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Reverse flotation process tests were conducted for marine sedimentary silicon-calcium phosphate ore in this research. The research findings showed that by adding antifoamer, a concentrate with P2O5 32.36%, SiO2 10.69%, MgO 0.67% was obtained, with recovery of P2O5 being 88.12%. Such is a satisfying result, when compared with the original mineralogical component of P2O5 26.64%, SiO2 11.51% and MgO 3.36%. When using antifoamer, the SiO2 grade of the concentrate increased 0.55%, the MgO grade decreased 0.64%, while P2O5 recovery increased 2.69% compared by adding no antifoamer. Adding antifoamer is favorable to increase the grade and recovery of P2O5. Therefore, antifoamer is necessary. Tests of synergistic reaction of antifomer indicate that the appropriate consumption of the antifoamer is 275g/t CY and 1Kg/t TWF. Keywords: silicon-calcium phosphate ore, desilication, antifoamer, reverse flotation

Sep 1, 2012

By Xin Tan

In this paper, two types of low-grade complex zinc oxide ores (sandstone and limestone ores) from Yunnan province, China were investigated. A large number of argillaceous and alkaline gangue makes it infeasible to treat the ores with heap leaching. Although wet metallurgy can be considered, the lower efficiency of liquid-solid separation, the high cost, and low revenue limit this technology to be put into practice in large-scale. In order to solve this problem, a new technology combining mineral processing method with metallurgy technique is studied to process this refractory ore that consists of sandstone ore with 5.84 per centZn and limestone ore with 6.50 per centZn. The results of the tests showed that zinc can effectively be recovered from two types of the ores by using the new technology, and the acid consumption can be remarkably reduced. For sandstone sample, 82.96 per cent Zn was recovered by flotation and final Zn recovery by flotation+ hydro-metallurgy can be up to 78.17 per cent from the ore. In addition, for sandstone, acid consumption can be reduced from 270kg/t by direct acid, leaching to 76.92kg/t by flotation + hydrometallurgy combination. For limestone sample, 85.90 per centZn was recovered by flotation and totally 80.95 per cent Zn can be recovered by new technology which is a combination of mineral processing and metallurgy. Besides, H2SO4 consumption can be reduced from 450kg/t for sandstone originally to113.79kg/t after using new technology. One merit of this new process technology is that the zinc sulfides and oxides can be recovered without desliming in the flotation cells at the different stage and make sure the concentrate products as a good feed for hydrometallurgical technology. This study provided pretty good technical support for tapping low-grade refractory zinc oxide ores. Keywords: low-grade zinc oxide ores, limonite, non-desliming beneficiation, flotation + hydrometallurgy combination

Sep 1, 2012

By Zhou Yucai, Zhou Jing, Zhu Yimim

"In this article, research on the beneficiation process for a carbon containing copper-molybdenum deposit in Henan province has been carried out. The elemental composition, mineral composition and relative content, characteristics of embedded and symbiotic relationship, the forms of the copper-molybdenum particlesand their disseminated features, and particle size distribution have been worked out. Flotation behavior of copper-molybdenum mixed flotation and separate flotation in the systems of different collectors and depressants, and the influence of different flowsheets on the copper-molybdenum separation have been investigated by actual ore flotation tests, The separation problem of copper-molybdenum for a carbon-containing copper molybdenum ore has been solved.INTRODUCTION In this paper, technological mineralogy, small experiment of flotation recovery of copper Molybdenum ore, and expansion experiment of mineral recovery of copper Molybdenum ore are introduced. (1) The results of process mineralogyshow that the content of copper is 0.42%, molybdenum is 0.021% in the raw ore, they mainly exist in the form of sulfide, with low oxidation rate. (2) The results of flotation tests show that the combination of butyl xanthate and isopropyl ethylthionocarbamate reagents is effective collector of copper-molybdenum mixed flotation for carbon copper molybdenum, (3) When the grinding fineness is -0.074 mm taking 71%, and regrinding fineness is -0.038 mm taking 85%, the flowsheet of first copper-molybdenum mixed flotation and then regrinding rough concentrate and last separation flotation of copper and molybdenum was adopted, which realized the effective separation of copper and molybdenum for carbon-containing copper molybdenum ore. Good flotation indexes were gained with copper concentrate containing 20.96% copper and copper recovery 90.06%, and molybdenum concentrate containing 46.78% molybdenum with molybdenum recovery 72.68%. (4) The seven days average concentration index of scale-up the continuous dressing experiment is as follows, the copper content in copper concentrate is 20.16% and the recovery is 89.61%; the molybdenum content in molybdenum concentrate is 24.58% and the recovery rate is 74.09%."

