Simulation and optimization of grinding circuit case study of Tiran zinc company

Today, simulation is a great tool for examining processes of a plant .In this paper, grinding circuit of Tiran zinc company was simulated by BMCS software. Grinding circuit of this company includes two ball mills, that first ball mill is in open circuit and another is in closed circuit with hydro cyclone. Overflow of hydro cyclone is known as product of grinding circuit. After initial studies on circuit of this company, it was found that high value of P80 of hydro cyclone overflow is a One of the main problems, because value of this parameter is almost 107 micron at the moment and it is different with determined target of 74 micron. Also input load to circuit is changed in the range from 370 to 430 t/day, that it is much less than determined nominal capacity of 500 t/day. After simulating the circuit, in order to optimization of conditions was used from the experimental design of CCD (Central Composite Design). In this study, reducing P80 of hydro cyclone overflow to the target size, increasing capacity and reducing percent of circulating load were main targets. Finally, it was found, that in the obtained optimal conditions (compared to the current state of the circuit), the capacity increases from 425.27 t/day to 476.79 t/h, P80 of hydro cyclone overflow decreases from 107 microns to 93 microns and also percent of circulating load decreases from 219.77 to 181.59.