Can coal dust be quashed?

The Australian coal mining industry is demanding change.

A string of recent cases of Coal Workers’ Pneumoconiosis, a.k.a. Black Lung, has ignited an inquiry into how Australia, and its individual states, deal with coal dust exposure, its control measures, and screening standards.

According to University of Tasmania associate professor Graeme Zosky, from the School of Medicine in the Faculty of Health, while many people considered this a disease of the past, these new cases in Queensland show more needs to be done to eliminate CWP, which was responsible for 25,000 deaths globally as recently as 2013.

State-run mines in China report Black Lung afflicts between four and 17 per cent of workers; in Colombia, a growing coal producer, 36 per cent of miners were recently found to have Black Lung; and in Australia, CFMEU health and safety advisor Jason Hill believes current evidence points to around 16 per cent of current and retired coal workers could suffer from CWP.

“Most cases of CWP occur in the setting of poor occupational hygiene and dust control,” Zosky said.

“Recent reports of CWP in Australia are highly concerning and point to a potential decline in exposure control in Australian mines.”

Even state to state standards differ; with Queensland’s maximum allowable dust exposure level for a single shift 3mg per cubic metre of air whilst in NSW, the allowable coal dust limit in a single shift is 2.5mg per cubic metre of air, yet in the US the national standard is 1.5mg of coal dust per cubic metre, only highlighting Australia’s uneven safety standards.

A number of methods are being developed worldwide to combat exposure to respirable dust, relying not just on PPE, but dedicated dust removal systems.

At the University of Kentucky, two engineers have developed working models of longwall shearers featuring scrubber systems that can reduce operators’ exposure and cut the potential for Coal Workers’ Pneumoconiosis, however, these can only be fitted to new machines as they believe it would be impossible to retrofit it to existing shearers due to height restrictions and the impact on production.

However, an Australian team has done exactly this; not only creating a functioning longwall shearer scrubber that can be retrofitted to existing shearers, but also trialling it in live operations at BMA coal mines in Queensland and in New South Wales.

Particulate Matter Management’s Patrick Brady, and Dr. Brian Plush – who features heavily in the Senate report on Black Lung – have developed a scrubber that has demonstrated an ability to slash coal dust at the source.

“The US is saying it can’t be done,” Plush told Australian Mining, “we are saying it has been done.”

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A hinged design allows it to remain pointing at the cutting face

In fact trials, carried out with an independent third party and verified by SIMTARS, showed the technology “significantly reduces a workers’ exposure to respirable dust by up to 76 per cent and integration with other solutions [will see it] achieve up to 90 per cent reduction in dust levels,” Brady said.

The major innovation in this development is that it allows miners to control dust at its source, limiting workers’ exposure levels to respirable dust by using computational fluid dynamics to effectively draw the dust away from the longwall as it is cut, and using an innovative hinged mounting arrangement that allows it to remain centred on the cutting point and shift up and down as the shearer’s ranging arm moves.

Plush added that the system had immediate measureable and recordable effects on dust levels, stating that with less than two weeks of trials a New South Wales coal mine recorded a 70 per cent reduction in coal dust exposure from baseline levels, and within two weeks the site had a 14 per cent reduction in stone dust.

Crucially, the longwall attachment also is able to measure dust levels in real time, allowing the mine to directly address safety and issues revolving around potentially explosive coal dust.

The system also aids efficiency, as it lets workers see where they are shearing.

“This can aid in reducing the cost of coal,” Brady explained, “as it cuts coal dust so they can see the longwall to actually shear.”

“Operators could potentially get one to two extra shears per longwall per shift.”

It is also easy to install.

According to Brady, trials at the BMA and NSW coal mines have shown the system is able to be fully installed within a single maintenance shift, adding that it can be to retrofitted on a Bucyrus EL3000 and an Eickhoff SL100 within two hours.

Peabody added, “This longwall shearer scrubber technology can be adapted and used on any underground longwall mine in the world.”

As Plush stated in the very first line of the Senate’s Select Committee on Health’s Fifth interim report released earlier this year: “Black Lung in whatever form is totally preventable.”

This machine is aiding miners in achieving this goal.

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