In the Bayer Process, spent liquor is reheated in heat exchangers and concentrated in evaporators before being recycled back to digesters. The thickener overflow is supersaturated with dissolved aluminum compounds. When the aluminum compounds spontaneously precipitate from the overflow, a phenomena referred to as auto precipitation, the aluminum values within those precipitated compounds are commingled with the red mud and are lost.

 

Solvay CYFLOC®️ auto-precipitation reduction aid is a hydroxamated polymer that is added to thickener or washer feed in conjunction with regular flocculants to reduce auto precipitation across washers, thickener and filters.