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By Venkata S. Buddhiraju

Pelletization of iron ores involves balling on a rotating disc to produce wet pellets and induration of wet pellets on a moving grate to produce fired pellets. The quality of pellets produced and the productivity of the pelletization process depend strongly on the characteristics of the feed to the pelletization disc, especially the particle size distribution and the moisture content. The upstream processes involved in the preparation of pelletization feed include grinding, thickening and filtration of the iron ore slurry. The focus of the present work is the closed circuit wet grinding of iron ores. The circuit consists of a primary ball mill, a regrind mill and a hydrocyclone. A population balance model was developed to predict the grinding kinetics and an empirical model was fitted for the separation of fine particles from the coarse particles in the hydrocyclone. Batch grinding kinetics experiments were performed on a laboratory scale ball mill to obtain the ore breakage parameters which were subsequently used for the simulation of the industrial mills. The models were customized for the industrial operations and the effects of different process variables like feed flow rate, water flow rate, etc., on the size distribution of product from the grinding circuit were studied. Additionally, different circuit configurations were simulated to determine operating conditions that could result in the desirable product particle size distribution. The results of simulation were in close agreement with plant observations and the new circuits explored through simulation have helped in identifying potential opportunities for process optimization and control

Sep 1, 2012

By Victor V. Karmazin

"The appearance of the precise equipment for analysis of results of the laboratory tests with using of the computer processing allows raising accuracy of the estimation of the expected indexes of the mineral processing. Certainly, laboratory tests will not be able to substitute completely industrial ones, but allow reducing the amounts of the industrial tests, that vastly reduces the cost of technological forecast and preparation of data for projection.Calculation of the potential indexes of mineral technology (mass yields and the metal content in products) is fulfilled on the base of results of measurements of the mineralogical liberation parameters using special formulas.The quality of the concentrate ßc = a + ?l • ?s • ?i (ßt - a) can be achieved on a level of the theoretical metal content of a mineral - ßt only if coefficients of mineral processing, of liberation ?l and selectivity ?s of grinding, effectiveness of separation, will reach 1 (a - metal content of the row ore).Increase ?l by overgrinding automatically decrease ?s, and only by destroying of particles of ore along surfaces of accreting of minerals (?i = 1) and when values of all three coefficients will aim to 1, then ßc ? ßt.The degree of liberation of the useful mineral is the ratio of mass of free grains of the useful mineral in the product to general mass of the same mineral in this product. The factor of the liberation, which is defined by curves of dressability by angle of slop of the curve of the elementary faction - ?, is Kr=1 – tga. Kr changes from 0 to 1 when a changes from 45o to 0o. The liberation is reached by grinding of the material, although degree of the liberation, as a rule, is lower than the degree of the grinding."

Jan 1, 2003

By A. J. Lynch, L. Ergun, M. Oner

"A research program on modelling cement grinding circuits has been in operation at Hacettepe University, Ankara, for four years. It has concentrated so far on tube mill and air separator grinding circuits for cement clinker, with emphasis on plant sampling surveys, including axial sampling inside the tube mills. The methodology is to use plant data to build the models and to supplement this by laboratory data where necessary, for example the determination of breakage functions. The plant data come from comprehensive sampling surveys and so far 33 surveys of clinker grinding circuits have been carried out in 9 plants. The operating conditions have been• mill sizes – 3.2 to 4.8 metres diameter and 8.5 to 15 metres long,• mill feed rates – 46 to 158 tonnes per hour,• air flow through mills – 25000 to 125000 cubic metres per hour,• cement clinker work indexes – 10.3 to 18,• separator sizes – 2. to 3.1 metres diameter,• separator feed rates – 132 to 689 tonnes per hour,• separator speeds – 12.3 to 21 metres per second.The ball mill model is Whiten’s perfect mixing model and the separator model is the Tromp curve with a fish-hook. This paper emphasises on the importance of calculating the breakage rates and the discharge functions with three case studies at five different circuits which were selected for discussion because they show how particular features of circuit operation can be included in the general models. Size distributiongraphs are used to illustrate every aspect of the discussion.In case I the special emphasis on calculating the breakage rates and discharge rates separately is given in a high pressure grinding roll-ball mill-separator circuit. The tonnes of each size fraction in the mill and the calculated values of R/D, D and R are determined. The values of R per mw are also given to allow comparison with mills of other sizes. The circuit allows the comparison of the static type (V Sep) and dynamic type separators (SKS). Comparing the reduced efficiencies shows that the dynamic separator is slightly more efficient than the static one.In case 2 data are given from two compartment tube mills having the same diameter and the motor power but different ball size gradation. The breakage rate particle size variation of the second chamber of two mills indicate that having finer ball size distribution causes higher breakage rate values."

