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By J. Lindström, J. Hamuyuni, M. Lundström, J. Aromaa

"The rising demand for metals today, coupled with the scarcity of primary sources for raw materials threatens both technological advancements and industrial manufacturing. In order to meet the demand, metals and other resources trapped in waste streams, have to be harnessed. This philosophy supports circular economy, where metals and other resources are kept in a closed loop. The pickling acid recovery system of most stainless steel production is one such example where the dissolved metals such as iron, nickel and chromium are currently not completely recovered due to the limitations of the current technologies. The aim of this study was to assess the available metals recovery methods from extremely concentrated acids. The main aim is to simultaneously recover metals and keep sulphuric acid reusable in acid circulation process. From the available literature, the most promising methods were chosen for laboratory experiments. Based on experimental work, the results and observations of electrodeposition, solvent extraction, and freeze crystallization are provided. KEYWORDS Pickling acid, metal recovery, solvent extraction, cathodic polarization, Freeze crystallization. INTRODUCTION Pickling in stainless steel production is an essential surface treatment process (Regel-Rosocka, M. (2010); Agrawal and Sahu, 2009). It is applied for removing surface films such as oxides and chromium-depleted layers to improve the corrosion resistance and surface finish of steel (Regel-Rosocka, 2010). Whilst the process greatly improves the surface finish of the stainless steel, it generates large amount of used acid, containing dissolved metals including chromium, iron, and nickel (Agrawal and Sahu, 2009). Recovery of acid is common practice for most steel producing industries (Nyman and Koivunen, 1986). In this work, acid regeneration process is investigated so as to simultaneously reusing sulfuric acid and recovering the dissolved metals. Recovery of valuable metals even in very small amounts would also bring additional revenue to the steel production industry. At a time when metal production has also been challenged by lack of natural resources for raw materials, secondary sources for metals such as the acid pickling process therefore, have greater potential as supplements. From earlier studies, electrodeposition (Giovanardi and Orlando, 2011; Kuznetsov et al., 200; Rögener et al., 2012; Surviliene et al., 2006), solvent extraction (Alguacil and López 1996; Haghshenas et al., 2009; Kesieme et al., 2013) and freeze crystallization (Beyer et al.,2003; Hasan et al.,2017; Van der Ham et al., 1999) are some of the most established potential methods. Earlier studies have also shown that simultaneous recovery of acid and metals would require combination of different methods. This is primarily due to the nature of very stable metal containing complex compounds formed during pickling. These complexes must be broken down to free the metals for further recovery processes."

Jan 1, 2018

By Sergey Gudkov, Yuri Yemelianov, Stanislav Balikov, Andrey Boldyrev, Andrey Bogorodsky

"The results of POX of refractory gold-bearing concentrates using halide-ion as a lixiviant for precious metals and activated carbon as an adsorbent are given. It was found that gold did not recover to the solution when halide was added during POX. Silver partially dissolved in the solution. When halide-based reagents and activated carbon were added during POX, gold dissolved and loaded onto the activated carbon. The degree of sulfides oxidation was 99.3-99.6%. The recovery of gold onto granulated carbon was 94.7-94.8% when using chlorine-bearing lixiviants: NaCL, CaCL and carnalite and 98-99% when using KJ and KBr. This treatment process of refractory gold-bearing concentrates combines sulfide oxidation, dissolution and adsorption of precious metals. The results of the metals recovery achieved using this process can be compared with the recovery during POX-cyanidation. In this case, sodium cyanide was not used. This allows the reduction of capital and operational costs due to the absence of cyanidation, CIL and detoxification of leaching tailings circuits."

