Mitsui has said it will trim its thermal coal assets in the long term but would continue to invest in coking coal - a key raw material for steel-making.
Glencore expected to achieve annual cash savings of more than $300 million in its coal business by the end of 2018, but now it expects savings of more than $450 million by year-end.
The project sits atop the Incahuasi Salar and it is located on the Chile/Argentina national border some 75 kilometres southeast from the Atacama Salar.