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By Zhen Hu, Chenghang Wang, Jianjian Zou, Xiujuan Li, Hanwen Li, Tai Wang, Baoxu Song

A rare earth deposit in Sichuan, China is rich in wulfenite in addition to bastnaesite and barite, and the deposit has already adopted high intensity magnetic separation technique to pre-enrich the rare earth minerals, during which the wulfenite and barite have been left in the non-magnetic product. Because the chemical composition of wulfenite is only 24.17% Mo and 42.15% Pb, it is very hard to obtain qualified lead or molybdenum concentrates by physical separation process. To pre-concentrate the wulfenite, flotation has been first introduced, and by using 100g/t GY-7 as dispersant, 1500g/t CP-1 as depressant and 160g/t GY-4 as collector, a floatation concentrate assaying 15.52% Mo with a recovery of 86.12% was obtained. Then a leaching process was conducted by using 1.2mol/L Na2S as leaching agent, and molybdenum can be translated into sodium molybdate in the solution with a leaching recovery of 99%. To recover rare earth oxides (REO) and lead from the leaching residue, a magnetic separation process has been conducted. Above all, by the whole process, the molybdenum recovery reaches 86.16% in the sodium molybdate solution, and a lead concentrate assaying 54.59% Pb with recovery of 27.99% could be obtained.

Jan 1, 2014

By D. Johann, E. Zanetti, I. A. S. Brum, P. M. Zancan, A. F. Castro

"This study was done from a sample of coal mined at the Vale-Mozambique mine, located in Moatize district, Tete Province. The aim of this work is to analyze the reagent system in the flotation of coal fines belonging to the Upper Chipanga layer (UC). Among coal processing methods, flotation stands out as one of the most important for the concentration of this material, in particular in the treatment of fine particles. The total feed of the Vale-Mozambique processing plant is 8,000 tph of coal, where 10% of this feed corresponds to the fine fraction that feeds the flotation circuit. The material used in this study had a particle size of 96% smaller than 0.25 mm. The reagents used in the flotation tests were betacol and diesel oil as hydrophobizing agents and MIBC as frother. The range of betacol concentrations in the first test phase was 200 g/t to 500 g/t, and in the second phase 200g /t to 500g /t while diesel oil and MIBC were kept constant at 300 g/t. The immediate analysis followed the Brazilian standards NBR 8289, NBR 8293, NBR 8290; and NBR 8299. The results showed that it is possible, from a feed with ash content around 22.84%, to obtain products with levels below of 10% ash, with a mass recovery around 50%. The recovery of carbonaceous matter was also evaluated and presented positive results. Complementing this study, the effect of H2O recovery was evaluated and it was observed that for the concentrations of betacol the recoveries ranged from 6 to 9%, and for diesel oil plus MIBC were 4 to 7%.INTRODUCTION Considering the increase in population and energy consumption as humanity has been living along the last decades and the consequent demand for non-renewable natural resources, it is clear the challenge of the mineral industry in the search for new technologies and improvement of the existing ones. This challenge is justified by the need for better industrial results and to meet the market specifications, taking into account the reduction of deposits with higher contents and the need for beneficiation of more complex ores, lower levels and lower release granulometry. Usually in these situations, processes already well-established as the gravimetric (Sampaio and Tavares, 2005) have not good results."

Jan 1, 2018

By Tong Guan, Guangqin Fu, Lihong Deng, Xiaotong Zhou

The raw ore contains many kinds of valuable metal elements. It is rich in valuable metal elements, such as Pb, Zn, Sb, Sn, Ag and is associated with S,Fe,As,In,Cd. A new technology which includes medium intensity magnetic separation, preferential lead flotation, zinc-sulfur bulk flotation, zinc-sulfur flotation separation, tin gravity separation and tin slime flotation was chosen to recover valuable minerals in the raw ore, and the iron concentrate, the lead concentrate, the zinc concentrate, the sulfur concentrate and the tin concentrate can be obtained. To the zinc-sulfur bulk concentrate with the grade of 7.21%Zn and 16.97%As acquired by the zinc-sulfur bulk flotation, two different flowsheets of Zn-S separation technology are chosen to study. The lab test shows that when using lime+DM as depressor, the zinc concentrate assaying 47.73%Zn with the recovery of 95.01% can be obtained and the test indexes are better than that of the flowsheet which using lime as depressor. At the same time, the Cd content is 0.65% and the In content is 0.10% in the zinc concentrate, so they all reach the smelting comprehensive recovery standards and the As content decreases to 0.23%. Finally the flotation separation of christophite and As-bearing sulfide minerals can be successfully realized.

