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.
