JOHANNESBURG (miningweekly.com) – A new fully automated low-seam mining system, which unlocks resources too difficult to mine, is able to achieve high outputs of 10 000 t a day in seams as low as 1.3 m.
Joy Global VP products management underground mining Ben Snyman, who spoke to Mining Weekly Online on the sidelines of the Southern African Institute of Mining and Metallurgy symposium, said the first system would be operational in an underground mine by the end of this year.
Supervised from a remote operating centre, the automated longwall system cuts and supports the roof automatically, with sheared coal falling onto an armoured face conveyor system for transporting from the face.
In terms of process execution, the system mimics its high-seam counterparts, but with a number of novel designs and extensive automation to allow it to provide a step change in low-seam mining productivity. This allows low seams to be mined as efficiently as would be the case with the higher seam counterparts.
“It performs all the work while keeping people out of harm’s way,” said Snyman.
Its output of three-million tons a year is a considerable step up from current levels of conventional low-seam production.
“You’re talking improvement of anything from 20% to 80%, depending on the seam,” he added.
All the relevant systems data is transmitted to surface where advanced monitoring is performed to predict potential equipment failures, recommend process improvement opportunities as well as defining specific maintenance needs like replacing filters, re-filling oil etcetera.
“When that machine is operating, you don’t want to stop mid shift to perform any actions. It has to run continuously between maintenance interventions,” said Snyman.
With only 860 gigatons of the world’s 17 000 gigatons of coal resources being economically mineable, the system has the potential to convert vast volumes of resources into economically viable reserves.
South Africa and Africa have substantial volumes of low-seam coal and 20% of China’s coal resources have seam heights below 1.5 m.
In the main, seams with heights greater than 1.5 m are depleting and much of the low-seam coal remains unexploited, which creates considerable scope for the new system.