Mill Optimization for Underground Ores

Client: PT Freeport Indonesia

Location: Papua, Indonesia

Business Segment: Urban Solutions

Industry: Mining & Metals

Services: Construction

Map showing the location of Mill Optimization for Underground Ores

Executive Summary

PT Freeport Indonesia (PTFI) selected the Fluor-led joint venture Fluor Petrosea Joint Organisation (FPJO) to install a new grinding mill at its Grasberg copper and gold mining district. The minerals district is located in the remote highlands of the Sudirman Mountain Range in the province of Papua, Indonesia.

Client's Challenge

PTFI was in the process of transitioning from primarily an open pit operation to an underground operation through its development of the Deep Mill Level Zone (DMLZ) and Block Cave (GBC) underground deposits. This underground development had been ongoing for the previous 10 years. While similar in characteristics, the underground ore required that certain modifications be made to the company's infrastructure.

Fluor's Solution

FPJO constructed a third semi-autogenous grinding (SAG) mill adjacent to the existing milling facilities as the mining district continued to ramp up underground production primarily from the DMLZ and GBC mines, following completion of mining in the open pit in 2019.

The design capacity of the third mill was 75,000 tonnes per day (tpd). With the additional SAG mill, the site's total milling capacity was expected to reach approximately 240,000 tpd.

Fluor's Perth, Australia, office led the project with support from our offices in Jakarta, Vancouver, Manila and Johannesburg.

Conclusion

The project was expected to deliver a copper concentrate capacity of 3 million dry metric tons per annum on a sustained basis for the Grasberg mine facility in Papua, Indonesia.