Jan 1, 2003

By Valery V. Kostjuk, Victor. N. Bredikhin, Alexander I. Shevelev, Evgeny A. Kazban

"The investigations to improve the process data have been done in order to stabilize the functioning of drying units. The scheme of turnings preparation with centrifuging and subsequent thermal degreasing (tandem) is proposed. To improve the efficiency of the process the scheme of reclamation of the centrifuge fugate is developed with production of oil and service circulating water. Empirical dependences of the turnings temperature influence on the lubricant-coolants content in centrifuging are gained. When the turnings temperature is increased to 80 C the residual content of LC is decreased by 1.5%. The investigations aimed to improve the preparation of non-ferrous turnings have allowed to decrease the melting loss by 15-20%; to stabilize the process of thermal drying of turnings; to decrease sharply (by 60- 70%) the volume of LC combustion products; to reclaim the centrifuge fugate and produce oil and servicecirculating water.Non-ferrous turning and primarily aluminum and copper alloys turning is a stable source of secondary raw materials for metallurgical works.Direct by lubricant-coolants (LC) of various types: synthetic, semi synthetic, oily and emulsions.On the base of investigations concerning various methods of the non-ferrous turning processing the favorable one has been selected taking in to consideration the economy, ecology and quality of the finished product (alloy). Two-stage process is developed. The main idea of the process is the elimination of the lubricant-coolants (LC) to the limit specified in advance. The applied method is centrifuging with subsequent final elimination of LC by thermal method.Constant value of LC content at the inlet of the thermal unit excludes practically the oxidation of metal and as a consequence increases the output by 10 –15 % in metallurgical processing."

Jan 1, 2003

By J. Broadhurst

"A number of metal supplying industries have in recent years seen the compilation of life cycle inventories (LCIs) and life cycle assessments (LCAs). The activity has largely been driven by the interest of ultimate metal users, such as the automotive industry, in the interest of designing more sustainable products. Often, the compilation of such inventories has been little more than an auditing exercise. However, the process of conducting an LCA can have more value, guiding designers and operators to points within the technology train where significant emissions and impacts originate. The LCA product can thus be used to inform on-site environmental management, and, where process data is used to construct dynamic operational models, to support strategic decision making in the realm of project planning and technology selection. LCA thus serves as a valuable tool to support the industry’s drive to support the sustainable development of the societies in which it operates.This paper reviews and compares the priorities of environmental and closure planning in the design phase, with environmental management and auditing during operation, and with green procurement of minerals and metals products. It shows how life cycle assessments of various complexities can be used to reconcile these various objectives, ensuring that the latter, critical to business success, can be addressed from the outset in a new project. The paper then reviews a case study of the use of LCA in the base & precious metals industry, where the complexity of the operation disallowed the simpler auditing process so that a detailed process understanding had to be built up in order to compile a meaningful life cycle inventory."

Jan 1, 2003

By A. V. Bauman

"Important for thickening processes is the ability of slurries to form under certain conditions aggregation and sedimentation stable systems. Substantial part of difficult to sediment solid particles in such systems may be in colloidal state. The technique to study the sedimentation and aggregative stability of the slurry developed by the author with co-authors makes possible to define kinetics of changes in the aggregative stability of the system with solid phase varying concentration in it and produce data on sedimentation stability of the system in preliminary investigation of the thickening process. Research of aggregative and sedimentation stability of the slurry complement standard methods of laboratory studies to prevent errors in development of water-slime thickening balance and water circulation to design new and upgrade existing processing plants. Statistical analysis of process audits of more than one hundred upgraded and newly commissioned processing plants carried out in recent fifteen years showed that more than two-thirds of problems arising in commissioning the processing plants are associated with misdesign and errors in thickening and water circulation system. Among the main reasons of process design failures are: non-conformity of actual characteristics of the raw material to design characteristics, low quality of preliminary studies at the stage of sedimentation process simulation, design failures, wrongly selected equipment for the thickening and water circulations systems. As of today a number of problems associated with laboratory studies of sedimentation process, first of all, with interpretation of precipitation curves produced at the stage of laboratory refinement of the thickening process have been pinpointed. (Bauman A.V. Outstanding issues in design of thickening and water circulation diagrams in processing plants // Ore processing. 2016. ?3 P. 58-62) ?????? ?.?. ?????????? ??????? ?????????????? ???? ???????? ? ??????????? ?????????????? ??????. // ?????????? ???. 2016. ?3. ?. 58-62))"

