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By Kaustubh Joshi, Pradip, Beena Rai, Venugopal Tammishetti

"Rapid depletion of high grade iron ores coupled with the increasing demand for the blast furnace grade iron ore in recent times has shifted the research focus on the development of appropriate technologies for the utilization of low - grade alumina rich iron ore slimes. These slimes are currently being dumped into tailing ponds owing to their high alumina content. Typical constituent minerals present in the Indian iron ore slimes are hematite, goethite, gibbsite and kaolinite. Considering the fine particle size distribution (<37 microns) in the slimes, selective dispersion-flocculation seems to be one of the most appropriate process which has been explored by us. We present our successful results on a natural iron ore slime sample obtained from one of the mines in India. We have been able to achieve a concentrate assaying >67% Fe, and <3% Al2O3 and 2.8% loss on ignition (LOI) from the slime sample assaying 60.4% Fe, 7.7% Al2O3 and 5.45% LOI with an Fe recovery of 62-69% simply by adjusting the pulp pH. We have scaled up the process to a semi batch scale as a prelude to commercialize it for the beneficiation of low grade iron ore slimes."

Jan 1, 2014

By Y. Posedko Eugene, S. S. Gudkov, Yu. E. Emelyanov, A. V. Bogorodsky, A. V. Boldyrev, S. V. Balikov

"The article presents the results of precious metals leaching using halogen solvents and their precipitation on a sorbent in the process of pressure oxidation. A technology of pressure oxidation – carbon-in-leach treatment (POX-CIL) of refractory sulphide gold-bearing flotation concentrates with the addition of a halogen solvent and a sorbent was developed based on the laboratory studies and pilot plant tests. The technology involves the following steps: oxidation of a flotation concentrate; precious metals dissolution and recovery on a sorbent; precious metals elution; electrolysis of eluates; smelting of cathode precipitates with producing Dore beads. This approach ensures oxidation at least 98% of sulphides and gold of more than 95%. The POX-CIL process have the following patents: a patent of the Eurasian Patent Organization No.017438 “A method of processing materials containing precious metals and sulphides” and a patent of the Russian Federation No.2625146 “A method of precious metals recovery from refractory sulphide gold-bearing materials”.INTRODUCTION Gold-bearing ores are classified as readily amenable to cyanidation, or non-refractory, and not readily amenable to cyanidation, or refractory [1]. Special attention should be given to the three most common technological types of gold-bearing ore materials, according to the Irgiredmet’s classification: pyrite-arsenopyrite ores with finely disseminated gold locked in sulphides (physical depression of gold in cyanidation process); cupriferous gold-bearing ores, when cyanidation comes along with chemical depression of gold by mineral compounds (cyanisides); carbonaceous ores showing higher sorption activity to precious metals dissolved in cyanide. Direct cyanidation of refractory sulphide gold-bearing materials does not provide high recovery of precious metals. There are the following methods of refractory gold-bearing ores and concentrates preparation to subsequent gold recovery: roasting, fine grinding, bacterial and pressure oxidation (POX) [2]. Existing POX-cyanidation flowsheets involve high costs due to a large amount of process operations and using expensive and environmentally hazardous sodium cyanide."

Jan 1, 2018

By Rodney J. Hundermark, Sharif Jahanshahi, Shouyi Sun

"The major platinum producers in South Africa make use of electric furnaces for the melting of PGM bearing nickel - copper concentrates. To gain better understanding of the furnace operation, research was conducted at CSIRO Minerals in Melbourne, Australia. One aspect of the research project was the investigation of the factors affecting the electrical conductivity of melter type slags.Electrical conduction in slags can occur through two mechanisms: ionic and electronic. There is good understanding of the ionic mechanism. In slags containing high levels of iron, the dominant mechanism is electronic. There is limited understanding of the electronic mechanism and one of the aims of the research was to investigate this mechanism further.Experimental work was carried out on Al2O3.CaO.FeOx.MgO.SiO2 slags similar in composition to the melter slags. Conductivity increased significantly with iron oxide content. Above 20wt% FeOx, electronic conduction was significant and the conductivity varied with the oxidation state of the slag. As the iron oxide content was increased further, the electronic mechanism became more dominant. The conductivity reached a maximum at around pO2 = 10-7 to 10-4 atm., although this value was dependent on the total iron oxide content and basicity of the slag."

