HotHeap™

HotHeap™ is a proprietary process control management system designed to optimize biooxidation conditions (temperature, pH, Eh, solution chemistry) through the control of irrigation and aeration rates, and is based on a sophisticated control algorithm. The system allows the temperature in the heap to be optimized, firstly by defining the air flow required by the oxidation process, and then by balancing the amount of irrigation with the rate of aeration. By controlling the ratio of the irrigation to aeration in the heap at the correct value, the washout (down) and/or blow-out (up) of heat from the heap can be prevented, and therefore heat can be retained.

The required aeration is measured by oxygen utilization. Oxygen measurements are taken from the top of the heap, and used to determine and then adjust the aeration flow to the heap. The irrigation setpoint is changed at a predetermined ratio to the aeration setpoint. The pre-determined setpoint is defined via the HotHeap™ algorithms, and is varied later in the cycle based on interpretation of the temperature profiles from measurements within the heap.