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By Wayne I. van Drunick

"Energy balance modeling has recently been shown to be a competent tool in the estimation of SAG mill discharge rheology. Work performed by van Drunick and Moys (2001) validated the ability of an energybalance filter to estimate the slurry density from an operating SAG mill. The importance of rheological data is highlighted by several authors who show the effects on load behaviour and thus mill performance. Energy balance models were developed to account for the dynamic energies in the mill discharge sump. The models then made it possible to infer the mill discharge density. A sampling campaign was performed and the errors from the sump energy balance were within tolerable limits.Since the initial results were published, it has been decided to further develop the modeling techniques in order to focus on balancing the energies around the entire mill. The critical measurements for the energy balance will be the temperatures of all the streams entering and leaving the mill, including energy losses to the environment. Metso’s OCS© (Optimising Control System) currently controls the 3 SAG mills at Anglogold’s Mponeng Gold Plant (South Africa). The OCS has built-in Kalman filtering tools to effectively handle variances and noise in the models and the mill circuit data respectively. The new models are therefore constructed in the OCS platform, and will be run in parallel with Metso’s current modeling and filtering systems. The work is a collaborative effort between Anglogold, the University of the Witwatersrand and Metso. The benefits of energy modeling, compared to mass modeling, are that energy data are more accurately measurable than mass data. The inferred mill parameters can therefore be improved provided that a competent set of models is produced to process the (accurate) thermal measurements."

Jan 1, 2003

By S. J. Neethling

"Flotation is a complex process with many factors that influence the performance of a cell. This paper examines the impact of several key variables on the performance of flotation cells. The study makes use of a simulator for the froth phase of the flotation vessel, as the main purpose of this study is to separate the impact of different variables from one another.In experiments it is very difficult to separate the effect of variables from one another as a change in a singe input parameter, such as air rate, invariably also affects many of the other key variables, such as bubble size and bubble bursting rates. This interaction between variables makes it very hard to experimentally separate the impact of, for instance, the air rate from that of bubble size or bursting rate. In the simulator, though, it easy to make independent changes to these variables.In order to achieve this a base case simulation that is typical of many of the rougher cells found in sulphide flotation circuits was carried out. Four key variables, air rate, incoming bubble size, surface bubble size and the fraction of the bubbles flowing out of the cell unburst, were varied in order to obtain the system’s response.The most significant results were obtained when the bubble size was varied. An increase in the incoming bubble size has the effect of reducing the pulp zone recovery, but increases the froth zone recovery. If it were possible to vary the incoming bubble size without influencing the overflowing bubble size, the impact of the change would be unclear because of these two competing effects. The effect of a change in the overflowing bubble size has an opposite effect on the froth recovery, with larger bubbles resulting in lower froth recoveries."

Jan 1, 2003

By B. C. Qi

"In water treatment, flocculation or coagulation with aluminium or ferric salts has been widely used for many years to remove natural organic matter (NOM), including humic acids. However, the adsorption of NOM to aluminium hydroxide flocs during conventional coagulation/flocculation processes is very complex, with the flocculation of aluminium hydroxide particles and the adsorption of NOM molecules on flocs occurring simultaneously. Any effect on the surface characteristics and micro-structures of the humic acids and aluminium hydroxides could affect the adsorption efficiency.It has been widely observed that if a reaction system (liquid-liquid or liquid-solid) is exposed to an ultrasound field, under appropriate conditions, a variety of physical (emulsification, aggregation/flocculation) or chemical (the production of radical and exited species; single electrotransfer) actions may be activated. Though the ultrasound effects have been used in biological and chemical decontamination in many conventional environmental protection practices, the idea to explore the ultrasound effects in the removal of humic acids by preformed aluminium hydroxide flocs is relatively new. In this paper, the effect of an in-situ ultrasonication on removal of the humic acids extracted from the acidification fermentation of lignocellulosic residues, by a preformed aluminium hydroxide, was evaluated; the effect of ultrasonication on the surface complexation of the humic acids with the preformed aluminium hydroxides was investigated."

