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By Kyle Bartholomew, Robert McIvor

"Functional performance analysis of closed circuit grinding provides valuable insight into the two components of ball mill circuit grinding efficiency: classification system efficiency and mill grinding efficiency. Classification system efficiency isolates the combined effect of classifier performance and circulating load ratio from other circuit variables, such as ore grindability and the mill grinding environment. Optimization of classification system efficiency ensures grinding energy is applied to particles needing further size reduction and not to overgrinding. Entirely based on size distribution data, classification system efficiency precisely distinguishes subtle changes in classification system performance. Use of the functional performance equation to isolate mill grinding efficiency allows for proper optimization of the mill grinding environment by isolating confounding effects of changes in classification and ore grindability. Variables such as mill percent solids and grinding media selection can be optimized using the mill grinding efficiency subcomponent of functional performance. First published by McIvor in 1988, the functional performance equation provides a set of standardized, quantitative optimization criteria, simple and powerful, which link circuit performance to plant design and operating variables that can be manipulated. Functional performance optimization has been applied in numerous mineral processing plants globally and continues to gain acceptance as a practical means for grinding circuit optimization. In this paper, examples of derivation and industrial application demonstrate the means by which functional performance analysis dissects grinding circuit efficiency into its subcomponents allowing the reader to apply this straightforward, powerful optimization methodology at their mineral processing operation."

Jan 1, 2014

By Shuji Owada, Yang Geng, Natsuko Kuroki

Micro-bubble flotation is considered to be an ideal method for the separation of fine or ultra-fine particles, which are difficult to be separated with conventional flotation and other solid separation technologies. Micro-bubble flotation can increase the probability of bubble-particle collision more than conventional milli-bubble flotation. However, there are also some problems. For example, it is known that the rising velocity of micro-bubble is quite low; therefore, the flotation rate reduces. And also, the bubble-particle adhesion probability becomes lower than that of milli-bubble flotation, which is proved in our prior research. In this paper, we applied ultrasonic irradiation to the micro-bubble flotation system in order to solve the above problems and focused on the bubble-bubble and bubble-particle interactions. For clarifying the behavior of bubble-bubble interaction, bubbles behavior was recorded by high-speed camera under irradiation of various ultrasonic frequencies. As a result, in the case of bubble-bubble interaction, it is proved that bubbles are highly coalesced by ultrasonic irradiation especially in the lower frequency and it can enhance more precise separation. In the case of bubble-particle behavior, it is found that the floatability become higher with the ultrasonic irradiation of higher frequency, and it is indicated that ultrasonic irradiation might improve the bubble-particle adhesion probability. Additionally, it is also found that the apparent CMC of the micro-bubble flotation under the ultrasonic field become much lower with higher frequency than with lower frequency, and it is suggested that the dramatic improvement of hydrophobization is achieved.

Jan 1, 2014

By Crasta Jeason, T. Sreenivas, M. Narasimha

The subtle nature of the flow inside the hydrocyclone has encouraged development of mathematical models for predicting its performance, which are widely used in simulation of comminution circuits. But most of the models available are based on single average feed density. But the feed to hydrocyclone classifier is generally mixture of particles of different densities. This effect of varying density of feed particles on performance of hydrocyclone has been reported in literature. Further investigation of the effect of multi component feed on the performance of hydrocyclone is the objective of this work. This work involves experimental work to study multicomponent behaviour in various size cyclones. The performance of hydrocyclone for feed mixture of magnetite and quartz has been studied. The effect of presence of magnetite, a high density material on efficiency of separation of quartz has been analysed. It was observed that the effect of component interaction increases with feed solids concentration leading to an increased cut-size for a given optimum cyclone conditions. Based on the multi-component exiperiments available in literature, a concept for modeling the performance of hydrocyclones is proposed. A set of semi-empirical model equations for cut-size, sharpness of separation are presented. An attempt to validate the new hydrocyclone model on multi-component behaviour is made.