Jan 1, 2018

By Vladimir S. Zharov, Vyacheslav A. Tsukerman

"Conceptual imitative dynamic model of developing enterprises for medium and long-term period permitting to ensure coordination of interests of the enterprise and territorial environmental authorities has been developed to enable the process of the prognostication and management of a concentrating mill development, in which a symbol language and terminology familiar to the manager of the company are applied. An algorithm of practical application of this model of company development was elaborated as well as a general methodological approach to the prognostication of the development and procedures of its implementation. The general methodological approach to the implementation of the model has been defined. Within the framework of system approach, a concentrating mill is considered as a subsystem of an ore mining and processing company or a mining and smelting one. A concentrating technology is considered in dynamics, its change is determined by the task of making the company operation profitable. Technological indicators are secondary relative to financial and economical indexes. At the same time, technological and economical indexes are determined in their interrelation with ecological parameters. The elaborated model allows us to estimate all necessary economic, financial and technological indexes in their interrelation both for the company as a whole and as separately redistributed estimating the basic prognostication documents - accounting balance-sheet, profit and loss report, as well as the funds flow statement. When varying the managing parameters, all necessary result-producing financial and economical indexes are estimated and a need in and a possibility of an external funding by various sources are considered.The implementation of the model enables one to determine the required scale of production capacity, as well as the amount of raw-material resources needed. In case of shortages of the latter, there should be considered various scenarios of the production capacity enhancement or the possibility of commissioning of new sites or deposits and introduction of improved technologies."

Jan 1, 2003

By Xiong Dahe

"SLon vertical ring and pulsating high gradient magnetic separator utilizes the combined force field of magnetism, pulsating fluid and gravity to beneficiate weakly magnetic minerals with the advantages of large beneficial ratio, high recovery, matrix not easy to be blocked and excellent performance.We have developed SLon-750; SLon-1000; SLon-1250; SLon-1500; SLon-1750 and SLon-2000 VP HGMS. Now more than 200 of them have been successfully applied in China.Application in Qi Dashan Mineral processing Plant of Anshan Iron and Steel Company: The iron ore consists of magnetite and hematite. In 2001, six SLon-1750 magnetic separators are applied to control the tails grade of fine hematite. The results of flowsheet is: feed grade 30.15%Fe, concentrate grade 67.00%Fe, iron recovery 75.86%. The results set up the historic high record of this plant and the processing coast is greatly reduced.Application in Gushan Iron Mine of Ma Anshan Iron and steel Company: There are 6 SLon-1750 and 4 SLon-1500 magnetic separators applied in this mine to treat refractory hematite ore. The feeding grade is about 45%Fe. The final iron concentrate grade is about 60%Fe and the iron recovery is about 76%. The results are much better than the previous gravity flowsheet.Application in Meishan Iron Mine of Shanghai Baoshan Iron and Steel Company: The mined ore consists of magnetite, hematite and siderite. Because of a relatively high content of phosphorus, the iron concentrate could not meet the market requirements. Now 18 SLon-1500 magnetic separators are applied to reduce phosphorus, which is reduced from about 0.4%P to 0.246%P. The quality of iron concentrate is greatly upgraded.Application in Panzhihua Ilmenite Processing Plant: In the past, the -0.045mm ilmenite fraction was discarded in to the tails because of lack of high efficient equipment. In 2001, the plant built up a magneticflotation flowsheet to recover the fine ilmenite from the -0.045mm fraction with 6 SLon-1500 magnetic separators. The total results are: feed grade 11%TiO2, concentrate grade=47% TiO2, recovery 44%. Each year the flowsheet recovers 60,000t fine ilmenite concentrate."

