Selection of Piloting Parameters in Pressure Hydrometallurgy

Pressure hydrometallurgy is becoming an increasingly common unit operation in the treatment of gold and base metal ores and concentrates. The design of an adequate and appropriate pilot-scale testwork program is, therefore, essential in order to minimise the risks associated with developing a project in which autoclaves form a key part of the operation. This paper identifies the approaches that have been taken in the piloting of oxidative and pressure acid leach operations. Particular emphasis is placed on the determination of scale-up ratios between the pilot and commercial plants and the pilot-plant run durations. The issues, both metallurgical and project-specific, that can impact these key parameters are reviewed.