Study on Enhanced Leaching of Mechanically Activated Ilmenite

Mechanical activation of rock-type Panzhihua ilmenite was investigated with a tumbling ball mill at 70:1 ratio of ball:ore mass. XRD analysis demonstrated the crystallite size of ilmenite decreased with the increasing of milling time, and remained practically unchanged beyond 4h of milling. The dissolution kinetic experiments at various temperatures showed the apparent activation energy of the ore reduced from 55.7 kJ/mol in initial leaching stage to 23.7 kJ/mol with the extending of milling time. It was found that the apparent Arrhenius energy is closely related to the crystallite size. The digestion of activated ilmenite at a sulfuric acid of 30%~50% concentration was also studied. With increasing of the activation time, the effect of acid concentration on leaching dropped, this indicates that the dissolution of ilmenite under low acid concentration and low leaching temperature is feasible.