Peruvian miner Minsur S.A., controlled by local holding company Grupo Brescia, is engaged in the exploration. processing and marketing of tin. It operates the San Rafael mine in Puno department and the Funsur smelter and refinery in Pisco. In 2012, Minsur acquired 70% of local firm Marcobre S.A.C. owned by Hong Kong-based CST Mining, whose main asset is the Mina Justa copper deposit in Ica region. Minsur was founded in 1977 and is based in Lima, Peru.