Freeport-McMoRan Inc. (NYSE:FCX) is in talks about buying an Arizona copper smelter from Grupo México, S.A.B. de C.V. (BMV:GMEXICO B) as the US mining giant seeks to increase its domestic processing capacity, according to people familiar with the matter. Executives from Phoenix-based Freeport recently toured the Hayden smelter -- owned by Grupo Mexico unit Asarco -- to appraise the operation, said one of the people, who asked not to be identified because the discussions are private and may not lead to a deal. Grupo Mexico and Freeport both declined to comment.