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Seventh International Conference & Exhibition on Mass Mining – MassMin 2016 Paper Number: 109

Deep Mill Level Zone, PT Freeport Indonesia – From Feasibility to Production

T Casten1, A Priatna2, H Rumbino4

1. Director – Underground Planning Freeport-McMoRan Inc. 2. Manager – DMLZ Engineering PT Freeport Indonesia 3. Vice President – DOZ and DMLZ Production PT Freeport Indonesia

ABSTRACT This paper discusses the progress of the Deep Mill Level Zone (DMLZ) mine from the pre-feasibility study completed in 2005, through commencement of development access in 2008, completion of the feasibility in 2010 and cave initiation in late 2015. This fourth lift of caving in the East Ertsberg Skarn System (EESS) is located 500 m below the currently producing Deep Ore Zone mine and represents approximately half a billion tonnes of ore and around 1,900 planned drawpoints, scheduled to be mined at a peak of 80,000 tpd.

The paper reviews the mine design, access requirements, the planned footprint sequence and major fixed-facility installations such as ventilation, oreflow and shops. A discussion of the pre-production development and construction activities and some of the critical technical challenges overcome during this time frame are addressed as well as the cave initiation process undertaken in late 2015 and the ramp-up of production and progression of caving.