Jan 1, 2014

By C. Suazo, O. Alruiz, A. Hofmann, I. Fernandez, W. Kracht, N. Mora

"Compañía Minera Dona Inés de Collahuasi, CMDIC, has developed a methodology that allows estimating economic benefit taking into account the variability of the ore characteristics (geometallurgical models). Currently, the grinding model allows predicting the treatment capacity, specific power and balls consumption for short, mid and long term planning. An alternative impact test to estimate SAG grinding parameters is presented in order to bring the geometallurgical model from mid and long term to short term planning. The impact test uses either the production bench or geological drill holes. This allows Geologists increasing the density of grinding parameters within the block model improving the geostatistical estimation of the rest of the blocks. The test requires a small amount of sample to obtain the requires grinding parameters for the grinding model in comparison to the well known grinding test and also, it can be performed easily and quickly by the geology team of a mining company. The alternative grinding test is presented in this article. The grinding model using this short grinding test has been successfully used in mining planning and the accuracy of the model is demonstrated using monthly average instantaneous throughput from January 2013 to March 2014, showing an average relative error of 5% and an R2 value of 0.9. Also, 111 individual variability samples were divided into two each, in order to compare the estimated grinding parameters based on this alternative test to the grinding parameters obtained from the conventional grinding test. The comparison shows an average relative error of 4% and an R2 value of 0.9."

Jan 1, 2014

By M. Brennan, A. Majumder

"The mineral processing research community has devoted enormous efforts to the modelling of mineral separators over the last 50 years. While many efforts have been made to use only fundamental physics as a basis for the models, fluid flow patterns in separators are not simple while the motion of particle swarms through fluids is extremely complex.One of the simplest separators is the sluice, in which separation takes place in a flowing film a few millimetres thick. The particles are suspended by turbulent eddies and motion relative to the fluid takes place in so-called hindered settling mode.In an effort to test the extent to which fundamental fluid mechanics can provide a prediction of particle separation, a study on a simple parallel-sided sluice has been carried out using glass beads at various particle concentrations and flow rates.The actual particle separation taking place was compared to predictions made by first describing the fluid flow by a modified ‘law of the wall’ model.Particle concentration distributions were described using Hunt’s sediment transport model, assuming the particle eddy diffusion coefficient to be the same as that for the water. Settling velocities were calculated using either the Richardson and Zaki or Brauer and Thiele models. The latter takes into account particle size and density distributions and solids volumetric concentration.The resulting predictions of particle separation are remarkably good, even though the model does not model the local settling velocity in the slurry."

Jan 1, 2003

By S. Narra

Converting biomass into valuable fuel requires various preprocessing of the raw materials. Biomass densification is one of the conversion processes for its utilization. The aim of densification is to produce biomass pellets, which can withstand regular handling stresses and exhibit high densities with uniform size and shape. Physical properties, such as the particle size distribution after comminution is of highest importance for the binding mechanisms in the pelletisation process. Durability and strength of the pellets play an important role indicating the ability to withstand handling stresses. Particle size distributions of the cereal straws (Rye and Wheat) after specific comminution and liberation processes have been carried out with the help of three different image analysis (Microscope, Camsizer and Fibreshape). The durability of the pellets have been investigated as specified in the standards (ASAE standard S269.4) with a quadratic crate and the strength of the pellets with compression and tension testing machine (Zwick Roell type: ZMART.PRO). The particles size results showed differences in both length and width after different comminution processing. An exact comparison between the particle size analyses with the three different image analyses was not possible. The particle size distribution and the different comminution processes displayed influences on the durability and strength of the produced pellets. The particle size distribution displayed approximately 40 % of fines and 60 % of fibers. The particle size distribution displayed a direct relation to the durability of the pellets. Further durability and strength of the pellets displayed a good correlation.

