Regis Resources has taken over IGO’s 30% interest in the Tropicana gold mine in WA.
The $903m deal was approved by WA Mines and Petroleum Minister Bill Johnston, with the Governmental green light being the last stage needed for the acquisition.
AngloGold Ashanti owns the remaining 70% of the Tropicana mine under a joint venture (JV), with Regis to replace IGO as the JV partner.
AGA interim chief executive officer Christine Ramon said Tropicana was a key asset in the company’s portfolio.
“Having decided, in this context, and after considerable deliberation to waive our pre-emptive rights, with the sale process behind us we are looking forward to working with Regis to deliver Tropicana’s considerable potential over the coming years,” she said.
AGA discovered Tropicana which, with a Mineral Resource of 7.64Moz of gold and Ore Reserve of 2.7Moz, is a key asset in its portfolio and one of Australia’s best gold mining assets.
In February of this year AngloGold Ashanti outlined a multi-year organic growth plan, to increase production over the coming four years from brownfield investment in its existing suite of mines and then investment in greenfield projects in Colombia.
The company’s strategy is premised on disciplined capital allocation at conservative gold price assumptions, with an initial focus on increasing reserves from exploration on its mine sites.
Last year, the company added 6.1moz of gold on a gross basis, further extending the life of its portfolio.
IGO’s divestment of Tropicana was due to the company’s focus on clean energy technologies.
IGO managing director and chief executive Peter Bradford said since discovery in 2005, Tropicana had been an important part of IGO’s history and a key driver of its sustained growth.
“But while IGO continues to believe that Tropicana is a high-quality Tier 1 gold asset with strong upside potential, it is no longer aligned with our focus on commodities critical to clean energy,” he said.
“This transaction, along with the recent investment in Tianqi Lithium assets in Australia, solidifies IGO’s position of becoming a globally relevant pure-play battery minerals producer and developer, uniquely exposed to tier 1 nickel, copper, cobalt and lithium.”
AGA senior vice-president Mike Erickson said IGO had been an excellent partner for well over a decade, through exploration to development and then operation.
“We wish them well in their new strategy and focus on battery metals,” he said
Regis managing director and chief executive officer Jim Beyer said the move provided significant strategic benefits to Regis.
“When combined with our existing assets, it provides a larger-scale, longer-term financial and operating platform to pursue internal and external growth opportunities,” he said.
2020 In Review
Tropicana achieved several major milestones, starting underground production at Boston Shaker and pouring its three millionth ounce of gold.
The Boston Shaker underground mine transitioned into commercial production in September 2020 on schedule, below the A$105.7m budget and importantly, with no safety incidents.
Boston Shaker will deliver approximately 1.1mt of ore per annum at an estimated grade of 3.5g/t, contributing approximately 100,000oz per annum to gold production over a seven-year mine life.
The first production stope was fired in June 2020 and the design production rate achieved earlier this year.
The Boston Shaker mineralisation extends down-dip and remains open at depth, limited only by drilling information.
Tropicana’s three-million landmark was achieved just seven years after pouring first gold.
During this period ore has been sourced from the Tropicana, Havana, Havana South and Boston Shaker pits, which have been mined as a series of cutbacks, sequenced and scheduled to maximise value at a mining rate that delivers the best mining unit cost for the scale of the operation.
Late in 2018 a second ball mill was added to the Tropicana processing plant increasing throughput capacity to more than 8mt per annum, and providing flexibility to balance throughput and recovery.
The modern processing plant uses conventional carbon-in-leach technology and includes high pressure grinding rolls (HPGR) for energy-efficient comminution.
Up until June 2020 ore production from the open pits exceeded the plant capacity, allowing higher grade ore to be preferentially treated (grade streaming) while lower grade ore was accumulated on stockpiles.
During the second half of 2019 and the first half of 2020, the Tropicana pit and Havana pit were completed, in line with the mine plan. As a result, grade streaming came to an end and stockpiled ore is currently being used to supplement the mill feed from the Havana South and Boston Shaker pits.
A decision was made in the June 2020 quarter to invest in the next cutback of the Havana pit (Stage 2) which will allow access to the deeper Havana open pit ore from 2022 onwards.
While this cutback is being completed, mill feed will be sourced from the Boston Shaker open pit, supplemented by approximately 4mtpa of low grade (0.85 – 1.05 g/t) stockpiled ore, resulting in a lower milled grade over the period.
The lower grade will be partially offset by the Boston Shaker underground mine. The plan remains for annual gold production (at 100%) in 2020 and 2021 to be between 400,000-450,000oz lifting to between 450,000–500,000oz from 2022 onwards as the portion of stockpiled ore in the mill feed is replaced by both Boston Shaker underground ore and an increasing contribution of ore from the Havana pit as the cutback progresses.
Significant potential remains to unlock known extensions of mineralisation beneath the Tropicana and Havana open pits and the extensions at depth of the Boston Shaker underground mineralisation.
Recent operational excellence work at Tropicana included the successful trial of autonomous open pit blast hole drilling which demonstrated that significant productivity gains could be achieved. As a result, five platform drill rigs have been converted to autonomous operation.
The Growth Plan
The Tropicana gold mine is expected to play a big part in AGA’s growth, as it reverts to normalised production levels following the reinvestment in its life extension, Ms Ramon said.
“As well as Tropicana, the primary drivers of production growth in the company’s five-year indicative outlook are expected to be the ramp-up to steady-state production at Obuasi, in Ghana, following the site’s redevelopment into a world-class asset.
“There are also planned production gains above 2020 levels from the miner’s Mineração, in Brazil, and Siguiri, in Guinea, operations, as well as the Sunrise dam, which is in Australia.
“From 2024, the Gramalote project, in Colombia, will start contributing to group production. This will be followed in 2025 by the startup of Quebradone, also in Colombia.
“These projects are, however, dependent on a positive investment decision by the company’s board in each case.”