Ivanhoe Mines and Zijin each hold now an indirect 39.6% interest in the Kamoa-Kakula project, thought to be Africa's most significant deposit of the red metal ever found.
During the mining trial done at a depth of 4,153 feet, engineers extracted each day around 16,000 cubic metres of gas, with methane content of up to 99.5%.
Move comes on the heels of calls from shareholders including activist investor Elliott Management and Australia’s Tribeca Investment Partners for a change of BHP's corporate structure.