Sep 1, 2012

By M. Amani, A. Akbarinasab, M. Bazmandeh

The fourth iron ore production plant at Golgohar mining and industrial company consists a ball mill and wet medium intensity magnetic separators (3500 Guss). The ball mill product applies directly into MIMS and the MIMS concentrate directly transfers to the low intensity magnet separators (LIMS). The thickener is used for dewatering of MIMS and LIMS tailings. By sampling from streams of ball mill and separators, it was defined that the grade and iron recovery were 60% and 80% respectively while they would be 66% and 90% respectively based on the designing documentation. The average of P80 in the ball mill was 342 micron in a month that is coarser than optimized value. This problem was related to unsuitable operation of grinding. For optimization of grinding efficiency, the amount of charge volume was investigated as a variable. The measurements illustrated 32% charge volume. For increasing grinding efficiency, the charge volume was increased 1% and 1.6% in two stages. The results showed ball mill power draw average reached from 3650 kw to 4120 kw and the average P80 reached to 329 micron. All of parameters calculated about 35 day before and after change. Average of Ball mill feed iron ore grade before and after change was 49.24% and 50.32% respectively. This change caused an increase in efficiency of MIMS, where the enrichment ratio and concentrate grade increased 2% and 1.9% respectively. For increasing the iron grade of the MIMS concentrate; the orifice of the tail flow exit pipe changed from 4 inch to 6 inch and the concentrate grade increased 2%.

Jan 1, 2014

By Sarthak Kaushik

Zeta potential measurements show that the isoelectric point of crandallite, in aqueous solution of 10-2 N sodium chloride is at about pH 5.5. Measurements of turbidity confirm the point of zero charge or crandallite. Calcium ions specifically adsorbed on the surface and thus changed the zeta potential and turbidity. From the measured data, it is confirmed that starch acts as a flocculent for crandallite. Oleic acid, which is a collector used in phosphate ore processing is weakly adsorbed on the surface of crandallite. This results in hydrophobic coagulation of particles resulting in a lower turbidity.

Sep 1, 2012

By Gus Van Weert, Samuel A. Bolorunduro, David B. Dreisinger

"INTRODUCTIONAcid pressure oxidation of high-grade natural acanthite was investigated in the range of 110-150°C and in the sulphate media. High acidity and low pulp density were used to prevent the precipitation of silver.RESULTS AND DISCUSSIONTwo sets of acanthite specimens were obtained from La Valenciana and Ingleterra mines, Mexico. Pressure oxidation tests were conducted on 1 litre scale in a standard 2-litre Parr titanium autoclave.EFFECT OF TEMPERATURE ON THE REACTION OF ACANTHITEThe effect of temperature on the rate of oxidation is presented in Figure 1. The rate of reaction increased with increasing temperature."

Jan 1, 2003

By P. Huang

Chitosan was tested as a depressant in the differential flotation separation of chalcopyrite and galena. The micro-flotation results showed that chitosan selectively depressed chalcopyrite while galena was floated by potassium ethyl xanthate in acidic solutions. With the addition of 0.67 mg/L chitosan (CT) in the slurry of chalcopyrite-galena mixtures at pH 4, the recovery of galena was 95% while that of chalcopyrite was 30%, indicating that chitosan could potentially be used in differential Cu-Pb sulfide separation. Furthermore, the study of chitosan with either low (LCT) or high molecular weight (HCT) in the differential flotation indicated that better separation was achieved by the chitosan with lower molecular weight (LCT). ToF-SIMS was employed to study the distribution of CT on the surface of chalcopyrite-galena mixtures by ion mass spectra analysis and surface imaging, which showed that CT adsorbed heavily on chalcopyrite but barely adsorbed on galena. The positive ion ToF-SIMS spectra provided information on the surface composition of chalcopyrite-galena mixtures after CT treatment. It appears that the selective adsorption of CT on chalcopyrite was originated from the strong interaction between NH3+ and Cu. Keywords: differential flotation, micro-flotation

