Automate your gold leaching circuit with Gekko Systems

Carbon Scout & OLGA at Gruyere Gold Mine in Western Australia.

Gekko Systems has developed an integrated ground-based system, changing the way gold-leaching circuits are monitored and controlled. This system utilises technologies developed by Gekko in collaboration with world-class researchers from the CSIRO (Commonwealth Scientific and Industrial Research Organisation) and Curtin University over the last 15 years to automate gold-leaching circuits.

The new integrated system seamlessly incorporates state-of-the-art technologies, including the Carbon Scout, OnLine Gold Analyser (OLGA), Cyanide Analyser, and Neon (real-time data analytics platform).

By integrating these technologies into a unified system, Gekko provides metallurgists with a comprehensive set of data to monitor and control the CIL (Carbon in Leach) circuit effectively. The real-time insights obtained through the ground system enable metallurgical professionals to make informed decisions, optimise processes, and enhance overall operational efficiency.

The Carbon Scout is a self-contained, ground-level sampling system that measures individual tank carbon concentration (in g/L), pH, dissolved oxygen (DO), and slurry density in carbon-in-leach (CIL) and carbon-in-pulp (CIP) circuits. The new feature of the optional X-ray fluorescence (XRF) analyser to measure gold on carbon loading, for real-time gold circuit inventory, brings the Carbon Scout another level above its competitors.

The device collects slurry samples from CIL/CIP tanks to determine the concentration of the activated carbon in the pulp for each tank, to an accuracy of ±0.5 grams of carbon per litre of pulp. The carbon concentration level data is then used to automate carbon movement to optimise carbon distribution across the circuit. The Carbon Scout improves the accuracy, regularity, and consistency of carbon concentration measurements in CIL/CIP circuits.

Nigel Grigg, Gekko’s Global Sales and Solutions Manager stated that “the data from the Carbon Scout alone can be used to move carbon to control carbon profiles, to control solution losses, and even schedule elution strips based on carbon loadings. The ability to perform gold-in-circuit (GIC) inventory calculations with a push of a button is very handy to any metallurgist wanting to know the gold inventory in their circuit.”

The OLGA is the only real-time measurement system purpose-built for gold. The unit is typically installed to measure the cyclone overflow stream in CIL leach circuits, solutions from the electrowinning circuit, and on flotation feed, tails, and concentrate streams. With the multiplexing function, the OLGA can switch the measurement of grade from stream to stream. “The technology represents a significant step forward in the potential to automate gold leaching circuits,” Grigg says.

The OLGA has at its heart the world-first proprietary “Golden Eye” lens technology developed and designed in Australia’s pre-eminent government-funded CSIRO research laboratories. This innovative component measures gold grade in slurries and solutions combined including low-grade slurry streams down to as low as 0.1 ppm. Other detected elements include copper, arsenic, lead, silver, platinum, and nickel. The multiplexing feature will allow for up to six streams within a processing plant to be assessed for gold grades.

Another key feature of OLGA is the dedicated sample feed line, facilitating continuous sampling of large volumes with no potential for cross-contamination. The system also offers an additional manual sample point for ad-hoc samples, providing flexibility and adaptability to changing operational needs. Furthermore, the ad-hoc samples can be analysed as batch samples, minimising sampling errors and potentially substituting the need for other sampling systems.

The OLGA Mk3 has undergone rigorous testing and refinement to ensure its robustness, reliability, and accuracy in various operational conditions while offering minimal maintenance requirements.

At this stage, Gekko has incorporated a third-party OEM system into the integrated ground system. Grigg stated that “several cyanide analysers have been available commercially for many years and are working well on many plants globally. Gekko has decided to utilise the analyser that the clients are most comfortable with, as the ground station can incorporate most commercially available models. Currently incorporated into the design is the TAC 1000 unit that will measure both Free and WAD (Weak Acid Digestible) cyanide levels”.

The ability to control and optimise cyanide addition is a particularly important part of the overall control philosophy of the system.

The collected data is then available for mining companies to incorporate into their own DCS systems or can be incorporated into their logic control systems. Gekko has developed a platform to assist clients who might not have the same in-house programming capability. The program ‘Neon’ is an equipment optimisation platform available online through your phone or desktop. The platform allows for real-time data analysis and event monitoring. Neon aims to increase the plant's efficiency, safety, and stability through timely accurate analytics.

Gekko Systems is a global leader in mineral processing technology, specialising in design, development, manufacturing, and commercialisation. For nearly 30 years, Gekko has provided integrated solutions for mining companies, focusing on gold processing, pre-concentration, and energy-efficient methods. Based in Victoria, Australia, Gekko supports a variety of minerals including gold, silver, tin, critical minerals, and polymetallic ores, and maintains strong technical support and research collaborations.