Optimisation of the grinding circuit at arafertil, Brazil

Arafertilʹs regrinding circuit is responsible for the recovery of apatite with a low degree of liberation, representing approximately 11% of the overall apatite concentrate production. Low grinding capacity prevented an ideal size distribution of product for maximum recovery in the subsequent flotation stage, as shown in a liberation study. ork was aimed at attaining the required increase in regrinding capacity, using process simulation by computer mathematical modelling, with the objective of implementing an optimised grinding and classification circuit. ll mill and hydrocyclones models were calibrated, and their equations were defined, from industrial data acquired in the old concentrator configuration and results from laboratory grinding tests with power consumption measurements. del was validated by means of comparison between the results predicted by simulation and those achieved in the plant after refurbishment. The apatite flotation recovery increased from 31.5% to 48.0%, in agreement with the previous apatite liberation study.