Jan 1, 2014

By D. Gucbilmez

Three spiral concentrators having different geometries were compared in a chromite processing plant. They had different diameters, helix-cross sections and capacities. Two of the spiral concentrators were manufactured in China and one of them was manufactured in Australia. The tests were carried out in a closed circuit experimental setup by using a low grade chromite ore. The pulp densities kept the same during the operation, and the samples were taken simultaneously. The effects of the different positions of the splitters on separation and the feed rate were the parameters that were observed during the experiments. The performances of three spiral concentrators were found to be different. To clarify the effect of the particle size on the separation in spiral concentrators, the screening was applied to the feed. The samples were sieved from 75µm. The test results indicated that the separation performance decreased dramatically in very fine particles. Although fine particles caused some problems in spiral concentrators, fine grinding is required for this particular chromite ore for better liberation. A suitable method for the fine particles should be investigated for acceptable recovery.

Sep 1, 2012

By C. Y. Wang

Anodic reaction mechanism of complicated antimony-lead concentrate in Slurry Electrolysis has been investigated by the anodic polarization curves determined under various conditions. The main reactions on the anode are the oxidation of FeCln (2-n), though the oxidation of jamesonite particle on the anode can occur during the whole process, it is less. With the help of mineralogy study and relevant tests, the leaching reaction mechanism of jamesonite and gudmundite during Slurry Electroly-sis has been ascertained also. Because of the oxidation reaction of FeCl3 produced by antimony-lead concentrate itself, the non-oxidation complex acid dissolution of jamesonite, the oxidation complex acid dissolution of gudmundite, and the oxidation of air carried by stirring, the leaching ratio of antimony reaches to about 35% when using HCl-NH4Cl solution to leach antimony-lead concentrate directly. So given the theoretical electric quantity, which to oxide antimony in Slurry Electrolysis, all of antimony, lead and iron, which contained in antimony-lead concentrate, are leached.

Jan 1, 2014

By H. Tiefel, M. Schneider, T. Neesse, J. Regler, J. Dueck, F. Donhauser

In practice the advantages of high-quality hydrocyclone separation are often reduced due to varying feed suspension properties, solids concentrations and particle size distributions. Control systems of large hydrocyclones are usually fitted with controllable underflow nozzles, which is not practical for small hydrocyclone batteries. Therefore, a new control system for a battery of hydrocyclones with a nominal diameter of 150 mm was invented at the LUR in cooperation with AKW Apparate und Verfahren GmbH & Co. KG. This process was developed for bentonite slurry regeneration associated with tunnel excavation using bentonite slurry as a transport aid and lubricant.

Jan 1, 2003

By James Y. Oldshue

"Very seldom is it possible when contacting a gas with a slurry to measure the dissolved gas concentration in the slurry, and even where possible, equilibrium data with a suitable Henry.s law constant are seldom available.In general, by assuming a reasonable value for the dissolved gas concentration in the slurry and a corresponding equilibrium gas partial pressure P*, KGa values can be calculated for the pilot plant and then scaled up. Then, with the same P* value at various reaction conditions, a mixer can be designed which is quite satisfactory, having a reasonable design factor for full-scale performance."

