Search Documents

By F. Concha

A robust theory of sedimentation-consolidation evolved and was accepted by researchers world-wide in the last two decades of the 20th century. This theory provides a reliable method of thickener design and simulation. However, a process model, simple or sophisticated, empirical or phenomenological, is useful only if it is possible to determine, in an objective way, its experimental parameters. Research workers at the University of Concepción, together with Cettem Mineral Technology Center, created an integrated system of thickener design, simulation and control, including instrumentation, algorithm and software, which can be used by personnel in industry without specialized knowledge of thickening theory. In the paper, the development of three instruments for the measurement of pulp concentration, solid flux density and sediment compressibility is described. Each instrument uses software for data input, parameter calculation and results display. The paper also describes software for the optimization of the experimental parameter and for the design and simulation of industrial thickeners. Finally, mathematical algorithm and control strategies based on the phenomenological model are presented and compared with classical feedback control.

Jan 1, 2014

By A. Oleynik

The paper presents the modeling and simulation experience in field of research into the mineral row material separation. Features of the subject domain generate a need of different approaches using for modeling and simulation. The general scheme of separation modeling process and some examples of developed simulators are presented. Due to different features and standards of knowledge, different formal models should be used to describe and analyze separation processes in the frame of general scheme. The main types of simulators are modeling tools based on statistical, analytical or expert (logical) methods. Advantages and disadvantages of each method above are mentioned in the paper. Based on the studies in the field considered, an aggregated mathematical model of a separation process has been generated. The aggregated model is presented by two combined equations. The actual apparatus model is formed by substitution of the particular functional expressions of the forces acting in the apparatus into the aggregated model. The developed simulation tools are based on integration of limited experimental data and on ex-pert knowledge available on separation processes. Simulation does not allow producing an optimal, in terms of mathematics, solution. But it gives an opportunity to produce and compare quite adequate solution variants in real time. The results obtained are the theoretical and methodological base for integrated information technologies to support studies in the field of mineral processing.

Jan 1, 2014

By M. R. Hosseini

Among all gravity concentration methods, Shaking-table is the most effective one from the metallurgical point of view. In this study, Shaking-table was used for concentrating a manganese ore sample from Ghasem Abad area in Kerman, Iran. Experiments were designed by using L8Taguchi design with five variables and each variable in two levels. The influence of each variable and their interactions on the operation of the device was studied. The variables under investigation were: table slope, table frequency, water flowrate, feed rate, and particle size. The manganese concentrate grade and recovery were used as response variables. It was shown that water flowrate, table slope, feed rate, and particle size are the significant variable on concentrate grade; while, all the variables influence manganese recovery.

Jan 1, 2014

By S. Fiore, M. C. Zanetti, C. Clerici

The processes and fluxes of a cast iron foundry plant located in the North of Italy were analyzed in order to determine the amount and kind of wastes produced from the different activities. The main fractions are the molding sands, furnace muds and powders coming from the dust abatement plant, the exhaust lime, the furnace refractory, the metallic shotting and the sludges and powders coming from the dust abatement plant of molding lines for a total production equal to 800 t/d. All wastes were sampled and particle-size and chemically characterized to evaluate the best recycling or reuse solutions. Wastes were sieved and divided in three categories according to the particle-size dimensions: below 0.1 mm, between 0.1 and 0.6 mm and above 0.6 mm. The fraction above 0.6 mm dimension underwent magnetic separation to recover and quantify the potentially available iron fraction. The fraction between 0.1 mm and 0.6 mm was chemically characterized in order to understand if it could be fed to the sand regeneration plant. The below 0.1 mm fraction was characterized to evaluate the following recycling and reuse solutions: additive for molding sands and/or raw material for the concrete industry.

