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By Smuts. E. M.

This paper describes a methodology used to develop a numerical model for the study of particulate suspension rheology. Initially, Computational Fluid Dynamics (CFD) models of different rheometer geometries were tested with both a Newtonian fluid (water), and a non-Newtonian Herschel-Bulkley slurry. Rheograms were reproduced from these models and compared to experimental values. Once a single-phase model had been validated, a coupled model combining CFD and the Discrete Element Method (DEM) was created. Two open source software packages were chosen. CFD is implemented using Open FOAM®, and DEM using LIGGGHTS. These two different codes were coupled via another program called CFDEM. This coupled model is currently capable of modeling spherical particles in a suspending liquid. DLVO forces have been included in some models to account for inter-particle forces due to the surface charge on the particles. The coupled model is currently being validated. Preliminary results show good qualitative behavior of the model. Keywords: rheology, cfd, dem, suspensions, modeling

Sep 1, 2012

By D. J. Zhao

The reduction of ilmenite pellets was investigated at 950°C and 1000°C under a CO-N2 gas mixture with 10 L/min gas flow rate. All the reducing reactions were conducted in a furnace with a thermogravimetric analysis system. The reduction rate is higher at 1000°C than that at 950°C. At the early stage of the reactions, with the CO concentration increasing in the gas mixture, the reduction rate increased at 1000°C. In addition, at the early stage of the reactions, a rapid temperature increment and a rapid conversion of oxygen were observed on the curves of temperature versus time and conversion of oxygen versus time under different experimental conditions. The solid reaction products obtained in these experiments were analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometers (EDS). Metallic Fe with small amount of Ti dissolved in it and oxides of Ti were found in the solid reaction products, but the formation of any nitride phases was not found under the prevailing conditions.

Jan 1, 2014

By S. J. Ma

With the very effective depressant and collector developed by China Bluestar Lehigh Engineering Corp (hereinafter referred to as LEHIGH), satisfied results are obtained from laboratorial beneficiation tests on phosphate samples from Karatau, Republic of Kazakhstan by the direct flotation process. In this paper the effect of single factors on performance of flotation is studied and their applicable ranges are proposed. The final test results are described as follows: As the feed contains 23.20 % P2O5, and 3.96% MgO, a phosphate concentrate assaying 29.77%P2O5 and 1.54% MgO is produced, and the P2O5 recovery in concentrate is 88.28%. The beneficiation tests make it possible to simplify existing technology with fine grinding-desliming, followed by reverse & direct flotation system and consequently improve the concentrate grade and recovery for the future beneficiation plant

Jan 1, 2014

By Renato S. Costa, Afonso H. Martins, Flávia D. Mendes

"This paper presents some important aspects regarding the ion exchange treatment of an Ni and Co sulphate acidic liquor using chelating resins. Chelating resins possessing iminodiacetic or bis-picolylamine functional groups were compared in terms of nickel and cobalt recovery. The experimental resin with bispicolylamine functionalities (Dowex M4195) was evaluated with respect to Ni and Co uptake, and compared with Rohm &Haas commercial chelating iminodiacetate acid resin. The Rohm & Haas chelating resin, Amberlite IRC 748, with its weakly acidic groups, did not work in acidic solution but exhibited good results at pH 4 and above. The resin that efficiently removed metals from high acidic solutions was the bis-picolylamine resin. Maximum nickel uptake values ranged between 85 g and 112 g Ni per Kg of resin.The experimental part dealt with the working conditions, resin characteristics and the influence upon the resin maximum exchange capacity of the following factors: nickel concentration, temperature, pH and resin-to- solution ratio. Based on the experimental data obtained, it has been proposed a innovative technological treatment."