Jan 1, 2003

By Zhou Junwu, Sun Chuanyao, Wang Fuli

"In this present paper, the authors introduce the artificial neural networks into the modeling of the industrial flotation process, integrating information technology, control theory and intelligent optimizing method to flotation technology. The new idea gives a new way to solve the difficulty in this field, and therefore brings the study on the automatic control of flotation process in China into a new start.The Radial Basis Function (RBF) network, featuring a quick learning speed, is one of the feedforward neural networks. It has attracted much attention from automatic control recently for its implementing the nonlinearity mapping through adjusting the parameters of the nonlinearity transfer function. One of the online adaptive learning algorithm—the nearest neighbor-clustering algorithm, which can automatically determine the number of hidden units, has been implemented in the MATLAB programming language in this paper, laying the foundation for the flotation models.The relation model between ore pulp characteristics and reagents consumption has been proposed using the RBF networks based on the industrial lead rougher flotation of lead & zinc ore, and the simulation has been conducted in the laboratory with the results matching the samples data very well. The Xilin Lead & Zinc Mine Flotation Process Intelligent Consultation System of Reagents Consumption, which suitable for industrial process, has been developed. The reagents consumption advised by this system would stabilize the flotation process, and increase the recoveries. It could be used for providing the technological consultation to flotation operators in site, and for training new operators."

Jan 1, 2003

By Chen Shuwen, Yao Zhihua

In the process of thickening dewatering_the motion state of two- phase flow in a thickener has a very great influence on thickening efficiency. The investigation was made using copper mill tailings. In this investigation the authors explored the formation conditions and motion range of density current in the thickening process by model experiments, and analyzed the influence of density current on thickening efficiency. The results have shown that the formation of density current has relations with the structure parameters of a thickener and thickening process. The density current and its forming location affect thickener’s working efficiency. The author measured the motion state of two- phase flow in a 53-m dial. thickener for copper mill tailings under its operation conditions and analyzed the density distribution and motion state of two-phase flow in the thickener. The results obtained by the industry tests have shown that the motion state of two- phase flow in the thickener can be greatly improved by modification of its structure, achieving a great improvement in its thickening efficiency. It is concluded that, a thickener’s working efficiency depends on the formation and motion range of density current in it, which is of great importance to designing and establishment of thickener’s working parameters.

Jan 1, 2003

By Patrick A. Turner, Timothy J. Olson, Abraham J. Schutte, Roman van Ommen

"The use of classifying devices in grinding circuits dates back to the early 1900’s when classifiers were installed to close ball mills. The search for ways to further improve grinding circuits led to the use of hydrocyclones in place of mechanical classifiers in South Africa in the early 1950’s. Today Hydrocyclones are considered as the best classifying devices to close grinding circuits. After 50 years of development the hydrocyclone has changed significantly when compared to the designs of the early days, but the focus to circuit optimization must be expanded to an understanding of the integral system consisting of mill, cyclone feed pump and cyclone.The key to good cyclone circuit design and operation in primary grinding circuits will be discussed including individual cyclone design features such as cone angle or materials of construction, as well as orientation and manifold configuration.Cyclone performance issues as well as maintenance considerations will be detailed in an effort to achieve consistent cyclone operation with minimal coarse solids in the overflow. “The importance of constant cyclone feed conditions is unquestioned today. The challenge of Cyclone sizing is a large number of not fully known variables prior to startup. The most significant unknown variable is slurry viscosity. Because of this, engineers often specify a conservative cyclone system that produces a finer than required separation. However, this approach often leads to higher circulating loads and a higher overflow density in order to produce the required separation. The higher cyclone overflow density results in a less efficient cyclone separation. The average concentrator can pick up 2-4% finer overall grind by having a more aggressive cyclone operation.”"

Jan 1, 2003

By Shailin Lalloo, Allan B. Nesbitt

"Gravity separation by centrifugal equipment, particularly in the mineral processing industry is a novel approach of optimising product recovery. The manufacture and sale of centrifugal equipment by recently established companies is now beginning to have a significant impact on the industry. Some benefits of operating at increased gravity include: reduced environmental issues, a shorter lead time, lower capital cost and improved recoveries of elemental mineral before entering the grinding circuit.Of topical discussion is the use of centrifugal separators for the recovery of less valuable minerals that will form a greater proportion of the feed compared to traditional scalping circuits where the gold content is extremely low. This ultimately results in the centrifugal system having to have a greater mass pull. In addition, the relative density difference between gangue and valuable mineral is likely to be less and therefore modelling and optimisation of this separation process will be necessary. Some researchers have muted using fluidisation models to model the forces present in the separation zone of a centrifugal separator2. It is not unusual for the manufactures of centrifugal separation equipment to use fluidisation terminology to describe what happens in the separation zone. Most fluidisation models are based on the empirical/classic relationship between superficial fluid velocity and voidage postulated by Richardson and Zaki. However, no researcher has proved the effectiveness of this relationship in an increased gravity Environment."