Jan 1, 2003

By Rod Hocking, Nenad Djordjevic, Randolph A. Pax

"Semi Autogenous (SAG) mills exhibit complex interactions between the competing processes occurring inside them. Traditional practice is to measure the operation of the SAG mill at an operating point in terms of its load, power draw, steel load, ore throughput rate, water addition rate and more recently the feed size distribution. However significant departures from standard operating conditions can occur due to changes, for example, in ore hardness, the quest for higher throughputs and mill internal geometry.Fundamental to SAG mill operation are the internal processes that ensure that a given ore throughput and discharge grind size are obtained and maintained. These processes can be measured using non-contact acoustic emissions from the SAG mills which utilise the information rich noise that is generated by the grinding, flow and charge movement inside a mill. Non-contact acoustic in-mill measurements can be used for the validation of discrete element modelling (DEM). The approach being reported in this paper is to model the individual physical processes and then to simulate the assemblage of a physical mill.By modelling the assemblage of steel balls in a 1 m pilot mill and duplicating the experimental arrangement exactly with the PFC3D model, it was possible to replicate the pattern of falling balls in the experimental mill. Furthermore, the key features of the acoustic emission spectrum that was calculated compared favourably to the measured spectrum at low frequencies. The experimental spectrum is shown in Figure 1."

Jan 1, 2003

By L. G. Schumskaya, ?. S. Yusupov, ?. ?. Kirillova

"It has been shown on the example of cassiterite that grinding in mills of the increased power lead to destruction of the fine crystal structure and consequently to change in physical and chemical properties of the mineral, that is its transition into mechanically activated state. The increase in mineral reactivity is related to both the growth of mineral specific surface and sharp decrease in the sizes of primary crystallites accompanied by essential increase in number of microdefects that is clearly expressed in its increasing solubility during interaction with corrosive mediums, especially with acids. Calorimetric measurements indicate that the thermal effect of SnO2 solubility increases considerably.These observations allow us to propose two techniques of hydrometallurgical treatment of cassiterite: direct dissolution of the mechanically activated mineral in acids, although it is a very power-consuming process, and mechanical activation of cassiterite in presence of metals that are able to release hydrogen from acids. Active hydrogen is released during interaction between the mechanical mixture of SnO2 and metal with acids and reduces tin from the mineral transferring it into solution.In addition to other technological properties, the flotability of cassiterite has been thoroughly studied. It has been found that it steadily decreases as activation proceeds because of increase in the degree of hydratability of particle’s surface. In this case, the mechanical activation is provided through tribotreatment of a surface rather than through fine grinding. On this basis we developed the technique of inverse cassiterite flotation with its subsequent transfer into a chamber product that considerably increase the quality of a tin concentrate.The observed technological effects may be generally explained by occurrence of the valenceundersaturated, strained (deformed) chemical bonds and other active centers on the cassiterite surface while decrease in its flotability - by formation of the hydrolyzed tin species and impurity iron, such as Sn(??)4°, Fe(??)2 +, Fe(??)3° hydroxocomplexes and others."

Jan 1, 2003

By J. D. Miller, C. L. Lin

In general, x-ray computed tomographic (CT) techniques are able to provide 3D images of the internal structure of opaque materials in a nondestructive manner. The unique cone beam geometry allows acquisition of all 2D projections with only one rotation of the sample thus providing for fast data acquisition and better x-ray utilization, as a complete 2-D detector array receives the cone-shaped flux of rays. Thus, an isotropic 3D volume can be reconstructed without the mechanical translation and the stacking of sequential slices as is the case for more conventional CT scanners. In this regard, a state-of-theart, custom designed x-ray microtomography facility to provide very detailed 3D spatial analysis of multiphase particles has been installed and is in operation at the University of Utah. The reconstructed 3D tomographic volume allows for an adjustable spatial resolution from 5 to 20 microns for sample dimensions from 10 to 40 mm in diameter, respectively. For example, a packed bed of coal particles is shown below in which different crystalline froms of pyrite are distinguished in 3D.

