The CCUT block cave design for Cullman Diamond Mine

摘要

Petra Diamonds' Cullman Diamond Mine (CDM) is currently producing from two mining blocks that are nearly depleted and highly diluted. CDM is developing the CCUT mining block as a mechanized block cave with an advance undercut that would replace the current mining blocks and increase production to approximately 4 Mt/a. The CCUT block production level on 839 m level is approximately 200 m below the current production areas on the 630 and 645 m levels.The planning of the CCUT block with a lift height of approximately 194 m at CDM under Petra's ownership commenced in 2008. The access declines to the block started in 2009 and 2010. Most of the shaft deepening and waste development have been completed, with the planned 'deep' shaft and ground-handling system planned for commissioning in June 2016. The first undercut ring was blasted in July 2015.This paper reports on the design process and evolution of the project, including: Geotechnical design criteriaAdvance undercutting sequence and strategy Undercut advance rates, slot designs, and rings designs to achieve the undercutting objectives (of high early tonnages and high undercut advance rates)The production level development philosophy in utilizing advance undercutting, production level design and drawbell opening sequence.