Jan 1, 2003

By C. Dorfling, S. Bradshaw, J. Eksteen, M. Khesa, C. A. Snyders

Titaniferous ores serve as a major feedstock for the production of a white titanium dioxide pigment, a titanium metal and several other titanium-based products. Such ores exist mainly as heavy mineral sands. Ilmenite is upgraded to intermediate products namely synthetic rutile and titania slag through the synthetic rutile route and the reductive smelting route respectively. Tronox KwaZulu Natal Sands (Pty) Ltd recovers high titania slag via the reductive smelting process while slag is used as a feedstock to the pigment industry and furnace dust from the gas cleaning plant is disposed as waste. Previous investigations have shown that such furnace dust can contain significant amount of titanium-bearing minerals. This study looks at the characteristics of the furnace dust obtained from Tronox KwaZulu Natal Sands and investigates a possible high temperature recovery route in detail. The furnace dust was examined by using x-ray fluorescence, x-ray diffraction, microscopy and laser-diffraction size analyses. The characterization work showed that the furnace dust was rich in titanium and iron, containing 49.4 wt% ??????2 and 29.5 wt% ????2??3. These oxides were associated with Si, Mn, K, and Al oxides as impurities. A Carbolite® vertical tube furnace was used to investigate the extent of formation of titania slag and metallic iron on a laboratory scale at 1500°C, 1600°C and 1650°C. The laboratory reduction tests revealed that the slag samples with an equivalent titanium dioxide content ranging from 70.9 -76.9 wt% at 1600°C and 1650°C could be obtained. The Fe content of the metallic iron samples produced ranged between 93.0 and 97.1 wt%. The experimental results were found to be in relatively good agreement with the FactSage simulations, both of which demonstrated the potential of producing a titania slag and a metallic iron from the furnace dust.

Jan 1, 2018

By Y. H. Hu, X. X. Zhang, Z. F. Dai, H. J. Huang, Q. S. Huang

"In order to get a more comprehensive understanding of the interaction of fine fluorite particles and bubbles, the electro-flotation was conducted, a high speed CCD was used to determine the bubble size distribution, and the results were analyzed using the models of collision and attachment. The electro-flotation was performed in a modified Hallimond tube. The results show that for different fluorite with size of 0 -10µm, 10 -38µm, 38-74um, there is a matching range between the different particle sizes and cathode aperture size (38um, 38um, 74um) to reach highest recovery. In addition, improving the concentration of collector is benefit for the flotation recovery due to the ability of collector to decrease the bubble size and prevent the merger of bubbles. Furthermore, theoretical calculation of collision, adhesion probability and collection probability is in agreement with the experimental data for electro-flotation recovery of fluorite.INTRODUCTIONFluorite is widely distributed, and has been found in more than 40 countries around the world. As fluorite minerals are easy to float, flotation is used as the best method of the current recovery of fluorite (Yang and Ai, 2016; Chen et al., 2017). In the field of mineral processing, the flotation of fine particles is particularly difficult, caused by the small quality and large surface (Sun et al., 2006). Flotation is now considered to contain three subprocesses, including the collision, attachment and detachment between the particles and bubbles (Sun et al., 2011). The collision of particles with bubbles is related to factors such as particle size and density, bubble size, bubble rise rate (Qin et al., 2012). Zongfu Dai et al. (2000) summarized the particle-bubble collisions models in detail and compared the experiment results with the model predictions. However, particle-bubble interactions occur in complex and turbulent flotation environments (Xing et al., 2017). Both thermodynamics and dynamic factors affect the adhesion of particles on bubbles surface (Schulze, 1989; Shahbazi et al., 2010). Scheludko et al. (1976) believes that the necessary condition for successful adhesion of particles on bubbles is that the contact time is greater than the induction time. The probability of adhesion between particles and bubbles increases with the increase of bubble size, but if the particle size is too small, the probability of adhesion decreases instead (Ren, et al. 2014; Norori- McCormac et al., 2017). After the particles adhere to the bubble surface, the particles will slide down to the bottom of the bubble due to gravity. At this point, the gravity, inertial centrifugal force and fluid force promote the desorption of particles from the bubble surface, while the surface tension, surface hydrophobic force maintain the stability of particles-bubble combination (Ralston et al.,2017). In addition, in the process of rising to the foam layer, desorption can also occurs. The purpose of this study is to observe the flotation behavior of fine fluorite with different size and to get a more comprehensive understanding of the interaction of fine fluorite particles and bubbles."