Jan 1, 2003

By E. Lee

With the growing environmental concern, as well as the increasing concern for sustainability of natural resources, the need of improving the performance and efficiency of today?s crushers is be-coming increasingly important. However, the development of existing crushers requires an extended basic knowledge about the crushing process itself. The aim of the present study is therefore to find the theoretically optimal way of crushing compressively under given circumstances. In the present paper, optimizations have been performed with the purposes of maximizing product yield and minimizing energy consumption. Performed on an ideal crushing stage free from physical limitations, the optimization results have been obtained in terms of number of compressions and their corresponding compression ratios. Complementing earlier results on interparticle breakage (Hulthén et al., 2006), presented here are thus the results from corresponding optimizations with single particle breakage and interparticle breakage. It is concluded that modern crushers are not working optimally in any of the studied aspects for gneiss. In fact, optimizations indicate that a lowering of the compression ratio, as well as a shortening of the crushing sequence, are theoretically favourable. The outcome of this study is therefore highly promising as to giving new ideas and suggestions of improvements in existing crushers, and can even result in redesign of compression crushers.

Jan 1, 2014

By M. Kalicinski, M. Lyssyy

"Access to information is a key component for making improvements to any process. This is particularly true for all aspects of the iron mining and steelmaking process. The ability to make rapid control decisions can significantly influence process outcomes, including ensuring product specification, mining quality, transportation limits, upgrade factors, waste bypass and direct shipping, among many others. While traditional laboratory methods provide feedback for such processes, having access to analysis results in real-time can lead to positive reactive and predictive control decisions to be made rapidly, leading to significant improvements throughout the process. Scantech has been designing, manufacturing and supplying technological products to the minerals industry since 2002 to enable the availability of such real-time information to a mine or plant, with the benefits being enjoyed by a wide range of operators. This paper provides a summary of the available technologies used in the iron ore and steel industries, as well as providing case studies of their use in African and Australian iron ore and European steel, as well as a description of the potential benefits of a range of analysis equipment.INTRODUCTION Access to information is critical for any process, and is a fundamental component for making process control decisions. In order to yield effective processing outcomes, it is important for that information to be readily available, preferably as quickly as possible, and to be as accurate as possible. While speed and accuracy are often traded off against each other, there are numerous technologies available in a processing environment that allow for both rapid flow of information and a high level of accuracy. The use of on-belt analysis equipment has a long trusted history of use in a number of mining and processing environments and industries, providing information such as elemental composition and grade of conveyed materials, moisture content, waste proportion and energy information. Australian company Scantech has been a provider of such equipment since 1981, and has become an industry leader in both the supply and development of on-belt analysers across a range of industries."

Jan 1, 2018

By O. A. Bascur

"In recent years, metal producing companies have increased their investment in automation and technological innovation, embracing new opportunities to enable transformational change. Internet of Things (IoT) is one of many transformational initiatives, which can fundamentally revolutionize how industrial complexes operate. Whatever the issue, the answer is in the abundant and growing quantity of real time data and events collected in the grinding and flotation circuits in a mineral processing plant. Based on earlier work, today a grade recovery model permits identifying the best operating conditions in real time. We will review the strategy for increasing the value of the abundance instrumentation in current plants. An optimal Gaudin size distribution model provides augmented information from traditional sensors to find the optimal grind cut to reduce metal losses in the flotation circuits. The large amount of sensors in a flotation circuits permits to estimate the recovery and to find the optimal froth depth and aeration using an air holdup flotation model. The paper will describe the strategy of classifying data for on line generation of insights to using operational intelligence tools. We will discuss the implementation Recovery/Grind strategy with industrial examples in non-ferrous mineral processing and iron beneficiation.INTRODUCTIONThe declining supplies of high grade ores and increasing consumption of mineral and metal products have demanded higher operational efficiencies with minimum capital investments. The objective of copper flotation objectives are based on maximizing the dollars return on the concentrate produced. The economic efficiency is maximized by manipulating the circuit along the grade/recovery curve relationship. To achieve such objective improved stabilization of the grinding and flotation circuits are required (Oosthuizen, Craig, and Jamsa-Jounela, 2017)."

