Russian gold mining major Polyus gave some detailed insights into its continued use of state of the art flotation technologies – namely the Jameson Cell and flash flotation – across its main processing facilities during its 2021 Capital Markets Day presentation on June 23.
First and foremost, Polyus expects to increase the throughput capacity at the Olimpiada processing complex from the current 14.3 Mt/y to 15 Mt/y by mid-2022.The project includes the upgrade of grinding, crushing, gravity and flotation circuits and a number of initiatives related to infrastructure development. Polyus is progressing with operational efficiency improvement initiatives aimed at expanding the throughput capacity of the Natalka mill up to 12.5 million tonnes per annum in 2021-2022. In addition, the company is focused on improving the recovery rate at Natalka and is currently calibrating a new flash flotation flowsheet. Finally the new Blagodatnoye Mill-5 will have a nominal processing capacity of 8 Mt/y bringing the total throughput capacity at the Blagodatnoye complex to 17 Mt/y. Polyus expects to launch Mill-5 in 2025.
Looking at the Jameson Cell from Glencore Technology as an example, this technology produces smaller bubbles to traditional flotation, allowing particles to settle on a larger surface area. The consistent fine bubble generation is achieved without external equipment or spargers, and allows maximum grade in concentrate in a single step. It offers a fast and easily controlled response, with a high level of automation and its simplicity and small footprint makes it well suited to brownfield plant expansions. So far Polyus has installed five Jameson Cells across Olimpiada and Blagodatnoye, which has resulted in an additional recovery rate of 0.45% and 0.35% respectively. This may not sound like much but for a relatively small piece of equipment and investment this equates to an extra 7,000 oz and 2,000 oz. Polyus is adding another two Jameson Cells at Olimpiada and another four at the new Blagodatnoye Mill-5.
Onto flash flotation – Polyus has deployed multiple Metso Outotec SkimAir flash flotation across its operations – with eight installed between 2017 to 2020. Half were at Olimpiada – a unit at Mill-1, another at Mill-2 and two at Mill-3 all installed in 2019. These have added 1.1% of recovery, equating to 20,000 oz of added gold production in 2020 alone. The technology recovers liberated valuable minerals in the cyclone underflow (recirc load) before it is returned to the mill preventing the material being overground and lost to tailings. Flash flotation will be used at the new Blagodatnoye Mill-5 while it has also proved to be effective at Natalka and the rollout of the technology there (two units) is in progress.