Desilication of low alumina to caustic liquor seeded with sodalite or cancrinite

The aim of this study was to improve understanding of scale formation mechanisms and to provide theoretical support for development of scale inhibition strategies. Sodium aluminosilicate scaling on plant surfaces is a critical problem in Bayer refineries, particularly within digesters and heat exchangers. Although numerous studies have been carried out to understand the mechanisms of scale formation and to develop scale inhibition strategies in double-stream circuit Bayer plants, there is still insufficient relevant research on single-stream Bayer plants. We have studied the desilication behavior of a liquor of similar composition to spent cleaning caustic liquor, for which the aluminate concentration and A/C are both less than heat exchanger liquor. These concentration conditions were chosen in order to investigate the early stage of scale formation in single-stream Bayer plants by increasing the component of aluminosilicate bulk precipitate upon seeding and decreasing the relative degree of scaling.