de Beer, W, Jalbout, A, Riyanto, E, Ginting, R, Sullivan, M & Collins, DS 2017, 'The design, optimisation, and use of the seismic system at the deep and high-stress block cave Deep Mill Level Zone mine', in M Hudyma & Y Potvin (eds), UMT 2017: Proceedings of the First International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 233-245, https://doi.org/10.36487/ACG_rep/1710_18_Collins
(https://papers.acg.uwa.edu.au/p/1710_18_Collins/)
Abstract: The PT Freeport Indonesia Grasberg mine in Papua, Indonesia is composed of the Grasberg open pit and four underground mine operations. The Deep Mill Level Zone (DMLZ) is one of the currently active block cave underground operations. The DMLZ orebody presents a number of significant engineering challenges and technical risks when compared to other operating block caves. Due to its mining method and the depth of the operation (+1,500 m), mining-induced seismicity was identified as one of the key factors that will affect the rock mass stability. The seismic system is one of the main tools that is used to track and understand the rock mass response for this cave propagation.
This paper presents initial results from the DMLZ, and includes details about the rock properties, seismic system optimisation using blast data, and seismic analysis examples to help aid in the safety and productivity of the block cave operation.

Keywords: microseismic, monitoring, block caving, system, optimisation, seismicity