Jan 1, 2003

By T. Fujita

The incinerated bottom ash includes titanium oxides and a small amount of chromium oxides. Initially, 89 % of chromium was removed from ash at magnetic flux density at several stages of wet magnetic separation from 0.05 T to 6 T. The bottom ash from an industrial waste incineration process includes about 10 % of TiO2. The minerals that contain titanium are rutile and perovskite. These minerals are paramagnetic and show low magnetic susceptibility, therefore, the high magnetic field strength, created by a superconducting magnet, is necessary to capture these minerals. At the first stage of separation, a magnetic field strength of 6T was applied in order to attract the particles that contain iron oxides to the higher magnetic field region. At the second stage of separation, the magnetic capture rate of weekly magnetic particles decreased with increasing the magnetic susceptibility of the aqueous solution (i.e. the medium for dispersing the particles) in order to separate the highly magnetic materials. The para-magnetic salt such as ferric chloride was dissolved in the water to increase the magnetic susceptibility of the medium. After a two-step wet HGMS with superconducting magnet, the grade of TiO2was increased from 10 % to 28 % with a recovery of 64 %.

Jan 1, 2014

By Zhiyong Gao, Ruiying Fan

"Crushing and grinding are the prerequisite processes in many industries, such as minerals processing and powder technology. During crushing and grinding, minerals will cleave or fracture along the directions by broken the interlayer bonds (e.g., ionic bonds), generating some commonly exposed surfaces. The broken (or dangling) bonds at the generated surface makes the surface more active and determine the reactivity of the surface. In this work, the population of broken (or dangling) bonds on commonly exposed surfaces of fluorite mineral (a chosen model mineral) was calculated. Based on the calculated broken bonds information, the anisotropic surface reactivity of fluorite such as surface energy, surface relaxation, dissolution, wettability, surface charge and adsorbability, were discussed. The results show that the surface broken bonds density, which is positively related to the surface energy, can be used to predict the cleavage nature, surface relaxation degree and surface stability of fluorite crystal. The distribution characteristic and the number of broken (or unsaturated) bonds of surface active atoms (like Ca for fluorite crystal) can be used to predict and explain the anisotropic wettability, surface charge and adsorption mode and strength of organic molecules on different commonly exposed surfaces. It is easy to conclude that the calculation of surface broken bonds can serve as a fast and accurate way to start the mineral chemistry studies. These findings will be helpful to the mineral/material chemistry research in related interfacial science communities.INTRODUCTIONGrinding for mineral liberation is a prerequisite for a successful flotation separation. Also grinding for size reduction is a prior process for a favorable powder technology. During the grinding process, the minerals / materials will cleave and fracture along certain crystal directions with relatively weak interlayer chemical bonds1 to form a number of common exposed surfaces. Exposed surfaces are the outer boundary of a solid substance. In the mineral / material block, the bonding orbital of the atoms is filled with electrons and the atoms are in a steady state. Atoms on these exposed surfaces appear to show dangling bonds (or broken bonds) by losing chemical bonds to adjacent atoms in the previous block. Therefore, surface broken bonds serves as an initial property of a fresh surface. The lattice arrangement and crystal orientations causes differences in the number of dangling bonds on each exposed surface, i.e., anisotropic surface broken bonds2. The anisotropic dangling bonds enable the exposed surfaces to show varying degrees of surface reactivity (including surface energy, surface charge, surface relaxation, dissolution, wettability and adsorption behavior), known as anisotropic surface reactivity."

Jan 1, 2018

By J. J. Lui

Surfactant plays a critical role in many industrial processes such as petroleum, mining, environment and food processing, and daily life. For ionic surfactant systems, adsorption of surfactant at oil-water interface imposes a net charge to the interface. The nature and magnitude of the charges at the oil-water interface depend on charge characteristics of surfactant molecules, concentration of surfactant and solution pH. In our previous study, zeta potential measurement of hexadecane drop-lets in industrial process water was shown to be a simple, yet powerful method for identifying various types of ionic surfactants present in the aqueous system. In this paper, the site-binding model was applied to prediction of zeta potential of oil droplets in aqueous solutions containing a mixture of cationic and anionic surfactant molecules. The total number of interfacial sites for various types of surfactant involved was determined by applying the Gibbs adsorption equation to the measured interfacial tension-surfactant concentration profiles. The distribution of various types of surfactant molecules at the interfaces was evaluated by Langmuir isotherm constants. With the ionization constant of surfactant taken from the literature, the predicted zeta potentials of oil droplets in surfactant solutions from site binding model were shown in a reasonable agreement with the measured zeta potential values.

