Document Type
Conference Paper
Publication Date
2-2016
Abstract
Historically, the Crinum mine has experienced significant falls of ground when longwall production slowed down in preparation for recovery in weak roof areas. These conditions continue through the recovery process and result in both safety concerns and delays. When mine plans and exploration revealed that most of the future longwall recoveries were located in weak roof areas, a decision was made to try pre driven recovery roads as a solution to the problem. After completing eight pre-driven recovery roads with varying degrees of success and numerous lessons, Crinum North Mine now utilises a modified Pre-driven Recovery Roadway (PDRR) to improve the longwall take off process in weak roof areas. During mine development a standard roadway is driven where the final recovery location of each longwall is planned. After the installation of secondary support, the PDRR is backfilled with a cement-flyash mix to provide support to the roof, and confinement to the ribs and floor of the roadway. The method has been refined over the last four years to provide greater strata stability and improved operational and safety performance compared with conventional takeoffs at Crinum, and has resulted in a site record of longwall relocation in 11.5 days (pull mesh to picks in coal). This paper describes the evolution of the PDRRs from Crinum East to Crinum North including lesseons from initial attempts and changes to; the secondary support regime, the operational approach during the final stages of retreat, the backfill strategy and also describes plans for the future.
Publication Details
Yass-Marie Rutty, Dan Payne and Adam Mackenzie, The Evolution of Pre-driven Recovery Roadways at Crinum Mine, in Naj Aziz and Bob Kininmonth (eds.), Proceedings of the 16th Coal Operators' Conference, Mining Engineering, University of Wollongong, 10-12 February 2016, 177-189.