The proposed revised mine plan for Blakefield North includes an extension and re-orientation of some longwall blocks and main heading roadways beyond the conceptual mine plan footprint identified in its 2003 environmental impact study, but still within the currently approved development consent boundary.
The proposed changes to the mining layout and sequence are a result of improved understanding of the geology and geotechnical regime, the company said.
The reduction in the number of longwall panels will result from the panel extraction widths being extended from 265m to 400m, as approved in the 2003 EIS.
The 2003 EIS approved 12 longwall panels at widths of about 265m, with approval to extract at widths of up to 400m.
The conceptual mine plan shows all mining in the Blakefield Seam across all underground mining areas being completed by Year 22 (around 2025).
The conceptual mine plans were identified as being possibly subject to change, but subject to approval in terms of mining layout and mining sequence due to improved understanding of geology, advances in mining technology, and changes as a result of the review of impacts.
The revised longwall layout is directly beneath the already mined longwalls in the overlying Whybrow Seam.
Xstrata was granted development consent to mine “via underground methods” within the Whybrow, Blakefield, Glen Munro and Woodlands Hill seams for approximately 27 years.
The approved mine plan for the Blakefield North is via retreat longwall and continuous mining methods.
Mining of approved Blakefield North longwalls BB1-5 has already partially occurred as part of the open cut operations. The project will result in longwall mining commencing in approximately Year 14 (2017) with completion around Year 19 (2022).
The revised mine plan will not result in changes to the existing coal production rates for the Blakefield seam in the Blakefield North underground mine.
There will be no change to the approved annual ROM coal production rate for mine from the maximum of 14 million tonnes per annum. There will also be no change to the approved total coal mined at the mine.