Jan 1, 2018

By Rebecca Hope, Derick Moolman, Frikkie Malan

"Despite the lip service that has been paid to pro-active plant maintenance processes over recent years, a significant portion of maintenance in industry is still reactive. The business driving force to prevent expensive production opportunity costs arising from “break-down maintenance” is obvious. Various benefits can be derived from successfully deploying remote equipment diagnosis technology and associated business processes.From an end-client’s viewpoint these include the ability to predict and take actions to prevent equipment breakdowns, increasing the lifetime of equipment by responding to appropriate operating instructions and therefore improving the return on capital expenditure. Better planning and scheduling of maintenance priorities and resources with performance measures like an Equipment Health Index are also possible. The knowledge that a qualified supplier engineer is constantly in touch with the operating conditions of their equipment, albeit remotely, is more than a comfort, and can be translated into quantifiable cost savings and improved supplier service levels.This paper analyses the reasons for the inadequate level of pro-active plant maintenance practice in industry today, and presents a number of important criteria in selecting appropriate solutions to this problem. A case study of a specific real-time, remote equipment management application is presented."

Jan 1, 2003

By Brian Loveday, Sandile Nkwanyana, Indresan Govender

"Recent batch experiments by the authors in a pilot scale ball mill (Ø = 0.6m) have demonstrated that a partial replacement of the ball charge by pebbles (25 % pebbles; 75 % steel balls) optimally reduces the ball and power consumption without altering the rate of production of fine material (passing 75 microns). At higher pebble volumes, the production rate of fines was reduced progressively. With the 25/75 composite charge a saving of 13 % in power consumption was achieved, and a saving of 25 % in steel ball consumption is implied. A partial replacement of steel balls by pebbles reduces the overall density of the grinding media in the charge. Taking into consideration that the production rate of fines is usually proportional to the bulk density of the charge in the mill, it would be expected that a composite charge (e.g. 25/75) would coarsen the grind and consequently reduce the rate of production of fines. Pebble wear contributes a small proportion of fines and it doesn’t provide a full explanation of why the 25/75 composite charge has no (or minimal) adverse effects on the rate of production of fines. Clearly, the production of fines across the mill is directly related to the shear and compressive power dissipation density. Accordingly, we hypothesise that the spatial power dissipation distribution meeting the minimum requirements for fines production— at the so-called active regions—are equivalent, or minimally comparable, for both the 25/75 composite and 100 % ball charge operating conditions. To test the hypothesis, we performed DEM simulations to analyse power dissipation in the active regions. 1. INTRODUCTION Comminution remains to be the most expensive process in mining operations, particularly because the energy consumed in this process accounts for 30-70 % of the total cost of a mining operation (Nadolski et al, 2014). Optimization of comminution circuits has been focussed on reducing capital and operating costs and maximising throughput capacity. For existing operations, it is often a challenge if the optimization process recommends retrofitting new ‘major’ equipment. The challenge arises from new capital cost and the difficulty of retrofitting in an existing circuit, while maintaining production (Major et al, 2001). Thus, for existing mining operations, optimization of comminution (cost and throughput) is often limited to operating conditions and/or addition of auxiliary equipment (such as pebble crushers, additional screens and high pressure grinding rolls (HPGR)) (McIvor and Greenwood, 1996; Hart et al, 2001; Powell et al, 2015b)."