Sep 1, 2012

By K. Trybalski

Facing the optimization activities, which purpose is to minimize the copper processing costs, the main sources of their occurring were presented. In this purpose, the costs analysis was performed, divided to individual standings, for one of the polish copper beneficiation plants. It was proved, that the main component of the copper beneficiation costs is energy consumption, generated mainly in grinding and classification node, particularly by operating mills. The technological system ? grinding and classification node ? in KGHM Polska Miedz S.A., ZWR region Lubin was then selected to investigation. To evaluate the grinding and classification node, the energetic factors W were proposed, calculated on the basis of the energetic-technological data of process, given by node monitoring system. The correctness of the energetic factors selection to evaluate the work of this node and their practical application in industrial conditions was experimentally proved in other technological object. The selected technological object ? grinding and classification node ? was then mathematically modeled and optimized. The calculated energetic factors were the basis to build mathematical models, identifying industrial copper grinding and classification process. The models described correlation and character of dependency between factors and energetic-technical data of the process. These were regressive and neural networks models. On the basis of factors models, the optimization tasks were determined, which purpose was to select the optimal points of grinding and classification node work. Also, the estimated economical effect, possible to achieve after introduction of given monitoring values to grinding and classification node optimization system, was presented.

Jan 1, 2014

By L. A. Nemchinova, M. A. Arustamian

"For a long time tailings piles of mining and smelting complexes have met the eye being a prospecting feedstock source for many industries. Nowadays, 6.5 million tons of copper and cooper-zinc processing tailings are stockpiled in the Urals annually, as there is no technology of its processing to provide a full and complex metal extraction within mining and processing operations. In spite of large volumes of mining wastes, not more than 20% of annual overburden, approx. 10% of processing wastes, approx. 40% slags (1) are involved into processing.Based on today’s complex of economic, environmental and social challenges of ore processing, waste processing technology using existing capacities is a burning issue. Mining wastes characteristics (including fine dissemination, variability of physical and chemical properties of mineral surfaces under impact of oxidizing, leaching, etc.) predetermine challenges arising out of its involving into processing and justify high capital intensity of new construction or reconstruction projects followed by replacement of existing processing lines with new ones.In this paper, the authors propose flotation technology for mature tailings of copper, copper-zinc and polymetallic ore processing. The technology developed provides for upgrade of existing process flowsheet diagrams at minimum costs to produce additional saleable products including low-grade copper concentrate, saleable zinc concentrate and gold concentrate thus facilitates sustainable use of depleting minerals and operational efficiency due to cost-efficient processing of already mined materials, being in fact, final semi-products located near existing operations. This is particularly important for operations with standby capacities and not engaged workforce."

Jan 1, 2018

By L. J. Li, Q. Zhang, Z. H. Liu, Q. L. Chen

Phosphogypsum (PG) is an industrial waste from the production of phosphate fertilizer. The utilization of PG is restricted by its containing impurities, and the pretreatment is crucial to eliminating these impurities. The purpose of the research is to recycle pretreatment PG as raw material for preparation of a-calcium sulfate hemihydrate (a-HH) by salt solution method. The effect of pretreatment technologies of lime neutralization and washing on dehydration rate, phase composition and morphology evolution of a-HH were investigated by crystal water content analysis, XRD and SEM. Furthermore, the change of pH in the reaction process was also discussed in detail. The results show that the dehydration rate of conversion PG to a-HH increases and the corresponding induction period, crystal growth period and total time decrease with an increase in CaO dosage from 0.2% to 0.6%. In the presence of 0.4% CaO or 0.6% CaO, the a-HH presents a long hexagon-prism-shaped crystal with a purity of 94%, and the end face of a-HH presents polyhedron. The system pH sharply decreases with the reaction time under different CaO dosage, and the pH variation from the initial alkalinity to acidity. The main reason is that as the co-crystallized phosphorus dissolved and released HPO42-, and with the pH decreasing to 4-5, HPO42- transformed into H2PO4-. The dehydration rate of washing PG is lower than that of original PG. Compared with the original PG, a-HH with the larger width and smaller aspect ratio can be achieved from the pretreatment PG subjected to lime neutralization and washing, meanwhile the crystal surface is more smooth.

