Evergreen: Reduce water usage in gold processing through tailings density prediction
Can you build an algorithm that predicts tailings underflow density (and therefore process water content) three hours ahead of time?
In metals processing, large tanks (thickeners) are used to separate the mineral solids from the process water. Thickeners separate the mineral solids and water by discharging a stream of the settled mineral solids in the form of a sludge (underflow) and a stream of clarified water from the top (overflow). The separation of water from tailings (mineral processing waste product) is a critical process as it enables the recycled water to be reutilised within the processing plant. This reduces the operating cost for ongoing processing of the ore and improves the environmental sustainability of the operation.
Sustaining a high tailings underflow density is a challenge Newcrest routinely endures. By only achieving a low tailings density (<54%), this results in several unfavourable consequences. A low tailings density reduces the recoverable water content that can be reused within the processing plant. It also results in larger volumes of slurry being pumped to the tailings storage facility to store the necessary mass of waste product. The culmination of these issues is a higher cost of operating due to increased energy consumption and water consumption, and it also impacts the social reputation of Newcrest during periods of sustained drought within the Orange region. Increasing the annual average tailings density by 1% saves approximately 500ML of water per annum.
- Based on provided processing data, can you predict the tailings density % 3 hours from now?