Energy consumption and liberation of minerals in explosive electrical breakdown of ores

The disintegration of brittle composite dielectrics - in particular, ores and smelting slags - by explosive electrical breakdown is discussed. Electrical pulses are used to produce intergranular fragmentation and can liberate the constituents of composite solids with higher efficiency than conventional mechanical comminution. The energy consumption of the process can be reduced by the choice of the electrode configuration and by adjustment of the waveform of the pulses according to the spark constant of the disintegrating dielectric. As an example, the liberation of platinum-group metals from a South African ore is analysed from metallurgical and energy consumption perspectives.