Jan 1, 2014

By V. G. Minenko, V. A. Chanturiya, A. L. Samusev

Eudialyte is one of perspective resources of zirconium and other rare earth elements (REEs). Large reserves of eudialyte concentrated in the Murmansk region of the Russian Federation. Usually, technologies of REE treatment include the decomposition of eudialyte concentrate in different acidic, extraction and utilization of all components. The main problems in the leaching of eudialyte include are: the formation of an unfiltered silicon-containing gel; low recovery of REE; difficulty extraction of metals from the productive solution; high aggressiveness of the reagents. One of the promising trends of intensification of the processing of hard-to-degrease rare metal raw materials is the use of energy methods for affecting mineral suspensions. These methods make it possible to increase the efficiency of break up fine-dispersed mineral complexes and extracting micro- and nanoparticles of a valuable component in subsequent deep processing. The purpose of this work is to investigate the effect of energy impacts on the nitric acid leaching of eudialyte concentrate. Experimental studies were carried out in a developed laboratory facility that makes it possible to evaluate the effect of electrochemical, ultrasonic and combined effects on the leaching of zirconium and REE from eudialyte concentrate. The studies carried out on the samples of eudialyte concentrate with the size class of -0.315 + 0.063 mm showed that the use of electrochemical and acoustic effects increases the extraction of ZrO2 in the production solution in 1.6 - 2.5 times, REE in 1.3 - 2.2 times, respectively. An analysis of the microstructure and phase composition of the surface of the eudialyte concentrate showed that the intensification of the leaching process is due to surface cleaning from the silicon-containing gel, as well as the opening of capillary channels and microcracks, which accelerates mass-transfer processes. The results obtained open wide opportunities for creation of modern and effective technology of processing of eudialyte concentrate, producing high-quality zirconium products and REE.

Jan 1, 2018

By S. A. Vorobyev, Yu. L. Mikhlin, Ye. V. Tomashevich, A. A. Karacharov, M. N. Likhatski1, A. S. Romanchenko, S. V. Saikova

"A set of state-of-the-art methods have been applied to study ultrafine particles and nanoscale species arising on mineral surfaces upon milling, interaction with flotation reagents, and leaching of base metal sulfide ores in order to gain insights into interfacial mechanisms. The fine fractions produced by ball milling of a Pb-Zn Gorevsky ore and four Cu-Ni sulfide ores studied with laser diffraction, dynamic light scattering, zeta-potential measurement, Xray photoelectron spectroscopy (XPS), SEM, TEM and other techniques. The particle size distributions had, aside from the peaks at 20-60 ?m, maxima near 1-2 ?m; the flotation was considerably suppressed when the yield of positively charged ultrafine particles approached tenths % (several kg per ton). High-energy XPS and X-ray absorption spectra revealed that sulfide minerals depleted in metal in air and aqueous solutions were composed of outer “polysulfide” layers, strata with disulfide species, and heavily defective underlayers, and “passivation” was explained by stability of the metal-deficit structures. Dixanthogen at pyrite and copper-activated sphalerite, dixanthogen and then cuprous xanthate on chalcopyrite, and chemisorbed xanthate at galena were specified as the main interfacial products using cryo-XPS of fast-frozen flotation slurries. The particle size, zeta-potential and behavior of colloids of Cu and Pb xanthates and dixanthogens were largely determined by the initial ratio of a cation and collector; the properties of copper xanthate nanoparticles were also affected by incorporated dixanthogen (about 15 wt.%). Submicrometer gas domains of 3-8 nm in height and “hydrophobic” forces upon the probe retraction were found on xanthate-treated minerals using atomic force microscopy and spectroscopy; their impact on flotation is briefly discussed.INTRODUCTIONInterfacial phenomena play a key role in flotation, leaching, water purification and related environmental processes. The mineral processing and extraction of metal from sulfide ores commonly involves milling the ore, which produces, along with the particles of 20 µm to 100 µm, mineral entities ranging from micrometer to submicrometer and nanometer scale. Furthermore, ultrafine particles of flotation reagents, products of metal sulfide oxidation, and so on may form spontaneously and accumulate in production water, flotation froth, deposit on mineral surfaces, affecting the flotation performance, and then enter waste waters, mine and natural drainage, polluting soils, surface- and ground waters (Miettinen et al., 2010; Wang et al., 2014). The efficiency of flotation and hydrometallurgical recovery of values, environmental issues are crucially dependent on the state of mineral surfaces. Particularly, it is generally accepted that the surface non-stoichiometry of sulfide minerals induced by oxidation and leaching should affect their hydrophobicity and reactivity, including so-called “passivation”, but the nature of such surface layers are still a matter of controversy (see, for example, Holmes and Crundwell, 2013). Another phenomenon attracting rapidly growing interest in several areas is low-dimensional gas species (“nanobubbles”) at hydrophobic surfaces that may play a decisive role in particle-bubble attachment in flotation but remains scarcely investigated up to now (Xing et al., 2017). Here, we survey our recent results on the abovementioned problems applying a series of rather new methods and approaches; more details can be found in refs. Karacharov et al., 2016; Mikhlin et al., 2015; 2016; 2016a; 2016b; 2016c; 2016d; 2017; 2017a; Vorobyev et al., 2017."

