The closure of Alcoa’s Kwinana alumina refinery is tipped to free up 5 per cent of Western Australia’s domestic gas consumption, but industry advocates say the company and other big consumers still hold major concerns about long-term domestic gas supply.

Alcoa announced on Tuesday that it would cease production of alumina at the 60-year-old facility, resulting in the loss of at least 750 jobs, citing costs, market conditions and bauxite grades.