotation of lead and zinc sulphide is carried out to obtain a concentrate of lead and zinc, followed by the lead and zinc separation. (Yuan et al., 2012). Apart from concentration of lead and zinc by flotation, there are a few literature that reports concentrations of lead and zinc by gravity and hydrometallurgical methods with remarkable success (Goktepe, 2005; Yanbo et al., 2016)."

Jan 1, 2018

By V. E. Vigdergauz

The work presented shows results of electrochemical study of pyrite hydrophobicity evaluated by air bubble induction time (IT) measurements. On the basis of measured IT?s an average thickness of the thin liquid film prior to its rupture has been evaluated, which confirms long-range character of the interactions between air bubbles and hydrophobic surfaces. Obtained data are discussed in the frame of recent studies of structures of solid-liquid interface based on molecular dynamics simulations and results of surface force measurements.

Jan 1, 2014

By Arkady Senchenko, Sergey Rybkin, Svetlana Lagutina, Alexander Aksenov

"The application of autoclave leaching technology for sulfide concentrates containing base and precious metals is spreading nowadays. In the process of concentrate leaching silver accumulates in the forms of jarosite compounds, transforms into passive chemical state and is mostly found in solid phase. Effective technology development for silver recovery from solid phase of concentrate autoclave leaching raises the necessity for comprehensive research of silver forms of occurrence and their properties in this product. The possible form of silver presence in solid phase of concentrate from autoclave leaching is argentojarosite. This article is about the study of physical and chemical properties and structure of synthetic argentojarosite - AgFe3(SO4)2(OH)6. A method of argentojarosite synthesis has been developed under conditions simulating the process of autoclave leaching of sulfide concentrate, and includes silver dissolution in the form of Ag2SO4, Fe3+ sulfate hydrolysis, AgFe3(SO4)2(OH)6 build-up. X-ray data of synthesized argentojarosite completely correspond to those of natural mineral. The structural formula of this complex compound has been studied and confirmed. The chemical properties of synthetic argentojarosite, its solubility in acids and alkalis have been investigated. Phase changes when heating argentojarosite with the build-up of iron oxide and silver sulfate stop at the temperature equal to 650 ºC. Based on the results received the technological solutions for solid phase of autoclave leaching of concentrate have been developed with silver recovery of 95-98%."

Jan 1, 2014

By Javier Baladron, Mijail Villar, Brandt Henriksson

"In this presentation an overview will be given of what has been observed by the authors in the copper concentration industry, with a large diversity of tailing thickeners operating under different conditions, although many of them are located in the same neighborhood. A closer look will be taken at the reported performance from different sites and from different thickener designs, either conventional or high rate, including those that were retrofitted, regardless of the thickener brand. An analysis is also made of the generic correlation of the size of the thickener and the performance in terms of solids loading (or unit area) and % solids. The paper envisions a technology development route, makes a brief analysis of the economic impact of the suggested route and points out the need for development in technologies around tailings thickeners, such as automation, yield stress measurement, slurry pumping and construction methods."

Jan 1, 2014