Copper futures advanced in London and New York on Wednesday on hopes of rising demand, but prices in Shanghai fell on fears of policy tightening by top consumer China.
Barrick's comments come on the heels of a report published this week, which claims its Tanzanian subsidiary has been under-reporting the amount of metal in its shipments to evade taxes.
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.
Two days before Antofgasta's annual general meeting in London, an 18-pages long report by the London Mining Network slams Los Pelambres' environmental record.