The meeting counted with President Macri's presence and included presentations from the public and private sectors in Salta, Catamarca and Jujuy.
With grades falling, production heading back to 2018 levels, and costs rising, the Chilean copper miner will face issues starting 2020.
The deal could be signed in the coming week during an official White House visit by President Bolsonaro, according to Bloomberg.
At its first meeting, the senate commission agreed to convene the former CEO of Vale, Fábio Schvartsman, who was removed from post on March 2, and current chief executive Eduardo Bartolomeo.
Yellow metal exports dropped to US$360mn in January, in part due to lower prices, with silver exports on the rise.
Companies issue financing, option and appointment updates relating to gold, lithium and coltan projects in Mexico, Nicaragua, Argentina, Colombia and Brazil.
However, shipments of aluminum oxides, iron ore pellets and unalloyed cast iron performed well in the first two months.
Companies operating in Mexico and Guyana provide updates.