One of the few remaining miners digs out soil which will later be filtered for traces of cassiterite, the major ore on tin, at Nyabibwe mine, in eastern Congo, on August 17, 2012. Photo: AP.

One of the few remaining miners digs out soil which will later be filtered for traces of cassiterite, the major ore on tin, at Nyabibwe mine, in eastern Congo, on August 17, 2012. Photo: AP.