Jan 1, 2018

By Ben Murphy, Alejandro Yanez, Tatu Miettinen

"Flotation using large volume cells has grown in importance during recent years, particularly given the increasing demand for minerals whilst ore grades are decreasing. Outotec introduced the TankCell® e300 in 2007 to enable concentrator plants to process these higher tonnages. From the beginning, TankCell® e300s with FloatForce® mixing mechanisms have demonstrated good metallurgical performance with decreased operating costs and high availability. This paper deals with specific engineering challenges that need to be considered when installing these units rather than giving examples of performance. Today there are over 100 TankCell® e300s operational worldwide. As more of these units are installed new technical challenges are encountered and solutions developed to maximize their productivity. Lessons have been learnt by operators, engineering companies and the cell manufacturers on how best to design and layout these cells in modern concentrators to ensure smooth transition from design to installation to operation. This paper presents information on important design considerations and learning that has been obtained through the design, installation and commissioning of the TankCell e300 around the world. Areas pertaining to cells layout such as feed and discharge arrangements along with items of metallurgical concern such as sampling, reagent addition and the potential benefits of installing a variable speed drive on the motor will be covered in depth."

Jan 1, 2014

By T. Sun, J. Kou, C. Sun, D. Gong

"HPGRs (high pressure grinding rollers) have demonstrated higher energy efficiency than conventional comminution equipment due to their application of particle-bed breakage mechanism. In the past decades, a large number of studies have been conducted to understand the characteristics of particle-bed breakage, however, few of them concerned the difference between single-particle and particle-bed breakage in compression comminution. This comparison is able to demonstrate possible advantages of particle-bed against single-particle in a breakage event due to the isolation of the effect of force loading mechanism. The present study investigated progeny fragment size and energy efficiency of these two breakage methods at variable energy inputs and particle sizes. The results show that at low energy inputs of around 0.25 kWh/t, the numbers of fines resulting from the two breakage methods are very similar. However, at higher energy inputs of around 1.0 or 2.0 kWh/t, particle-bed breakage generated significantly more fines. From the perspective of newly generated surface energy, particle-bed breakage is obviously more energy efficient than single-particle breakage at energy inputs between 1.0 and 2.0 kWh/t. It was also found that HPGRs demonstrate high energy utilization rate in generating new surface energy within their typical range of specific energy input. INTRODUCTION Rock comminution is an important and energy-intensive process in mining operations. Nowadays, decreasing head grade and mineral liberation size of ore deposits greatly increase the energy cost of comminution process. HPGRs have been successfully applied in the mining industry to improve the energy performance of comminution circuits. Typically, 10 to 30% of energy saving can be achieved due to the application of HPGR (Wang et al., 2013; Casteel, 2005; Günter et al., 1996)."

