Double refractory ore concentrate contain ore micron gold particles encapsulated in sulfides (pyrites and arsenic pyrites) together with high concentrations of organic carbon, that is why conventional methods such as cyanidation or heap leach gives very low recoveries. For refractory ore, processing options include pressure oxidation (POX), bio oxidation (BIOX) and roasting. POX delivers the lowest SO2 and AS203 emissions, cyanide consumption and OPEX, though it is the most capital intensive.
What is amursk POX-2
Amursk POX-2 is designed for processing double-refractory ore and aimed to make 100% of the Company’s refractory ore to be processed in-house.
POX-2 differs from POX-1 in the way that it will operate at two-times higher pressure and 40 *C higher temperature, and it will use a larger and more advanced autoclave (one of the biggest in the world), lined with titanium rather than brick. Total capital costs for the project in 2019-2021 are estimated at US$ 431 million.
Please follow the link for more information about the results of the project feasibility study.
The new plant will be located next to the existing POX facility in Amursk so it will benefit from sharing some of the external infrastructure (gas main, access road, water main) while additional electricity supply will be provided through a new dedicated power line from the regional grid.
The project is managed by the team of more than 30 professionals who actively participated in the successful execution of the original POX (2013) and POX debottlenecking (2018) projects.
Why it is important
Currently 55% of Polymetal’s reserves are double refractory. In 5 years , almost 40% of the annual production will be double refractory. With this POX-2 will allow 100% in-house processing rather than selling to offtakers, which will result in lower costs, higher recoveries and reduced environmental footprint. Overall, it is expected that POX 2 will reduce all-in sustaining costs per ounce for refractory assets by $100-150.