Jan 1, 2018

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 Juan Estrada, Mirtha Frómeta, Rubén Alcalá, Emilio Montejo, José Castellanos, Juan Berto, María Rivas

"The oxidized nickel ores from San Felipe deposit are composed mainly Smectites which gives to the pulps very unfavorable rheological .properties (cinematic viscosity and high shearing strength) for transportation processes (pumping), very low settling velocities and very low thickened pulps. These properties do not allow the preparation of high % solids, which affects the economic efficiency if a high pressure acid leach (HPAL) process is used. Pulps of close to 30% solids have very high BYS making pumping impossible. CIPIMM developed three technologies to solve these problems and to substantially increase the % solids in the pulps to be leached without a thickening step. These technologies are: • CIPIMM 2. At Preparation of pulps using additives. This method is based on the effect of some additives (inorganic salts) to improve the pulp’s properties. The use of this method allows increasing the % solids in the pulp up to 40% with good rheological properties • CIPIMM 2B. Preparation of pulps by thermal treatment of the ore previous to the preparation of the pulps. This method is based on the thermal destruction of the clays structure. Its use allows to obtain pulps with 50 - 60 % solids with excellent rheological characteristics. As a collateral effect, the Ni and Co grades increases by 10 - 15%. • CIPIMM 2C. Pulp preparation by chemical treatment. This method is based on the chemical transformation of clays, to obtain without thickening, pulps with 43- 45% solids and excellent rheological properties. The use of one of the three technologies depends on the chemical and mineralogical composition of the ores and the results of technical-economical evaluations to determine which one is the best alternative before running higher scale tests."

Jan 1, 2014

By U. S. Chattopadhyay

The estimated requirement of the nation by the year 2020 is approx. 80 Mt of steel and more than 0.2 million MW installed capacity of the electricity, thereby increasing the consumption of the coking and non-coking coal, which is expected to be in tune of about 75 Mt & 500 Mt respectively. One of the major deleterious factors in achieving the goal is the deteriorating quality of the feed coal used in both steel and power industries. Indian coking coals, in general, are typified by high ash, high inert (both organic and inorganic), low rank, low reactive macerals content, heterogeneous petrographic make-up, inferior coking properties and poor amenability to washing, thereby necessitating suitable washing measure. Coke-based steel industries in India require washed coking coal containing ash % varying between 17-19. The situation demands taking on immediate challenges to fill up the gap between the requirements and supply of coking coal. This paper reviews the R&D attempts in this laboratory and throws light on the key measures as long-term solution to the problem. Search for alternative source of coking coal, like LVC coal and their judicious preparation technology. The low volatile coking coal (LVCC) constitutes about 50% of the total coking coal reserves in India. These coals are characterized by high raw coal ash content (37 to 40%) and very difficult washability potential. If these coals are treated in the existing washeries, which are generally 2 or 3-product systems, the cost of clean coal is high as the byproduct sale value is low. It has been proposed to produce a new type of by product, which enjoys high demand and good coking properties.

Sep 1, 2012

By Vinay Jain, Dharmendr Kumar, Beena Rai, Venugopal Tammishetti

"Selective dispersion-flocculation is considered to be an effective process for the beneficiation of ultrafine particles. This process is based on the preferential adsorption of a flocculant on the mineral particles to be flocculated, leaving rest of the mineral suspended. It has been successfully implemented at plant scales for the beneficiation of ultrafine particles of iron ores, for which conventional methods such as gravity separation, magnetic separation and flotation do not work efficiently. However, the key element responsible for the success of any selective flocculation process is the appropriate choice of the flocculant used for achieving the desired selectivity. At our lab, we are working on design and development of such selective reagents for mineral processing applications, including the beneficiation of iron ore slimes, using a combined molecular modeling and experimental approach. In this study we have employed density functional theory (DFT) to calculate the interaction energies and explain the interaction mechanisms of chitosan with the main minerals present in iron ore slimes, namely, hematite [a-Fe2O3], goethite [a-FeO(OH)], gibbsite [a-Al(OH)3] and kaolinite [Al2Si2O5(OH)4]. The magnitudes of the computed interaction energies follow the trend: Hematite > Goethite > Gibbsite ~ Kaolinite Al-OH terminated > Kaolinite Si-O terminated Analysis of the optimized geometries and electronic structures reveals that the O & N atoms of chitosan molecule form coordinate bonds with surface Fe-atoms of hematite while only weak hydrogen bonds are formed in the case of goethite, gibbsite and kaolinite surfaces thus explaining reasons behind the stronger interactions with the hematite surface. The theoretical findings were validated by performing selective flocculation experiments using chitosan as a flocculant. The selective flocculation experimental results show that a final concentrate of ~60% Fe can be obtained from a feed containing 53.13% Fe with Fe recovery of 74%. The mineral estimation in the obtained concentrate indicated that hematite and goethite are recovered in concentrate while gibbsite and kaolinite are rejected in the tails. These observations were consistent with our theoretical findings. Our work highlights the promising role molecular modeling techniques such as DFT can play in the design and development of selective reagents for beneficiation of alumina-rich iron ore slimes."