Jan 1, 2003

By N. ??dyanik, Z. Kugukaldinova, O. Mishurina, Y. Glazkova, E. Mullina

"This paper describes the process flow of a selective processing method for acidic mine waters formed in the copper sulfide industry and characterized by a high content of copper, iron, and manganese ions. The proposed method comprises a series of sequential processes: the 1st stage is the recovery of Cu2+ ions by precipitation, the 2nd stage is the recovery of Fe2+ and Fe3+ ions as a dispersed phase by acid-base precipitation, followed by recovery in the 3rd stage of Mn2+ ions by converting Mn2+ with an oxidizing agent into insoluble forms of manganese and subsequent recovery of the dispersed phase by electroflotation. The developed method was tested on the acidic tailing storage facility (TSF) water of a mining project in the Urals region. The practical results of the implementation of the developed method have shown that its implementation will allow to recover copper, iron, and manganese in the form of salable products with a simultaneous decrease in their concentrations in adjacent water bodies down to the applicable MPCs. The process is a simple one, does not require any sophisticated expensive equipment and can be implemented either as a standalone solution or as part of existing treatment facilities. INTRODUCTION As a result of unsustainable utilization of natural resources in Russia, only a small fraction is processed into commodity products, while the rest is systematically dumped as emissions, effluents, and other wastes, polluting the environment. By amount of waste and concentration of valuable components, those wastes can be classified as aqueous technogenic resources [1, 2]. Therefore, the development of processing methods for this mineral resource category is an urgent and priority task that will significantly improve the industry’s profitability and the environmental conditions in the respective regions. MATERIALS AND METHODS Following research methods were mainly applied in this study: lab-scale and pilot-scale tests in a diaphragmless two-chamber electric flotation cell; for solutions and recoverable process products — chemical analysis using photometric determination techniques for metal cations and atomic adsorption determination techniques for the processing products. The phase composition of the precipitates formed in the process was investigated by X-ray phase analysis in the general-purpose diffractometer with a copper anode DRON-1."

Jan 1, 2018

By R. Bugueño, W. Calderón, G. Montes-Atenas

From the point of view of industrial performance of metal extraction, the efficiency of a column leaching operation depends strongly on the leaching agent and the ore properties such as mineral composition, mineral liberation and particle size distribution. One aspect that has become particularly important is how the leaching solution flows through the porous structure which contains the valuable minerals. It is known that the output flow rate of leaching solution depends mainly on factors of the input flow, environmental condition and porous bed properties. The latter factor is often evaluated and reported under saturated conditions but in practical leaching systems unsaturated conditions are dominant. This investigation has the purpose of determining the residence time of the leaching solution in columns with different diameters under unsaturated conditions by using experimental data and numerical simulations. Laboratory leach test were performed using isothermal jacketed columns with top cap to reduce the evaporation. The simulations were performed using the software SVFlux® which incorporates material properties such as Soil Water Characteristic Curve (SWCC) and Unsaturated Hydraulic Conductivity. Preliminary results indicate a non-linear asymptotic behavior of the saturation rate with respect to the operation time. Results from numerical simulations show the same non-linear behavior and a considerable delay between input and output flows. Further analysis concerning with the effect of transpiration and evaporation mechanisms is discussed.

Jan 1, 2014

By D. P. Hatfield, G. de Jager

"Recent developments in image analysis techniques and the power of computer hardware have spurred international interest in the potential uses of image analysis techniques in a range of industrial applications. One of these applications is the control of the complex flotation process. Despite years of work, the flotation process is still poorly understood. Current attempts to control flotation cells focus on consistently duplicating the control achieved by human operators.In human control of flotation two of the dominant visual cues are the froth flow speed and the froth stability. These two factors can be measured and inferred respectively from image analysis of video of the froth surface. Two important hydrodynamic variables for control of the flotation process are the air addition rate and the level of the froth pulp interface.The current work focuses on the relationship between froth flow speed and the rate of recovery of concentrate from a flotation cell. Results are presented that show a strong relationship between flow speed and concentrate yield. These results include tests where the conditions in the cell were not changed, as well as tests involving changes to the cell level and air addition rate. Preliminary results are presented which show a correlation between froth stability and froth percent solids.Future developments of the system will include comprehensive froth texture typing, colour space and stability analyses."

