Importance of considering classification and liberation when optimising comminution and flotation

Abstract

With the world demand for minerals accelerating, there is an increasing need to optimise grinding and flotation processes to maximise flotation recovery and minimise energy use. This paper aims to demonstrate that it is important to consider liberation in these optimisation studies. Classification is a key process linking grinding and flotation. This paper presents a series of case studies that compare the liberation produced by different classification options, as well as additional work that has been performed to explain the behaviour observed and the subsequent effects on flotation recovery. It is demonstrated that screens can improve grinding efficiency and downstream flotation performance because of less misclassification of fines and improved particle liberation. However, the difficulties associated with screen operation mean that it is not a viable size classification device for most mineral processing applications, providing motivation for more research into alternative classification technologies. The importance of considering liberation when optimising emerging new grinding, classification and flotation technologies is also discussed.