The Australian coal mining landscape is predominantly driven by surface or opencast mining with about 65% of coal production attributed to opencast mining methods. In Australia, brown coal is typically mined in the southern part, while black coal is mainly found in the basins of New South Wales and Queensland. Majority of surface mines are located in Queensland and New South Wales, but the discussion will evaluate coal mining and workplace health and safety in Australia as a whole. Generally speaking, surface coal mines are only economical when the coal seam is relatively close to the surface, and the recovery rate of coal is higher than underground methods. Overburden exposure and coal exploration are the two distinct stages for surface coal mining operations and coal dust generation can be traced back to use of machinery such as draglines, dredgers, dozers, trucks and shovel operations. In order to have a better appreciation for the need for workplace safety and health in Australian coal mining, it is key to have a good picture of the types of coal mines operating in Australian states. In Queensland there are 10 underground and 30 surface mines, New South Wales has 27 underground and 25 surface mines, Western Australia has 6 surface mines, Tasmania has 1 underground and 2 surface mines, Victoria has 1 underground mine and 7 surface mines and finally South Australia has one surface bringing the total of coal mines in Australia to 110. With such a coherent background to coal mining in Australia, the article will evaluate workplace health and safety from an Australian coal mining perspective, the respective legislative approaches and Global Road Technology’s innovative solutions for coal dust suppression.  

Not a new thing

Literature from the British Journal of Industrial Medicine dating back to 1939 shows a list of industrial diseases found in coal mine workers ranging from silicosis and coal mine workers pneumoconiosis. Fast-forward to the turn of the millennium, which has seen the rising trend in the occurrence of coal worker’s pneumoconiosis even in developed countries such as Australia where it was believed to have been eradicated. The past few years have been spent trying to understand why the sudden resurgence of coal mine workers pneumoconiosis happened more especially in an era where technology has advanced, and legislation has grown to be more stringent in additional to more functional health surveillance systems. The methods employed for coal dust suppression have traditionally included water which perhaps is the biggest drawback to the assumption of how effective water is for coal dust suppression but what then is the effective solution for effective coal dust suppression in times where coal mine workers health and safety is at stake. In Australia, it was suggested that that coal workers pneumoconiosis was absent for the last 30 years until more than 10 coal mine works were diagnosed with coal mine workers pneumoconiosis in 2016. The projections suggested that up to 1000 coal mine workers in Queensland could have coal mine workers pneumoconiosis among the 150,000 unprocessed x-rays. Studies went on to show that 7.3% of the sample of 248 coal miners in Australia had an early stage of coal mine workers pneumoconiosis. 

Are environmental regulations, health and safety concerns or potential profit loss a concern right now?

Underground mining

In Australia, 10% of coal mines exposed longwall operators to the coal dust level that equals to or was greater than the exposure limit in 2012 which was further increased to 60% in 2014. Surely the disconnect between innovative solutions to coal dust suppression and working within acceptable limits is imperative to eliminate health-related hazards associated with coal dust. Different studies have been performed on different coal dust suppression products and techniques which include ventilation dilution, water spray suspensions and stabilizing dust using the form. Water (needed for spark arrest anyway) has always been the main approach owing to its low cost and easy maintenance although other schools of thought suggest water as expensive. This is because in the long run, owing to the need for repetitive watering, unlike some solutions which cater for the chemistry of the coal surface, the porous nature of coal and its different coal rankings which overall affects the wettability of coal. Variables such as the concentration of surfactants, the temperature of surfactant in alternative solutions have also yielded better results. The focal point in most cases has been the dust suppression product which rather is counterproductive to a certain extent as coal is not the same across the spectra. In fact, the varieties of coal depend on the metamorphic stage at which the coal has developed to and much of the details pertaining to coal dust suppression depend solely on the material science behind coal itself which should first be understood before choice of coal dust suppressant. 

The last 5 years

Following the resurgence of coal mine workers pneumoconiosis in Queensland, the Queensland government introduced the Coal Mining Safety and Health Regulation 2017. The regulation which commenced in September 2017 applied to both surface mines and underground mines. Provision of the basic elements in a coal mine’s safety and health management system included risk identification and assessment, hazard analysis, hazard management and control and lastly reporting and recording relevant safety and health information and data. The specific requirements of workplace health and safety health assessments in the legislation include examination of coal mine workers respiratory function and chest x-ray examinations prior employment as a coal mine worker, for a coal mine worker who is aboveground at least once every 10 years and for a coal mine worker is or was an underground worker at least once every 5 years. The legislation extends its enforcement of accountability to retirement examinations which are supposed to happen during the 6 month period that begins 3 months before the person retires and at a time or times during that period when the person is available for examination. 

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Industry-leading solutions

Global Road Technology’s innovative dust control solutions actively solve the problems associated with free silica and coal dust. The coal mines’ safety and health management system is mandated to provide ways of ensuring each coal mine worker’s exposure to respirable dust at the mine is kept to an acceptable level and the worker does not breathe an atmosphere at the mine containing respirable dust exceeding an average concentration, calculated under AS 2985:2009 equivalent to the following 3 milligrams per cubic meter air for coal dust and 0.1 milligrams per cubic meter air for free silica. In addition, if a person works a shift of more than 8 hours at the coal mine, the system must provide ways of ensuring the person’s dosage of respirable dust is not more than the equivalent dosage for a person working an 8-hour shift. As we focus on practical solutions for coal dust suppression, Global Road Technology offers products GRT Activate UG and GRT Activate which can make water work. The choice of coal dust suppressant should factor in effects on coal calorific values, the percentage used per ton and ability to super-activate water. Scenarios differ and GRT products are tailor-made to best suit any coal dust suppression needs to the satisfaction of the client. Generally, non-ionic surfactants are considered to be the ideal coal dust suppressants owing to the highest efficiency in coal wettability although cationic surfactants can outperform both non-ionic and anionic surfactants in some instances. Therefore, to achieve workplace safety and health standards and compliance for both surface and underground coal mines we strongly recommend GRT engineered coal dust surfactant technologies to cater to all the needs of coal dust control. 

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REFERENCES 

Chang et al. 2020. Evaluation of the coal dust suppression efficiency of different surfactants: A factorial experiment. Colloids and Surfaces A. 595. 124686. 

Fisher, S.W. 1944. Health Hazards of Coal Mining. Br J Ind Med. 1. 

Queensland Government. 2017. Coal Mining Safety and Health Regulation 2017. 

Scott, B., Ranjith, P.G., Choi, S.K., and Khandelwal, M. 2010. A Review on Existing Opencast Coal Mining Methods Within Australia. Journal of Mining Science. 46:3. 

Xu et al. 2018. Surfactant aided coal dust suppression: A review of evaluation methods and influencing factors. Science of the Total Environment. 639.