The proposal would still face a vote from the full assembly to be included in the final draft text, which would itself go before a national referendum vote later this year.
Copper prices are set to languish this year, a Reuters poll of analysts showed, weighed down by weaker demand as rising interest rates curb economic growth.
Billionaire claims the Brazilian mining giant was well aware of allegations that the Guinean mining rights it agreed to buy had been secured illegally.