Tag Archives: PT-Freeport Indonesia

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.”

Metso Outotec to provide copper smelting engineering, tech to PT Freeport’s Manyar project

Metso Outotec has signed a major engineering and technology contract as well as licence agreements for the delivery of what it says is a landmark copper smelter complex to be built in Gresik, East Java, in Indonesia.

The project owner is PT Freeport Indonesia, with PT Chiyoda International Indonesia being the engineering, procurement and construction contractor. Four-fifths of the approximately €360 million ($424 million) contract has been booked in the company’s Metals’ September quarter order intake and the rest in Minerals’ September quarter order intake, it said.

Metso Outotec’s scope of delivery is based on the licensed Metso Outotec Flash Smelting, Flash Converting and Lurec® technology. It includes the design and supply of key process equipment and process control systems for the main areas of the smelter complex, the copper electrolytic refinery, the gas cleaning and sulphuric acid plant, the slag concentrator and the effluent treatment plant.

Metso Outotec has previously provided certain front-end engineering design and other advance engineering services for this 1.7 Mt/y copper concentrate smelter complex, which is expected to be commissioned in 2024. According to PT Freeport, the Manyar smelter will be the largest copper processing site in the world upon start up.

Pekka Vauramo, President & CEO, Metso Outotec, said: “Our joint efforts with Freeport Indonesia and Chiyoda will set a new standard for the copper smelter industry in fulfilling the strictest international environmental standards and efficiency requirements. We are very happy to work together to implement this game changing copper smelter.”

Jari Ålgars, President, Metals business area at Metso Outotec, added: “We have worked with Freeport Indonesia and Chiyoda for several years to ensure and select the best available process design and technologies for the Manyar project.”

Metso Outotec has delivered 51 Copper Flash Smelters around the world, with the company’s Copper Flash Smelting the most widely applied technology for copper smelting in the world, it said. The solution is also one of its Planet Positive solutions. Using this technology, Metso Outotec’s customers avoided more than 1.6 Mt of CO2 emissions in 2020, the company said.

PT-FI makes headway at Grasberg Block Cave underground copper-gold mine

Freeport McMoRan has confirmed that, during the second quarter of 2019, PT Freeport Indonesia (PT-FI) commenced extraction of ore from the Grasberg Block Cave underground mine, in Papua, Indonesia.

This is the same orebody historically mined from the surface in the open pit, Freeport noted.

Since its discovery in 1988, production from the Grasberg open pit has totalled approximately 27,000 MIb (12.25 Mt) of copper and 46 Moz of gold. Over its life, PT-FI expects to produce an additional 17,000 MIb of copper and 14 Moz of gold from the Grasberg Block Cave underground mine, making Grasberg one of the world’s largest copper and gold deposits.

In 2023, PT-FI expects to produce an average of 130,000 t/d of ore from five production blocks spanning 335,000 sq.m in the large-scale Grasberg Block Cave underground mine. At average reserve grades of 0.96% Cu and 0.72 g/t Au, this is expected to equate to production of 850 MIb of copper and 700,000 oz of gold per year.

During the June quarter, Freeport noted:

  • Undercutting in the Grasberg Block Cave underground mine exceeded 20,000 sq.m, over 20% above forecast. Inception to date, undercutting in the Grasberg Block Cave underground mine totals 48,000 sq.m;
  • Initiated drawbelling in two additional production blocks, bringing the active production blocks to three. Eighteen drawbells were opened, exceeding forecast. Open drawbells in inventory in the three active production blocks currently total 29;
  • Ore extraction ramped up from an average of 5,000 t/d in March quarter 2019 to an average of around 9,000 t/d in June 2019 and is expected to reach 15,000 t/d by the end of 2019, and;
  • The fully-autonomous, state-of-the-art underground rail system is supporting efficient transport of ore to the oreflow system for delivery to the mill processing facility.

Freeport said: “Monitoring data on cave propagation in the Grasberg Block Cave underground mine is providing increased confidence in growing production rates over time. As existing drawpoints mature and additional drawpoints are added, cave expansion is expected to accelerate production from an average of 30,000 t/d of ore per day in 2020 to 130,000 t/d in 2023.

The Deep Mill Level Zone (DMLZ) underground mine, located east of the Grasberg orebody and below the Deep Ore Zone (DOZ) underground mine, is expected to produce 8,000 MIb of copper and 8 Moz of gold over its life.

In 2022, PT-FI expects to produce from three production blocks in the DMLZ underground mine spanning 200,000 sq.m. At average reserve grades of 0.92% Cu and 0.76 g/t Au, 80,000 t/d of ore is expected to equate to production of 500 MIb/y of copper and 560,000 oz/y of gold.

During the quarter hydraulic fracturing operations at the DLMZ were ongoing and continue to be successful in conditioning the rock for large-scale mining, according to Freeport. Undercutting approached 4,000 sq.m, in-line with forecast (inception to date, undercutting totals 58,000 sq.m).

In June 2019, undercutting commenced on the second production block to establish two large production blocks in the DMLZ underground mine for ore extraction, while a total of four drawbells were opened, bringing total inventory of drawbells to 74.

Lastly at DMLZ, production ramped up from an average of 6,800 t/d of ore in the March quarter to an average of some 9,000 t/d in June. The DMLZ underground mine is expected to reach 11,000 t/d of ore by the end of 2019.

Ongoing hydraulic fracturing operations combined with continued undercutting and drawbell openings in the two production blocks are expected to expand the cave, supporting higher rates of production with an average of 28,000 t/d of ore estimated in 2020 and 80,000 t/d of ore in 2022.

Meanwhile, PT-FI continues to mine the final stages of the Grasberg open pit. During the most recent quarter, PT-FI opened an additional mining area to extend pit life options into the September quarter and potentially longer (previous estimates were based on mining through June 2019).

“The mine sequencing changes in the open pit delayed access to the high-grade material previously forecast to be produced during second-quarter (June quarter) 2019, resulting in lower copper and gold production from the open pit than the April 2019 estimates,” the company said.

Revised 2019 mine plans for the Grasberg open pit are expected to meet and provide an opportunity to exceed the April 2019 estimates for copper and gold production for the year 2019, Freeport noted. PT-FI will continue to monitor geotechnical conditions to determine the extent of mining in the open pit, with material not mined from the open pit available to be mined from the Grasberg Block Cave.