Jan 1, 2018

In the present work, the influence of coagulant, polymeric flocculant structure type and mode of addition on flocculation performance and dewatering behaviour of plant mineral waste tailings of diverse mineralogy (kaolin, quartz, goethite/hematite feldspar, gibbsite, rutile, and Illite) is investigated. High molecular weight, non-ionic polyacrylamide homopolymer and anionic (acrylate) and cationic (quaternary acrylate) copolymers were used in orthokinetic flocculation of colloidal-ly-stable, aqueous dispersion of negatively charged particles. It is demonstrated that, through prudent selection and mode of addition of polymer structure types, synergistic effect between certain cationic and anionic flocculants can be readily achieved, leading to significantly improved dewaterability of the heterogeneous mineral waste tailings.

Jan 1, 2014

By B. Peszko

There are many measuring methods of grain sizes. Taking into consideration the fine grained materials, one of the existing techniques is measurement of grain size by the Coulter Counter method. This method is based on the measuring the changes of electrolyte resistance during grains flow through the calibrated diaphragm. This method is relatively simple to apply, significantly precise and the results are given quickly. However, the problem is that the measurements are limited by the size of diaphragm. Because of this situation, measurement of grain sizes by this instrument is possible in range from 10% to 60% of diaphragm diameter. This limitation causes the necessity of re-placing diaphragm in case when the measured grain size distribution concerns the material of large size range. In purpose of determining the total grain size distribution, the synthesis of some partial distributions, given for individual grain fractions (with different diaphragm applied), is required. This is possible to do by calculating the mixture of distribution functions, created from the partial distribution functions. Two materials were selected to research: quartzite and glass, which were comminuted in cylindrical crusher, additionally grinded, screened and then analyzed by Coulter Counter for five grain fractions: 0~125 µm, 0~80 µm, 0~56 µm, 0~40 µm and 0~25 µm. For each fraction, five different partial distributions were given (in case of glass ? four), which are the basis for the creating the joined grain composition. To assure the adequacy of the given distribution function, it is necessary to obtain the possibly best approximation of partial distributions. In the work, both the parametric and non-parametric methods of density approximations of investigated random variable. For each grain fraction the approximations were done by three traditional distribution functions: RRB, GSA and log-norm distribution functions and three methods of non-parametric approximation: Gauss kernel, Epanechnikov kernel and orthogonal Fourier series method. As the criterion of the certain distribution function acceptance, the value of the residual deviation was assumed, given by the formulae:

Jan 1, 2014

By Homero Delboni, Mauricio Guimarães Bergerman

"At the regrind or secondary grinding stages of metal ores, usually the concern about the energy efficiency is extremely important. In general, the specific energy consumption at this stage is higher than in the primary stages of grinding. In addition, it has been observed a tendency of finer grinding in the new projects of metallic ores, due to the finer mineral liberation, which leads to an increasing capital and operational costs. In Brazil, during the last 10 years, regrind P80 sizes of approximately 40 to 20 ?m have been necessary in all new iron and copper plants. The use of conventional ball mills, adequate for primary grinding, can result in low energy efficiency with products below a P80 of 50 ?m. This paper presents an overview of the regrind circuits in Brazil that operate with vertical mills and the results of industrial surveys at selected vertical mill circuits. Where possible, comparison is made between the plant results and the design criteria and laboratory regrind tests used for the mill sizing."

