Abstract:
The role of surface-chemical phenomena and the physical processes that participate in the dewatering of a suspension of alumina trihydrate were subjected to a systematic investigation, which has increased understanding of the influence of surface tension, contact angle and adsorption is the process, The results of the dewatering experiments demonstrate that the residual moisture content of the cake can be reduced significantly through the use of surface-active agents in slurry pretreatment or as a wash-water additive. If scaled up to industrial operation of the dewatering step of the Bayer process, the use of these chemical additives could bring a substantial improvement in process economics by reducing the fuel costs for thermal drying.