Jan 1, 2018

By A. G. Bulaev

Biohydrometallurgical technologies based on activity of acidophilic microorganisms oxidizing ferrous iron, sulfur, and sulfide minerals are widely used to extract base and noble metals from sulfide ores and concentrates. As sulfide minerals oxidation is exothermic, industrial processes are usually preformed at 40–50°C. Moderate thermophiles predominate under these conditions. Most of moderately thermophilic acidophilic microorganisms that oxidize metal sulfide are mixotrophic, i.e., they use both organic nutrients and CO2 as carbon sources. Carbon availability is crucial for microbial activity and affects efficiency of biohydrometallurgical processes. Aeration with CO2-enriched air is often used to increase microbial activity in biooxidation reactors. Organic nutrients can be used as alternative carbon source for moderately thermophiles performing biooxidation of sulfide concentrates. We performed several experiments with different sulfide concentrates to study effects of organic carbon sources on biooxidation efficiency and demonstrated that application of such organic nutrients as yeast extract (YE) and molasses made it possible to increase biooxidation efficiency. For example, addition of 0.02% YE in the nutrient medium increased biooxidation rate of pyrite–arsenopyrite gold bearing and chalcopyrite concentrates in batch mode at 45°C. YE addition increased oxidation rate of sulfide sulfur and gold recovery level from 65 to 87% and from 73 to 81%, respectively. Similarly, YE addition increased copper extraction from 47 to 54%. At the same time, YE addition increased efficiency of biooxidation of pyrite–arsenopyrite gold bearing concentrate in continuous mode. Without YE addition, oxidation rates of pyrite and arsenopyrite were 65.7% and 94%, while gold extraction was 71%. YE addition (0.02%) made it possible to oxidize 74% and 95 % of pyrite and arsenopyrite and extract 78% of gold. Addition of molasses (0.02%) similarly affected biooxidation efficiency. Thus, addition of organic nutrients in nutrient media is a promising strategy for improvement of biohydrometallurgical processes.

Jan 1, 2018

By C. Hazotte, M. -O. Simonnot, V. Houzelot, B. Laubie, M. Guilpain, B. Jally

"More than 400 plants in the world are able to accumulate nickel (Ni) in their aerial parts at concentrations higher than 10 g per kg of dry biomass. Then, Ni can be recovered from the biomass of these hyperaccumulator plants. Agromining is a chain consisting in growing such plants and producing metal. It has been developed thanks to the combined know-how of agronomy and hydrometallurgy. Hydrometallurgical processes have been designed; two different pathways were developed: i) acid leaching of ashes after biomass combustion and ii) direct Ni water extraction after biomass grinding. Experiments with 2 species of Ni hyperaccumulators (A. murale from the Balkans and R. bengalensis from Malaysia) have shown that the first process is very robust and transposable. For the second one, the way Ni is stored in the plant has a strong influence on extraction. A. murale transformation was explored in more details from the lab scale to the pilot scale. Results proved that Ni is totally transferred into the aqueous phase after 2 hours at 90 °C. A life cycle assessment has clearly shown the environmental interest of this approach (especially by detoxifying agricultural soils). INTRODUCTION Agromining is an emerging phytotechnology aiming at recovering metals thanks to hyperaccumulating plants (van der Ent et al., 2018). These plants are able to accumulate very high concentrations of metal in their aerial parts. For example, for nickel, the hyperaccumulation threshold is 0.1%, i.e. 10 grams of metal per kilogram of dry biomass. There are some advantages to use this technology instead of conventional mining techniques: •,Treating unconventional metal resources: they can be (i) natural soils with low concentrations but also low fertility because of the metal presence (like serpentine soils for Ni) (Bani et al., 2015), (ii) mine tailings or (iii) industrial wastes (like surface treatment sludge) after soil construction (Rue, 2017);"