Jan 1, 2014

By B. J. Zhang

Conventional spirals are capable of providing excellent clean coal recovery, although at a relatively high ash content. Compound spirals, which provide two stages of spiral cleaning in a single taller unit, have been commercialized in recent years to improve upon the cleaning performance obtained from conventional spirals. The present study aimed at optimizing the performance obtained from a compound spiral for cleaning especially high sulfur fine and ultrafine coal. Industrial-scale spiral units were utilized for this study in a pilot-scale facility at the Illinois Coal Development Park. A statistically designed experimental program was conducted to optimize ash and sulfur cleaning performance of the compound spiral. It was found that significant cleaning of ultrafine coal (i.e., 150 microns × 45 microns and even 45 microns × 25 microns size coal) is achievable with the compound spiral. However, operating conditions for cleaning finer coal fractions (-150 microns size coal) have to be significantly different from those used to clean coarser coal fractions (+150 microns size coal). The sulfur rejection trends were different from ash separation efficiency trends in all size fractions except 45 microns × 25 microns. The probable error (Ep) and effective specific gravity of separation (SG50c) determined for the compound spiral cleaning of the overall particle size were as low as 0.07 and 1.62, respectively. However, the bypass of a small percentage of clean coal to the tailings stream of the compound spiral, may need further adjustment of the key process parameters.

Jan 1, 2014

By G. Atesok

Turkey?s EU affairs started in 1963 with the Ankara Treaty. On 31 December 1995 the Customs Union between Turkey and the European Union came into effect. In order to achieve the Copenhagen Criteria?s, Turkey, made laws parallel to the Framework Programs. On 3 October 2005, with the confirmation of ?Membership Framework Document? the negotiation process of Turkey has started. Coal had important role in the industrialization of EU and it is directly related to Energy and Environmental subjects. In this point many restriction became with the some protocols, in last decades. European Union composed Energy and Coal Policy, therefore engaged to reduce the emissions, and made new regulations. This regulations concern Turkey?s energy future, since large; but low quality of lignite reserves of Turkey, it is expected to have some difficulties with Union?s Environmental Legislation during Turkey?s congruity process. With the last natural gas import agreements of Turkey, the production and consumption of coal sunk in last seven years. However, considering environmental sustainability, the role of coal in energy production will rise up in the coming future. In this paper, in terms of Turkey Energy Sector, production and consumption problems of coal discussed and evaluated considering EU?s coal, energy and environmental rudiments.

Jan 1, 2014

By P. K. Fedotov

At projecting mining-concentrating complex at the deposit ?Zapadnoye? (Russia) it was considered to enable an opportunity of refusal from conventional SAG-mills. First time a scheme of gold bearing ore destruction using Roller Press RP 5-100/90 had been developed and integrated. The plant was launched in summer 2003 and presently it has achieved designed technological parameters, processing throughput comes to 1 million tons of the ore per year.

