LIMA (Reuters) - Workers at the Shougang Hierro Peru iron mine and Cerro Verde copper mine will go on strike next week to demand better wages and a larger share of profits, union leaders said Wednesday.Miners at Shougang Hierro Peru will put down tools March 29, while workers at Cerro Verde will strike March 31.Shougang Hierro Peru, a unit of the Chinese Shougang Group, is Peru's only iron producer.