Jan 1, 2003

By S. V. Volkova, S. V. Mamonov, T. P. Dresvyakyna

"The purpose of the work is complex processing of sulphide-magnetite ores with the separation of iron into iron concentrate, copper and noble metals into copper concentrate.The work shows the research results of the material composition of the sulfide-magnetite ore in the South part of the Peschanskoye deposit. According to the research results it is found that ore contains 0.59% of copper, 66% of which is related to chalcopyrite; 39.9% of iron, 81% of which is magnetite and 3.87% is sulfur, 42% of which is associated with pyrrhotite, 65% of which is a monoclinic modification. According to the results of the mineralogical analysis, it is found that the main iron-containing mineral in the ore under study is magnetite, the content of which is 45%. In addition to magnetite, iron is found in carbonates, pyroxenes, amphiboles, chalcopyrite, pyrrhotite and pyrite. The main copper mineral in the sample is chalcopyrite; covellite, chalcosine, bornite have a subordinate value. The total content of copper minerals in the sample is about 1%. The processing technology provides the three-stage grinding of the ore to a size of 65% of the class-71 µm; a cycle of copper flotation; a cycle of pyrrhotite flotation; wet magnetic separation of flotation hosts. The following optimal parameters are established for the ore under study: the alkalinity of the slurry is 250-280 g/m3 of free calcium oxide in the liquid phase of the slurry; the duration of the main copper flotation is 20 min; the consumption of butyl potassium xanthate is 20 g/t; the consumption of the foam generator T-92 is 15 g/t; the consumption of copper sulfate for the activation of pyrrhotite is 300 g/t; the magnetic field strength is 1500 Oersteds.A complex flotation-magnetic technology for the enrichment of sulfide-magnetite ore has been developed in the laboratory in order to produce a copper concentrate containing 21.6% of copper with 91.7% extraction and an iron concentrate with 66.5% of iron mass fraction and 1.2% of sulfur with an extraction of iron into the concentrate of 87.9%."

Jan 1, 2018

By D. Jamróz, A. Surowiak, T. Niedoba, P. Pieta

"The separation of coal material of three types of coals originating from three various Polish hard coal mines (types 31, 34.2 and 35, according to Polish nomenclature, which were steam coal, semi-coking coal and coking coal) into particle size fractions and then into particle density fractions was done and then the following parameters were measured for each particle size-density fraction: combustion heat, ash contents, sulfur contents, volatile parts contents, analytic moisture. In this way a 7-dimensional vector of data was created. Using methods of factor analysis the important features of coal were selected, which decide about their membership to individual types. To evaluate the appropriateness of the applied method the Bartlett’s sphericity test as well coefficient of Kaiser-Mayer-Olkin (KMO) were used. To select important factors the Kaiser criterion and Cattell’s scree test were used. The obtained results were compared with the results obtained in previous works by means of observation tunnels method. The results showed which particular features are crucial to define the type of coal what is also important to select appropriate method of its enrichment.INTRODUCTION Coal extracted from the mine is often a mixture of coals of various quality originating, for example, from various coal layers. One of the most important issues is to determine its quality, what means to verify if it fulfills certain requirements. Usually, such parameters as combustion heat, ash contents, sulfur contents, volatile parts contents and analytic moisture decide what the coal quality is (Drzymala, 2009). Such investigations are expensive and time consuming. That is why it seems to be important to determine the mutual connections and interactions between them what would make possible to reduce the amount of the necessary parameters. This issue was already investigated with successes in several works [Jamróz and Niedoba, 2013; 2014; Niedoba, 2015]. This work is another approach to this problem. Here, the investigation of possible reduction of researched parameters was done on the basis of the factor analysis. The obtained results confirm the earlier observations."

Jan 1, 2018

By Hong Zhong, Shuai Wang, Zhanfang Cao, Ting Dai

"Manganese is widely used in industries such as the steel industry and is now an essential element in modern industry. Technologies for the efficient and clean utilization of manganese resources must be developed and employed to ensure the sustainable growth of the manganese industry. Our research focuses on the use of beneficiation technologies to improve the grade of ores or the replacement of low-grade manganese carbonate ores with high-grade manganese oxide ores, and thus, to reduce reagent and energy consumption and the yield of electrolytic manganese residues from metallurgical processes; the study of leachate purification technologies; the study of electrochemical behaviors during electrolysis and energy-saving electrolysis methods; the development of chromium-free passivators as alternatives to the highly toxic potassium dichromate passivator; the non-hazardous treatment and resource utilization of electrolytic manganese residues and other manganese by-products; and the development of new manganese products. INTRODUCTION Manganese is widely used in the steel industry, nonferrous metallurgy, the chemical industry, electronics, batteries, agriculture, etc. Globally, more than 90% of manganese is consumed by the steel industry, and thus, it is said that ""No steel industry without manganese""(Banerjee et al. 2017, Zhang et al. 2017). Current manganese resources mainly include manganese ores, marine manganese nodules and waste catalysts. The total global output of manganese ore from land deposits is 18 million tons (metal volume), and the reserves, most of which is in the form of manganese oxide ores, are estimated to be 620 million tons (metal volume). More than 400 manganese ore deposits with a total reserve of 1.22 billion tons have been discovered in China. These deposits are predominantly manganese carbonate ores. Marine manganese nodules exist on the surface of the deep seabed at depths of 2000-6000 m. These nodules, which are also called polymetallic nodules, manganese balls, manganese aggregates and manganese tumors, are mainly composed of iron and manganese oxides. The total reserves of these resources add up to more than 3 trillion tons. Furthermore, the manganese in manganese-containing catalysts can be recycled after they become inactive."

