Ivanhoe Mines co-chairs Robert Friedland and Yufeng ‘Miles’ Sun have announce that underground development at the Kamoa-Kakula Copper Project in the Democratic Republic of Congo (DRC) mined and stockpiled 269,000t of ore grading 5.36 per cent copper in December from the Kakula and Kansoko mines, a 7.6 per cent higher tonnage than November, while the copper grade was 10.5 per cent higher.