a process is described for removing dissolved silica from process solutions or slurries formed in the bayer process for producing alumina from bauxite . in the novel process , a bayer process solution or slurry is contacted with porous agglomerates of a material containing bayer process desilication product and bonded together by a polymer resin which is resistant to chemical degradation by high concentrations of caustic present in bayer process liquors . the desilication product is essentially complex hydrated sodium aluminum silicates and typical bonding resins are polyvinylchloride or polypropylene .