Jan 1, 2018

By S. L. Gubin, T. V. Ignatova, A. V. Levshin, D. O. Sharkovsky

"Flotation process applied for concentration of unoxidized ferruginous quartzites by PJSC Mikhailovsky GOK (MGOK) is based on wet magnetic separation of strong magnetic minerals. However quality of the resulting concentrate (Fe65-66%) is insufficient for production of metallics. Quality upgrade of magnetite concentrate via flotation has been implemented by MGOK to produce premium quality magnetite concentrate.Flotation is a challenging process due to sensitivity to varied amounts of reagents, fine and coarse mineral ratio, particle contact (retention) time and temperature of feed. Tomah’s PA-14 reagent (USA) has proven efficient for application in flotation of MGOK’s magnetite concentrate.Objective of this work is to select and prove applicability of selective agents for flotation upgrade of magnetite iron ore concentrate.Series of flotation tests has been carried out with application of new highly selective collecting agents produced by Akzo Nobel (Sweden), Clariant (Germany) as well as Akzo Nobel’s and Tomah’s cationic collector mix to improve performance efficiency of flotation process. Tomah’s flotation agents and Akzo Nobel’s Lilaflotproved to be the most effective for purposes of concentrate quality upgrade to Fe69.0% via flotation.Testing Method: Following scientific research methods were applied for testwork: system analysis, mathematical statistics, observation, comparison, trial (experiment).To determine key process factors a series of pilot tests was carried out. Most of the testwork was performed by PJSC Mikhailovsky GOK’s Central Process Laboratory.Work Results:-optimized flotation performance modes were defined to ensure production of three types of low-silica concentrate, i.e. containing SiO25%, SiO24% and below SiO23% by weight. Most efficient selective agents applicable for flotation have been defined. Mixture of higher aliphatic amines has proven to intensify selective flotation of quartz. It enables higher yield of chamber product maintaining desired quality of concentrate.Achieved process operation and performance factors have been revaluated.Value for Advancement and Expansion of Mineral Processing:Flotation of concentrate has enabled expansion of PJSC Mikhailovsky GOK’s production capacity, improved production quality, helped to maintain sustainability and competitive advantage of the company."

Jan 1, 2018

By Andrei Yevdokimov, Ivan Sidorov, Olga Lanchakova, Olga Khmelnitskaya, Tatiana Chikina

"The paper focuses on the results of the research on development of hydrometallurgical process of gold recovery from refractory sulfide flotation concentrates based on fine and ultrafine grinding. Refractory concentrates (the degree of refractoriness is 16.9%-82.6%) were chosen for testing. The efficiency of the process based on fine and ultrafine grinding to treat flotation concentrates with gold intergrown with sulfides and rock-forming minerals was shown. Based on the test work conducted, the process option was chosen. In included grinding of flotation concentrate to the size of 98% minus 20µm in a bead mill, lime treatment with air blow, CIL, filtration and detoxification of liquid phase of the slurry. This process (compared to the basic option) provides the recovery of gold from 82.6%, up to 94.0% and decreases the residual grade in the tailings from 3.3g/t to 1.1g/t at the consumption of 12.6NaCNkg/t. Based on the results of the test work and pilot plant testing, project design criteria of flotation circuit at a Russian plant was developed."