Jan 1, 2018

By S. Jagdish

India ranks fourth in the world of iron ore production and exported 55% of the total iron ore production of 180.9 million tons in 2006-07. As per United Nations Framework Classification (UNFC), the total iron ore reserves in India is 25249 mt. This consists of about 14630 mt of Hematite ore and 10619 mt of Magnetite ore. While the deposits of magnetite iron ore are limited to the states of Karnataka, Andhra Pradesh and Tamil Nadu, hematite ore is available in abundance in Jharkhand, Orissa, Chhattisgarh, Karnataka and Goa. National Steel Policy, declared by government of India in 2005 envisages 110 million tons of steel production by 2020. This is likely to be revised upwards. Massive exploration work in iron ore is needed to convert the available resources of iron ore into reserve category. Steel Authority of India Limited (SAIL) produced more than 24.5 million tons of iron ore during 2006-07 and plans to produce 42.0 million tons per year by the year 2010-11 to meet the requirement for a hot metal production of 26.2 million tons. While processing iron ore, the challenge faced would be the reduction of the gangue materials ? alumina and silica. It is proposed to bring down alumina and silica in the iron ore to less than 2% each from the current level of 2.5%~3.5% each. Appropriate beneficiation schemes are being developed depending upon the mineralogical characteristics of iron ores at different mines in the country. The state-of-art beneficiation technologies like Hydro-cyclone, jigging, magnetic separation etc. will be incorporated. SAIL?s corporate plan envisages blast furnace burden of 15% iron ore lumps, 15% pellets and 70% sinter by 2010. This strategy opens up the opportunity of utilization of micro fines generated in the mining and beneficiation processes for pellet making. This also directs towards all together new technological approach to the beneficiation process. SAIL is planning to set-up three pelletisation plants of 2~3 mtpa capacity. Environmental issues like reduction in slime loss and utilization of dumped low-grade iron ore are very important. R&D Centre for Iron and Steel, SAIL has carried out extensive laboratory investigations in the above area. This will help in reducing the loss of valuable iron through slimes and also increase the iron ore resource base. Laboratory investigations indicate that low grade dumped ore fines with Fe: 55.5% can be upgraded to a product with Fe: 66.2% with about 48% recovery.

Jan 1, 2014

By V. M. Bystritsky, M. G. Sapozhnikov, G. M. Nikitin, A. B. Sadovsky, Yu. N. Rogov

"At present kimberlite ore is processed in crushers or grinding rolls with subsequent grinding in wet mills down to a size of 0.2 mm. The basic disadvantage of the standard diamond processing technology is that crushing kimberlite ore can damage the most valuable large diamonds of few carats. Tagged neutron method offers a possible solution to this problem. It allows detecting diamond inside kimberlite ore without its disruption. The results of the tests of the neutron separator prototype carried out at the Lomonosov processing factory of PJSC Severalmaz are discussed. The possibility to detect the diamond in the rock whose size is 10 times larger than the size of the diamond is demonstrated.INTRODUCTION At present standard diamond processing technology implies disintegration of kimberlite ore in crushers or grinding rolls down to a size of 0.2 mm. It inevitably leads to high probability that large and most valuable diamonds could be damaged. The fraction of diamonds which lost integrity in the process of ore enrichment could be as large as 35-65% [1]. Tagged neutron method (TNM) [2] offers a possible solution to this problem. It allows detecting diamond inside kimberlite ore without its disruption. The main idea of the TNM is irradiation of an object by fast 14.1 MeV neutrons from binary nuclear reaction d + 3H ?4He + n (1) and detecting (tagging) the 4He (a-particle) that accompanies neutron. That gives possibility to determine direction of the neutron momentum. Those tagged neutrons irradiate kimberlite ore under investigation and produce gamma rays via inelastic scattering reactions with nuclei"

