Method for producing potassium sulfate from potassium chloride and sulfuric acid
AssigneeVeolia Water Technologies, Inc.
InventorsSebastien Bessenet, Didier Le Flammec
Life of this patent
Estimating the term…
Abstract
A process is provided for producing potassium sulfate from potassium chloride and sulfuric acid. The process entails mixing potassium chloride with the water to form a potassium chloride slurry which is mixed with recycled sulfuric acid to form a K+, Ct′, SO42″ acid mixture. This mixture is subjected to a crystallization process that produces potassium sulfate crystals and a hydrochloric acid-water vapor. The hydrochloric acid is separated from the hydrochloric acid-water vapor to form a hydrochloric acid solution.
Claims26
A method for producing potassium sulfate and hydrochloric acid comprising:
- mixing water with potassium chloride to form a potassium chloride slurry or solution;
- mixing the potassium chloride slurry or solution with recycled sulfuric acid to form a K+, Cl−, SO42− acid mixture;
- subjecting the K+, Cl−, SO42− acid mixture to an evaporative crystallization process and producing a concentrate containing potassium sulfate crystals and a hydrochloric acid-water vapor;
- directing the concentrate containing the potassium sulfate crystals to a solids-liquid separator and separating the potassium sulfate crystals from the concentrate and yielding a filtrate;
- washing the potassium sulfate crystals with water;
- and
- wherein after separating the potassium sulfate crystals from the concentrate, mixing the filtrate with a source of sulfuric acid to produce a hydrochloric acid-rich vapors and a stream of sulfuric acid that forms at least a part of the recycled sulfuric acid mixed with the potassium chloride slurry or solution;
- and mixing the hydrochloric acid-rich vapors with the hydrochloric acid-water vapor produced by the crystallization process and wherein the hydrochloric acid-rich vapors and the hydrochloric acid-water vapor are directed to an adsorption unit which produces a hydrochloric acid solution having a concentration of 20-35% hydrochloric acid by wt.
A method for producing potassium sulfate and hydrochloric acid comprising:
- mixing water with potassium chloride to form a potassium chloride slurry or solution;
- mixing the potassium chloride slurry or solution with recycled sulfuric acid to form a K+, Cl−, SO42− acid mixture;
- subjecting the K+, Cl−, SO42− acid mixture to an evaporative crystallization process and producing a concentrate containing crystals comprising potassium and sulfate in the form of K2SO4, KHSO4, or a mixture of both;
- directing the concentrate containing said crystals of potassium and sulfate to a solids-liquid separator and separating said crystals comprising potassium and sulfate from the concentrate and yielding a filtrate;
- washing the crystals comprising potassium and sulfate with water;
- and
- wherein the evaporative crystallization process is carried out in a crystallizer unit and the method includes directing the filtrate to a dechlorination unit and mixing sulfuric acid from a sulfuric acid source with the filtrate to produce a sulfuric acid-rich stream and recycling the sulfuric acid-rich stream to the crystallizer unit.
Dependencies are inferred from the claim text.