Jan 1, 2014

By Chanki Jeong, Heechan Cho

In this study, batch flotation experiments were conducted to recover rare earth elements (REE) from an REE ore deposit in the Mushgai Khudag area, Mongolia. Apatite was found to be the major REE mineral while monazite and xenomite were observed as minor minerals. The main purpose was to float apatite to increase the REE content. Oleic acid was used as collector and MIBC was used as frother. Sodium silicate was used as a depressant for iron compounds. NaOH was used to adjust the pH of the flotation to about 9.5~10.0. The particle size was 90% less than 152 ?m (- 100 mesh). The content of REE elements was analysed by ICP - OES to determine the contents of REE such as Ce, La, Nd, Pr and Y. When sodium silicate was used, the best result was obtained using 0.2 mL of sodium silicate, 2 mL of oleic acid and 2 mL of MIBC. Under these conditions, the recovery of REE was about 78% and the grade of the first froth product was 42,995 ppm Ce, 24,088 ppm La, 14,236 ppm Nd, 4,388 ppm Pr and 1,570 ppm Y. When conducting flotation after iron minerals were removed by magnetic separation, a better result was obtained; with 2 mL of oleic acid, 2 mL of MIBC and no sodium silicate, the recovery was increased to 90% and the grade was also increased to 58,600 ppm Ce, 28,624 ppm La, 17,160 ppm Nd, 5,348 ppm Pr and 1,971 ppm Y.

Jan 1, 2014

By Sashnee Raja, Mehdi Nemati, Ashley Sissing, Susan T. L. Harrison

"Extreme thermophiles, operating at 65 - 90°C, are finding increasing application in biohydrometallurgy These microorganisms have the advantage of exhibiting better oxidation kinetics in terms of reaction rate and extent of mineral solubilisation. These extreme thermophiles are Archae, characterised by a different cell envelope structure perceived to provide reduced structural strength in comparison to bacterial envelopes, and customised metabolic pathways.The active tank bioleaching process, used for high rate leaching, is conducted in a slurry bioreactor. Here sufficient energy dissipation is required to ensure suspension of the mineral phase as well as to sustain high rates of gas liquid mass transfer. It is well known that subjection to hydrodynamic stress of sufficient magnitude may alter the physiological state of a range of micro-organisms through changed viability (ability of the microbes to grow), metabolic activity and integrity.In this paper, we report on studies carried out to quantify the ability of the extreme thermophile Sulfolobus to withstand the hydrodynamic stress environment generated at high pulp densities in the slurry bioreactor. Both a pyrite system (as a model system) and a chalcopyrite system (as an application) were studied. In laboratory reactor systems, the nature of biological responses to stress induced at high pulp density have been identified in terms of ability of the microbes to grow, their metabolic activity and rate of leaching and cell integrity. Critical operating conditions within the laboratory reactor are identified and the mechanism mediating reduced performance considered."

Jan 1, 2003

"The global demand for the copper metal is continuously increasing however, the high-grade copper ore deposits are constantly depleting. As a result, ore bodies with complex mineralogy characteristics and rich in arsenic-copper bearing minerals are increasingly processed. Arsenic-copper sulphides such as enargite can represent a significant amount of arsenic in concentrate, which causes high financial penalties by smelters. On the other hand, arsenic (As) is a highly toxic inorganic pollutant, which causes human health and environmental problems. Recent research studies have demonstrated promising results showing the possibility of separating arsenic-copper sulphides from copper sulphides using controlled pulp potential (Eh) flotation at laboratory scale. However, the selective removal of arsenic-copper minerals in real ore systems is not well understood. Two ore samples were selected from the Tampakan copper-gold deposit located in the Philippines named the HAS (high arsenic sample) and the LAS (low arsenic sample) samples and the mineralogical analyses were performed on both samples. The floatability of enargite in a batch flotation system under controlled pulp potential conditions was investigated for the HAS and the LAS samples. It was observed that it is possible to selectively separate enargite from other copper minerals after reducing the pulp potential to about -200 mV SHE at pH 11 in the LAS sample. However, no separation between enargite and other copper minerals was observed at a reducing potential for the HAS sample. Mineralogical analyses and surface chemistry studies were undertaken for both samples to find out the reasons for different observations. This study has an important implication in sulphide flotation to achieve sustainable development in the utilisation of arsenic-copper mineral resources. INTRODUCTIONAs the demand for copper is increasing, the extraction and development of resources including complex deposits is becoming necessary. These complex deposits often have issues such as: lower grade ores, floatable non-sulphide gangue, very fine-grained ore and therefore poor liberation and significant regrinding, mixed copper mineralogy, complicated galvanic interactions, economic levels of gold and silver, and high levels of impurities such as arsenic. There is currently no established methodology for separating arsenic-bearing copper minerals from other copper sulphide minerals by flotation. The possibility of separating arsenic-copper sulphides from other copper minerals by controlling the potential of the flotation pulp has been shown in previous studies. However most of these studies were conducted on single mineral systems and the selective removal of arsenic-copper minerals in complex ore systems is not well understood. The flotation behaviour of arsenic-bearing minerals within complex ores differs significantly from that of pure mineral systems due to the effects of mineralogical composition, the degree of liberation, and the surface oxidation. The understanding and manipulation of these effects can lead to improvements in the selective flotation recovery of arsenic-bearing species from complex ore systems."

