In the third of our series of online articles covering technology developments at Russia’s gold mining major Polyus, based on IM attendance of the Polyus Capital Markets Day in London, we look at the company’s antimony project which is focused on its Olimpiada operations.
The project has mainly come about for two main reasons. Antimony is a bio-oxidation inhibitor and so currently, Polyus has to blend its ore from the Olimpiada operations to maximise the efficiency of its BIO technology. Second, Olimpiada’s Vostochny pit has reserves of high-content antimony ore and the mineralogical properties in the pit suggest the deeper horizons having an increased amount of this material. Even in 2016-2017 a conservative estimate for the high antimony ore mined at Olimpiada is estimated at 11 Mt. The new high antimony material will be mined as a result of the planned 4th cut back.
Polyus plans to start selling Au-Sb flotation concentrate on the global market and is already produced it successfully (Au 50-100 g/t; Sb 20-40%), with future plans to also produce antimony metal. By separating the processing of low content and high content antimony ore, Polyus can increase recovery from the low antimony ore at Olimpiada’s Mill 2 and Mill 3 via gravitation/flotation then the BIO and hydrometallurgy stages. The combined Au-Sb flotation concentrate is produced from the high antimony ore at Mill 1 via gravitation/flotation then filtration (and at a later date metal production). The key is that Polyus can get a premium for the antimony ore or concentrate but the project doesnt require much in the way of capital or operational expenses. The group’s TCC should decrease by $10-15/oz.
Antimony has a range of uses: fire retardants, battery production, ceramics, glass, even steel galvanisation. Global supply is dominated by China at 69% share or 82,000 t in 2017. Chinese official and unofficial production accounted for 91% of global supply. SEA, Russia, and Tajikista contribute in total another 28,000 t or 22% of the official mine supply but mostly export their DSO or concentrates to China for smelting. Polyus expects its production of combined Au-Sb to reach up to 200,000 oz of contained gold and 15-20,000 t of contained antimony.
