The problem was particularly bad where the coal dropped from the crusher to the underground bin.

At full production Mandalong turns out 5.5 million tonnes per annum of coal so it was a problem that had to be sorted out.

Tecpro Australia managing director Graeme Cooper said Centennial tried a number of approaches to do away with its dust – all to no avail.

“When these didn’t prove as effective as they wanted they contacted Dr Ting Ren from the University of Wollongong for advice,” he said.

Ren and his team conducted computational fluid dynamics modelling to identify the source and direction of the airflow that was carrying the dust.

He also suggested Centennial contact Cooper.

“In partnership with Ben Cruickshank from Centennial Coal’s engineering team and Ren we discussed the best approach to suppressing dust in the vicinity,” Cooper said.

On the back of these discussions Tecpro designed a dust suppression solution.

“With the information we had from the CFD modelling we developed detailed drawings indicating the best positioning of hose and droppers to combat the dust,” Cooper said.

From this they could choose the appropriate spray nozzles.

“Our system works by directing a fine curtain of water droplets inward from the rim towards the crusher in the centre and has the effect of containing and suppressing the dust being generated,” Cooper said.

“Aided by gravity the dust particles fall into the bin instead of remaining airborne.”

After the system was installed Coal Services Health measured its impact. At the time of testing only half the nozzles were in operation yet dust emissions were reduced 68%.

“We are confident that now all the nozzles are operating the dust suppression system will be reducing the dust by more than 90 per cent,” Cooper said.