Abstract: A process and apparatus for the regeneration of contaminated acid. The process involves cooling the contaminated acid to a lower temperature sufficient to form at least one liquid hydrate of the acid without forming a solid hydrate of the acid, maintaining the contaminated acid at the lower temperature for a time sufficient to form at least one liquid hydrate of the acid and precipitate an amount of the contaminants, separating the precipitated contaminants from the cooled acid, and warming the acid to decompose the liquid hydrate.

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.