Jan 1, 2018

By Zhou Junwu, Han Long, Song Zhenguo, Sun Chuanyao

The deposit genesis, the ore property, and the mineral characteristics, which has a close relationship with the beneficiablity, could be regarded as the “Genetic Properties”, actually are the determining factors for beneficiation process development. However, in conventional concentrator’s process development and engineering, there have been lack of systematic research and test on those genetic properties, also lack of well-established collecting, statistics and analysis system for those huge amount of data such as the historical mineral processing technique research, process mineralogy study, practical operating and engineering data. Obviously it is far less than enough for profound integration combining modern IT together with traditional mineral processing technology, as a result there are a number of disadvantages in mineral processing R&D and engineering, such as long term, high cost, low efficiency as well as repetitive testwork not making full advantage of previous experiences. Aiming to make utmost of those Genetic Properties and overcome above disadvantages in mineral processing R&D and engineering, the concept of “Genetic Mineral Processing Engineering (GMPE)” is put forwarded, and the strategical study has been conducted on this regard, with the main focus on following aspects: a) Testing and extraction of the “Genetic Properties”; b) Establishment of data base and data warehouse of GMPE; c) Intelligent decision making system for beneficiation process; d) Verification testwork; e) Virtual concentrator. The technical route proposed is to firstly conduct research and test on those Genetic Properties mentioned above, based on that the specific data base will be set up and applied for intelligent process recommendation and simulation with a few verification testwork conducted in the meantime, finally achieve a fast, high efficiency and precise determination of technology and process for ore beneficiation. The systematic study on the three-in-one GMPE would make an innovative breakthrough in conventional mineral process testwork research and engineering methodology, and provide technical support for the concentrator’s design and upgrading.

Jan 1, 2018

By D. R. Nagaraj

The traditional (popular) approach to reagent development and optimization, which has become entrenched in both research and practice for many decades, is highly reductionistic, incremental and costly, does not produce robust chemical solutions, and is not sustainable. There are also several other key drivers and changes in the mineral industry that clearly warrant a new approach. In response to these, an intense effort was made at Cytec over the past fifteen years to develop a meaningful, efficient, and sustainable approach to develop new reagents and robust chemical solutions in mineral separations. This effort culminated in three important outcomes: a) development of the holistic approach, called FLOTATION MATRIX 100? process, b) novel reagents, and c) enhanced application knowledge for reagents. In this paper, the efficiency, utility and power of the holistic approach will be demonstrated with examples using both existing and new reagents in the processing of Cu-Au, Au and Cu-Mo ores.

Jan 1, 2014

By T. Tumidajski

The purpose of the separation processes in coal processing is obtaining products of certain ash contents. In the most of cases it is assumed that the separation process is described by one, selected parameter, which usually is grain size or material density. The separation may be described by means of statistical distributions of random variables, what allows forecasting the separation results of certain enrichment method. There are very well known the applications of approximations of Tromp separation curves or distribution functions of Erasmus, Meloy or Weibull. It is necessary to say that if the fitness of the approximation more suitable, then the characteristics of the process itself is also better. In purpose of obtaining more appropriate results, these methods were modified by application the mathematical functions, as i.e. hyperbolic tangens function. Furthermore, on the basis of empirical data, so-called interpolations may be performed in purpose of getting more appropriate results of approximation. One of the most known techniques of interpolation is Hughes method. This method for interpolating standard data involves breaking down each interval into a number of smaller sub-intervals. The results of such one-dimensional approach not always contain the full in-formation of the searched distribution. It happens because such interpretation of the problem is not completely correct. In practice, the separation process depends not only on the one parameter (i.e. grain size), but also on many other features characterizing certain material (i.e. its density). It seems then that in some cases the application of multidimensional grain characteristics distributions will be more appropriate. In this paper, the technique of joining the distributions of grain size and density by means of so-called Morgenstern distributions is shown. The general form of these distributions is as following:

