The proposed modification would integrate with future planned mining operations while allowing for continued efficiency in operations, the company said in its environmental assessment.
It would also integrate with the underground access for the proposed Blakefield North modification.
The company is currently reviewing submissions on the modifications after they were open for exhibtion during October.
“The proposed modification is aligned with the ‘Bulga Coal Optimisation project’ with proposed modified mining sequence integrating with the initial stages of the optimisation project, if approved,” Xstrata said.
Although production at the mine has remained within its approved limit of 12.2Mtpa, open cut operations will reach the approved western limit of coal extraction within the Bulga open cut pit earlier than previously planned, the company said.
The proposed modifications will involve extending the currently mined Bulga open cut pit to the west, to re-mine through the shallower Whybrow Pit, in an area that has been previously subject to open cut mining.
The modified sequence would be integrated into the currently approved optimisation plans and occur over about seven years.
The extension would require handling of an additional 10 million bank cubic metres of overburden to access the additional coal resource.
Approval is also being sought to allow additional overburden emplacement to the north of the existing Blakefield North dump area, within existing disturbed mining areas, to provide an improved final landform in this area.
These works will be under an agreement with Coal & Allied’s Mt Thorley Warkworth operation and include dumping of overburden along the common boundary between these operations.
Mining operations will occur within the currently approved disturbance footprint and the total ROM coal extracted under its existing mining permit will remain unchanged at 12.2Mtpa.
Mining operations will use the existing mining fleet and infrastructure. All approved operations outside of the proposed modified mining sequence would continue in accordance with existing approvals.