Jan 1, 2018

By Sanjeeva Latchireddi

The effective utilization of the energy in comminution devices depend on how efficiently the broken particles leave the breakage field as soon as they reach product size. In crushers the transport of broken particles smaller than CSS is done by gravity (vertical) thus allowing the energy to be applied to new particles. However, in AG/SAG mills, gravity becomes the energy field and the transport of particles is horizontal which needs a suitable discharge mechanism and has been found to have significant effect on grinding efficiency. The material transport in AG/SAG mills depend on how efficiently the discharge system (grate and pulp lifters) operates. Material transport plays a significant role on efficiency of horizontal grinding mills ? AG/SAG/Ball mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a Greenfield milling operation at Mirabela Mineração?s SantaRita Nickel operation located in northeastern part of Bahia in Brazil. This grinding circuit was commissioned in October 2009, which was designed as a typical SABC circuit to grind 4.6 mtpa (575tph) to produce a P80 of 125um with 10-12% ball charge in SAG mill. However, it has been operating as ABC circuit without any grinding media in SAG mill. The nameplate design capacity has been achieved in few days and has gradually increased to an average of +800 tph and still it is operating in ABC mode. The milling circuit commissioning resulted in small and relatively simple measures to rectify, which was reflected in the rapid commissioning of the milling circuit and it achieved the nameplate capacity within days. The Santa Rita grinding circuit consists of one 30?x 15.4? 8.5MW SAG Mill fitted with Outotec patented Turbo Pulp Lifters (TPL TM ) in close circuit with HP400 short head pebble crusher and one 20? x 28.4? 5.5MW Ball Mill in closed circuit with Warman cyclone cluster fitted with 10 x 26? CAVEX cyclones. This paper examines the comminution design process, operating philosophies, experiences, post commissioning optimization, and future development works. Evaluation of the milling circuit performance relative to the design criteria is also discussed. Keywords: Autogenous Grate (AG), Semi-Autogenous Grate (SAG, Turbo Pulp Lifter (TPL)

Sep 1, 2012

By O. Kökkilic

This study covers the tests to develop separation process for production of clay and colemanite rich concentrates, and aims to serve the clay and colemanite concentrates extracted from the tailing dams to the industrial applications. For this purpose, samples from the tailing dams in Kestelek Boron Plant (Turkey) with an average B2O3 content of 8%~11 % were subjected to the investigations. The separation process of hydrocyclone--to make clear the way to obtain either clean clay or cole-manite--was initially discussed. Therefore, following the gentle scrubbing (to keep the bimodal size distribution between clay and colemanite) of the tailings to disperse the slurry, two alternative multistage hydrocyclone processes; allowing to recycling the overflows or underflows to concentrate clay and colemanite were respectively tested. As a result of the preliminary tests, the multistage hydrocyclone separation in direction to the clean colemanite concentrates (recycling the underflows) gave the better separation efficiencies. So, all the parameters such as apex and vortex finder diameters and feeding pressures were examined with the multistage hydrocyclone process allowing the recycling the underflows. The detailed multistage hydrocyclone separation process of the tailing dam wastes yielded with colemanite concentrates (approx. 12 % of the feed, w/w) with B2O3 content of 35.0 % and the clay concentrates (approx. 42 % of the feed, w/w) with B2O3 content of 2.1 %. Colemanite concentrates were found good enough either to re-feed in to the separation process or to keep upgrading for final product ready to use in Industry whereas the attempts on production of light bricks from clay concentrates has failed. But it is worth to point out that these clay concentrates can be used for agricultural purposes just in the form as it is.

