Patent ID: 6475447
Filing Date: 2002-11-05
Classification: C01D

Abstract:
Apparatus for treating a slurry containing sodium sesquisulfate crystals to promote formation of sodium sulfate solids and sulfuric acid and to separate the sodium sulfate solids from the sulfuric acid, the apparatus comprising:an upright treatment vessel having an upper end and a lower end and a separation wall defining on one side a mixing zone and on another side a clarifying zone, the separation wall including a lower edge spaced above the lower end of the vessel to enable fluid flow communication between the mixing zone and the clarifying zone by flow of liquid under the lower edge between the zones; a collector located in the treatment vessel generally below the mixing zone and spaced above the lower end of the vessel the collector including an upwardly opening reservoir for collecting solid particles descending by gravity through the mixing zone; a diffuser in the reservoir of the collector connected in flow communication with a source of pressurized gas for releasing a flow of gas bubbles through solid particles collected in the reservoir to agitate the particles contained therein and break up sodium sesquisulfate crystals into smaller crystals and/or sodium sulfate solids and sulfuric acid and to provide a flow of gas bubbles up through the mixing zone to promote a turbulent mixing flow regime within the mixing zone and dissolution of sodium sesquisulfate crystals into sodium sulfate solids and sulfuric acid; an inlet conduit connected in flow communication with the mixing zone for delivering the slurry into the mixing zone; a water inlet for introducing water into the mixing zone for mixing with the slurry; an outlet conduit adjacent the upper end of the treatment vessel for directing liquid including sulfuric acid from the clarifying zone to a liquid processing unit; and a solids outlet adjacent the lower end of the treatment vessel for directing solids including sodium sulfate solids out of the vessel.