Jan 1, 2003

By Ronald Smeink, Ton de Gouw

"Reagents are an important cost-factor in the flotation of minerals. The mechanism of collectors and frothers has been studied extensively, but on depressants – probably the biggest cost-factor in the reagent suite – very little is actually known. Theories are frequently faced with the bare facts, pointing in another direction. Fundamental research is complicated by the fact that the amount of possible interactions in the flotation cell is almost unlimited and makes “change-one-parameter-at-a-time” experiments questionable and at least difficult to interpret. Also, the adsorption of depressants on the ore is very strong and desorption merely impossible. Detection methods therefore tend to be indirect and – therefore - non-specific about the location of the depressant on the ore.Depressants are supposed to adsorb selectively on gangue minerals; not on the valuable minerals in the froth. In order to be able to develop better and ‘’smarter’’ depressants, an analytical method is therefore required that will enable to detect which (=qualitatively) depressant, in which concentration (=quantitatively) sits where exactly (= selectively) on the mineral surface. (Answering the question: ‘’ Which minerals is located direct under the depressant?’’)And also: does the depressant compete with other reagents for that location? (like collectors) This analytical method is under development. The actual status of the method is promising and the results will be shown."

Jan 1, 2003

By Jan J. Cilliers, Nicolas Barbian, Esther Ventura-Medina

"Froth structure and stability are known to play an important role in determining flotation recovery and selectivity. An industrial sampling campaign was performed to develop a clearer understanding of the effect of flotation variables on froth stability and the role played by the resulting stability on flotation performance.Froth stability was estimated as the fraction of bubbles bursting on the surface of the froth through image analysis and the solids loading on the bubbles at the top surface. The image processing was performed using the Smartfroth software on the top surface of the froth. The system gives measurements of bubble size distribution, average bubble size and froth velocity. The froth velocity was used to estimate the volume of bubbles overflowing the weir yielding to the fraction of air overflowing the cell. This measurement is the complement of the rate of bubble bursting on the top surface. Also samples of the lamellae were taken by touching the top surface of the bubbles with a glass slide. Then, the amount of solids and liquid per unit area in the bubble lamellae was estimated gravimetrically. Both measurements were used to establish stability criteria.It was generally found that high air flowrates resulted in a drop of froth stability showed by a drop in the fraction of air overflowing and a decrease in the solids loading and simultaneously produced low copper recoveries and low concentrate grades. Deep froths only allowed a small fraction of air to overflow and consequently produced low recoveries. An increase to high frother dosage did not result in an improved fraction of air overflowing, hence producing low recoveries. Likewise, low frother addition only allows low recoveries because the resulting unstable froth cannot support itself. Low aeration was found to be preferential as it allowed high particle loading, therefore high bubble stabilisation, and low gangue entrainment, resulting in the highest flotation performance."