Jan 1, 2014

By Osvaldo A. Bascur, J. Pat Kennedy

"The profitability of mining and metallurgical operations continues to lag behind that of other industries despite the technical advances that have occurred in recent years. A primary reason for poor performing in this economic sector is the lack of integration of mining and metallurgical information. The mine cut-off grade can be optimized if mining and metallurgical engineers have the data to optimize milling for the type of ore in hand.Integration of mine transactions, stockpile inventories, process flows and assays is the key to determining the economics for each blast strategy in a mining site. Real-time information from manufacturing assets greatly affects the profitability and flexibility of a company, but gross errors from faulty sensors, inaccurate instrument calibration, or incorrect process models may corrupt actionable information. New software tools can model the process, sift through available data to identify and eliminate gross errors, and use statistical data reconciliation to create materially balanced and consistent readings. The reconciled data is unified for use by both monitoring and decision making processes.Creating a real-time information environment where upgrade and change are allowed is becoming an accepted methodology to accelerate and simplify the integration of applications such as production monitoring, equipment performance management and yield and inventory management.This paper describes the data integration requirements in a mine, concentrator and port for unification of the redundant data. The capture of the mining events, stock pile management and the metallurgical information is the base requirements for a dynamic environment to reduce the overwhelming amount of information to unified set of information. Part of any decision support program should entail these results to continuously improve the measurement system to address the costs in mine and milling the ore."

Jan 1, 2003

By H. Q. Peng

The study of synergistic reagents combination of mineral floatation is more and more important with the decreasing of bonanzas now. In order to determine the chemical reaction mechanism, here we present the synergistic reagents combination: amyl-xanthate, butyl-dithiophosphate and N,N-diethyldithiocarbamate ester, which dissolved by different organic solvents. The reagents were applied by an Anhui mine to float low-grade covellite as a substitute for ethyl-xanthate. One reaction products Na2HPSO3?5H2O (disodium hydrogen-thiophosphate pentahydrate) which was re-crystalized and measured by X-ray diffraction analysis. In its crystal structure, the two crystallo-graphically different Na ions are six-coordinated and are bridged by two covalent bonds with the O atoms of water molecules to give a basket unit. However, we can?t get Na2HPSO3?5 H2O by combining butyl-dithiophosphate and N,N-diethyldithiocarbamate ester under the same condition. This discovery may provides a intuitionistic evidence that in the process of reaction, the three com-pounds would cooperate with each other, but the decisive reaction may be the hydrolyzation of amyl-xanthate.

Jan 1, 2014

By Leming Ou, Longsheng Yi, Qiming Feng, Yiping Lu, Qing Shi, Kun Liu, Guofan Zhang, Yanfei Chen

"Three important components of stirred tanks involved in energy consumption, the impellers and baffles, were investigated to intensify the agitation pretreatment on the flotation of nickel ores. Flotation tests revealed that the stirred tanks with two impellers had an advantage over those with one impeller in intensifying agitation pretreatment, and the higher agitation speed led to better flotation performance of nickel ores. Installation and removal of baffles were also employed in the stirred tanks, and flotation tests demonstrated that with baffles, the flotation grade increased significantly. These agitator design improvements were used to demonstrate that the energy supplied to the system significantly influences the flotation recovery and that if the energy consumption of the agitation pretreatment is ideal, flotation efficiency can be improved. Data from full-scale operations backed up these results.INTRODUCTIONThe flotation recovery of nickel-copper sulphide ore at the Western China nickel mine has historically been difficult due to the presence of large amounts of serpentine minerals (Feng, et al., 2012). Many studies reported that serpentine minerals tend to have a positive potential at pH values up to 9.5, while sulphides (such as pentlandite and chalcopyrite) have a low isoelectric point(Feng, et al., 2012). Serpentine minerals can form surface coatings on negatively charged sulphides surface due to electrostatic attraction when they interact with each other, which may also reduce collector adsorption and increase the hydrophilicity of the sulphide particles. In order to improve the flotation of nickel sulphides, sodium hexametaphosphate, sodium silicate, carboxymethyl cellulose (CMC), and other agents are used to disperse serpentine coating from sulphide surfaces in the flotation of the Jinchuan deposit and other nickel ores in China ( Kirjavainen and Heiskanen, 2007; Lu, et al., 2011). However, it is difficult to improve of the sulphide flotation due to the high dosage and the lack of selectivity."

