The company said arrangements have been made to lift the blockade at its mine on Thursday.
Mexico's environmental agency (PROFEPA) said the mine's operators had completed about 85 percent of the recovery of the spilt material.
Grupo Mexico's Chief Financial Officer Daniel Muñiz said the mine would help the company diversify its mining operations, particularly with regards to zinc.
Mexican media reports on Wednesday said thieves stole around 300 kilograms of gold.