Dust suppression in longwall mines has not been developed adequately to keep up with cutting technology says Alex McGaw, who first began working underground in Wales some 36 years ago.

McGaw is managing director of Engart Australasia, which is introducing its range of UK designed dust extractors into Australia, suitable for fitting to any type of continuous miner, roadheader or tunnel boring machine.

Two Engart extractors have recently been installed on Eimco continuous miners used for developing roadways at the Goonyella Exploration Adit and Moranbah North.

At Goonyella, where Allied is carrying out the development contract for BHP Coal, the Engart dust extractor is removing dust so efficiently that trickle dusters in returns have been turned off. McGaw said he believed this was the first time in Australia this had been the case.

McGaw said the US Mine Safety and Health Administration (MSHA) has expressed interest in the current range of dust extractors. Three such systems are destined for the US later this month. In Australia eight systems are currently on order or have been delivered and interest was growing, McGaw said.

Engart also offers a range of free-standing auxilliary ventilation fans/dust extractors which work something like a high capacity vacuum cleaner. Dust laden air is drawn into the fan, dust is collected and clean air discharged onto roadways.

"Our entire contention is that it is no longer necessary to introduce any dust into roadways. This means people can now work in returns with comfort."

McGaw says the introduction of ventilation systems that totally remove dust has numerous benefits including reduced costs and potentially less of a requirement to develop returns. But he does acknowledge the need for miners to change their thinking about dust management.

Engart's largest extractor fan has a 40,000 cubic feet per minute capacity and removes in excess of 99% of respirable dust.

In addition, the company is currently patenting the rights to the technology for a longwall face dust management system, which he believes could reduce current levels of shearer generated dust by over 60%.

While McGaw was reluctant to provide any further details at present while the patent process is ongoing, the technique may utilise a variation of the venturi effect currently used in some American mines including Twentymile.

"The system has been designed for thick seam, rapidly retreating longwall faces which generate a lot of dust," McGaw said.

The MSHA has also expressed interest in this latter system. If proven viable it will be manufactured in Australia.