Jan 1, 2018

By Shibayama A.

In this research, an investigation of a process to selectively remove arsenic (As) and antimony (Sb) contained in enargite (Cu3AsS4) and tennantite/tetrahedrite ((Cu1,Fe)12(As,Sb)4S13) copper resources by leaching and precipitation were performed. First in the leaching process, the target was to selectively leach As/Sb and reduce their contents in the ores to <0.5 wt% followed by a second process to remove As/Sb dissolved in solution for environmental control. Enargite ore contained 3.65 wt% As while tennantite/tetrahedrite ore contained 5.40 wt% As and 4.85 wt% Sb. Alkaline leaching using NaHS?NaOH media at varying experimental conditions (temperature, pulp density, time, reagent concentrations) were performed to investigate the process. As/Sb precipitation studies were also performed to control high As/Sb concentrations in leach solutions by using elemental sulphur (So). Results from leaching studies showed that over 99% of As/Sb in the impure copper ores can be removed and their contents in the final solids reduced to <0.5 wt%. It was also established that such very high leaching could be achieved at 80°C within 1?6 h and pulp densities as high as 1000 g/L. The study also revealed that leach solution containing very high As/Sb concentration ranging from 5 to 20 g/L can be used as fresh solution for leaching of fresh ores until concentrations exceeding 35 g/L when it was sent to precipitation circuit for As/Sb removal. Addition of elemental sulphur at 90°C and fast cooling to 30°C allowed over 60% As/Sb precipitation and removed as Na3AsS4 and solution with reduced As/Sb concentration to leaching circuit for continuous use. Keywords: Enargite; Tennantite/Tetrahedrite; Selective Leaching; Precipitation; Sodium hydrosulfide;

Sep 1, 2012

By Marianella Perez, Williams Calderón, Gonzalo Montes-Atenas

The lack of fresh water sources, particularly in the Northern part of Chile, has driven the mine sites to search for new and sustainable paths to obtain water resources to run minerals processing operations. Among them, the use of seawater in concentrators appears as an interesting solution to this problem. However, the presence of seawater will have an impact onto the operation, not only because it will enhance corrosion reactions in the equipment installed in a plant, but also because it may affect how particles will effectively be processed across the numerous unit operations existing in the mine site. Among such unit operations, the grinding stage is a highly regarded as it defines the success of the separation of valuable minerals from gangue material in the froth flotation operation. Then, one important aspect to be addressed is to understand how the presence of seawater will affect the different mechanisms acting during the operation of a ball mill. The aim of this research work is to assess the effect of changing the aqueous matrix from process water to seawater in ball mills onto the mill performance. The methodology considered the use of Fluent® software and its capabilities to run numerical simulations with heterogeneous media. On one hand, from the data analysis, it is possible to infer that breakability mechanisms should not be significantly affected. On the other hand, the high ionic strength of the matrix should impact importantly particle transport mechanisms within the mill. Particularly, when transporting finer particles. Rheology results were in agreement with previous published research studies suggesting the suspensions to behave as Newtonian, Dilatant o Pseudo-plastic fluid depending on the amount of fine particles present in the grinding media. The latter will result in changes in the residence time of particles in the mill producing overgrinding or an excess in the circulating loads.

