Polymetal installs 'world's largest' gold autoclave

Cyprus-based precious metals mining group Polymetal International has installed what it claims to be the world’s largest gold autoclave vessel at its Amursk POX-2 project in Russia’s Far East.
Polymetal installs 'world's largest' gold autoclave Polymetal installs 'world's largest' gold autoclave Polymetal installs 'world's largest' gold autoclave Polymetal installs 'world's largest' gold autoclave Polymetal installs 'world's largest' gold autoclave

The POX-2 autoclave installation

Built by Belgium's Coek Engineering, the autoclave is 50m long, has a diameter of 6m and weighs 1,100 tonnes, said Polymetal. It has cost US$27 million in total for the equipment and its shipment to Amursk.

The vessel, which is made of steel and has a titanium lining, will operate at the temperature of up to 240 Celsius and a pressure of 45 bar, and is the largest in the gold industry globally.

"The installation of the autoclave vessel is a crucial project milestone. We accomplished it on time despite the COVID-related restrictions and complex logistics. It marks our consistent progress towards start-up in Q3 2023", said Vitaly Nesis, chief executive of Polymetal.

Amursk POX-2, which is designed for processing double-refractory ore, is expected to have a 250-300 Ktpa concentrate capacity after it comes online in 2023.

The company has said that its POX-2 process differs from its POX-1 facility as it will operate at twice the pressure, and 40 Celsius higher temperature.

This requires the use of a larger and more advanced autoclave that is lined with titanium rather than brick.

Total capital costs for the POX-2 project in 2019-2021 are estimated at US$431 million.