Study on high acid leaching reactive calcined kaolin

Leaching experiments on metakaolin show that the final Al extraction ratio reached in a batch reaction is strikingly influenced by the inferior pore structure geometry of the metakaolin pellets. By calcining Kaolin particles adhered in low humidity state, a variety of metakaolin pellet, inside which a large openings structure developed, has been prepared. The structure remarkably benefits leachant ion transference, so, the variety has high acid leaching reactivity, even coarse as the pellets are, its aluminum extracted ratio still has a linear relationship with leaching time, and the leaching kinetics is maintained zero order up to a significant conversion degree. A revised Pellet-Particle Model has been developed to interpret the structure influence on Al extraction ratio.