Xstrata said it also wanted to develop the ongoing underground operations with a focus on maximising resource recovery within the Liddell seam and improving the efficiency of coal recovery.

It is seeking an increase to the approved life of mine to facilitate the complete extraction of the Liddell seam by just over six years from the April 18, 2018 to July 31, 2024.

“To improve mine progression and maximise the efficiency of resource recovery, an opportunity to refine the currently approved mine plan for extraction within the Liddell seam at Ravensworth underground mine has been identified,” the company said.

“The Liddell seam project does not involve any change to the currently approved project site boundary, hours of operation, coal production rate, methods of coal extraction, handling and processing, coal transport, site servicing or waste management.”

Xstrata is proposing a modification to the currently approved mine plan for coal extraction within the Liddell seam, comprising changes to the width, orientation and location of the longwall panels, in order to maximise the efficiency of coal recovery and allow for improved mine progression.

The company is proposing the installation of additional goaf wells to facilitate improved gas drainage and management. While these wells may initially be fitted with free-vent stacks for a period of approximately six months, it is likely that they will be flared from commissioning.

It is also seeking to install a small bleeder ventilation shaft at the western end of every one to two longwall panels in the Pikes Gully Seam to provide intake air and enable sealing of the bleeder roadway.

These shafts will be “intake” shafts requiring no fan infrastructure.

Xstrata would need additional employees to cover current operations and the Liddell seam project for services, development and production. Re-development and upgrade of the Ravensworth office facilities and pit-top area within the current disturbed area would be necessary.

Installation and operation of ventilation fans at shaft No. 4 with an overall greater capacity than those previously approved would be required. The proposed configuration comprises three fans with a combined capacity of 550 cubic metres per second.

The installation and operation of an air compressor house at ventilation shaft No. 4 surface facilities to power pneumatic tools and equipment in the underground mine workings and the installation and operation of a borehole at ventilation shaft No. 4 surface facilities to be used for the delivery of stone dust to the underground workings, together with an associated bulk stone dust storage tank, would also be needed.

There is also the possibility of water sharing strategies with Macquarie Generation on an opportunistic or mutual beneficial basis via pipelines from Mac Gen’s open cut voids to Ravensworth infrastructure.