In the 1990s,  Southern Peru Copper Corporation ("SPCC") was seeking to modernise its smelter at Ilo in southern Peru as part of 1997 commitment to the Peruvian government to capture at least 91.7% of the sulfur dioxide generated in its smelting operations by January 2007. It initially selected flash smelting technology to replace its reverberatory furnaces, at a cost of almost US$1 billion; however, one of the first actions following Grupo México's acquisition of ASARCO was to review the proposed Ilo smelter modernisation plans.