how is ore extracted at grasberg mine

The Grasberg Mine, located in Papua, Indonesia, is one of the world's largest copper and gold mines. Operated by PT Freeport Indonesia, the mine employs both open-pit and underground mining methods to extract its rich ore deposits.

Open-Pit Mining
The initial phase of extraction at Grasberg involved open-pit mining, which began in 1990. Massive trucks and shovels were used to remove overburden—the layers of rock and soil covering the ore body. Once exposed, the ore was drilled, blasted, and hauled to processing facilities. The open-pit operation reached depths of over 400 meters before transitioning to underground mining as the pit became too deep to operate economically.

Underground Block Caving
As the open-pit reserves dwindled, Freeport shifted focus to underground mining techniques, primarily block caving. This method involves undercutting the ore body to create controlled collapses, allowing broken ore to fall into tunnels below for collection. The Deep Ore Zone (DOZ) and Grasberg Block Cave are key underground operations that utilize advanced technology like automated loaders and conveyor systems for efficient extraction.

Ore Processing
Extracted ore undergoes crushing and grinding before being processed via flotation to separate copper and gold concentrates. These concentrates are then transported via pipeline to a port for shipment to smelters worldwide.

Due to its remote location at high altitude, logistics remain challenging, requiring extensive infrastructure including roads, pipelines, and an airport. Environmental concerns and community relations also play significant roles in ongoing operations at Grasberg Mine.