Calibration of Plitt's Model in Pperformance Optimization of Hydrocyclone Package at Aghdareh Gold Processing Plant

In Aghdareh gold processing plant, grinding circuit product size has a significant effect on downstream gold leaching process. Therefore, the performance optimization of hydrocyclone package in order to decrease the size of overflow stream to less than 70 μm (present value) will considerably increase the gold recovery. In this research, optimization of Aghdareh’s hydrocyclone package performance was done by application of Plitt’s model and its calibration and simulation of classification process. Two plant sampling campaigns were carried out to collect samples from the streams around the hydrocyclone package. Screen analysis tests were performed to obtain particle size distributions (PSD). Then, measured PSD and flow rates of various streams were adjusted using NorBal data reconciliation software. Then, BMCS (BMCS-based Modular Comminution Simulator) was used to predict the PSD of overflow and underflow streams for the first sampling campaign and also calibrating Plitt’s model to operating Aghdareh hydrocyclone package. Then, BMCS simulation predictions based on the calibrated Plitt’s model were validated using the second sampling campaign. The simulations showed that by using vortex and spigot internal diameters equal to 75 and 70 mm, respectively and with 6 operating hydrocyclones, the P80 of the overflow product can be decreased to 68.5 μm. Also, simulations by using vortex and spigot internal diameters equal to 94 and 53, respectively with 6 operating hydrocyclones showed that the separation sharpness, m, can be increased from 1.18 to 2.81 which indicates a 2.38 times increase in classification accuracy.