Abstract: A process for purifying a sulfuric acid solution such as by cooling a sulfuric acid solution to at or near its freezing point to form a slurry of a solid phase and a liquid phase. The slurry has an acid-rich region and an acid-poor region. The acid-rich region is separated from the acid-poor region on the basis of density.

Abstract: A freeze crystallization concentration system is disclosed for separating a liquid feed stream into a more purified liquid and a concentrate in which only a single pass through a freeze-crystallizer and ice separator is required. The crystallizer, which converts the initial feed stream into a slurry of ice and concentrate, includes a scraped surface heat exchanger that produces, pumps and removes an ice slurry and uses a secondary cooling system to ensure that the crystallizer will operate in any required position and is not sensitive to motion. The separator includes a rotating drum which separates the ice crystals from the surrounding concentrate by the use of centrifugal force and without the use of screens or filters. An auger, rotating at a different speed than the drum, may be located at the center of the drum for removing the ice crystals.

Abstract: A freeze crystallization concentration system is disclosed for separating a liquid feed stream into a more purified liquid and a concentrate in which only a single pass through a freeze-crystallizer and ice separator is required. The crystallizer, which converts the initial feed stream into a slurry of ice and concentrate, includes a scraped surface heat exchanger that produces, pumps and removes an ice slurry and uses a secondary cooling system to ensure that the crystallizer will operate in any required position and is not sensitive to motion. The separator includes a rotating drum which separates the ice crystals from the surrounding concentrate by the use of centrifugal force and without the use of screens or filters. An auger, rotating at a different speed than the drum, may be located at the center of the drum for removing the ice crystals.

Abstract: A freeze crystallization concentration system is disclosed for separating a liquid feed stream into a more purified liquid and a concentrate in which only a single pass through a freeze-crystallizer and ice separator is required. The crystallizer, which converts the initial feed stream into a slurry of ice and concentrate, includes a scraped surface heat exchanger that produces, pumps and removes an ice slurry and uses a secondary cooling system to ensure that the crystallizer will operate in any required position and is not sensitive to motion. The separator includes a rotating drum which separates the ice crystals from the surrounding concentrate by the use of centrifugal force and without the use of screens or filters. An auger, rotating at a different speed than the drum, may be located at the center of the drum for removing the ice crystals.