Abstract: A freeze concentration apparatus comprising a warm concentrator tank; a conduit to deliver an aqueous liquid mixture feed stream to the warm concentrator tank; a cold concentrator tank; a conduit to feed the liquid mixture from the cold concentrator tank to a primary freeze exchanger for indirect cooling by heat exchange to a cold fluid to form ice crystals in the liquid mixture; a conduit to feed the liquid mixture containing ice crystals from the primary freeze exchanger to the cold concentrator tank; a conduit to withdraw liquid mixture from the cold concentrator tank concentrated by the freezing of water therefrom; a conduit to withdraw an ice slurry from the cold concentrator tank and deliver it to the warm concentrator tank; a conduit to withdraw an ice slurry from the warm concentrator tank and deliver it to an ice slurry washer; a spray system to wash the ice slurry in the washer with water and to collect washed ice and an aqueous mixture; a conduit to remove the aqueous mixture from the washer and de