METHOD OF PROCESSING SODIUM SULFATE SOLUTION Russian patent published in 2008 - IPC C01D5/00 C01D5/16 

FIELD: nonferrous metallurgy.

SUBSTANCE: invention relates to processing sodium sulfate solutions produced during treatment with sodium sulfate solution of sulfur-containing gases from electrolysis shops of aluminum production plants. Processing comprises removing fluorine compounds and sulfur dioxide from sodium sulfate solution by sprinkling it in wet scrubbers with sodium sulfate solution and isolating sodium fluoride in the form of calcium fluoride from a part of circulating sodium sulfate solution. From mother sodium sulfate solution freed of sodium fluoride, impurities-free macrocrystalline anhydrous sodium sulfate is precipitated via evaporation of mother solution to concentration of titrated carbonate alkali in evaporated solution 75-100 g/L (calculated as Na₂CO₃) and density of evaporated solution 1.30-1.31 g/cc at 70-105°C.

EFFECT: reduced loss of sodium carbonate.

1 dwg