Jan 1, 2014

By D. Izerdem, S. L. Ergun

"Beneficiation of the finely disseminated valuable minerals has been an important issue in the mineral processing field for decades. Treatment of the fine materials becomes difficult with using traditional gravity concentration equipment. To investigate particles behavior in a commonly used conventional gravity concentration equipment, a comprehensive study was undertaken in a plant, which only consists spiral concentrators as concentration units. Spiral concentrators require relatively coarse material to effectively concentrate valuables as well as offering greater simplicity for especially higher grade feeds. In the current work, chromite ore (d80 = 290 µm) was treated using spiral concentrators and the performance of spiral concentrators was examined. The design of the separation circuit comprised of rougher, cleaner and scavenger stages. The resultant fractions produced by each separation unit and feed samples were analyzed to identify the particle sizes, mineral liberations and chromite content. Grade and recovery comparisons were presented in size-by-size manner and the separation tendency of the particles were determined in varying feed rate conditions. The overall results indicated valuable mineral loss of the plant and alternative suggestions were pointed to reach the target values.INTRODUCTION Spiral concentrators are simple low energy consuming devices, which are generally used for pre-concentration of the minerals. They are cost efficient equipment separating minerals mainly based on density differences of the minerals. The adjustable splitters remove the concentrate as the remaining stream continues to move down the spiral. Separation on a spiral is achieved through a combination of forces that act on particles as they move down the trough of the spiral. The main forces known to act on the particle on a spiral are the gravitational force, centrifugal force, hydrodynamic drag and Bagnold force (Atasoy and Spottiswood, 1995; Burt, 1984). Since the classification in a spiral concentrator depends on particle specific gravity and size, the operation of spirals can be analyzed using size recovery or partition curves (Bazin et al., 2014). Spiral concentrators possess multiple design parameters for a variety of applications. The design parameters that govern the performance of the spiral can be identified as the diameter, number of turns, slope, pitch and the profile of the trough. For an efficient separation on a spiral concentrator, the properties of the slurry flowing on a spiral, ore texture, percent solids and flow rate play important roles."

Jan 1, 2018

By I. A. Agapov, I. S. Anisimov, N. V. Rylov, A. M. Sagitova

"The smelter slags represented silicate crystalline rock with medium to coarse-grained structure with spinifex skeletal network of olivine in hedenbergite matrix. Accessory magnetite, pyrrhotite and copper sulfides chalcopyrite, bornite, covellite, chalcocite and digenite occurred in dissemination in silicate matrix. The sample was studied by optical and electron microscopy with support of quantitative XRD. Modal mineralogical composition included olivine, pyroxene, magnetite, chalcopyrite, quartz, pyrrhotite. Copper deportment showed copper distributed in chalcopyrite (40 %), cuprite (22 %), covellite (21 %), bornite, chalcocite, digenite (5 %), Cu-bearing pyrrhotite (4 %) and spinel (2%). Liberation of copper minerals in the material ground to P80=71 µm was good with over 90 % sulfides in free grains and floatable binaries. The results showed theoretical possibility of 65 % copper recovery by flotation. Conclusion based on mineralogical data was precisely confirmed with flotation tests studies that proved to recover around 60 % of copper to commercial grade concentrate. INTRODUCTION Annual world copper matte smelter slags production is estimated to be millions of tones and contain thousands tones of unrecovered Cu, Zn and significant amounts of Ag and Au. Mineralogical study of one large processing sample of material of historical piles of Cu matte smelter slag was carried out to find possibility to recover copper and define theoretical recovery by flotation. The study of the slag material was aimed to determine possibility of upgrading the material on existing copper flotation plant to develop additional mineral resources. The objectives for mineralogical investigation were to target for best liberation fineness, determine theoretical recovery and possible concentrate quality for sulfide flotation tests. MATERIALS AND METHODS Large representative processing sample was collected by mixing of 120 t of slag material representatively excavated from historical piles of Cu matte smelter slag. The sample was used to define the processing technology to recover copper and gold from the material."