Jan 1, 2018

Under the AMIRA P9 project the three-product cyclone-an off-shoot of the conventional hydro-cyclone-that produces three distinct products has been developed. The three-product cyclone shows great promise as a classifier in mineral processing. Industrial and pilot plant trials performed to assess its performance in the classification of the UG2 platinum ore, indicate that the presence of an extra overflow product stream that captures the mid-sized particles, provides improved classification efficiency. To assess the split on component density, samples from the feed and product streams were screened and assays by size for chromite (? = 4.8) and silica (? = 2.65) were obtained. Results from tests performed using this type of hydrocyclone in a number of applications indicates that it can be applied successfully in circuit configurations where the conventional hydrocyc-lone is not suitable. Utilising the three-product cyclone to classify the UG2 platinum ore resulted in an intermediate overflow product stream containing the mid-sized low density silicates and relatively fine high density chromite particles while the finer overflow contained mostly fine silicates and chromite particles. The coarse chromite and silicates reported to the underflow. Due to the increased number of products, the method of using efficiency curves was extended to cater for the increased number of products in the three-product cyclone. Although significant differences in the classification performance of the three-product cyclone were noticed with variations in machine variables a consistent method of assessing the performance was applied. The efficiency curve was adopted and applied and separate efficiency curve properties were obtained for each product stream. The methodology was applied to the component data, and efficiency curve proper-ties for each key component were obtained and compared. This paper discusses the application of the efficiency curve to cyclones producing more than two products and extending the methodology to the different components in the feed.

Jan 1, 2014

By Thi Hien Tran, Huy Hoan Nguyen, Thi Thu Hien-Dinh, Hong Son Nguyen, Duy Anh Dao

"Lithium discovered in La Vi deposit, Quang Ngai province in the Central of Vietnam was estimated with a reserve of approximately 1.5 million tones of lithium ore, which was characterized by mainly lepidolite with muscovite, albite, and quartz. This study investigated reasonable flowsheet and optimal conditions of enrichment technology for lepidolite from the mined ore by flotation process, and producing Li2CO3 and LiCl from lepidolite concentrate by hydrometallurgical process. The significant conditions for froth flotation of lithium ore including particle size, pH of ore slurry, pulp density, chemical spending (collectors, activators, depressants, and frothers), stirring and flotation time were investigated. The identified reasonable flowsheet and optimal conditions for froth flotation the La Vi lithium ore processed lepidolite concentrate containing up to 4 wt.% Li2O with a recovery of 87.61 wt.%. The processes of sulfation roasting lepidolite concentrate using FeSO4.7H2O, then leaching in H2SO4 solution, and removing impurities were carried out to prepare a pure lithium-bearing solution for producing Li2CO3 and LiCl. The products containing 99.05 wt.% of Li2CO3 and 99.02 wt.% of LiCl were obtained with recoveries of 82.97 wt.% and 85.77 wt.%, respectively. The obtained results indicated that lithium ore in La Vi deposit can be processed to produce commercial lithium products and lead the study to develop technology for a new industry of lithium processing in Vietnam.INTRODUCTION Lithium is the lightest metal, which has many superior properties in both metal and compound (such as Li2CO3, LiCl...) states since its discovery in 1817 by Swedish chemist Johan August Arfwedson. Lithium is a favourable material for many high technology fields such as aerospace industry and chemical industry. Some industrial fields which present the main consumptions of lithium include ceramic, glass, aluminum alloy, lubricants, rechargeable Li-ion batteries, synthetic rubber, and pharmaceuticals. The worldwide production of lithium in 2014 was 31,700 tones, continually increased in 2015 of 5% presented 32,500 tones (USGS, 2016). The demand for lithium tends to increase because of the raising in consumption of lithium batteries. Lithium is mined from salar brines, mainly in Chile and Bolivia, but also from granites and pegmatites, which contain minerals with high lithium content such as spodumene - LiAlSi2O6 (Heinrich et al., 1978; Linnen et al., 2012); petalite - LiAlSi4O10 (Sitando & Crouse, 2012); zinnwaldite - KLiFe2+Al(AlSi3O10)(F,OH)2 (Paukov et al., 2010; Kondás J. & Jandová J., 2006); lepidolite - K(Li,Al)3(Si,Al)4O10(F,OH)2 (Luong et al., 2013); and amblygonite - LiAlPO4F (Garrett, 2004)."

