Crystallization of sodalite particles under Bayer-type conditions

The formation of desilication products (DSPs) is an important process in the pre-desilication step of the Bayer process, helping to limit the potential for unwanted scale on the heat exchangers by limiting the amount of silicate in the Bayer liquor. These solids generally have a crystalline sodalite structure, however, the fundamentals of crystallization are still to be fully understood. We show in this work that the DSP formed is initially amorphous when solution silicate is used. When kaolinite solids are present DSP is initially heterogeneously nucleated on the kaolinite but there is also a secondary nucleation event that occurs. (C) 2013 Elsevier B.V. All rights reserved.