ENUSA mines an ore-body in the 'Schisto-greywacke complex' near Ciudad
Rodrigo, close to the Portuguese border. The uranium ore (pitchblende
) is associated with sulphide minerals (pyrite, chalcopyrite). The who
le Spanish yellow cake production (250 t U3O8/year) is obtained from t
his mine (MINA FE) by bioleaching, although at the beginning, in 1973,
it was an acid heap-leaching operation.