The AngloGold Ashanti’s Australia operations produced 125,000oz at a total cash cost of $1,157/oz for the quarter ended 30 September 2021, compared to 149,000oz at a total cash cost of $932/oz for the quarter ended 30 September 2020. The region’s AISC was $1,363/oz for the quarter ended 30 September 2021, compared to $1,174/oz for the same period last year.
Sunrise Dam produced 58,000oz at a total cash cost of $1,276/oz for the third quarter of 2021, compared to 74,000oz at a total cash cost of $967/oz in the same period last year. Production was impacted by lower head grade and a decrease in metallurgical recovery, which was partially offset by higher tonnes mined in the underground mine.
Mine-to-mill grade reconciliations stabilised during the third quarter of 2021 and higher-grade underground ore is anticipated in the fourth quarter of 2021 as areas in the Western Shear Zone and the first stope in the newly discovered Frankie orebody are mined.
Total cash costs were higher year-on-year primarily due to lower production, as well as costs relating to the Golden Delicious open pit operation. The increase was partially offset by lower royalty costs due to the lower spot price in the third quarter of 2021 and favourable ore stockpile movements.
Mining of the Golden Delicious satellite open pit is progressing well. Triple-trailer road trains were commissioned in September 2021 to lift ore haulage rates from the pit to the Sunrise Dam processing plant in line with the mine plan. Exploration drilling continues to deliver high grade intercepts from the Frankie and Carey orebodies which have the potential to reduce reliance on the Vogue orebody and improve mining flexibility.
At Tropicana, production was 67,000oz at a total cash cost of $947/oz for the third quarter of 2021, compared to 75,000oz at a total cash cost of $830/oz in the same period last year. Production was lower year-on-year due to a lower mill feed grade as stockpile drawdowns increased while mining focused on waste removal in the Havana Stage 2 Cutback.
Production has also been impacted by the wall failure in the Boston Shaker open pit in June 2021 which has delayed ore delivery. Boston Shaker has been the primary source of open pit ore in 2021. The resulting 13% drop in mill feed grade in the third quarter of 2021 compared to the corresponding quarter last year was partially offset by a 5% increase in mill throughput following completion of the thickener duty swap project in June 2021.
Tropicana has also been impacted by labour market shortages which have impacted open pit and underground material movement. The increase in total cash cost was mainly due to lower production, inventory movement and the impact of higher underground and open pit mining costs. The Boston Shaker underground mine continued to ramp up to full production in the third quarter of 2021 with grade control drilling advancing well ahead of the mining schedule.