A review of electrokinetic, ultrasonic and solution pulsing methods for mass transfer enhancement in in-situ processing

There is increasing interest in the in-situ leaching or in-situ recovery of metals because of the method’s potential for a lower operating cost and the potentially smaller environmental impact. Only preliminary investigations have been conducted to understand the factors that influence the rate of recovery that may be achieved in in-situ recovery operations. This review focuses on the potential of three methods to accelerate the movement of lixiviant ions in an in-situ recovery process, namely: electrokinetic, ultrasonic and solution pulsing methods. The aim of the review is to summarise available information on the three methods of relevance to improving the rate of mass transfer in in-situ recovery and to discuss the mechanism of ion migration under different accelerating conditions compared with that by diffusion only.