Jan 1, 2018

By H. M. Gao

According to the difficulty of dolomite removal from collophanite,normal-reverse floatation process has been adopted in floatation with the use of highly selective collector G-4 and depressant S721. Good indexes of flotation have been obtained with the run-of-mine ore containing 17.96 % P2O5 and 2.31 % MgO being upgraded to a concentrate containing more than 30% P2O5 and less than 1% MgO. The reagent interaction mechanism in low grade collophanite flotation has been stu-died by FTIR analysis and theoretical calculation. The results indicate that the interaction between collector G-4 and collophanite is the result of chemical adsorption in combination with physical ad-sorption with chemical adsorption playing the major role. Depressant S721 adsorbs on dolomite surface to form a water film and effectively depresses the flotation of dolomite and reduces the MgO content in the concentrate.

Jan 1, 2014

By Qidong Zhang, Yongsheng Song, Wenjuan Li, Guiying Zhou, Kun Song

"Molybdenum is a very important rare mineral resources, which exists largely in oxidized ores and sulphide ores in nature. About 99% of metallic molybdenum comes from molybdenite. The talcose molybdenum resources are abundant but the resources utilization is low, because the talc is naturally hydrophobic and the floatability of talc is similar with molybdenite, which lead to difficult separation by flotation. Talc is easy entry into concentrate in flotation which can cause the content of MgO overhigh, therefore the molybdenum concentrate grade can not meet the industrial requirements. Thus the utilization level of talcose molybdenum resources has been restricted greatly.The adsorption of water on talc and molybdenite surfaces and natural floatability of minerals were studied by density functional theory method. The results showed that molybdenite and talc were layered minerals which exhibited similar surface wettability and H2O molecule prefers to stay with water rather than the minerals surfaces. N2 is adsorbed on talc and molybdenite surfaces more easily than H2O. The interaction and flotation behavior were studied by SEM and flotation experiments. The reason why talc interferes with the flotation molybdenite has been revealed. The agglomeration between molybenite and talc was caused easily in neutral or acidity solution, and it was dispersing between molybenite and talc particles in alkaline solution. The flotation results showed that good floatability of talc was the key factor causing a low grade of concentrate in alkaline solution. Thus, it is the key factor to enlarge floatability difference between molybdenite and talc.INTRODUCTIONMolybdenum is a kind of important rare metal and strategic reserve resources (Zhitao Y et al, 2016a). Due to excellent characteristic, such as high melting point, good thermal property and et al, it’s widely used in metallurgy, machinery, chemical, aerospace, and many other areas. It has become an indispensable metal in modern industry. Molybdenum generally exist in the form of molybdenite which is a kind of mineral with excellent natural floatability. Talc is a kind of typical hydrous and layered magnesium silicate minerals (Beattie D et al,2006a), which is one of the most common gangue mineral of the platinum group metal ores and metal sulfide ores (Tao L et al,2011). Due to its good native floatability, talc is easy entry into the concentrate product with foam in the process of sulfide ore flotation (Kelebek S and Smith S, 2006b), which resulted in decreasing concentrate indexes. Not on that, the high-content MgO of concentrate will also produce a series of adverse impact to the subsequent smelting (Lotter N O et al, 2008). Therefore, it is difficult to separate talc from sulfide ore concentrate effectively."

