How Do We Operate

PT Freeport Indonesia (PTFI) currently employs two mining methods, the open-pit mining method in Grasberg, and underground mining in Deep Ore Zone (DOZ). Ore extracted from the mine is hauled to the mill to be crushed and ground into very fine particles. This is followed by a flotation process using a reagent based on alcohol and lime to separate concentrate containing copper, gold and silver minerals. The residue with no economic value (tailings) is channeled by means of a river to a deposition area in the lowlands.

Concentrate in the form of slurry is channeled from the mill by means of a 110 km long pipeline to a dewatering plant in Amamapare port. After it is dewatered, the concentrate, which is PTFI’s final product, is shipped to smelters in the country and abroad.

Mining and processing operations

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Mining:  includes drilling and blasting, loading and hauling ore, and crushing to produce copper ore.

Processing: includes grinding, flotation, and dewatering to produce copper concentrate, which buyers pay for the copper, gold, and silver content.  

Copper concentrate is PTFI’s final product, with value added 95%.  

Refining operations in Gresik – East Java
  • Refining includes smelting and refining to produce copper cathode
  • Refining is carried out by PT Smelting, Gresik, which was established in 1997 and is jointly operated by PTFI & Mitsubishi.
  • At this time, PT Smelting is the first and only copper smelter in Indonesia
  • The smelter takes in 40-50% of PTFI’s output
  • In support of the industry downstreaming policy, PTFI is expanding or building an additional smelter on a site adjacent to PT Smelting

  Refining operations in Gresik – East Java