Jan 1, 2003

By I. A. Makalin, V. N. Yakovlev, S. V. Imangulov, I. V. Zyryanov

"The presented studies aimed at solving the problem of recovery of low-luminescent diamonds, which are not recovered using X-ray luminescence method of processing of diamond-bearing ore. The purpose of the studies is the determination of possibility and feasibility of recovery of such crystals using dual-energy X-ray transmission separation technology. In preparation for studies methods were developed for testing technical and process parameters of XRT-400 Aliud GmbH (Germany) sorter, manufactured according to design specifications of Yakutniproalmaz Institute, and XRT/D TOMRA Sorting Solutions GmbH (Germany) sorter, designed for processing of -50+5 mm ore, as well as RGS-1M, RGS-2 X-ray sorters, developed by JSC NPP Bourevestnik (St. Petersburg) in cooperation with Yakutniproalmaz Institute, for material size of -6+3 mm. In 2018, in-process tests of RGS-OD-3 X-ray sorter prototype on material size of -3+1 mm are scheduled. Studies to determine the content of low-luminescent diamonds and feasibility of their recovery using XRT-400 and XRT/D sorters at the Processing Plant #3 of Mirny Mining and Processing Division (MPD) were carried out. The results of the studies confirmed presence of such diamonds and possibility of their recovery using the dual-energy X-ray transmission method. In-process tests of RGS-2 X-ray graphic sorter were carried out at the Processing Plant #16 of Nyurba MPD. According to the results of sampling of RGS-2 sorter separation products, the recovery of -6+3 mm sized diamonds from tailings of X-ray luminescence sorters was achieved at the level of 96%, while the diamonds recovery was 98.5% in value terms, the concentrate yield was 0.1%. In-process tests of RGS-1M sorters at final recovery of the grease separation concentrate at the Processing Plant #3 of Mirny Division were carried out. Recovery of low-luminescent -6+2 mm sized diamonds by RGS-1M sorter amounted to 92.4% for single operation, and with the double control operation reached 99%. As a result, -6+2 mm sized base product recovery increased by 0.2%."

Jan 1, 2018

By Hermann Wotruba, Lars Weitkämper

"Dry coal dressing was popular during the 1950’s and 60’s in many parts of the world. The devices mainly used were air jigs and air tables.The increase in ash and moisture content of run-of-mine coals due to the wide advanced mechanisation of mining methods during and after this period led to that pneumatic devices being unable to treat run-of mine coals with the desired efficiency. Since the 1960’s almost all new coal preparation plants have been based on wet processes that are highly efficient in terms of coal recovery and their ability to handle damp and sticky run-of-mine coals. (Frankland, 1995)However, water is becoming increasingly costly and the disposal of fine products, containing most of the water, is an environmental concern. There would be significant cost savings and a lower total energy consumption if coal could be cleaned dry. Efficient dry coal treatment would be an interesting solution in desert, arid or cold areas.In Germany one dry coal dressing plant is in operation. This is the last operating dry coal dressing plant existing in Europe. The actual technical standard of dry coal dressing has been analysed during test-work and sampling in this plant (Saar Region in Germany). The process and the advantages and disadvantages are presented. The plants problems are low efficiency in the fine fraction –6 mm and the coarse fraction +30 mm and a low overall throughput as well as the lack of an automatic process control system. The separation results in the medium size fractions between +6 and -30 mm are excellent"

Jan 1, 2003

By Máximo Pérez, Julio C. Videla, Rosa Dzioba

"This paper reports the hydrometallurgical treatment of gravity concentrates of gold samples and outcrops associated with graphite ores obtained from:• flotation tailings of crystalline graphite minerals• outcrop samples of graphitic rock associated with auriferous minerals and free gold located in the Villa Union district and surrounding areas - La Rioja Province - Argentina.Previous studies of the flotation potential of crystalline graphite minerals failed to consider the presence of noble metals.The samples represent a mineralized zone of crystalline graphite which is distributed in different formations with a NE - SW trend in Maz, Punta Colorada and Las Ramaditas hills, covering an area of about 300 square kilometers."

Jan 1, 2003

By Susanna G. de Jager, Francis W. Petersen

"To enable the prediction of reagents suitable for fine coal flotation, it is necessary to develop a methodology applicable to different South African coal types. Statistical confirmation of the applicability of this methodology is important to avoid recommendation of reagents on a trial and error basis.The study included 5 coal samples from different collieries and included Highveld seam 3 and 4 coal (as one sample), Waterberg coal (zone 10 -11), Highveld seam 5 upper coal and Witbank seam 2 and seam 4 coal. Seam 3 and 4 (mixture) coal, Waterberg and the seam 5 upper coal were all found to be vitrinite rich coals. The coal characterisation study included petrographic analysis, proximate analysis, float-sink analysis, oxygen-containing functional groups, surface extraction, flotation release analysis and contact angle measurements. Flotation tests were used to validate expectations from the characterisation of the coal samples.RESULTSThe flotation data indicated that all of the coal samples were amendable to froth flotation. The best results were obtained with the Witbank seam 2 coal and the poorest flotation with Syferfontein seam 5 coal. The flotation tests showed that the best reagents to float all of the coal samples studied were iso-decanol and dodecene. These reagents produced flotation products that were near to the release curve, which are the optimum flotation results (obtained when using iso-paraffin as collector). Dodecene resulted in low ash products and iso-decanol in high yield products."