Jan 1, 2018

By Shailin Lalloo, Allan B. Nesbitt

A fluidised bed was exposed to high gravities by placing it in a centrifuge. The bed expansions were measured and compared with the bed expansions predicted by the Richardson-Zaki model (1954). The Richardson-Zaki model was found to predict effectively the fluidisation behaviour of defined particles in this increased gravity environment.

Jan 1, 2003

By P. M. Solozhenkin, V. N. Kovalev

Russia is a global antimony market leader. The three major antimony production provinces are Sakha Republic (Yakutia), Krasnoyarsk Territory and Trans-Baikal Territory. Russia’s largest antimony resources are Zhipkozhinsky and Solonechensky deposits in Sakha Republic (Yakutia) and Olimpiadinskoe deposit in Krasnoyarsk Territory. This work demonstrates the efficiency of computer programs and chemical technology aimed at the study of the behavior of collectors used in the processes of flotation of antimony, arsenic and Au (I – III) minerals. The most promising collectors for the flotation of ores containing antimony and gold on the basis of P(V) and compounds with S, O and N atoms were chosen. The mechanisms of interaction with the mixtures of two or three components of collectors were studied. High recovery of antimony and gold was reached in the processing of Au-Sb ores of Sarulah and Sentachan deposits in Sakha (Yakutia). X-ray radiometric methods of separation of antimony ores of Trans-Baikal Territory deposits were proposed. In order to choose the most cost-effective solvents for hydrometallurgical processing of Sb, Au-containing concentrates the method based on clusters formation between transition solvents and antimony minerals was suggested. The nature of Au losses was theoretically revealed in the sulfide-alkaline process. On the base of computer simulation, the formation of various complexes of (KAu) types was developed, for example, hydrosulphidic gold, thiosulfates of gold - Na3AuS4O6, antimony and arsenic gold, trithiostibate (III) and trythioarsenate (III) KAu were produced. The practice of processing of goldantimony concentrates to produce high-quality antimony trioxide and antimony-gold containing alloy (AGCA) regarding the special conditions of the Far North region, were analyzed. The affinage of AGCA was recommended. Creative project development of antimony industry in Russia in order to produce antimony compounds and pigments, including pyriform compounds and flame retardants (antipyrenes) is discussed.

Jan 1, 2018

By Jochen Petersen, Steven Bradshaw, Guven Akdogan, Ngoie Mpinga, James Mwase, Jacques Eksteen, Cornelius Snyders

"The platinum group metals (PGMs) and associated minerals are particularly refractory to most traditional direct leach processes. However, the remoteness of many new ore deposits, socio-political risks, the scarcity of skilled labor and constraints on the availability of water and electrical power makes it increasingly more difficult to implement the conventional mill-float-smelt-refine process routes to extract and refine PGMs in remote areas. This paper discusses a process to extract PGM’s from low grade ore and concentrate using a sequential stage heap leach process entailing heap bioleaching and high temperature cyanide leaching, and evaluates the feasibility of implementing a carbon-in-pulp process to recover the PGMs from the pregnant leach solution. The heap bioleaching extracts the base metals in an acidic sulfate medium using a mixed culture of thermophiles. After heap bioleaching the heap is reclaimed, rinsed, agglomerated and restacked for high temperature cyanide leaching where the cyanide liquor is directly heated via solar energy in panels. Palladium, gold and platinum are recovered during the cyanide leaching stage. The pregnant leach solution was evaluated for potential carbon-in-pulp adsorption and subsequent elution similar to gold processing. The kinetics of adsorption and elution compared well with gold adsorption and elution."