Jan 1, 2018

By P. Gao, J. W. Yu

"Magnetizing roasting-magnetic separation is an important route for the beneficiation of refractory iron ores. In this investigation, a pilot-scale fluidized magnetizing roasting reactor was introduced and used to study the effects of roasting temperature and the flow rates of reducing gas CO and fluidizing gas N2, on the magnetizing roasting performance of an Anshan-type carbonate-bearing fine iron ore. The results showed that the hematite was almost reduced to magnetite by a gas mixture of 4 m3/h CO and 1 m3/h N2 at a roasting temperature of 540 °C. Under the optimized conditions, a high-grade magnetic concentrate assaying 66.1 wt.% Fe with a recovery rate of 91.2% was achieved from an Anshan-type carbonate-bearing fine iron ore assaying 42.0 wt.% Fe. The XRD, VSM, and optical microscopy analyses revealed that the siderite was successfully converted to magnetite by roasting. Some coarse hematite particles were difficult to reduce to magnetite completely; however, these generated magnetite particles with a fine hematite core could also be effectively recovered by magnetic separation after liberation from gangue minerals due to their strong magnetism. INTRODUCTION Magnetizing roasting followed by low-intensity magnetic separation has been considered as an effective solution, both technologically and economically, when upgrading refractory iron ores (Zhang et al., 2012; Peng et al., 2012; Li and Zhu, 2012). According to the type of roasting reactor, the magnetization roasting can be divided into shaft furnace roasting, rotary kiln roasting, and fluidized bed roasting (Zhu and Li, 2014).Shaft furnace magnetization roasting system is mainly composed of heating and reduction processes. The hematite ore is first heated to 700~800 °C in the heating zone, then falls into reduction zone where the weakly magnetic hematite is reduced to magnetite by coke oven gas at 550~600 °C (Yan et al., 2012). However, several years of engineering practices indicate that the shaft furnace can only process the hematite ores with a granularity of 15 ~75 mm, and the shaft furnace roasting is also characterized by heterogeneity of roasted product. Hence, the shaft furnace magnetization roasting technology is gradually replaced by high-gradient magnetic separation with the development of high-gradient magnetic separator. The rotary kiln generally handles the hematite ores with a grain size of less than 30 mm (Zhu and Li, 2014), however the formation of clinker ring in the rotary kiln will affect the yield of iron resource. In the fluidized bed furnace, the hematite ore is shaken up by an upward current of gas which maintains the individual particles in suspension (Yu et al., 2018). The precise adjustment of the gas velocity to the particle size and the specific weight of the hematite ore, make it possible to generate a floating mixture of gas and solids which behaves almost like a liquid (Yu et al., 2017a). The process is reported to have the following advantages over the other roasting techniques: ease of control due to absence of moving parts within the reactor, homogeneity of roasted products, ability to handle fine particles, and high efficiency of heat transfer and mass transfer (Li et al., 2015; Yu et al., 2017b). However, the simultaneous heating and reductive magnetization of hematite ore occur at the same place in the conventional fluidized bed reactor. Therefore, the reductive atmosphere, as well as the safety and stability of anti-explosion are hard to be controlled. Besides, the roasting temperature for conventional fluidized bed furnace is usually up to 950~1150 °C (Liu et al., 2017). Thus, the formation of clinker ring caused by high temperature will affect the operating efficiency."

Jan 1, 2018

By Yuriy V. Gulyaev, Galina V. Sedelnikova, Valeriy D. Lunin, Valentin A. Chanturiya, Igor J. Bunin

"Probable mechanisms of disintegration of mineral particles in gold-containing sulphides and benefication products exposed to high-power electromagnetic pulses are discussed. Experimental data are presented to confirm the formation of breakdown channels and selective disintegration of mineral complexes as a result of pulse irradiation, which makes for efficient access of lixiviant solutions to precious metal grains and enhanced precious metal recovery into lixivia during leaching. Experiments with different gold-containing products revealed a synergetic effect of high-power electromagnetic pulses with widely varying parameters and moisture in mineral pores on breaking-up and gold extraction processes for various resistant goldcontaining mineral products.Several series of tests performed in IPKON RAS, IRE RAS and TsNIGRI yielded an absolute gain in precious metal recovery, up to 30-80 % for gold and 20-47 % for silver, with resultant gold recovery as high as 90 %. An essentially new, environmentally safe and energy-saving breaking-up technology has been developed for resistant gold-containing products. This new method would shorten the way from raw minerals to final products and help significantly reduce the cost of these products as it obviates the necessity for using the expensive procedures of energy-intensive and environmentally hazardous oxidative roasting and autoclave breaking-up for ore concentrates."

