After being closed since July 1999, mining operations finally resumed in March at the Oaky North mine in central Queensland.
The longwall was buried for nearly eight months after the roof started to collapse and floor conditions deteriorated. In a recovery operation believed to a be a world first, MIM Holdings used a dragline to dig out buried longwall equipment from the surface. The decision was made because it was deemed safer and gave greater certainty in timing.
All equipment has been removed, refurbished and taken back underground through existing roadways. Mining has now resumed further into the block where the monocline structure that caused the initial problem does not exist.
The final cost of the recovery process has been estimated at $13.4 million, which was slightly higher than the $10 million estimate made when the half-year results were released. However, the operation took about a week less than anticipated which meant the revenue stream was resumed earlier. For the period between March 10 and 22, the company reported achieving 87m of longwall retreat.
The Oaky Creek complex, which includes Oaky North, Oaky No.1 and the Alliance mine, generates about 6-7 million tonnes of high-quality coking coal per annum. It is 75%-owned by MIM which also manages the mine. Sumitomo (15%) and Itochu (10%) own the remaining equity.
Supply continuity to customers was maintained during the period Oaky North was closed by using existing stockpiles and ramping up production from other mines at the Oaky Creek complex.
Meanwhile, Oaky No.1 is undergoing a panel change which is expected to be completed early in April. Equipment undergoing a 2Mt overhaul are the shearer, both AFC drives and the bootend crusher BSL.
MIM mine management typically overviews panel moves but uses supplementary labour to assist with the process. Mackay-based REB Engineering is assisting with the current Oaky No.1 move.