(July 30, 2021) PT Freeport Indonesia recently ushered in the next level of production at its world-class Grasberg Block Cave mine with a second underground crushing system that will double the mine’s previous capacity.
“Crusher 602 is an incredible milestone for the ramp-up of GBC, which will be our main producer for years to come,” said Mark Johnson, Director, Executive Vice President and Chief Operating Officer-PTFI. “This crusher is a big part of the future for PTFI and Freeport-McMoRan.”
The combined pair of crushers and conveyor systems now give GBC the ore flow capability to process 130,000 tons of ore per day, as the mine continues to achieve its planned production ramp-up.
“Congratulations to all who have supported this. I am very proud of our achievements today,” Carl Tauran, Executive Vice President-Site Operations and Technical Mine Manager, told the crowd who cheered the successful startup during the May 15 ceremony, pictured, held nearly 1,000 meters underground. “This is a very important project to PTFI, so it is worth celebrating safe work that was completed despite significant challenges.”
Four massive jobs in one
As they did with older twin 601, PTFI built the 602 crusher in four major segments:
- Unloading Station where GBC’s autonomous 11-car train delivers ore
- Apron Feeder that guides the fallen ore into the crusher
- Gyratory Crusher that crushes the rock into mill-pleasing size
- Conveyor that delivers the crushed ore to the mill
All four phases of construction were finished amid the challenges and obstacles wrought by the pandemic, including delays in shipping due to the sheer size of the components that make up the massive system.
“Much of this work was done under the very difficult COVID-19 conditions, so every part of the process was complicated. Despite that, this job was done without a lost-time injury,” said Ulya Hidayat, Vice President-Central Services. “The thing that actually kept us from finishing was waiting for the right shipments to come in, so getting this done only a couple weeks later than we originally planned is a considerable success.”
The project that has been in the GBC mine plan since 2008 cost about $104.4 million and took two years to excavate and construct.
“After all the work that went into it and all those years of development, today is the day that we start producing from it,” Johnson told the crowd at the startup ceremony. “From here on out, we’re focused on safe production and the ongoing development of our underground infrastructure over the next 20 years.”
One, two, three
A third crusher will come online as GBC really starts to flex its muscles as one of the world’s largest underground copper mines, but PTFI will not simply be copycatting to build crusher 603. The third crusher will have additional capability to deal with the potential of wet muck.
“This crusher will have a circuit to handle dry ore like the other two, but there will be a screen at the beginning to separate the dry and large ore from the wet ore, so the dry ore will go the existing way, but the wet muck will drop into a separate circuit to a slurry tank that will be pumped directly to the milling circuit,” Hidayat said.
The dry side of Crusher 603 is slated to start chomping in September 2023. Hidayat and his team should have contractors putting the final additions on the wet circuit by then.
“We’ll be ready with the wet side when the conditions make it efficient to have it operating as the mine matures,” Hidayat said. “At PTFI, wet muck is something we plan and prepare for to safely operate, which is why we also have remote mine operators and automated trains.”