Jan 1, 2003

By Scott C. Brown, Brij M. Moudgil, Ivan U. Vakarelski

The manipulation of the apparent hydrophobicity of particlute surfaces is necessary to achieve optimal selectivity in flotation processes. Previously a number of works have investigated the role of microscale surface and particulate morphologies on chemically modified substrates. These works have suggested that microscale surface asperities lead to an increase in flotation efficiency by assisting in the rupture of wetting films. Yet, in mineral processing the presence of surface asperities may lead to a reduction in flotation. The reason for this may-in part-be due to the presence of nanoscale irregularities at the interface. In this work, it is proposed that the presence of roughness at the nanoscale may have a dominant impact on the apparent hydrophobicity of mineral surfaces during flotation. It is suggested that as inter-asperity seperation distances are reduced capillary effects are enhanced for high energy mineral surfaces leading to the formation of liquid domains, which adversely impact hydrophobicity. In addition, as these distances approach the surfactant headgroup size obstruction of surfactant self-assembly process may occur, thereby further limiting flotation.

Jan 1, 2003

By S. A. Bogidaev, M. Yu. Tiunov

"The paper describes the results of the flotation tests with complex rare metal ores from deposits in the Trans-Baikal Territory. Correlations between the quality of produced wolframite, hubnerite and mica concentrates with or without the presence of various alkaline modifiers are determined. Commonly, rare metal ores contain minerals of comparable value to main elements recovered in processing plants using gravitational methods. The paper describes the results of flotation recovery of valuable minerals – main and associated – from gravity tailings of deposits in the Trans-Baikal Territory. It was found that gravity tailings from the first deposit contained fine-grained wolframite, mica (muscovite, lepidolite etc.), feldspar; hubnerite, scheelite, beryl, fluorite, rubidium-containing muscovite from the second deposit, correspondingly. This paper presents the results of the stage flotation tests with the production of tungsten (wolframite, hubnerite), fluorite and mica concentrates from gravity tailings. Figure 1 demonstrates the flowsheet of tungsten ore minerals and mica stage flotation from gravity tailings of the first deposit.Wolframite can be floated using oleic acid with the presence of soda ash, a complexing collector (IM-50), under slightly alkaline conditions in combination with a nonpolar collector [1, 2, 3, 4]. The study included wolframite flotation using the combination of two alkaline modifiers. Flotation of wolframite was performed after pulp desliming, using tall oil saponified with soda ash. The recovery of wolframite in the concentrate of rougher flotation reached 80-85%; the concentrate contained up to 1% of tungsten oxide that can be upgraded to a saleable product using gravitational methods. This procedure was tested during flotation of wolframite, tantalite-columbite and pyrochlore, and provided high performance regardless of a season, at pulp temperatures of 8-10°C, though fattyacid collectors are significantly inefficient at such low temperatures due to low solubility, dispersion and increased collector consumption, consequently. The introduction of two alkaline modifiers in pulp appears to improve these characteristics.The first stage of the tests was focused on increase of iron-bearing tungsten ore minerals recovery from gravity tailings and stabilization of the cold pulp flotation process."

Jan 1, 2018

By Adam Jordens, Olga Kuzmina, Christopher Marion, Kristian Waters

"In order to meet the growing demand for non-Chinese rare earth suppliers many new rare earth (RE) mineral deposits are currently under development, however these deposits typically include many minerals for which there is little processing information available. One of these deposits is the Nechalacho deposit located in the North West Territories of Canada. This deposit contains multiple RE minerals including bastnäsite, zircon, fergusonite, allanite and monazite. The work presented here investigates the use of different classes of flotation collectors (carboxylic acids, hydroxamic acids, phosphoric acids) typically used in RE mineral flotation to float the Nechalacho ore directly. Flotation tests are also conducted as the final step in a beneficiation process incorporating centrifugal gravity concentration and magnetic separation. This combination of centrifugal gravity concentration and magnetic separation rejects low specific gravity gangue minerals such as K-feldspar and plagioclase and concentrates high specific gravity minerals such as magnetite and hematite. The removal of low specific gravity gangue helps to improve flotation and the removal of ferromagnetic iron oxides is important prior to flotation using certain chelating collectors."

