Method of increasing the stability of a bayer process liquor

A method of increasing the stability of a Bayer process liquor by controlling the precipitation of aluminium-containing compounds therefrom, the method comprising:

• contacting of the Bayer process liquor with a ppm quantity of a low molecular weight dextran to suppress or reduce precipitation of aluminium-containing compounds from the Bayer process liquor prior to and/or during filtration of the Bayer process liquor, wherein the ppm quantity of the low molecular weight dextran is less than about 15 ppm of active dextran and the dextran has a molecular weight less than about 500,000 Daltons.