The Carbon Scout is a self-contained, ground-level sampling system that measures the carbon concentration in CIL and carbon-in-pulp circuits to an accuracy of ±0.5 grams of carbon per litre of pulp. The unit also provides other operating data important to the leaching process including slurry density, pH, Dissolved oxygen (DO) and most recently the measurement of gold loading on carbon. Data profiles are provided from every leach tank, every hour.
The Carbon Scout is developed in conjunction with Dr Teresa McGrath MAusIMM and Adjunct Professor Bill Staunton FAusIMM from Curtin University. Gekko Systems has licensed the technology from Curtin and is responsible for manufacturing, sales, ongoing development/capability, and aftermarket support of the Carbon Scout.
The Gekko Carbon Scout was installed at Stawell Gold Mines (SGM) in 2019. The aim of the project was to provide a fully automated carbon movement system that can be operated from the control room and automatically transfer the carbon from each tank as it loads the gold from solution. The XRF functionality was later installed in 2021, allowing the operation to calculate real time gold in circuit (GIC) inventory (which is currently being tested and optimised.)
The introduction of the XRF technology will allow the operators and metallurgists to calculate GIC automatically, without waiting for assay data from the assay laboratory. The increased speed accessing the data will provide a real benefit to the project. The data from this unit will enable the plant to optimise carbon movement and ‘strip’ cycles, providing extra control of the plant. The Carbon Scout also aims to help the operators to optimise plant efficiency by reducing soluble gold losses.
The installation at the SGM has also provided valuable feedback that has been used to further develop and ‘mine-proof’ the product. The unit has undergone several modifications, as a direct result from the SGM operating team resulting in a new MK6 unit being developed. Some of the challenges included piping positions, valves specifications and the laser level positioning; however, in collaboration with SGM personnel, these issues have been addressed and are now being updated in the units globally.
The graph below displays the results of the Gekko Carbon Scout versus manual samples at SGM over a two-day period. Results indicate good correlation and further optimisation, and testing is ongoing.
Data indicates a strong correlation between the manual samples and the Carbon Scout. The graph highlights the Carbon Scout’s greater granularity and advanced measurements ahead of any unwanted excursions. This knowledge allows operators to significantly reduce soluble gold loss from the circuit.
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