Process for purifying aqueous buffer solutions
OwnerOlav Ergainventor
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Abstract
The present invention describes a procedure for the removal of sodium sulphate from a phosphate solution that has been used for absorption of SO2 from flue gases, whereby a precipitate forms when the absorption solution is regenerated by evaporation. In this procedure a part of the precipitate is separated from its solution and treated with water and SO2 for transformation of disodium-hydrogen phosphate into monosodium dihydrogen phosphate in the aqueous solution, whereby the sodium sulphate remains undissolved and is removed by filtration, whereafter the filtrate is added back to the main process.
Claims5
A-procedure for removal of sodium sulphate from a phosphate solution which has been used for absorption of SO2 from flue gases, whereby a precipitate forms when the absorption solution is regenerated by evaporation, wherein a part of the precipitate is separated from its solution and treated with water and SO2 for transformation of di-sodium-hydrogen-phosphate into mono-sodium-di-hydrogen-phosphate in the aqueous solution, whereby the sodium sulphate remains undissolved and is removed by filtration, whereafter the filtrate is added back to the main process.
The procedure of the preceeding claims,
- wherein the treatment is accomplished at an elevated temperature.
Dependencies are inferred from the claim text.