Jan 1, 2003

By L. A. Vaisberg, E. V. Shishkin, S. V. Kazakov

"This research is targeted at finding solution to the problem of reduction of specific energy consumption during disintegration of solid materials with the help of machines, operating in a quasiresonant mode. The objective of the research is the development of an energy-saving method of disintegration of supestrong rock and by-products on the basis of vibrational units with two movable crushing elements, operating in a rigorous synchronous-antiphase mode without stringent kinematic links. In the course of investigations a mathematical analysis of the dynamics of vibrational units was performed to determine required mechanical parameters, allowing for adjustment of the machine actuating elements to high-frequency synchronous-antiphase oscillations in the quasiresonant frequency range. As a result of performed pilot tests, the reliability of desktop studies was confirmed and the dependency of process parameters on the machine regulated parameters in the quasiresonant frequency range was identified. The analysis of obtained data showed that during machine operation with cone-shaped crushing elements in the quasiresonant frequency range, the yield of the high-quality finished product (WFA grits of -3+1 mm grain size class) in one pass reaches 35%, whereas the form of the particles corresponds to the grain form with sharp edge. The quasiresonant operation mode of the vibrational unit with two freely suspended crushing elements (without stringent kinematic links) provided substantial reduction of energy intensity during crushing down to 0.16 kWh/t, which shows reduction of power consumption for crushing by more than 15% compared to conventional equipment.INTRODUCTION The most common and energy-consuming processes in the mining industry are the crushing and grinding of various solid materials. Such large energy costs are due to the fact that the capabilities of the existing crushing and grinding machines are based on traditional methods of destruction, and are limited by their kinematic features, which do not allow to reduce the energy intensity of processes, to lower the irreversible loss of useful components, to improve the quality of marketable products. In connection with the foregoing, the task of energy costs reducing for disintegration is one of the most important issues in the enrichment of both minerals and processing of man-made raw materials. The solution of this problem is possible only through the creation of a fundamentally new highly efficient technique and technology for processing raw materials [1, 2]. It seems that the greatest prospects in this respect are the vibration methods of disintegration, in particular, the vibratory cone crusher based on a two-mass system without rigid kinematic connections between the crushing bodies, with vertical vibrations of the working bodies. In this machine, the principle of rational material destruction is realized – crushing without re-grinding [3-5]."

Jan 1, 2018

By James A. Finch, Linda Restrepo, Mitra Mirnezami, Amy Buchanan, Maryam Hashemi

Settling rate studies on slurries from Cu/Zn flotation plants occasionally reveals two aggregation maxima at pH 8-10 and 10-12 (Figure 1). From measurements on sphalerite and silica suspensions the double maxima could be replicated. These maxima correspond to the effects of Zn and Mg ions. The aggregation mechanism of both ions is related to the formation of the corresponding hydroxide precipitate. A combination of chemical and electrostatic bridging by the hydroxides is considered to be the aggregation mechanism.

Jan 1, 2003

By V. A. Ignatkina, V. A. Bocharov, T. I. Yushina, I. M. Petrov, A. A. Kayumov

"The purpose of this research was aimed at increasing recovery of metals from rebellious sulfide polymetallic ores of nonferrous and rare metal deposits. The ores under consideration have common processing features, including textural and structural complex characteristics, irregularity of impregnation and wide range of grain size, up to nanoparticle size, variable complex mineral composition, low content of precious metals etc. This all predetermines the need for advanced processing schemes with deep selective liberation and separation of minerals with intercycle release into rough concentrate and fractional products with the use of multi-stage cycles of individual dressing, based on an optimum combination of various integrated beneficiation and hydrometallurgical processes. The application of existing standard processes does not enable the production of high-grade selective concentrates without reducing the recovery rate due to incomplete separation of fine mineral intergrowths and overgrinding of brittle ore and rock minerals.The combined beneficiation processes for such type of resources, aimed at increasing recovery of nonferrous, rare, and precious metals are based on flotation methods in combination with gravity concentration to produce rich rough collective or selective concentrates, comprising readily floatable mineral fractions. At the same time, hardly recoverable and non-separable mineral associations are released into separate concentrated products for following dressing by individual processes. The proposed combined process provides for successive selective liberation of minerals with release of rich readily recoverable mineral fractions at the preparation and ore beneficiation stages. The hardly recoverable mineral associations shall be released in subsequent operations with the use of dressing, based on a combination of beneficiation and pyro- and hydrometallurgical methods."

