According to India’s Economic Times, company officials believe Australia’s assistance can help yield 70% additional coal from its closed, existing and future underground mines.

The state-run coal producer has used bord and pillar mining at about 230 mines – a method that leaves coal behind in the form of pillars for roof support.

“About 40 million tonnes of coal per mine is locked in the pillars at the moment,” a company official told the newspaper.

“We are interested in the technology that will help us extract coal that otherwise is left untapped.”

The new technologies under consideration included a technique that used flyash to fill in the gaps left by the mined-out pillars.