Published in March 2009 Australian Longwall Magazine

Airo-Dust Additive was developed by Queensland-based Mining Attachments and Applied Manufacture under an Australian Coal Association Research Program grant. The project was initiated in response to research which showed stone dust slurry could actually be ineffective in preventing the propagation of a coal dust explosion due to caking.

Under the project, Mining Attachments and Applied Manufacture developed a “crystal inhibitor” additive. This is added to stone dust slurry mix to stop caking and, in turn, allows the stone dust to make a mine’s atmosphere inert during an explosion.

Initial trials of the additive and Mining Attachments’ dispensing equipment, a modified wet dusting unit, were held at Caledon Resources’ Cook Colliery in Queensland.

Mining Attachments managing director Matt Ryan then took the technology over to CSIR Miningtek’s Kloppersbos testing facility in South Africa. There the company set off 17 methane explosions to test the suppression effectiveness of the new product.

Samples of Airo-Dust and normal dry stone dust were sprayed into trays and left to dry naturally for three days. The samples were then placed side by side in CSIR’s 200m explosion tunnel and blasted at the same time with methane levels of 7.5-9.0%.

The result was 40% more Airo-dust was lifted than dry dust.

“We went to South Africa hoping the two products would be similar, but 40 per cent is the best outcome we could have expected,” Ryan said.

The concept went commercial in January, with Applied Manufacture supplying the chemical and Mining Attachments supplying the Airo-Duster equipment. The trademarked Airo-Dust Additive and the underground process used to apply it have both been patented.

Ryan says he is getting an enquiry for information almost every day from operations in New South Wales and Queensland.

“Airo-Dust is not only a safety and productivity improvement, but it can also help mines cut costs,” Ryan said.

“Industry was going through a period of ‘get as much coal as you can’. Now it has turned around to ‘let’s get it out as cheap as we can’. Airo-Dust saves costs because it gives you a better lineal advance than stone dusting because you don’t get as much wastage.

“In conventional dry stone dusting it is sprayed onto the wall but a lot will fall onto the floor. Airo-Dust is strong enough to adhere to the roof and the walls, and when it dries it stays there.”

At time of writing, Mining Attachments had sold three Airo-Duster units and had two units out on hire. A unit is also bound for South Africa in May.