Jan 1, 2014

By Chen Zhiqiang, Luo Chuansheng, Chen Ziqiang, Liu Jianguo, Rao Jinshan

To comprehensively utilize the valuable resource in tailings, increase the economic benefit of mine, reduce the amount of tailings, prolong the service life of tailing dam, the comprehensive utilization of tailing resource is arousing the attention of more and more mines. Research of comprehensive recovery of feldspar and silica from Cu-Mo floatation tailings has been furthered. Technology of "De-sliming-Magnetic Separation-Reverse Flotation-Feldspar and Silica Separation" has been developed to utilize the resource. Slime is removed and reagents cost is reduced by de-sliming. The specific effective collector ZL is used in gangues reverse flotation, and GZ-818 is the collector in feldspar and silica separation. The grinding operation is vital to ensure the liberation degree of feldspar and to eliminate the reagents pollution on minerals surface. To a Cu-Mo flotation tailing assaying K2O 5.22%, Na2O 2.22%, Fe2O3 1.95%, Al2O3 12.05%, SiO270.66%, superfine K-feldspar and silica concentrates can be produced. The feldspar concentrate productivity is 29.67% assaying K2O 8.99%, Na2O 2.86%, Fe2O3 0.16%, Al2O3 16.99% and SiO2 68.92%. The silica concentrate productivity is 14.20% assaying 0.17% K2O, 0.04% Na2O, 0.01% Fe2O3, 0.55% Al2O3 and 98.17% SiO2. The technology provides technological reference model for the similar mines.

Jan 1, 2014

By A. N. Zagorodnyaya, Ye. G. Bochevskaya, E. A. Sargelova, Z. S. Abisheva, A. S. Sharipova

"In Kazakhstan, there is a unique sulphide copper deposit, in the ores containing the natural isotope of osmium-187 (more than 90 %). In the pyrometallurgical processing of concentrates for the target metal, osmium is mainly sublimated, with wet cleaning of metallurgical gases (dust and gas mixture) 40 % of it together with rhenium passes into washing solutions (wash acid). On the basis of this acid, the production of ammonium perrhenate was organized at the enterprise of the RSE ""Zhezkazganredmet"" and for the first time in the world practice - the isotope of osmium-187. However, the degree of its recovery from solutions does not exceed 8 % of the amount supplied with the charge or 25 % of the amount that was received for extraction. But the bulk of it (~ 75 %) remains in the raffinate, discharged to sewage treatment plants (wastewater). The studies presented in this work are aimed at solving the problem of osmium isotope-187 extracting from wastewater, which are a potential source of increasing metal production in Kazakhstan. The aim of this work is the development and scientific justification of osmium deposition regimes from wastewater using such reagents as thiosulfate and sodium sulphide. The influence of various physicochemical factors on the precipitation of the osmium was studied and optimal conditions for its maximum transition to sediment were chosen. An original method for obtaining osmium concentrate in the presence of sodium thiosulfate with the addition of potassium iodide from a new type of wastewater - man-made ammonia solutions has been developed. These solutions were combined mother liquors of solid-phase stripping operations and dissolution of pulp of crude ammonium perrhenate. On the basis of the obtained results, a settling technology for extraction of the osmium from man-made ammonia rhenium-containing solutions was introduced at RSE ""Zhezkazganredmet"". It should be noted that the degree of extraction of osmium, depending on its concentration in solutions entering on the settlement, and taking into account the addition of sulfuric acid, will vary from 60 to 90 %. The recovery of osmium during the test period was 58 %."

Jan 1, 2018

By Grigory Voyloshnikov, Sergey Petrov, Vladimir Petrov

"The treatment of high-grade copper gold-bearing ores is practiced extensively. However, due to low concentration of copper the application of a separate process for copper recovery can make this process uneconomical. The copper, in particular: in oxide minerals, intensively bounds with cyanide during conventional cyanidation. In this case, cyanide is not able to react with precious metals and the consumption of cyanide increases. The resulting copper cyanide complexes have a negative effect on the recovery of gold. Due to decreasing of the process parameters, a repeated use of the recycled solutions can be hindered, especially in the case of heap leaching. The technology of copper removal from the process solutions with simultaneous regeneration of free cyanide from copper-cyanide complex and producing of a saleable high-grade copper concentrate was developed. An important feature of this technology is simplicity, the absence of complex or dangerous operations and the use of common reagents. The choice of equipment depends on the ore treatment option: heap or vat leaching. Also, simpler equipment schemes are available. The studies, tests and industrial practice show that if the concentration of copper can be decreased down to the first numbers of mg per ppm or lower, it is reasonable to maintain the process copper grade in the recycled solutions at 30-50 mg/L. In this case, recycling of cyanide-bearing solutions is unlimited. The regeneration of free cyanide from that of bound with copper and other cyanide complexes is 95-98%. The grade of copper in the concentrate is 55-60%. This technology is an economically competitive option, in particular: with the account of the sales of copper concentrate. The removal of copper has a positive effect on gold recovery, especially during heap leaching. In addition to, this offers significant benefits in reduced costs."

