The owners of WA’s Ravensthorpe nickel mine have been fined for a high-risk accident two years ago.

The fine totals $40,000.

The Australian arm of Canada’s First Quantum Minerals entered an early guilty plea on charges of failing to provide a safe working environment after an acid tank ruptured in December 2014.

The breach sent around two million litres of sulphuric acid slurry flooding the site, trapping three workers in a control room before they were able to escape, luckily without injury.

The spill took out critical electrical equipment and left the entire site, 540 kilometres south-east of Perth, without power.

The mine was left closed for close to two months.

Department of Mines and Petroleum safety director Andrew Chaplyn said the company was aware of the risks.

“Its failure to carry out an effective maintenance program led to the catastrophic failure of this tank,” Mr Chaplyn said.

“The event had the potential to seriously injure or kill workers in the vicinity of the tank and was entirely preventable.”

First Quantum, which employs about 270 people at Ravensthorpe, is yet to comment.