The plant in Vietnam's Lam Dong province was originally expected to start up in February 2011.
While Marubeni of Japan has agreed to take 150kt of production, the remainder is likely to supply companies operating in China, Malaysia and the Middle East.
Trial runs are expected to last for three months with commercial production beginning in March 2013.
While alumina trades in 25 to 35kt lots, output from Lam Dong will initially be 15kt as shipments from the Go Dau river port are restricted to that amount.
It is likely that the plant will be operating at 50% capacity by late March.
