A proposed technique for measuring in situ the oxidation rate in biooxidation and bioleach heaps

Measurement of the time-dependent change in the oxygen concentration immediately after cessation of aeration is proposed as a method for measuring the sulfide oxidation rate in biooxidation and bioleach heaps. A similar method has been used to determine the sulfide oxidation rate in waste rock dumps at a number of mine sites. The measurement is rapid, is non-destructive, is in situ, allows repeat measurements at the same location and is not expected to interfere with the overall operation of the heap. The sulfide oxidation rate is a key indicator of heap performance, and its measurement provides a means for observing the effectiveness of any changes in heap operation made to optimise performance. In the case of a biooxidation heap, the measurement allows an estimate of the total amount of oxidised sulfide to be made.