Jan 1, 2018

By P. C. Beuria

Iron ore concentrate contains different mineral phases viz. hematite, magnetite, goethite, kaolinite, and gibbsite. Presence of some of these phases like goethite, kaolinite, and gibbsite contribute to the loss on ignition (LOI) content of the sample. Iron ore fines (pellet feed) are pelletized for utilization in DRI & BF processes. In the present pelletization technology i.e., straight grate and grate kiln processes, the LOI in the ore should be within the range of 2.0-2.5%. LOI content in the iron ore concentrate is found to be more than 4% after beneficiation of low-grade iron ore. It is therefore difficult to produce good quality pellet because of high LOI content. The LOI content of the sample is a detrimental factor in the pellet making. For effective pelletization, the LOI content in iron ore fines needs to be reduced before pelletization. It can be reduced by fluidized bed roasting. The objective of present work is to understand the kinetics of removal of LOI from iron ore fines. The effects of bed depth, temperature, and residence time on reduction of LOI content in iron ore fines were studied using muffle furnace. The process of roasting was carried out at four different temperatures varying from 400 to 950 °C with a variable residence time of 30, 45, 60 & 75 minutes and at bed depths of 16, 32, 48 & 64 mm. In all instance of experiments carried out, one of the parameters was kept constant. It was observed that at 850 °C and 30 minutes of residence time, there was sufficient removal of LOI in static bed condition even at a high bed depth of 64 mm. Keywords: LOI, pellet feed, fluidized bed roasting, goethite

Sep 1, 2012

By David G. Hulbert, Daniël J. Oosthuizen, Bernard Muller, Daniël de V. van der Spuy

"OVERVIEWExpert Online is a software system that aims to mimic an informed expert on a minerals processing plant. The primary objective of Expert Online is to provide operators with effective training and on-the-job assistance. Training will mostly be done off-line (e.g. using simulators of the plant), while on-the-job assistance will help the operator during normal operation to run the plant in an effective manner. Although Expert Online focuses on the operator, it is expected to also be of value to other plant personnel, including supervisors and plant managers.Expert Online will make use of novel artificial intelligence technology (developed by MINTEK) known as the Interpreting Expert System (IES). Previously the IES was only able to explain the actions taken by the controller. Expert Online will extend this functionality to also take the process dynamics into account.Expert Online is being developed by a South African consortium comprising MINTEK (focusing on the research and development of the system as a whole), Lonmin (globally one of the biggest platinum producers, with plants suitable to test Expert Online on) and the University of Natal (academic partner, providing consultation and focusing on complex process modelling). The initial application of Expert Online will be on milling- and flotation plants.This paper discusses the structural design of Expert Online for implementation on the latest version of MINTEK’s open control platform, PlantStar, as well as several advances and additions since the previous implementations of the Interpreting Expert System."

Jan 1, 2003

By S. J. Neethling

"This paper examines the impact of several key variables on the performance of flotation cells. The study makes use of a simulator for the froth phase of the flotation vessel, as the main purpose of this study is to separate the impact of different variables from one another. In experiments it is very difficult to separate the effect of variables from one another as a change in a singe input parameter, such as air rate, invariably also affects many of the other key variables, such as bubble size and bubble bursting rates.In order to achieve this a base case simulation that is typical of many of the rougher cells found in sulphide flotation circuits was carried out. Four key variables, air rate, incoming bubble size, surface bubble size and the fraction of the bubbles flowing out of the cell unburst, were varied in order to obtain the system.s response.The most significant results were obtained when the bubble size was varied. An increase in the incoming bubble size has the effect of reducing the pulp zone recovery, but increases the froth zone recovery. If it were possible to vary the incoming bubble size without influencing the overflowing bubble size, the impact of the change would be unclear because of these two competing effects. The effect of a change in the overflowing bubble size has an opposite effect on the froth recovery, with larger bubbles resulting in lower froth recoveries.A final interesting result is that all the effects examined affect the process to a similar degree, which implies that none of these variables can be disregarded, either in industry or in further research."

