Kinetics of leaching of a gibbsitic bauxite with hydrochloric acid

Leaching kinetics for the removal of iron from a low grade gibbsitic bauxit e with hydrochloric acid were studied. Temperature and acid concentration h ad strong influence on the removal of iron. Calcium removal was quantitativ e within a short period with dilute acid. The mechanism for the dissolution of iron followed first order equation, -ln(l - alpha) = kt, with an appare nt activation energy of 81.0 kJ/mol. Using 4 M acid removal of more than 98 % iron was achieved from hematite together with about 10% alumina from gibb site phases of the ore. (C) 1999 Published by Elsevier Science B.V. All rig hts reserved.