Jan 1, 2018

By Y. G. Seredkin, A. A. Vasiliev, A. Y. Senchenko, A. V. Aksenov

"The valuable materials resulting from the processing of gold-bearing ores are often refractory to direct gold recovery through cyanidation. There are multiple methods for chemical liberation of gold prior to cyanidation such as pressure and biological oxidation as well as atmospheric oxidation which is typically used in combination with physical activation of material by ultrafine grinding such as the Albion ProcessTM. This paper will examine the data from process testworks carried out to estimate the efficiency of the Albion Process™ for the oxidation of materials with a wide composition range prior to cyanidation. The data will be compared to that obtained by direct cyanidation of the feed (without oxidation) and from the testing of pressure oxidation on the feed prior to cyanidation. Albion Process™ tests were conducted in Institute TOMS with participation of Glencore Technology Pty Ltd (Australia). Refractory concentrates obtained from the ores of several Russian and CIS deposits were used as feed for the testing. These concentrates were also subjected to a material composition study and testing using conventional recovery methods. The resulted test data make it possible to perform an integrated assessment of process properties for materials with different compositions, compare performance of various process flowsheets for the materials under study, and conclude on efficiency of Albion Process™ application for gold recovery from refractory materials different in their composition.INTRODUCTION It is often the case that gold ore concentrates are refractory to gold recovery by direct cyanidation. This refractory nature is as a rule attributable to fine gold dissemination in minerals, most often in pyrite and other sulphides, as well as to the increased amount of components impeding cyanide leaching of gold due to cyanide consumption and reducing process conditions. The refractoriness of the concentrates results in low gold recovery values when conventional cyanidation technology is used. In this context, various additional processes are applied to breakdown such refractory sulphide concentrates, i.e. mechanical breakdown (fine and ultrafine grinding), chemical breakdown (atmospheric oxidation, e.g. Leachox, acid-oxygen oxidation, pressure oxidation – POX, bacterial oxidation – BIOX), and thermochemical breakdown (various roasting methods). Such breakdown processes allow for increase in recovery of finely disseminated gold during the downstream cyanidation, however, their application is cost-intensive and does not always ensure economic benefit."

Jan 1, 2018

By V. Avdochin

The main reason of flotation process fluctuations is mixing ores of various properties from various sections of a deposit. Other, also important reasons are changes in parameters of facilities of technological cycle, as well as properties of reagents applied. According to estimates, instability and non-optimized parameters of flotation owe 3% to 6% of valuable component losses. Without ore averaging systems flotation process is characterized by considerable fluctuations of all input, output and intermediate parameters. Stab One more way is optimizing the process, providing for determination and maintaining optimal parameters of the process. In these conditions application of various mathematic models does not allow controlling the process by the way of action on input parameters of the process with further precise reaching required values of output parameters. More effective is to be application of flotation models for solution of questions of choosing and optimizing of automatic control systems. The work presented examples of application mathematic model of flotation process for estimation of effectiveness and choice of parameters of automatic control system that reduces considerably a stage of preliminary studies in elaboration, designing and modernizing automatic control systems.

Jan 1, 2014

By D. Chen

The experiment adopted magnetic separation-priority flotation (first to float copper,then float lead) combined technology to deal with a complex Cu,Pb ,Zn multi-metals ore which has high sulphur content, difficult to separate Cu, Pb ,Zn minerals from sulphur and separate Cu from Pb. Floatable pyrrhotite was separated through magnetic separation which could eliminate the adverse effect on the flotation followed up. And then adopting the priority flotation process to recover the Cu, Pb ,Zn from the magnetic tailings. In priority, flotation Cu, BP(a kind of ethionine ester collector ) and ethyl xanthogenate were used as the collector, LD-1 and sodium sulphite were used as the depressant.The depressants combined with humic acid sodium and lime were used for chalcopyrite ? pyrite separation to further improve the copper concentrate grade. Considering the raw ore that contain 0.32% copper, 0.54% lead and 25.54% sulfur. The copper concentrate grade is 23.61%. The lead content of copper concentrate is only 0.85% . The recovery of copper is 75.03%,and the lead concentrate grade is 54.58%, the copper content of lead concentrate is only 0.81% and the recovery of lead concentrate is 62.24%. The mineral processing indexes were excellent, finally realizing the high effective separation of Cu, Pb , Zn and pyrite. This technique provides a new approach to highly utilize complex copper-lead-zinc ore.

