Patent ID: 8906239

Claim:
A method for flocculating and reducing a concentration of desilication product suspended in a Bayer process stream, the method comprising: intermixing a flocculant composition with a Bayer process stream, the intermixing occurring at a portion of the Bayer process stream selected from the group consisting of a settler feed, a settler overflow, a blow-off discharge and a combination thereof; flocculating a desilication product suspended in the Bayer process stream with the flocculant composition; and separating at least a portion of the flocculated desilication product thus formed, thereby reducing the concentration of desilication product suspended in the Bayer process stream, wherein the flocculant composition comprises a silicon-containing polymer flocculant having at least about 5 weight % silicon-containing groups and a hydroxamated anionic polymer flocculant, wherein the flocculant composition provides improved settling rate and clarity when compared to either the silicon-containing polymer flocculant alone or the hydroxamated anionic polymer flocculant alone.