Unravelling the mystery of coal bursts

Professor Ismet Canbulat brings his wealth of experience to bear on the phenomenon of coal bursts in Australian mines.

“My passion in the mining industry is safety,” says Professor Ismet Canbulat. “It is the driving force behind everything I do.” Professor Ismet Canbulat

Canbulat, who is the Kenneth Finlay Chair of Rock Mechanics at UNSW Mineral Energy Resources Engineering (MERE), brings strong industry expertise to his research having worked in consultancy and production in a number of countries. “I’ve consulted or worked for over 60 mines, from 3.5 kilometres deep to very shallow open-cut mines for coal, gold and platinum,” he says.

For the last 10 years, Canbulat has focused on safety in coal mines and has been heavily involved in ACARP, the Australian Coal Association Research Program that operates under a levy imposed on coal mining. ACARP was initiated in the early 1990s to research and implement health, safety and productivity initiatives at coal mines.

“ACARP is one of the best models in the world for translating research into practice and I worked there for about six years sitting on various committees responsible for distributing the $18 million average annual funding to researchers, consulting companies, mining companies and government agencies,” he continues.

Canbulat joined UNSW in 2014 and since then has been successful in applying for funding, including from ACARP. He is currently working on several open cut and underground mining safety research projects in collaboration with the University of Queensland, CSIRO and others.

One of these projects – the findings of which are currently being tested and verified – addresses a serious problem affecting the coal mining industry which has hitherto been a dangerous mystery: coal bursts.

Coal bursts pose one of the biggest safety and productivity risks in the mining industry and have the potential to cause multiple fatalities.

Professor Ismet Canbulat, the Kenneth Finlay Chair of Rock Mechanics at UNSW Mineral Energy Resources Engineering


“Coal bursts pose one of the biggest safety and productivity risks in the mining industry and have the potential to cause multiple fatalities,” he says. “A coal burst is an uncontrolled, violent, sudden failure of rock mass around an excavation site. It happens when the rock gets highly stressed, and due to that stress and other contributing factors it shatters into small pieces,” he says.

Canbulat says an analogy for thinking about the different types of energy build-up and release in a coal burst would be to imagine squeezing a spring between your fingers, then hitting your fingers while someone else flicks the spring. “Under all these stresses, the spring will eventually ping out of your fingers and it is the same with a coal burst. Once these energies reach a critical mass, they trigger a coal burst,” he says.

According to Canbulat, the size of a coal burst can be anything from 20 kilograms to 50 tonnes of rock mass ejecting at a speed of 5 to 50 kilometres an hour or greater. “Currently there is no one set of defining characteristics responsible for this phenomenon. The objective of this project, therefore, is threefold: we need to determine the energy source and magnitude required to initiate a coal burst; we need to assess the energy release mechanisms; and then we need to assess the risk factors,” he continues.

This first study dovetails perfectly with the next project Canbulat and his team have won ACARP funding for. Due to start in July 2018, they will be drawing on their previous research to improve ground support requirements in coal burst prone mines.

“Now we have a better understanding of the energy levels we’re dealing with, we can think about designing appropriate barriers on mining equipment that can absorb the energy of a coal burst, or we can install ground support systems that hold the ground together in the event of a violet failure,” he says.

Canbulat explains that by the end of this project, due to be completed in 2019, they will be able to identify the critical characteristics and considerations for ground support systems in coal burst prone areas.

“The outcome of this project will be a practical tool for coal mining operators to be able to assess the effective ground support techniques for coal burst control in Australian mining conditions,” he says.

“With its focus on coal burst mitigation and control, it will also provide a link to the broader ACARP coal burst research strategy and make our coal mining operations safer.”

UNSW would like to acknowledge the contributions of ACARP for their significant contribution to these research projects.

 

Written by: Penny Jones

 

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