The mine, behind schedule ever since it began producing in May 2014, has been affected by a series of technical problems in its ramp-up phase, costing its owners hefty impairment charges.
The writedowns are said to stem from Adani being forced to duplicate studies and redesign elements of the Carmichael project due to delays in regulatory approvals and ongoing legal challenges.
Decision follow relentless protests in a town near the mine, where locals accuse the company of polluting their source water and the air, causing humans and animals respiratory illnesses, miscarriages, birth defects and disabilities.
Alcoa and Rio Tinto announced the launching of Elysis, a joint venture company whose goal is to push towards commercial production a newly discovered, carbon-free aluminum smelting process.