How Cane Sugar is Refined - Recovery
The recovery house is the "dirty" end of the sugar refinery where, as the name implies, the refiner tries to recover as much as possible of the sugar in any residual liquors before rejecting them as the molasses. The problems of impurities inhibiting crystallisation become worse in the recovery house which usually relies on crystallisation alone for improving the liquor purities. Accordingly, the crystals at each stage are usually re-dissolved and fed forward to the previous stage while the mother liquor is fed back. Typically three steps will be employed before the mother liquor is considered exhausted. Even at that stage it will contain some 50% of fermentable sugars, albeit not all sucrose.