Ziaeddin Pourkarimi; Ali Dehghani Ahmadabadi; Mohammad Noparast; Seyyed Ziaeddin Shafaei; Mohammad Reza Soltani
Abstract
Simulation of grinding circuits has being performed from 30 years ago and is also to be more complete and powerful approach with improvement of mathematical models which simulate various processing units/machines. The modeling and simulation of various mineral processing circuits are presently performed. ...
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Simulation of grinding circuits has being performed from 30 years ago and is also to be more complete and powerful approach with improvement of mathematical models which simulate various processing units/machines. The modeling and simulation of various mineral processing circuits are presently performed. In order to simulate the present grinding circuits of Esfordi Phosphate processing plant, at first the breakage and selection functions of its ball mill’s feed sample were determined. According to obtained results, maximum value of selection function (selectivity of particles to be broken), was measured which was equal to 0.011886 min.-1 for 600 microns size fraction (d80 of ball mill feed at primary design). Then by using NGOTC software and measured residency times of particles in ball mill (average residency time in ball mill) which was 2.07 minutes (maximum time was 20 minutes), the selection function of ore was calculated in industrial scale, and accordingly the effect of using balls with various diameters were estimated. The results of selection function indicated that its maximum value reaches to 2.5238 min.-1, when balls with 25mm diameters to be used in ball mill. Finally by using BMCS software (ball mill circuit simulator), primary design data, and results obtained from various experiments, the circuit simulation was carried out. This procedure yielded optimized values of some required parameters such as size distribution and solid percent of ball mill product, and then the results were compared with current circuit values. However the estimated results and their vicinity to current ones proved the fact of estimation accuracy.
Ali Dehghani Ahmadabadi; Ziaeddin Pourkarimi; Mohammad Noparast
Abstract
Due to the importance of material classification issue in grinding circuits, the performance of primary and secondary hydrocyclones in grinding circuit of Esfordi phosphate plant was investigated by sampling within 7 days from feed, overflow, and underflow of these hydrocyclones. At first, ...
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Due to the importance of material classification issue in grinding circuits, the performance of primary and secondary hydrocyclones in grinding circuit of Esfordi phosphate plant was investigated by sampling within 7 days from feed, overflow, and underflow of these hydrocyclones. At first, the d80 of above streams samples were calculated by the screening analysis. The results showed that the average values of d80 of feed, overflow and underflow of primary hydrocyclone were respectively 238.7, 236.5 and 100.9 microns, and 100.9 and 94.1 microns for the feed and underflow of secondary hydrocyclone. For the primary hydrocyclone, with plotting distribution curves, its cut-points, the actual and corrected cut-points were calculated which were 35 and 45 microns, respectively; whereas they were equal to 100 microns according to the design documents. However based on the undesirable performance of primary hydrocyclone, it was tried to investigate on its performance using simulation software. The results indicated 80 microns cut-point and 192.30 kpa of pressure drop in particle classification. In addition, the amount of circulating load obtained 931.84% (in primary mill design, this amount was equal to 150%), and high feed rate to hydrocyclone was one the major reasons for this high circulating load. To solve this problem, it was considered one more hydrocyclone could be added to this circuit in the form of parallel and series, and results were studied using BMCS software. The results of this criterion of adding a parallel hydrocyclone, showed 86 microns of cut-point with 62.91 kpa of pressure drop which were suitable for the circuit.
Hossein Abolghasemi; Hadis Khakbaz
Abstract
1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation ...
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1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation process in BD unit of Jam and Amirkabir Petrochemical Company improves the relative volatilities of components by addition of a high boiling point solvent (namely N- methylpyrrolidone, 8.3%wt H2O). With respect to high mass ratio of total solvent to feed, the solvent has significant role in separation. In this study, extractive distillation system was simulated with the HYSYS3.1 software to investigate the effect of the temperature and as well as that of feed entry stage of the solvent on the separation. It was found that; the reduction of solvent temperature had no considerable effect on products’ specifications, but rather, it could minimize the solvent rate.
Caren Abrinia; Seyyed Ali Reza Fazli Rad
Caren Abrinia; Jalal Pour Hosseini Baboddashti
Abstract
In this paper the eccentric forward extrusion of sections has been simulated and analyzed using FEM Abaqus-explicit. The results have been compared to those obtained from upper bound theorem and experimental works. Close agreements was observed between the FEM and experimental work and as compared with ...
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In this paper the eccentric forward extrusion of sections has been simulated and analyzed using FEM Abaqus-explicit. The results have been compared to those obtained from upper bound theorem and experimental works. Close agreements was observed between the FEM and experimental work and as compared with the upper bound data more realistic and better predictions were made by the authors’ method. The sections considered in this work were circular and square shaped cross sections. Process parameters such as die length, friction factor and percentage of eccentricity have been investigated and their influence on the relative extrusion pressure and the curvature of the extruded profiles has been illustrated. The effect of die profile has also been studied and shown that a 10 percent reduction in the extrusion pressure could be achieved by using the optimum die profile.
