After the upgrade the plant will be capable of a throughput of 67,000 tonnes per annum (previously 42,000t) and WMC says it may consider increasing the capacity further to 70,000tpa.
The plant is on track to reach full capacity by mid-July 2001.
WMC's output has risen 35% in the past four years from 46,000 to 61,000tpa at a capital cost of US$0.20 per annual/lb.
"This is easily the cheapest expansion of its kind in the world," WMC executive general manager nickel, Peter Johnston, said.
"WMC's integrated nickel business is now the most profitable in the world."
He said costs had been kept low through increased process intensity, process control and improvements and targeted capital de-bottlenecking.
WMC's posted a half-year operating profit of $435.5 million before currency and commodity hedging.