Jan 1, 2003

By M. Brozek, W. Pawlos

"The separation of raw materials in the separator with ferromagnetic liquid occurs due to differences in magnetic and gravitational properties of respective components in relation to each other and to the liquid. In the separator with wedge-shaped pole shoes and the working space axis inclined at a certain angle to the horizontal direction, the paths of grain movement at fixed separation conditions depend on its physical properties. Due to this, the levels of grains outlet from the separator working space are differentiated according to differences in their physical properties. The distance between the levels of outlets from the separator working chamber depends on magnetization of the liquid which is proportional to the liquid density, on the magnetic field intensity and the inclination angle of the separator working passage to the horizontal axis. The separation accuracy is higher the larger is the distance between the outlet levels.The paper will present the methods of visual observation and recording of movement paths of coal grains of different physical properties in the paramagnetic liquid which was the water solution of manganese chloride. The paths were recorded with a video camera in the working chamber by means of a specially constructed device, acting as a periscope, which were then transformed into digital images. Experimental movement paths were confronted to the paths obtained in a theoretical way by means of solving differential equations of movement by a numerical method, achieving good compatibility of experimental and theoretical results. The equations of movement were solved with taking into consideration the drag force, expressed by formula for laminar and dynamic conditions of motion.The course of the path of grain movement depends on grain and liquid physical properties, magnetic field intensity and inclination angle of the working space to the horizontal direction. The two latter parameters can continuously control the process of separation."

Jan 1, 2003

By John Ralston, Jonas Addai-Mensah, Patience Mpofu

The flocculation and dewatering behaviour of kaolinite (non swelling) and smectite (swelling) clay dispersions has been investigated using hydrolysable metal ions Mn(II) and Ca(II) and anionic polyacrylamide-acrylate copolymer (PAM) at pH 7.5 and 10.5. A pH-dependent, specific metal ion adsorption behaviour, accompanied by a marked reduction in particle zeta potential and slurry shear yield stress, was observed to have a profound influence on the colloid stability of both types of clays. Due to the differences in the cation exchange capacity, the smectite clay dispersion required a higher amount of metal ions than kaolinite dispersion to produce similar effects. The adsorption density of the anionic PAM at the negatively charged clay particle surfaces correlated well with metal ion hydrolysis and adsorption behaviour, all of which had a strong effect on slurry settling rate and extent of consolidation. At pH 7.5 where Mn(II) ions hydrolyse, metal ion and flocculant adsorption densities were both greater in the presence of Mn(II) than Ca(II) ions. At pH 10.5, however, where Ca(II) ions begins to hydrolyse, higher adsorption densities were observed for Ca(II) ions in comparison with Mn(II) ions, as the latter hydrolysed completely and precipitated. The metal ion mediated flocculant adsorption led to improved hydrogen bond driven particle bridging and facilitated charge neutralisation flocculation mechanisms which significantly enhanced the dewaterability of both clay dispersions.

Jan 1, 2003

"The Merensky Reef is a platinum group minerals (PGM) bearing reef in the Bushveld Igneous Complex in South Africa. The reef has been treated by bulk PGM and sulphide flotation with the aim of maximisingthe valuable minerals recovery and gangue minerals rejection.Synthetic water with a calcium concentration of 80 ppm and 500 ppm was prepared and the flotation results obtained were compared to a simple electrolyte in order to determine the effect water quality has on pentlandite and pyroxene surface alteration and, ultimately, floatability. During the study, the possible effect of interactions between the minerals investigated and Ca2+ ions in the presence of sodium isobutyl xanthate was studied at pH 6 and pH 9 by means of zeta potential determinations, microflotation tests and ToF-SIMS analysis.The results obtained on 1:1 pentlandite-pyroxene mixtures showed that the quality of process water plays an important role in flotation. The flotation recoveries of pentlandite and pyroxene were lower in synthetic process water compared to those obtained in a simple electrolyte solution."