Sep 1, 2012

By J. Zou

With the increasing applications of the Chinese metal magnetic liners, the requirement for their technical specifications has become stricter and stricter. It is necessary to deeply analyse the metal magnetic liners in order to improve their reliability and economics. The key issue of metal magnetic liners is magnetic forces: their attractions to mill shell and protection layer. Mathematical models were developed using finite-element analysis software and systematic simulation analyses of the two most critical indexes of magnetic liners were performed to find out the most important parameters and their effect on the liner?s characteristics. The relationships between magnetic forces and installation gaps, thickness of permanent magnets and thickness of protection layer may be used to guide the design of metal magnetic liners for ball mills in order to achieve good economic indexes.

Jan 1, 2014

By M. Saghaeian, R. Hejazi, R. Barreiro, M. Tavousi, M. Ahadi, O. Asghari

"Banded iron formations are the major iron source for producing high grade concentrate. BIF are generally lower grade and more difficult to extract. In order to know how best to process BIF ore, it require comprehensive knowledge on ore bodies even in the early stages of the mining process. Geometallurgy combines geological and mineral processing information and allows for higher flexibility in response to changes in the plant feed when mining different parts of the ore. This can lead to economic benefits, owing to improved plant operation, yet is time consuming and correspondingly costly. The main focus of this paper work has been to develop a comprehensive geometallurgical testing framework for developing Yogi BIF low grade magnetite deposit located at Western Australia. In order to provide successful geometallurgical mapping, was collected data from several different disciplines (geology, chemistry, mineralogy) and parameters (physical properties, metallurgical response and geotechnical measurements) during drilling activities and test work. The investigation shown magnetic separation behavior of material had high variation and is most important element in the proper design of ore beneficiation plant. This paper provides an improved and efficient magnetic separation test methods used for the investigation of separation behavior and variability of the Yogi Ore deposit and evaluates their applicability and potential in the geometallurgical context. In this paper a small-scale magnetic separation has been developed that allows estimating from single pass separation test using small amounts of sample material. Verification of the evaluation method and validation was done with different mineral systems."

Jan 1, 2018

By E. V. Zelinskaya, A. E. Burdonov

"In the raw aluminum production processon electrolyzers with self-baking anodes, during technological operations, flow-regulated treatment and adjustment of the electrolyte chemical composition produced by diesel and floor-rail technology, alumina and fluoride salts are spilled through the ventilation grilles of the electrolysis body aeration channels, leakage in the equipment, machinery and motorized machinery construction elements. As a result of this, a part of the bus station and the level of ± 0 (the basement room with supporting curbstones and columns, on which electrolyzers are installed) are covered with technological raw material. This leads to an increase in the conductor (bus) resistance, contact connections deterioration, cell insulation failure and raw materials loss. For example, at the enterprise ""Rusal-Bratsk"", as a result of the activity, up to 420 tons per month of alumina-containing wastes that are unfit for use in the electrolysis process are formed due to the alumina substantial contamination with salts of iron and silicon, which significantly reduces the technical and economic parameters of the electrolysis process. The main scientific problem is the processing (cleaning) of alumina-containing waste having a complex mineralogical composition of the material, its contrast and structure, from oxides of iron and silicon, using ""dry"" separation methods. In the performing the work process, qualitative indicators of the influence of external factors (air humidity, precipitation, sunlight, temperature difference) on the physicochemical processes components interaction during the raw materials storage are established. On the basis of laboratory tests, it is established that alumina-containing raw materials can be separated and photometric and gravitational separation methods used. A mathematical model of the motion of particles of primary and prepared alumina-containing raw materials in a cascade-gravity classifier was developed. The criteria and factors characterizing the alumina-containing material, as well as influencing and determining the maximum material enrichment, are established."

