Tag Archives: Grasberg

PT Freeport Indonesia, Redpath achieve drawbell milestone at Grasberg Block Cave

Freeport Indonesia’s (PTFI) Grasberg Block Cave (GBC) operations in Indonesia, together with strong Redpath support, have successfully attained the milestone of constructing and blasting the 300th drawbell.

The milestone, which occurred on June 30, 2021, came in a record time of only 2.5 years from the production start date, according to Redpath.

The same production crews also surpassed the 100,000 t/d mark, by reaching a record of 107,000 t/d on June 26, 2021. This record surpassed the previous site record of 101,000 t/d.

In Redpath’s Advance magazine, I Made Pasek, General Superintendent, GBC Operations, said COVID-19 had not prevented the GBC project from becoming the world’s largest block cave mine.

“In addition to delivering safe and effective development meters, the GBC1 development team has reached the significant milestone of completing the excavation of the GVD 9 Fan Chamber (Grasberg Ventilation Decline), the fifth such chamber of the GBC ventilation system,” Pasek said when reviewing progress during the June quarter. Each of these chambers is equipped with a 5,500 kW fan able to produce 1.7 million cu.ft (48,139 cu.m) of air per minute.

The underground production levels of the GBC mine requires not two, but three crusher chambers to be excavated and constructed to deliver the targeted quantity of 160,000 t/d of ore. PT Redpath Indonesia’s GBC 2 crew are leading with the development of the #603 crusher chamber while concurrently initiating access to the #604 conveyor drives, according to Pasek.

GBC’s construction, MRC and MCM teams were challenged with the realignment of a key section of rail installation for the #602 unloading arrival station during the June quarter. This particular section of rail needed to be disassembled and raised in order to enable ore trains of 11 rail cars to enter the #602 unloading station as per design.

“Working seamlessly with the client’s engineering, planning and rail teams, the undertaking was safely and effectively accomplished ahead of schedule,” Pasek said. “The work itself consisted of drilling 1,000-plus holes for track support, epoxying track bolts into the existing concrete base, followed by meticulous forming works under each track base plate. The work required a high level of accuracy with tight tolerances to ensure rail alignment and smooth travel, in order to meet the established productivity rates.”

Pasek added: “These significant achievements would not be possible without a strong and deeply rooted safety culture in the GBC operations, paving the way for even greater successes in the future.”

Rio Tinto to net $3.5 billion for Grasberg stake

Rio Tinto has agreed to sell its interest in the prolific Grasberg copper-gold mine in Indonesia for $3.5 billion, with state-owned mining company PT Indonesia Asahan Aluminium the buyer.

The non-binding agreement between Rio, Inalum and majority owner Freeport McMoRan will see Inalum pay $3.5 billion for Rio’s right to 40% of production from Grasberg above a pre-agreed level. In 2017, with Grasberg producing 468,000 tonnes of copper, Rio’s share amounted to 5,700 t.

Post 2022, the agreement would have seen 40% of “all production” go to Rio, according to the company.

Separately, the agreement between the three companies sets out a long-awaited proposed transaction between Freeport and Inalum for the latter to buy an additional stake in Grasberg as well as additional terms relating to the future ownership and operation of the mine in Papua province. Many of those details have yet to be disclosed.

“All parties have committed to work towards agreeing and signing binding agreements before the end of the second half of 2018,” Rio said.

The deal is part of the government of Indonesia’s attempts to control a bigger portion of its mineral resources, with Freeport being the jewel in its crown. In recent years, it has installed raw material export bans and encouraged foreign operators to set up in-country processing facilities in attempts to retain more of its mineral wealth.

Until the deal is done, Grasberg is majority owned by Freeport, which holds a 90.64% interest, and the government of Indonesia, which owns the remaining 9.36%. Bloomberg reports that Freeport will pocket $350 million as part of a deal to cede majority ownership of the mine to Inalum.