Bijiashan mine is located in Cheng County, Gansu Province. The production started in 1984. The mine has an underground operation and a concentrator, producing both a lead concentrate and zinc concentrate. The mine, mill and transport infrastructure to the mine site was damaged in an earthquake in May 2008, halting production. Due to a combination of a resource near to exhaustion and weak market conditions in the latter half of 2008 and 2009, the mine re opened later in 2009 but at severely scaled back production.