Gold mine says Pike River-type explosion not possible

The entrance of the Newmont Waihi Gold company's underground Favona Mine at Waihi. Photo / Richard Robinson

The country's largest gold miner has reassured workers and their families an explosion similar to the one which killed 29 men in the Pike River coal mine on the West Coast last month could not happen at its mines.

The 16 miners and 13 contractors died when a methane gas blast ripped through the mine on November 19. Their bodies have yet to be recovered because authorities say it is still too dangerous to go into the mine.

Newmont Waihi Gold owns the Martha's Pit open cast gold mine and the Favona underground gold mine in the Bay of Plenty town of Waihi and said since West Coast tragedy, questions had been asked about whether a similar tragedy could happen in Waihi.

"We can reassure that the short answer is no," said the company in a newsletter.

"The type of incident that happened at Pike River would not occur in a gold mine."

It said coal was a source of energy so was combustible but gold was inert and could not combust.

Coal could also emit methane and other flammable gases but no methane had been detected at Favona.

Dust from coal under some conditions could spontaneously explode and also could amplify an explosion but dust from Favona ore and waste rock would not spontaneously explode under any conditions.

The company said the Favona underground mine also had three refuge chambers for emergencies.

Each of the chambers could provide up to 20 men with enough oxygen and basic requirements for at least 36 hours. Two more smaller chambers were to be installed soon, said the company.

Refuge chambers were in active work areas to limit travel distances to no more than 750 metres.

At any one time there were no more than 40 men underground and the Favona mine had several escape routes with ladders from the bottom of the mine to the surface.

Newmont Waihi Gold's general manager Glen Grindlay, who had worked in coal and gold mines, said mining was "not dangerous, but certainly unforgiving".

- NZPA