Jan 1, 2018

By A. T. Sutaone

"In the Dongri Buzurg Manganese Mine of M/s Manganese Ore (India) Ltd., high grade lumpy manganese ore required for iron and steel industries is produced through multi-stage crushing and screening. This has resulted in accumulation of 50,000 tonnes of low grade fines over the years. This production of such fines is still going on. The fines create environmental problems, like air and water pollution and siltation in adjoining fields. Besides containing lot of manganese values, they occupy large space which is very scare in mining area.The Indian Bureau of Mines under one of its statutory functions has suggested the company to explore the possibility of recovery of additional values under conservation and environmental aspects. Hence the company has sponsored a bulk sample for beneficiation studies in the Modern Mineral Processing Laboratory and Pilot Plant of Indian Bureau of Mines at Nagpur, India. The main manganese minerals present in these mine rejects have been identified as pyrolusite and psilomelane. The purpose of this study was to explore the possibility of evolving a suitable beneficiation flowsheet to obtain manganese concentrates assaying over 72% MnO2 to be used as raw material for the manufacture of dry cell batteries.The sample/material was subjected to characterisation studies in terms of chemical analysis, granulometry and mineralogical compositions. Based on these characterisation studies, the beneficiation process developed comprised of desliming, jigging and low intensity magnetic separation mainly to reject quartz, silicates and jacobsite. The manganese concentrate thus produced assayed 70.2% MnO2 with MnO2 recovery of 78% and weight per cent yield of 63.5. This natural concentrate could be mixed with the electrolytic manganese dioxide produced by the company and this blend can thus be used as a raw material for the manufacture of dry cell batteries by the end users. The paper deals with the details of test work carried out in evolving the process flowsheet."

Jan 1, 2003

By P. M. Solozhenkin

"Galvanochemical process (GChP)) cleaning of sewages is realized in the field of shortcirquited galvanic elements from the mixture current the materials place in purification’s solution and form multitude galvanopairs without external electric field in presence oxygen of the air. The galvanochemical process is electrochemical process utilizing galvanic pairs: coke - iron, iron - copper and others and process does not require chemical reagents.The effect of basic parameters of the cleaning effectiveness have been studied depending on oxidizing of galvanopairs. Adjusting nature, type of galvanic pairs and forming three component system possible to enlarge emf circuits to 2.378 V.The role of ?2, as basic agent, for generation of hydrogen peroxide and hydroxyl ions.It was stated, that removing of metal ions from solutions occur mainly on account of sorption and hydrolytic sedimentation of iron oxihydrates.Determined separate stages of the process: coagulation, sorptions of admixtures on freshly formed ferric oxides and oxidizing destruction of organic components of effluents in presence of ?2 ? ?2?2. Shown efficiency of the method for removing of Cu, Cr, Ni, Zn, As ions, as well as fluoride, phosphate and cyanide anions and oil products, surface-active and flotation reagents. Cleaned water can be recycled for some processes non-critical toward residual concentration of admixtures, as total salt contents is lowered on 60-75 % and reaching limits of concentration for toxic components.The concept of high power unit creation was developed, and galvanochemical pulsator is presented. The pulsator is not expensive, and exploitation expences are low, as well as servise is simple with high effectiveness, and capacity. The galvanoflotation process is developing, combining galvanochemistry and flotation of hydrofobic admixtures (oil, surface-active agents).The galvanochemical flotators are presented."

Jan 1, 2003

By Marco Le Roux, Martha Van Rensburg, Quentin Campbell

Fluidised bed drying is currently receiving much attention as a dewatering option during the beneficiation of fine (defined here as between 1 mm and 2 mm particles) coal. Apart from concerns about safety and combustion, the operating costs can be high if very high gas or air temperatures are used. The aim of this study was to investigate the removal of moisture from fine coal by using air at a lower temperature (25 - 55°C) within a controlled environment by lowering of the relative humidity of the air. It was firstly proven that fluidization has a major advantage over non-fluidized beds, with regards to drying rate and final moisture content. Hereafter several parameters that influence the dewatering rate and final moisture content were tested, from which it was concluded that the relative humidity of air acts as the largest driving force for dewatering. Parameters tested included relative humidity, temperature and coal composition. Energy balances showed a positive nett energy increase in the dried coal during combustion when related to the energy input during drying. In comparison with thermal drying technologies, fluidized bed drying was proven to be less energy intensive. It was therefore shown that this is a viable technology for the dewatering of fine coal.

Jan 1, 2014