Jan 1, 2014

"The thiosulfate leaching process developed by Barrick to treat sulfidic high preg-robbing gold ores uses calcium thiosulfate as the leaching reagent for ores pre-treated by pressure oxidation, resin for gold recovery with sulfite/trithionate elution and reverse osmosis as a means of reagent recovery. A large portion of the research that led to the development of the technology was based on previous studies completed by different groups over the years, mainly focused on the ammonium thiosulfate system. Operational limitations in the use of the ammonia-containing recycled water in the pressure oxidation circuit were some of the main drivers for the change from ammonium to calcium thiosulfate for the development of the industrial scale process. One of the main aspects for successful gold extraction and recovery in the thiosulfate system is the pseudo-equilibrium reactions that drive distribution of the different gold species (in solids, solution and on resin) in the system. Previous studies have been focused on the thiosulfate reactions and equilibrium constants for the oxysulfur ions (thiosulfate, trithionate, tetrathionate). However, the literature around the effects of the different metal-oxysulfur complexes (Cu and Hg complexes) that form when the ore is in contact with the leaching reagents, and the related effects on stability of the gold complex is limited. The main changes in the gold complex chemistry and stability in the calcium thiosulfate system as compared to the ammonium and sodium equivalents, as well as related effects on gold recoveries, were investigated in the presence of different types of double refractory ores. INTRODUCTION Barrick has developed a thiosulfate leaching process to treat double refractory gold ores, by combining the use of acidic and alkaline autoclave pre-treatment with thiosulfate resin-in-leach (RIL). The process currently in operation at the Goldstrike mine (the TCM process), uses calcium thiosulfate as the leaching reagent, resin for gold recovery with sulfite/trithionate elution and reverse osmosis as a mean of reagent recycle. The main feed to the process plant is highly preg-robbing sulfidic ore from Goldstrike’s open pit. Prior to feeding the pressure oxidation circuit, the ore is processed through the crushing and grinding circuits and treated in preparation for acid or alkaline autoclave processing (POX)."

Jan 1, 2018

By ?. S. Yusupov, V. P. Isupov, N. Z. Lyakhov, A. G. Vladimirov, S. A. Kondratiev

"Considering the shortage of lithium reserves, the desirability has been shown of studying the possibility of processing into spodumene concentrates the concentration tailings and low-grade ore reserves at Transbaikalian Mining and Processing Project (ZabGOK). The mineral and chemical composition and the particle size distribution of the mineral feed, separability and recoverability of spodumene have been studied, forming the basis for the development of a concentration process and flowsheet for the studied mineral resource. Prospects have been established for impact ore grinding in a disintegrator, the efficiency of mechanochemical processes has been shown in the separation of quartz and feldspar and the recovery of lithium from concentrates.INTRODUCTION Lithium is widely used in various industries - nuclear power engineering, defense technology, power generation, ceramics, special-purpose glass and other technologies. The increasing demand for lithium and its compounds (lithium carbonate and hydroxide) for use in the manufacture of high-tech products (lithium-based materials for chemical sources of electric power and electrochemical energy) explains the need for establishing a sustainable raw material base (Mohr et al. 2012; Moores, 2007). The main sources of lithium are spodumene pegmatites (Vladimirov et al. 2012; Garret, 2004), brines (salars), and hydromineral materials (Garret, 2004; Zeng and Liu, 2009; Kotsupalo and Ryabtsev, 2008). However, in view of the absence in Russia of extractable hydromineral resources of lithium, the practical significance of spodumene ores remains decisive. Russia controls some of the world’s largest reserves of rare-metal pegmatites holding over 8 million tons of Li2O: approximately 7 million tons on the Kola peninsula and 1 million tons in the Sayan mountains. The main lithium mineral in pegmatites is spodumene LiAlSi2O6 containing 8.1% Li2O. It can be efficiently recovered by gravitational concentration and flotation. However, most of the deposits are located in remote areas and none is currently developed. In this connection, special research is focused on technogenic raw materials, which are increasingly seen as a solution to the resource base problem (Chanturia, 2008, Kurkov and Kotova, 2007)."

