Implementation of major mining strategy changes at the Deep Mill Level Zone (DMLZ) mine, PT Freeport Indonesia

Authors: Lolon, S; Campbell, R; Edgar, I; Priatna, A; Haque, I Download Paper

Cite As:
Lolon, S, Campbell, R, Edgar, I, Priatna, A & Haque, I 2024, 'Implementation of major mining strategy changes at the Deep Mill Level Zone (DMLZ) mine, PT Freeport Indonesia ', in Daniel Johansson & Håkan Schunnesson (eds), MassMin 2024: Proceedings of the International Conference & Exhibition on Mass Mining, Luleå University of Technology, Luleå, pp. 73-85.



Abstract:
The Deep Mill Level Zone (DMLZ) is one of the underground mines operated by PT Freeport Indonesia (PTFI), located approximately 1,500m below ground level and consists of multiple production blocks on the same extraction level. The DMLZ experienced significant seismic activity, and to mitigate the risk, Production Block (PB) 4 was elevated 225m above the current DMLZ footprint elevation. PB4 sits adjacent to the existing and future cave formed by the lower production blocks. The development of DMLZ PB4 mine started in late 2021 following conceptual and pre-feasibility level studies, and development continues concurrent with detailed engineering targeting undercutting start in early 2025. This paper presents the challenges encountered, evolution of the design and mining strategy of PB4 during the rapid development and engineering of this new block. Lessons learned and ongoing work related to project and change management, undercutting plan, development schedule, and overall mine design are discussed in the paper.