Jan 1, 2014

By A. E. Sobolev

The kinetics of hydrochemical oxidation of antimonite in solutions of nitric acid was studied using the rotating disk method and the factor experiment design. The dependences of the antimonite?s oxidation rate on concentration of nitric acid solutions, temperature, disk rotation frequency, and duration of interaction were determined. The adequate kinetic models allowing calculating the specific oxidation rate at any combination of the values of the influencing factors were obtained. The oxidation process is found to proceed in a mixed mode, close to chemically controlled. Gradually, as the sediments of elemental sulphur and Sb2O5 accumulate on the disk surface, the process becomes controlled by internal diffusion. The observed high (more than second) order of the oxidation rate with respect to the concentration of nitric acid was explained by the autocatalytic action of the acid reduction products. The apparent activation energy depends on the stage of interaction. At the initial stage (in a mixed mode of the process proceeding), it depends on nitric acid concentration and varies from 31.5 kJ?mol?1 (in 2 M HNO3) to 36.1 kJ?mol?1 (in 10 M HNO3). This trend indicates the weakening of diffusion limitations with a nitric acid concentration increase. When the process is controlled by internal diffusion, the apparent activation energy was found to be 14.5 kJ?mol?1. The obtained kinetic characteristics enlarge the database on hydrochemical oxidation kinetics of sulphides and can be used for the elaboration of the recommendations for the effective comprehensive exploitation of antimony-bearing ores and concentrates.

Jan 1, 2014

By A. Vilinska

Microorganisms have a tremendous influence on their environment through the transfer of energy, charge, and materials across a complex biotic mineral-solution interface. Recent developments in biotechnology have not only aided hydrometallurgical leaching operations but also shown great promise in mineral beneficiation processes. The adhesion of bacteria on minerals alters the surface properties relevant to flotation and flocculation of minerals. The biomodification of mineral surfaces occurs through the attachment of microbial cells, oxidation reactions and adsorption or chemical reaction with the metabolite products. Several types of heterotrophic and chemolithotrophic bacteria have been successfully applied in flotation and flocculation processes for the last two decades. Al-though the potential of microorganisms in minerals beneficiation has been realised by several re-searchers from their laboratory investigations, the studies were mostly confined to pure mineral systems and there is hardly any sincere effort to apply the methodologies on ores. This paper presents a brief summary of the literature in bioflotation and bioflocculation, and attempts to outline new dimensions of research for a practicable application of this technology in mineral industry.

Jan 1, 2014

By G. M. Savov

Copper recovery via Solvent Extraction (SX) process is a well-known technique, which is practiced commercially for approximately 40 years. The main advantages of the SX process are: an absence of using high temperatures (not more than 50oC), complete recycling of barren solutions, very high selectivity at removal and purification of metals, metal conversion to a form, suitable for easy subsequent recovery. Despite the wide acceptance of Solvent Extraction, it does have some shortcomings, namely SX employs large quantities of volatile organic substances. This leads to huge plant ?footprint? of SX circuits. The SX is very sensitive to low temperatures and quantity of total suspended solids in feed solutions and this causes bad phase disengagement times and therefore poor process performance. And most important ? low grade solutions (with copper concentrations below 1 gram per litre) are very unattractive for treatment via Solvent Extraction process, because capital costs for SX plants are not a direct function of copper tenor in the feed. The combined process with Ion Exchange (IX) and Solvent Extraction ? further called IX/SX by IONTECH Engineering was developed. This combination eliminates SX negative characteristics shown above. The key findings of the IX/SX process are; (1) recovery of copper from pregnant leach solutions with metal concentrations, varying on a broad range; (2) can be operate effectively with very low-graded copper pregnant leach solutions; (3) the construction of large ponds for pre-filtration of the pregnant leach solutions is not necessary; (4) working with turbid solutions and solutions containing large quantities of suspended solids; (5) winter operation without troubles; (6) strongly reduces organic losses; (7) technological approach lead to plant sizes reducing. This paper reviews the main stages of the combined IX/SX process, the applications for metal recovery and introduces projects where the process is applied. Key findings of the process are also presented. A comprehensive technical comparison between processes has been carried out. This paper also evaluates the advantages of using combined IX/SX technology as a purification and separation step in copper production process, with the aim of further increasing the overall copper recovery and to ensure that a suitable copper concentration in the advanced electrolyte is achieved. The implementation of a Ion Exchange (IX) process in the classic Solvent Extraction-Electrowinning process(SX/EW) is found to be beneficial for processing of pregnant leach solutions both from spent and new copper heaps and dumps, acid mine drainage and other industrial streams without any preconditioning as well as in terms of achieving improved recoveries and copper cathode quality.

