US-based The Doe Run Resources Corp., the largest integrated lead producer in North America, is engaged in mineral production, metals fabrication, recycling and reclamation. It produces non-ferrous and precious metals, including integrated and primary lead, copper, zinc, silver and gold. Doe Run has operations in the US and Canada. The company, through its former Doe Run Perú unit, owned a polymetallic smelter at La Oroya and copper mine Cobriza in Peru. Built in 1922 by the Cerro de Pasco Corp., and acquired in 1997 in a privatization process by Doe Run, La Oroya halted its operations in 2009 after metals prices collapsed. The smelter restarted zinc and lead operations in 2012 but closed again in 2014, and will be put up for sale. La Oroya has the capacity to produce a dozen different metals, including copper and silver, but failure to meet environmental standards has shuttered the copper circuit. The unit's Cobriza copper mine will also be up for sale.