Jan 1, 2003

By Maurício Torem, Gabriela Huaman, Antonio Merma

The purpose of this review paper is to succinctly present the most significant works related to Mineral Processing and Environmental Bioremediation and developed by the Mineral and Environmental Technology Group (METG) of the Materials Engineering Department of the Pontifical Catholic University of Rio de Janeiro (PUC-Rio). In mineral processing it was emphasized the use of the Rhodococcus opacus bacteria as a bioreagent in the bioflotation of some mineral samples (magnesite, calcite, hematite, quartz and apatite). The adsorption of the bacterial cells on the mineral surface can be due to specific and/or non-specific interactions, which will depend on several factors, as their surface charge and hydrophobic character. The zeta potential evaluation of the mineral particles before and after interaction with the R. opacus cells showed that the biomass modified the zeta potential profiles of the minerals, which confirm the adsorption of bacterial cells on the mineral surface. Moreover, the bacterial cells adsorbed caused a change in the mineral flotability which is related to a change in their hydrophobic character, thus, the mineral bioflotability was found to be dependent on the pH and the bacterial concentration. On the other hand, the environmental bioremetiation assessed the biosorption potential of three metal ions (lead, copper, and cobalt) by four different biomass Streptomyces lunalinharesii, Rhodococcus opacus, Rhodococcus ruber and coconut shell powder. For this purpose, biosorption process was characterized under different operating conditions such as initial pH and biosorbent dosage. The Freundlich and Langmuir isotherm models were applied to the equilibrium data obtained at different concentration.

Jan 1, 2014

By Zoran M. Stevic, Mirjana M. Rajcic-Vujasinovic, Zvonimir D. Stankovic

"Huge electrochemical investigations have been performed on Technical faculty in Bor (Serbia) which main goal was the clarification of the copper sulfide minerals behaviour in hydrometallurgic and flotation processes. Modeling of these processes was a part of the effort for better understanding of the reaction mechanisms.The consideration of electrical analog circuit and mathematical model of processes at interfaces copper sulfide/electrolyte (CuS/(CuSO4+H2SO4), Cu2S/H2SO4 and CuFeS2/H2SO4), based on studies of the overvoltage – time transients, will be presented. The transients were obtained using single pulse galvanostatic method and electrochemical cell with standard three electrode assembly. In that goal it was developed an original system for computer measurements that enables the application of several methods for electrochemical investigations (galvanostatic, potentiostatic, cyclic voltammetry, electrochemical impedance spectrometry etc). The system was tested and adjusted using commercial electrochemical equipment made by AMEL, Milano.In the first stage of consideration the different equivalent electrical circuits have been tested by computer programme OrCAD 9.2 in order to identify the circuit with responses equivalent in shape to experimentally obtained ones. In that way it was established a configuration of an analog electrical circuit for investigated electrochemical system. That phase enabled only very rough determination of values of circuit components and their relative ratio.In the second stage the method for determination of all elements of electrical analog circuit is described. It is based on mathematical consideration of a given circuit on one hand, and valves of the overvoltages at selected times, obtained from charging and discharging parts of galvanostatic transients, on the other."

Jan 1, 2003

By Wang Xiaotie, Yu Yongfu, Che Liping, Zhang Fuguang

The flotation process of native Rare Earth minerals such as bastnasite, monazite, mixed minerals of bastnasite and monazite, using the new effective collector Dh was studied in this paper, respectively, and the flotation properties are described. The good qualities of the new collector Dh were revealed through comparing with other collector of Rare Earth minerals. The test results of different ore samples show that at moderate pulp pH (8.5-9.5), Rare earth minerals can be effectively separated from barium, calcium and silicon bearing intergrowth minerals (barite, calcite and silicate minerals) and high quality Rare Earth concentrates can be obtained successfully by the new collector Dh, acid silica gel, turpentine and reagents fitting together rationally. In order to determine optimum technical conditions, the effect of pulp pH, pulp temperature, pulp density and the effect of dosage of reagents (Dh and acid silica gel) on the flotation were investigated in the test.

Jan 1, 2003

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