The smelter, at Tiwai Point, also celebrated its 40th anniversary last month and is also on target for a record year of production of more than 354kt.
General manager Ryan Cavanagh said the high level of production was because of continual improvements to the smelter's equipment.
However, the price of aluminium had dropped by about 20 to 25 per cent in the past six months, from about US$2700 a tonne (NZ$3536) to about US$2100 (NZ$2750), he said.
The smelter's aluminium was used for a range of products, including in 60% of the world's computer memory disks and 40%t of the world's capacitors, which are used in cellphone batteries.
Source The Southland Times, New Zealand