Electricity costs and the financial feasibility of low grade gold ore processing

Gold processing is an energy intensive industry due to the operation of comminution equipment. Energy management in this industry has been given little regard since energy costs are heavily outweighed by the economic potential of precious metals. In practice any downtime on comminution equipment will be avoided in order to maximise ore throughput and in turn maximise revenue income. In some instances this is still the case, independent of the grade of the ore. In most cases the ore processing capacity exceeds that of the mining production. The surplus plant capacity is then used to process low grade ore. However, it is intuitive that it will become uneconomical to process a low grade ore below a certain grade threshold. The effective management of operational costs associated with low grade ore processing is therefore essential. This paper investigates the effect of electricity cost on gold processing operations. The results indicate that effective energy management can produce substantial electricity cost savings. This insight plays a significant role in determining the feasibility of low grade ore processing.