Engineering & Mining Journal

MAY 2019

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

Issue link:

Contents of this Issue


Page 15 of 83

REGIONAL NEWS - AUSTRALIA/OCEANIA 14 E&MJ • MAY 2019 Tropicana JV Developing Boston Shaker Underground Joint-venture partners AngloGold Ashanti Australia (70% and manager) and Inde- pendence Group (30%) have approved development of the Boston Shaker under- ground project beneath the currently active Boston Shaker open pit at their Tropicana gold operations in Western Australia. A feasibility study has confirmed that under- ground mining is technically and financial- ly viable, with an anticipated IRR of 39% for a capital investment of $79.3 million. Boston Shaker underground will con- tribute higher-grade mill feed, resulting in an improved gold production profile and enhanced cash flow. Importantly, the un- derground mine will provide improved cash flow during 2021-2023, when the mine plan includes periods of higher waste strip- ping in the property's Havana open pit. Ore from the underground mine will enable Tropicana gold production to be maintained at 450,000-500,000 ounc- es per year (oz/y) over the next five years. The project is getting under way in the second quarter of 2019, and first gold is scheduled for the third quarter in 2020. "Underground mining at Boston Shak- er will leverage further value from this high-performing operation, achieving pay- back in just over three years," AngloGold Ashanti COO International Ludwig Eybers said. "An ongoing focus on operational excellence has enabled Tropicana to con- sistently exceed expectations, and I am sure this world-class performance will ex- tend into the underground operation." The expanded ore production from the mine will capitalize on investments made in the Tropicana processing plant, including a second ball mill commissioned in Novem- ber 2018 that increased throughput capac- ity to 8.1 million metric tons per year (mt/y). The Boston Shaker orebody remains open at depth, and the JV partners will con- tinue to test high-grade extensions to the mineral resource beneath the Tropicana and Havana pits to assess the opportunity for further underground mining operations. The Boston Shaker ore reserve is es- timated at 2.8 million mt grading 3.84 grams/mt for 317,000 oz of contained gold. The mineral resource estimate stands at 12.5 million mt at 4.2 g/mt for 1.7 million oz. The feasibility study was based on mining 6.58 million mt, grading 3.84 g/ mt, assuming the systematic conversion of mineral resources to reserves over the life of the mine. The average underground mining rate will be 1.1 million mt/y, in- cluding development over an eight years to 2026 to produce 732,000 oz. Mining methods will be based on con- ventional mechanized mining and under- hand sublevel open stoping. The proposed mining fleet comprises two jumbos, two production drills, three remote-capable loaders and four trucks. An underground mining contract has been awarded to Macmahon Holdings, the mining alliance partner at Tropicana since commencement of open-pit mining in 2012. As Macmahon will operate both the open-pit and underground mines, significant operational and management synergies will be delivered. The underground operation adds an additional year to Tropicana's mine life, taking it to 2029 based on current mea- sured, indicated, and inferred mineral re- sources of 136.2 million mt at 1.76 g/mt for 7.7 million oz of contained gold. Decline development to access the Bos- ton Shaker underground orebody is sched- uled to begin before midyear 2019, with mining of the first stope scheduled to begin in August 2020. The portal for the decline will be located in the completed Tropicana pit to minimize interaction between under- ground equipment and the open-pit fleet working in the Boston Shaker pit. Rio Tinto Selects Mining, Processing Equipment for Koodaideri Rio Tinto announced it has selected FLS- midth and Caterpillar to supply the equip- ment to develop what it claims will be its most technologically advanced mine, the Koodaideri iron ore operation in the Pil- bara, Western Australia. This will be Rio Tinto's first Pilbara mine to be primarily operated using Cat equipment. Previously, Rio Tinto purchased Komatsu haul trucks for its Mine of the Future program. Through its local dealer WesTrac, Cat will provide a fleet of 20 autonomous trucks and four autonomous blasthole drills. Cat's machinery will be integrated with Rio Tinto's Mine Automation System (MAS), which collects and enhances data to improve productivity across Rio Tinto's entire iron ore network. With a turn-key contract for the design, supply, installation and commissioning, FLSmidth will supply key minerals han- dling equipment for Koodaideri. Rio Tinto will for the first time apply smart technol- ogy to interconnect all components in the mining value chain. FLSmidth will design the equipment to the latest Australian standards and incorporate smart 3D de- sign and a variety of advanced engineer- ing solutions, such as BulkExpert. "Koodaideri will set new benchmarks in digitalization and will feature the most technologically advanced solutions em- ployed to date in the iron ore sector," said Manfred Schaffer, president, FLSmidth Mining. Construction at Koodaideri will begin this year with the first ore expected to be fully functional by late 2021 with a production capacity of 43 million metric tons of iron ore per year. Development declines will begin soon under the existing Boston Shaker mine. (Photo: AngloGold Ashanti)

Articles in this issue

Links on this page

Archives of this issue

view archives of Engineering & Mining Journal - MAY 2019