The court ordered a retrial after upholding the department's appeal, with HWE charged with failing to provide a safe working environment.

Charges were brought against the company after an investigation into the HWE apprentice's death at BHP Billiton's Yandi iron ore mine.

Sargeant was driving a light vehicle onsite when it collided with a haul truck at around 3.30pm on September 4, 2008.

He was recovered from the vehicle but later died as a result of his injuries.

Part of the DMP's case alleges that visibility at the intersection where the vehicles collided was obstructed and the appropriate stop signs and warnings were also not in place.

State mining engineer Simon Ridge said there were no winners from such a tragedy but it was important to pursue action if the evidence suggested companies had breached their obligation to keep workers safe.

"As a department, this is what we do and will continue to do," he said.

The DMP is also pursuing a prosecution against BHP Billiton relating to the same incident, which is yet to be heard by the Magistrate's Court.

The department said it was conducting three prosecutions and a further 11 were pending.

The case is not the only investigation into BHP and HWE, with both companies last year fined $A238,000 over the death of Paul Sparkes, which also occurred in 2008 at Yandi.

Sparkes, a maintenance supervisor, was fatally struck after the arm of a tyre handler device sprung off as a heavy earthmover tyre was overinflated.