Alarms were raised at the Tiwai Point aluminium smelter on Thursday night after embers were seen coming from a chimney.
Fire and Emergency New Zealand (Fenz) shift manager Brent Dunn said two crews, from Kingston and Invercargill, were sent to the Southland-based plant about 9.30pm following reports of a fire understood to have started in the ducting system.
While Fenz crews were on standby, Tiwai’s industrial brigade moved quickly to put out the fire.
"The Tiwai brigade activated a deluge system which proved to be very successful," Mr Dunn said.
"Our crews were on standby to support them."
Deluge systems, which release water or other fire suppressants from all sprinkler heads simultaneously, are often used in high hazard areas such as power plants, aircraft hangars and chemical plants.
Initially, it was reported sparks had been seen coming from the carbon rodding at the smelter.
Rio Tinto director external relations Jennifer Nolan said the fire at the smelter was small.
"[It] was some soot that caught alight in our stack, as a result of an ember from the carbon bake venting."
The fire was brought under control "very quickly'', she said.
No injuries were reported.