Jan 1, 2018

By Shobhana Dey

A low volatile medium coking coal from Jharia coal field, India was used for this investigation. The proximate analysis of the sample shows that it contains about 25% ash, 21.4% volatile matter and 52.4% fixed carbon. The sizewise ash analysis of -0.5 mm coal indicates that -0.5+0.15 mm fraction contains lower ash (21.9%) than -0.15 mm fraction (29.7%). The flotation characteristics of the -0.5 mm coal were determined by release analysis. The study reveals that recovery of combustible at 15% ash is about 27% and 43% at 17% ash level. The low recovery is due to the presence of high ash in finer fraction. In order to improve the recovery, the -0.5 mm feed was classified into -0.5+0.15 mm and -0.15 mm fractions, and subjected to flotation separately. The recoverable combustible obtained from the release analysis of -0.5+0.15 mm at 15% ash level is 46%. The effect of collector dosage, frother dosage and aeration rate on flotation was studied. The responses of these variables in collectorless flotation of the -0.5+0.15 mm fraction containing low ash were also studied. A lower aeration and frother dosage favored the generation of clean coal with low ash. The ash content in the tailing stream from -0.5+0.15 mm flotation circuit is close to that of the original -0.15 mm fraction. The former is ground to -0.15 mm and the two fractions are processed together. As -0.15 mm fraction contains relatively higher ash, collector aided flotation using sodium silicate was performed to recover the clean coal with 17% ash. The products of the overall flotation circuit having different ash levels were recommended for use in different applications. The reject from -0.15 mm flotation circuit contained 56.4% ash which can be used for fluidized bed combustion (FBC). This eventually leads to complete utilization of coal.

Sep 1, 2012

By Chen Dong, Yang Wenwang, Liu Zhineng, Tan Ming

"To meet the requirement of production expanding of a certain potash ore dressing plant in Xinjiang province of China, industrial test of XCF/KYF-50 flotation machine was performed to process potash ore. The tank of XCF/KYF-50 flotation cell is in U shape, 50m3 of volume. This flotation cell is able to suck slurry by itself, and can be arranged on the same base level without high difference. In this paper, two sets of XCF/KYF-50 flotation cells were adopted to replace 8 sets of 8m3 flotation cell in original flow sheet of flotation. Aeration rate, slurry suction capacity, power consumption and slurry suspension are investigated. The measuring results show the slurry suction capacity of the flotation cell is larger than 12.80m3/min and solid particles disperse evenly in the tank without deposition. Industrial test result indicates that the final grade of concentrate is 26.69% at the recovery of 90.95%, which is up to expected performance. XCF/KYF-50 flotation cell has advantages of high flotation efficiency, significant energy saving and reasonable configuration of automatic control system, this kind of flotation cell can meet the requirement of production expanding of this potash ore dressing plant well."

Jan 1, 2014

By L. S. Gertsch

The production of minerals for human use at locations other than the Earth is expected to ?advance ? human prosperity in ? ways that [do] not compromise the potential prosperity and quality of life of future generations? (Brundtland, 1987); in other words, sustainably. This paper examines the interaction of extra-terrestrial mineral production (ETMP) with the following sustainability imperatives: ? The sustainability of human activities on Earth; ? The sustainability of human activities elsewhere; ? Human survival in general, the ultimate sustainability goal. Some of the consequences of mineral production on Earth are widely considered to decrease the future prosperity and quality of human life. Examples include noxious by-products or wastes and unsettling economic up- and downswings. Moving mineral production activities to extra-terrestrial locations, where appropriate, will decrease many of its deleterious effects. Terrestrial mineral production presently is decreasing in some countries and increasing in others, moving from the cheaper and easier ores to more expensive, difficult materials. When the full costs of maintaining the terrestrial environment in a sustainable manner are included, total mineral pro-duction costs must increase. The cost of extracting mineral products from extra-terrestrial sources will be substantially higher, especially in the initial phases, but as the full costs of terrestrial production increase, at some point in the future (different points for different minerals), the curves will cross (Fig.1). This will occur at different points for different materials, a process whose prediction will be complicated by substitution of cheaper materials for some uses as prices of the original material rise. In summary, mineral products from extra-terrestrial sources will tend to increase the sustainability of human civilization, once steady state has been reached.

