A method to evaluate the overall breakage degree of pre-weakening processing and its applications

Abstract

The product fineness indicator t10 and the pre-weakening degree indicator percentage change of A * b value (CAb) were used to described the two aspects of the breakage result of processing with pre-weakening effect. However, there lacks a method to evaluate the ‘overall’ breakage degree with a single index. It was observed that when the high voltage pulse breakage (HVP breakage or HVPB) induced cracks inside pre-weakened particles were consumed during impact breakage, the breakage characteristics of the progeny particles are the same to raw ore particles. Based on this phenomenon, the concepts of equivalent size Sie and equivalent size reduction t10e are proposed. Raw ore particles of size Sie is ‘equivalent’ to pre-weakened particles of size Si in terms of their impact breakage product size distribution. Therefore the value of Si and the consequently derived t10e can be used to evaluate the overall breakage degree of pre-weakened particles. The calculation procedure of Sie and t10e is demonstrated in the context of HVP breakage. It is found that the impact breakage product of pre-weakened particles can be well predicted from Sie. In addition to the evaluation of overall breakage degree of pre-weakening processing, this method also has potential to apply in the simulation of comminution circuits with pre-weakening processing and the development of breakage model for processing with pre-weakening effect.