Jan 1, 2003

By Bianca Foggiatto, Marko Hilden, Malcolm Powell

"Since the introduction of the concept of flexible circuits (Powell and Bye, 2009), it has been further developed and refined to the definition of ‚FlexiCircuits leverage ore variability to maximise resource utilisation?. The focus of flexible circuits is to investigate processing options that provide extra capacity through sophistication rather than scale. This requires a combination of smart ore characterisation, economic modelling and innovative processing plant design. Flexible circuit design can reduce energy requirements through gangue rejection or progressive ore upgrade; and increased robustness and controllability by leveraging off ore variation. Each rock type, as characterised through Geometallurgical ore modelling, may be processed more efficiently by individually optimising processing paths. The objective of FlexiCircuits is to transform the processing capability of comminution and concentrator plants - targeting step change in performance through integrating a range of interrelated improvement opportunities. Considerable effort has been applied to developing the modelling and simulations tools required to develop and demonstrate the potential of this concept. This paper presents a practical application as a test case. A realistic application of flexible circuits is provided through a conceptual circuit design of an iron ore processing plant. It is simulated as a multi-component feed with a range of new models in the researcher’s Model Developers’ Kit (MDK) to trial the ability of different circuit designs to respond to variable ore and quantifying the potential of these circuits to transform processing capability of variable ore feed. The outcomes of the simulations are presented and discussed, providing a practical demonstration of the level of modelling and simulation required and the potential of flexible circuit design."

Jan 1, 2014

By Erico Tabosa, Meng. Jun, Kym Runge, Matthew Brennan, Weiguo Xie, Dee Bradshaw

Turbulence and its distribution are of great importance in flotation cell design as they affect suspension of particles, air dispersion and particle-bubble collision rates, which in turn determine flotation performance. However, there is no mature technique to measure turbulence in three phase (liquid-solid-gas) systems such as in flotation cells. In this article, the authors present two new approaches that are suitable for measuring turbulence distribution in three phase systems and validate their applicability. The first technique uses a piezoelectric vibration sensor (PVS) to measure fluid kinetic energy standard deviation and the second technique applies electrical resistance tomography (ERT) to measure conductivity variation at a measurement position in a flotation cell. For the PVS technique, calibration of the sensor was performed to determine the values of parameters that were needed to calculate the force applied to the sensor. Then measurement was conducted in a 60L batch flotation cell and the results were compared with LDA measurement. This demonstrated that the piezoelectric sensor signal provides a good representation of fluid kinetic energy standard deviation at the position of measurement. For the ERT technique, conductivity distribution data was processed to give conductivity variations, which were then used to calculate fluid kinetic energy standard deviation at the measurement position. The spatial distribution of turbulence obtained by performing multiple measurements at different positions in the 60 litre batch flotation cell was found to agree with the PVS measurement results. These two techniques are potentially powerful tools for turbulence measurement in flotation environments, enabling a clearer understanding of turbulence’s influence on flotation performance to be determined.

Jan 1, 2014

By A. Usov

The studies carried out by the Russian researchers and those carried out jointly within some contracts with scientific organizations and companies of other countries, show that the electric pulse disintegration of materials (ED), proposed and investigated in detail in Russia (Kalyatsky, et al, 1980; Usov et al, 1987; Semkin et al, 1995; Usov and Tsukerman, 2000; Kurets et al, 2002) has been widely recognized and developed abroad (Andres, 1995; Inoue et al, 2000; Biela et al, 2008). The Russian and international journals and the proceedings of the conferences dealing with the electric pulse disintegration pay great attention to the principal principals of selective disintegration of materials. There is no, however, any information concerning both the technical means developed to implement the technique and the assessment of their performance, which would be necessary in objective assessment of the industrial use of the technology. The results of long-term studies of the technique and technologies of electric pulse disaggregation by research institutes such as Research Institute of High Voltages (Tomsk), Kola Science Centre of RAS (Apatity), Institute "Mekhanobr"(S.Pertersburg) described. Exploratory stands and technological installations are developed to carry out pilot tests and operations under production conditions. Basic circuits and classification of technical means electric pulse disintegration of the materials are proposed, the analysis of transportation schemes and classification of the material in the disintegration apparatus are given, construction of chambers for continuous stadial disintegration of ores and materials are presented. The features and technological efficiency of electric pulse disintegration of various types of ores, and the spheres of effective use of the method have been determined. Keywords: electropulse disintegration, disintegration machines, chambers of comminution, stadial comminution.

Sep 1, 2012