Jan 1, 2014

By Hillary Williams, Ronghao Li, Christopher Marion, Kristian E. Waters, Devin Hundt

"Zircon is an important mineral for ceramic, foundry, casting, and refractory applications; and it is the worlds primary source for zirconium. Zircon can also contain large and valuable proportions of other valuable metals, such as rare earth elements and hafnium. The Nechalcho deposit (Northwest Territories, Canad), is a hard rock REE deposit, which looks to recover zircon for its Zr and REE content. In this deposit, zircon is finely disseminated and associated with predominately silicate gangue minerals. Most of the work to date has focused on the beneficiation of mineral sand deposit, which typically remove silicate gangue minerals through physical separation steps. Therefore, the separation of zircon from silicate gangue, such as quartz, by flotation, has received little attention. This work used zeta potential measurements and microflotation experiments to understand the interaction between zircon and six different collectors (sodium oleate, sodium dodecyl sulphate, dodecylamine, SM 15, K-octyl hydroxamate and Florrea 7510). The results were compared with those of quartz. This study indicated that selective separation of zircon from quartz without the use of selective depressants or activators is likely challenging. The findings suggested sodium oleate and SM 15 only offered selective flotation of zircon in highly acidic conditions. Separation by the flotation of quartz is possible using sodium dodecyl sulphate, dodecylamine and K-octylhydroxamate. However, selective separation is highly dependant on collector dosage, for dodecylamine, and the selective activation of quartz, for sodium dodecyl sulphate and K-octyl hydroximate. Florrea 7510 offered poor recoveries for both zircon and quartz.INTRODUCTIONZircon (ZrSiO2) is a nesosilicate mineral which has a wide variety of applications, due to its hardness, opaqueness and resistance to heat and corrosion. Its major end uses are in ceramic, foundry, casting, and refractory applications (Bedinger, 2017). Zircon is also the most abundant zirconium (Zr) bearing mineral in the earths crust and is the principal economic source of Zr (primarily used in alloys for heat and corrosion resistance) and zirconia (ZrO2) (primarily used in ceramics) (Bedinger, 2017; Milnes and Fitzpatrick, 1989). Zircon forms in silicate melts and can often contain large proportions of other valuable metals such as rare earth elements (REE), and hafnium (zircon is the primary source of hafnium) (Bedinger, 2017; Belousova et al., 2002; Orlova, 2007). A common chemical formula showing the range of substitution in zircon is (Zr,Hf,Th,U,REE,Ca,Fe,Nb,Ta)(Si,P)O4 (Orlova, 2007)."

Jan 1, 2018

By M. Ito

The authors have developed the RETAC jig (a modified TACUB jig) and have reported that the RETAC jig can separate relatively low density particles such as plastics. To further improve the separation ability, a hybrid jig (a RETAC jig with an air bubbler under the particle bed), which can separate plastics having similar specific gravities by the differences in the wettabilities of the particles was developed. Surface modification of plastics with similar wettability enabling separation in the hybrid jig and the effects of wettability control of the plastics using reagents are reported.

Sep 1, 2012

By L. Y. Zhang

The metallic sulphides in Jinchuan Mine are relative friable and the gangue minerals suffer of wide secondary change, the overgrinding of metallic sulphides and sliming of gangue minerals are the main cause that makes the mineral separation indexes difficult to improve. So changing the process of grinding, and classification, and optimizing the particle size distribution of grinding product is the key improving the separation performance of Jinchuan nickel and copper ore.

Jan 1, 2014

Over the last four years, a major collaboration between CSIRO-MIS, UCT and JKMRC has produced two significant advances in the modelling of comminution. The Universal Comminution Model (UCM) uses parametric SPH/DEM studies of comminution and separation devices to calibrate mathematical models which are suitable for industrial use. The Virtual Comminution Machine (VCM) uses the same computationally intensive techniques based on discrete element modelling (DEM) and smoothed particle hydrodynamics (SPH) to directly model any comminution device by combining a CAD file describing the machine design, sophisticated ore characterisation methods and advanced particle scale flow and breakage simulation. The UCM should be useful for process analysis and optimisation of existing equipment and circuits while the VCM should make a major contribution to the evaluation and development of new machines. Progress to date is encouraging with several processes now well described using DEM. This paper also reports on progress towards combining DEM for particles with a realistic slurry model based on SPH for different types of comminution devices. In due course, this combination should allow accurate modelling of particle transport in wet mills to be combined with DEM models.

Jan 1, 2014