Jan 1, 2018

By Rintaro Hayashi

The enrichment of useful components from ores and/or wastes has become important with increasing recent worldwide resources demand and the amount of wastes generated from the urban mines, in order to establish real ?sound resource-cycle society? including the activity of resource exploitation. The first stage of the treatment in the process must be comminution and it is important to make good liberation among compositional phases in the targeted resources. Electrical disintegration (ED) is well known to make a selective breakage at phase boundary. However, the detailed mechanism of the phenomena is not clarified yet, in especial, on the influence of electrical properties of compositional materials on the liberation. This paper made a comparison between the liberation degrees of ED products and the results of electromagnetic field analysis using finite element method (FEM). In the experiments, we used several synthetic cement paste based samples in which mineral particles were dispersed to apply the ED, and in the electromagnetic field analysis, we calculated the charge density accumulated and the Maxwell stress at phase boundary. It was found, for highly insulating mineral samples, that higher breakdown voltage was necessary because electric charge was not easily accumulated at phase boundary but that higher liberation degree was obtained after the breakdown (ED). It was also found the tendency that higher liberation was observed for the samples which had higher maximum Maxwell stress calculated by the electromagnetic field analysis. From the results, the electrical charge and Maxwell stress induced at phase boundary could be driving forces of selective breakage. In addition, we also applied the ED to the printed circuit boards (PCBs) in order to concentrate miner rare metals, which were essential for producing electronic devices. It could be demonstrated that the devices installed on the PCB were easily detached from the board and that most of metal elements in the devices was exposed and liberated from the insulating plastic covers, which were broken in the ED, then, it is considered that the subsequent solid phase separation could be effective for concentrating such metal elements. Keywords: liberation, electromagnetic field analysis, printed circuit board, miner rare metal

Sep 1, 2012

By Hossein Zarei, Masoud Kashani, Mehdi Safari

The feed of flotation unit in Angouran mine, as a part of Iranian Lead and Zinc National Corporation, contains about 34.26% zinc (about 12% Zn sulphide) and 10.14% lead (about 2% Pb sulphide). The grade of Pb and Zn in the final concentrate (rougher+scavenger), under optimal conditions (200 g/ton PEX, 500 g/ton zinc sulfate, 30 g/ton MIBC and pH = 7.5), was 63.18% and 13.01%, respectively, and the total Pb (sulphide-oxide) recovery was about 19% which included 95% Pb sulphide. The grade of Pb and Zn in rougher concentrate step was about 71.86% and 5.97%, respectively, when PEX (Potassium Ethyl Xanthate) was used as collector. While in the presence of PAX (Potassium Amyl Xanthate), the grade of Pb and Zn in rougher concentrate step was 66.8% and 10%, respectively. Tailing of the galena flotation (with 8.48% Pb grade and 34.92% Zn grade under the optimal conditions) was used as a feed for sphalerite and oxide section flotation.

Jan 1, 2014

By Jacek Kolacz

A new sensor based sorting system has been developed, based on complex image analysis, where an image texture and a shape pattern is considered for identifying particles for separation. The sorting system employs different images generated by visual light and X-ray to provide maximal information about processed particles. Application of X-ray makes it possible to analyse the internal structure of the particles, which provides a 2D image with complicated texture, however, which contains valuable information. The advanced system for the texture and the pattern recognition is applied to analyse these images simultaneously, to provide the required identification of the particles for efficient separation. The mathematical models applied during identification and separation, are assisted by high speed calculations being specially optimised for this kind of process. This allows sorting with high capacity and high accuracy, which is critical for practical applications in mineral processing. The paper describes a number of tests during sorting of iron ore and coal with high separation efficiency.

Jan 1, 2014