BOUND SODA INCORPORATION DURING HYDRATE PRECIPITATION
Armstrong, L.
Soda is incorporated into aluminium hydroxide ("hydrate") during the precipitation stage of the Bayer Process.
Several mechanisms exist in the literature to describe soda incorporation in hydrate and the influence of organic liquor impurities and precipitation operating parameters. This is reviewed.
Our research on model organic impurities extends the literature by quantifying the effects of organics containing adjacent, acidic hydroxyl groups, particularly on the mass uptake of soda during the growth stage of precipitation. Further intricacies in the action of organics will be outlined, including organic compounds that in some conditions promote soda incorporation but have no impact on hydrate yield.