Sep 1, 2012

The concept of the Unified Comminution Model (UCM) was presented at the 23rdIMPC. The model utilises computational techniques to calculate the mechanical environment in any comminution device, and then incorporates the outcomes from rock breakage tests to predict the product from a device. The model is fully mechanistic, and incorporates the capability to simulate novel equipment. This paper presents the progress on the first application of this concept to applied comminution equipment. This novel comminution model aims to integrate all comminution models within a single struc-ture. This will provide a step change in the predictive power of comminution models, and include a wide range of particle properties that will enable it to be linked to the upstream and downstream process of mining and recovery. Major advances over current models will be the capability to predict liberation, preferential grinding, performance of new and novel devices, and to have power as an integral driver of the comminution simulation process. The methodology and model structure have been developed. An equation within a population balance framework has been derived as the basis for the UCM. A set of SAG mill pilot has been used as the first test case. The breakage characteristics of the ore have been extensively tested utilising a new range of breakage tests required by the rigorous UCM structure. The mill was simulated with the EDEM - DEM software. A partial test simulation of the pilot SAG mill has been conducted. This serves to demonstrate the feasibility of this modelling technique, but still lacks important ore characterisation components that are under development. The study has raised a number of significant challenges to the accepted understanding of the comminution process. Through addressing these challenges considerable insight has been gained into the energy environment in mills and the requirements of breakage testing. The ore characterisation methods and energy transmission derived from DEM simulations remain as major research items.

Jan 1, 2014

By A. F. Usov

The paper is concerned with an analysis of the experience gained in development of special electro-technical installations applied in electric-pulse destruction of materials. A principle scheme of an electric electric-pulse installation is given, and electric circuit variants of its blocks made on various element bases are discussed. Also assessed are some ideas to further improve the technical and economic characteristics of the equipment.

Jan 1, 2014

By Jorge Rubio, Gabriel Berkowitz, Fabiano Capponim, Carlos Perez Guerrero, Elves Matiolo, Denise G. Nunes

This paper describes some advances in flotation research in fines (“F” 38 to 13 µm) and ultrafines (“UF” < 13 µm) mineral recovery by two different techniques, at laboratory scale. Extender flotation and flotation with .multi-bubbles. (bubbles with a wide size distribution) of copper sulphide fines (ore feed of about 1 % Cu) were compared with a .standardised. mill laboratory procedure. Comparative evaluation was made through concentrate grade and recovery (size by size results included), .true. (bubbles-particles attachment only) flotation recoveries and process kinetics. Both techniques yielded higher metallurgical efficiencies than the mill standard but better results were obtained with the extender flotation, with emulsified diesel oil (90 gt-1). Concentrate recoveries were of the order of 85-90 % (84 % in standard conditions), 14-17 % Cu grade (15 % Cu in the standard) and 3.5-4.5 min-1 for the Klimpel rate constant (3 min-1 in the standard). Size by size and true flotation results proved that metallurgical and kinetic gains, obtained with the two techniques, might be attributed to fines and ultrafines enhancement. Data obtained are discussed in terms of physical and physico-chemical parameters related to aggregation and capture (of particles by bubbles) phenomena and the practical potential of these techniques are envisaged.

Jan 1, 2003