Jan 1, 2014

By Johan Nell, Paul den Hoed

"Carbochlorination tests were conducted with matched particle-size fractions of rutile, ilmenite and hightitania slag in a small bubbling fluidized-bed reactor. The effects of temperature, the type and proportion of solid reductant in the charge, and the fraction of Cl2 in the fluidizing gas were investigated. Tests confirm the need for solid carbon in the bed if chlorination is to run at high rates. With solid carbon in the bed, CO supplied with the fluidizing gas does not increase significantly the degree of chlorination after 75 minutes.When large proportions (30 wt%) of carbon are added to the charge, then the reactionTiO2 + 2C + 2Cl2 = TiCl4 + 2COis favoured overTiO2 + C + 2Cl2 = TiCl4 + CO2Ilmenite is chlorinated more quickly than titania slag, which in turn is chlorinated more quickly than rutile. Rates of chlorination at 1100°C and 1000°C are much the same and significantly higher than at 900°C. Chlorination is associated with significant increases in particle porosity (even for rutile), which is brought about by the rapid initial chlorination of FeO and MnO (in ilmenite and slag) and (it is argued) by the chlorination of Ti2O3 which forms at high-energy surface sites."

Jan 1, 2003

By M. A. Naimanbayev, Zh. A. Baltabekova, N. G. Lokhova

"Integrated utilization of natural resources using energy-saving and waste-free technologies is relevant around the world. This applies to such type of raw material as titanium-magnetite ore. Shortage of ilmenite raw materials in the Republic of Kazakhstan for titanium slag melting challenges the search of alternative titanium-containing raw materials, titanomagnetites in particular. At the same time there are deposits of indigenous titanomagnetite ores of huge reserves, which can become the complex raw material for production of iron, titanium and vanadium. Tymlay field in the South-Eastern part of Chu-Ili watershed is of particular interest, within the Karasay ore unit with iron content of 30,4 and titanium dioxide - 10%, and after beneficiation titano-magnetite concentrate contains Fe-52,4; TiO2-of 16,06%. Technology of titanium-magnetite concentrate ore-thermal melting was developed at Tymlay deposit producing hot metal and low titanium slag that can become the raw material for titanium production using chloride method. Slag produced in course of titanomagnetite ore-smelting consists mainly of alumosilicates and sodium silico titanates, magnesium and calcium titanates, titanium dioxide and lower titanium oxides. Following operations were carried out to improve titanium slag quality: slag sintering with sodium hydroxide; cake leaching with water to remove water-soluble impurities; to reduce the number of operations impurities leaching with hydrochloric acid was combined with pyrohydrolysis of titanic acid; rutile concentrate production (85% TiO2, 7,66% SiO2), silica removal by means of sodium hydroxide solution treatment, finally sellable rutile concentrate was produced with titanium dioxide 91-92% and silica 1,7 to 2,0% content. Based on research results technological scheme of titano-magnetite concentrate processing at Tymlay deposit was proposed producing hot metal and certified rutile concentrate, suitable for chlorination."

Jan 1, 2018

By E. Vahidi

In this study, a hydrometallurgical treatment involving solvent extraction of zinc using D2EHPA (di-2-ethylhexyl phosphoric acid) has been investigated to recover zinc from an industrial zinc leach residue. The residue was leached with sulfuric acid producing leach liquor which was subjected to solvent extraction for enrichment of zinc and removal of impurities. Operating variables for the zinc extraction process, such as pH of the mixed solution (0.5~5.0), concentration of D2EHPA (5%~40%, w/w), temperature (25~60°?C), A/O volumetric phase ratio (1/2~4/1), concentration of tri-butyl phosphate (TBP) as modifier (3%~7%, w/w), concentration of NaR2RSOR4R in aqueous phase (0.05M, 0.1M, 0.2M) were also studied. Practically all zinc was extracted from the aqueous solution at pH 2.5 with 20% w/w D2EHPA in kerosene. At this operating condition, zinc could be extracted at one theoretical stage at A/O phase ratio of 1/1, as calculated by the McCabe-Thiele method.

Jan 1, 2014