Abstract
Simultaneous ball milling and leaching by sulfuric acid was applied to enhance copper leaching from copper concentrate consisted of chalcopyrite and pyrite with small amount of bornite. When copper leaching was conducted in ball mill with enough air, copper recovery after 96 hours increased to 34.1％, whereas it remained 16.4％ in beaker test. Kinetic analysis results showed that leaching rate of chalcopyrite was increased about 100 times in ball milling test than in beaker test. XRD patterns of residue after leaching suggested that crystallinity of chalcopyrite was decreased in ball milling. Furthermore, leaching rate was mostly not increased when the particle size of sample was decreased. From above results, it was supposed that copper leaching with ball milling was enhanced by not only an increase of specific surface area of particles in sample but also low crystallization of chalcopyrite and explosion of new reaction surface of chalcopyrite.
