The effect of process variations on slurry rheology, washer performance and control strategy

摘要

Washing circuits at lateritic ore refineries can experience operational issues associated with the end of the washing circuit, where washer overflow becomes excessively turbid, the underflow thickens to the point that the rake cannot move it to the outlet, operation becomes unstable and underflow pumping becomes an issue. In this study, suboptimal flocculation was assumed to be the cause of these operational issues. On site flocculation testing, rheology testwork and particle size analysis, combined with analysis of washer operating data, shows that the effects of process variations on slurry flow properties are significant. Comparison of the control strategies employed by different washers highlighted opportunities to improve process control and subsequently stabilise washing train operation and performance.