Jan 1, 2014

By V. Yu. Ivanov, A. I. Yuryev, L. S. Lesnikova, M. S. Datsiev

"The Talnakh Concentrator was put into operation in 1981 using a direct selective process to produce copper, nickel and pyrrhotite concentrates.In 2001, a novel selective-bulk-selective (SBS) technology for the concentration of massive sulfide ore was implemented, that allowed to increase the valuable components recovery into target concentrates with feedstock grinding coarser than before. In 2003-2005, the process upgrading included the differentiated processing of nickelpyrrhotite products recovered at the different concentration stages and made it possible to significantly enhance the contrast of the pentlandite and pyrrhotite flotation properties and to simultaneously increase separation of polymineral intergrowths.The next stage of the PD concentration complex development is the Project ""Talnakh Concentrator Reconstruction and Technical Upgrading"" to raise its capacity by half. The project has three Phases.• Phase 1. Pilot startup was carried out in January 2015 following the installation of new OK-100 TC flotation machines, manufactured by Outotec.• Phase 2. The introduction of a new technology developed by the Polar Division specialists launched in mid-2016. The new technology is based on maximization of iron and sulfur removal into tailings and maintenance of non-ferrous and precious metals losses at the same level.After the realization of Phase 3, the annual capacity of the Talnakh Concentrator will raise by another ~ 40% at the expense of processing cuprous and disseminated ores currently being processed by the Norilsk Concentrator.By 2023, due to upgrading of the PD production facilities the emissions to the atmosphere will reduce by 75%.Polar Division of PJSC MMC Norilsk Nickel (PD) searches for the ways to solve its environmental issues. Thus, in 2016, the Nickel Plant was shutdown and a new flowsheet was introduced at Talnakh Concentrator. It resulted in the reduction of sulfur specific amount sent to pyrometallurgical processing as a component of the concentrates.The Talnakh Concentrator was put into operation in 1981 using a direct selective process to produce copper, nickel and pyrrhotite concentrates.In 1981, its design capacity for processing of Cu-Ni ores from Oktyabrsky and Taimyrsky Mines did not exceed 3 million tons per year.In 2001, a novel selective-bulk-selective (SBS) technology for the concentration of massive sulfide ore was implemented at the Talnakh Concentrator, that allowed to increase the valuable components recovery into target concentrates with feedstock grinding coarser than before."

Jan 1, 2018

By Chuansheng Luo, Qiuyang Hong, Lili Zhang, Dongyun Liang

"The metallogenic rock of a sandstone-type Cu ore is arkose-quartzite as well as siltstone and the cement is composed of argillaceous minerals including sericite, chlorite, etc. and carbonate minerals including calcite, dolomite, etc. A detailed process mineralogy study on this complex copper ore was carried out using MLA combined with traditional research methods. According to the results, there are many types of Cu minerals including copper sulfideminerals, secondary copper sulfideminerals, copper oxideminerals, copper carbonate hydroxide minerals and copper silicate minerals in the ore. Based on the occurrence of Cu, the copper existing as copper sulfide minerals (bornite, chalcopyrite and chalcocite) and copper oxide mineral (malachite) which have a good floatability accounts for 49.28% while the copper (chrysocolla) hard to be recovered by flotation and the copper existing in the cement (sericite, chlorite, psilomelane and limonite) accounts for 48.65%, and the copper existing in the carbonate minerals (calcite and dolomite) accounts for 1.72%. The process mineralogy study indicates that the process "beneficiation combined with hydrometallurgy" should be applied due to the various occurrence of Cu. The abundance of calcite and dolomite is about 12%, so removing these acid-consuming minerals by floatation is an effective way to reduce the acid consumption in the hydrometallurgical process and the lowest Cu loss is 1.72%. So the process "floating copper minerals-floating calcium minerals (calcite and dolomite)-leaching copper from the tailings" is used in the pilot tests. The recovery of floating copper and leaching copper from tailings is 46% and 30% respectively, so the total recovery of copper is 76%. Compared with the original process "leaching copper from crude ore-floating copper from the residue", the total recovery reduces by 1% but the acid consumption of producing per ton of copper decreases from 37t to 12t. The new technology process has a great advantage."

