A safety alert issued by the Queensland Department of Mines and Energy has revealed the men were engulfed by a fireball after checking on a train load-out bin that had undergone three days of extensive welding activities.

It was established that welding slag or hot metal was dislodged from the inside of the bin and fell on coal dust, causing the dust to smoulder and create glowing embers that were igniting when the men opened the chute door.

In a bid to prevent similar accidents in the future the DME has ordered mines to make employees aware of potential dust explosion hazards, conduct a formal risk assessment prior to starting work on coal bins and conduct a thorough cleaning regime before any hot work is begun on the bins.

Furthermore, the environment of the bin should be monitored while work is being undertaken, chute doors must remain open while hot work and cleaning activities are being undertaken, the bin must be cleaned after the completion of hot work and a hazardous area study should be undertaken to ascertain the classification of areas where combustible dusts are, or may be, present.

The two workers - aged 50 - suffered serious burns to at least 10% of their bodies during the explosion at the Boundary Hill mine in Biloela on October 18.