About a third usually goes to its domestic smelter at Gresik, with the rest exported as concentrate.

Alumina restarts in China are being absorbed by domestic smelter demand growth, but outside there it's a somewhat different picture.

Freeport has begun initial work on the construction of a domestic smelter and is looking at potential sites to build the $2.3 billion project.

In early August, the association said police carrying out an environmental crackdown in Bangka were hindering domestic smelters' supplies.

Chinese companies may start to look overseas more to feed domestic smelters, which supply the hub of the world's electronics industry.

Domestic smelter capacity is limited to Nexa Resources' Cajamarquilla plant, which produced 333,000 tonnes of refined metal in 2018.