Jan 1, 2014

By A. V. Abshilawa, D. G. Talakhadze, R. I. Sturua

"Processing of the tailings accumulated over the lifetime of Madneuli Copper Concentrator is an opportunity to extract additional salable copper and gold products. This paper presents a pre-concentration process for the valuable components (copper and gold) of the accumulated tailings. The developed process makes it possible to obtain a copper pyrite concentrate with a yield of 14.05%, copper grade of 1.36%, and recovery of 83.22% containing 3.78 g/ton of gold at a recovery of 84.31%. The bulk concentrate is produced by a combined process bringing together selective flotation to produce salable copper concentrate and hydrometallurgical processing of the selective flotation tailings to recover gold. KEYWORDS: FLOTATION, ALBION PROCESS, LEACHING, COPPER CONCENTRATE, SELECTION Madneuli Copper Concentrator, Georgia, was put into operation in 1975. Over its lifetime, 40 mn tons of tailings have been accumulated at the tailings storage facility (TSF). Sampling of the TSF has indicated that the average copper and gold grade is 0.23% and 0.56-0.65 g/ton, respectively. Accordingly, the TSF can be classified as a technogenic reserve. This paper discusses pre-concentration of valuable components using flotation, followed by processing of the bulk concentrate in the Albion process. Mineralogical analysis of the accumulated tailings showed that the main ore mineral is pyrite (11.71%). Copper minerals are mainly represented by chalcopyrite (0.7%). The main nonmetallic mineral is quartz (67.3%); sericite, chlorites, etc. also occur. Pyrite is present both as liberated grains and intergrowth. The absolute majority of copper minerals are found as intergrowth with pyrite, less often with quartz. Ore minerals are slightly oxidized. Chemical analysis results are shown in Table 1. Particle size distribution shows that the size class -0.2 mm - 0.045 mm has the highest grade of 0.85 to 0.97 g/ton of gold. Size class +1.25 mm has the lowest grade. Based on the chemical and mineralogical studies and particle size distribution, an optimized process was developed for pre-concentration of the valuable components prior to hydrometallurgical processing. Several gravitation, direct selective, bulk, and bulk selective flotation processes were trialed. (1,2)"

Jan 1, 2018

By Y. Y. Emelianov

The results of the test work of four treatment options of three refractory gold-pyrite and gold-arsenic flotation concentrates are presented. These concentrates were obtained during the concentration of primary ores of large gold deposits. It was found that ultrafine grinding of refractory flotation concentrates did not increase the recovery of gold during subsequent cyanidation. The elimination of sulfur and arsenic during oxidative roasting is 99 per cent. 88-93 per cent of gold is recovered by cyanidation from calcines. After biooxidation of the flotation concentrates with a mixture of strains Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans 88-91 per cent of gold is recoverable by direct cyanidation. The recovery of gold from flotation concentrates by pressure oxidation is 88-99 per cent. These results suggest that gold recovery is important but the following strategies would have an impact on a plant performance and would be considered when developing an option to treat refractory ores: capital and operating costs, ore reserves, mine location, infrastructure and qualified staff. Keywords: gold, flotation concentrates, recovery, cyanidation, roasting, biooxidation, pressure oxidation

Sep 1, 2012

By Antoineta Boteva

A significant part of the currently production of the non-ferrous and precious metals is from sulfide ores. Character feature of sulfide ores is the presence in them always pyrite and wide range of different sulfide minerals else. These minerals are the carriers of valuable for industry metals. Due to the low content of the main components, very often call on the use of collective- selective flow-sheets. The extraction of minerals in the collective concentrates determined in a large extent the effectiveness of the collective-selective sheets. In conditions of bulk flotation kinetics to floatate of the various minerals is different. Due to why it is and how it can be used for a more effective selection of minerals ?this is the main task of this report. For this purpose are used results from the bulk flotation of pyrite, copper sulfides, molybdenite, galena, blenda. It is separated and place of host rocks. Base it of large experimentation material, including both electro-kinetic measurements of mineral systems, as well as laboratory flotation tests and factories monitoring it is established kinetics of flotation of mineral particles in conditions of collective flotation. Made an effort to clarify the effect as of the species and the proportion of different sulfide minerals involved in flotation pulp else. Traced was the impact of the density and aeration of the flotation pulp on deferens in kinetics of mineral flotation in condition of balk flotation. The obtained results are used to increase the efficiency of the diffraction flotation of the complex sulfide ores containing precious metals. In the schemes, it is possible precious metals to fall in the most appropriate for the next processing products. Keywords: flotation, sulphide ores, kinetic extraction

Sep 1, 2012