Jan 1, 2014

By P. Somasundaran, Tarun Bhambhani, D. R. Nagaraj, P. Patra

"Certain non-sulfide gangue minerals are known to have a detrimental impact on flotation performance. When present in large amounts, they can negatively affect recoveries, grades and throughput at current operations, and dictate the viability and economics of a greenfield project. While the problem has been investigated for a long period of time, a scientific understanding of the mechanisms by which these minerals affect performance has not been obtained, and no acceptable solutions have been developed. This study focused on the role of physical aspects (e.g. shape, size and morphology) of these minerals as the underlying factors for poor performance. Flotation tests were conducted using model mineral systems to understand the impact of one phyllosilicate mineral (muscovite) on flotation kinetics, recoveries and grades. The study reveals that there is minimal impact on flotation kinetics, no impact on recoveries, but a very strong detrimental impact on concentrate grade. The traditional mechanisms of transport such as true flotation and entrainment are not sufficient in describing the extent of transport. The transport is attributed to the unique platy morphology of muscovite, which allows for action of buoyancy forces. Data also shows that the muscovite transport to the froth phase depends on particle size; coarser sized muscovite (100-150@) report to the froth phase in much larger amounts than medium sized muscovite (50-100@). At finer size fractions (<50@) the transport is also increased, and this is likely due to entrainment."

Jan 1, 2014

By Arkady Senchenko

The paper deals with the problem of refractory gold-containing material processing. It is observed that all traditional methods for liberation of fine gold from this type of products are characterized by a number of essential disadvantages, where the main ones are ? considerable expenses for ore processing and big environmental impact. As an alternative to the existing methods there is considered a gold liberation method, which is based on the combination of ultra fine grinding process with the consequent atmospheric oxidation. The theoretical justification of atmospheric oxidation was carried out, in the result of this the mechanism and the degree of sulphide minerals? oxidation was found out, the dependence of gold dissolution speed on the slurry content in liquid phase produced by grinding and oxidation was identified. The experimental data and results of pilot-plant testing are given and the most effective grinding and atmospheric oxidation mode is selected on this basis. The performed complex of research works allowed us to use the provided technology at the gold processing plant having capacity of 8 mln. tons of ore per year. The questions, problems, advantages and disadvantages of atmospheric oxidation technology for refractory gold-containing concentrates are considered in this paper. Keywords: refractory gold-containing material processing, gold liberation method, cyanidation

Sep 1, 2012

By H. Pearce, A. E. Lewis, A. Ochieng

Hydrodynamics and mixing are fundamental to the operation of mineral process systems such as flotation cells and metal precipitation reactors. The computational fluid dynamics (CFD) technique has been employed in the present work to study the hydrodynamics in a mixing vessel stirred with either a Rushton turbine or a pitched blade impeller. The multiple frame of reference (MFR) approach has been used to model both impellers. A draft tube was used only in the Rushton turbine stirred vessel. The flow profiles for the pitched blade impeller have been studied in three regions; below the impeller tip, at the middle of the tank, and near the liquid surface. The simulation results were compared with literature data obtained using a laser Doppler velocimetry in the three regions of the vessel, and it was found that the model predictions were better in the impeller region. There was a poor prediction of the experimental results in the region closer to the liquid surface; however, this was improved when the turbulence parameter (C2) in the k-e model was set to a higher value. The value of the impeller clearance at which the Rushton turbine generates an axial impeller type flow has been determined and it has been shown that, at this clearance, a draft tube can be used to enhance axial flow in a Rushton turbine stirred reactor.

Jan 1, 2003