METHOD OF RECOVERING SODIUM SULFATE FROM GAS CLEANING SOLUTION IN ELECTROLYSIS ALUMINUM PRODUCTION Russian patent published in 2004 - IPC

FIELD: nonferrous metallurgy.

SUBSTANCE: sodium sulfate recovery comprises freeing gases of sulfur oxides on scrubbers by spraying with sodium sulfate solution circulating within gas-cleaning system. Part of sodium sulfate solution with Na₂SO₄ concentration 70-75 g/L and Na₂CO₃ 10-15 g/L is freed of fluoride salts and subjected to evaporation in evaporator to achieve Na₂SO₄ concentration350-400 g/L, after which into concentrated solution is dosed soda consumed in gas-cleaning process cycle to achieve Na₂CO₃ concentration 310-350 g/L and thereby to precipitate anhydrous sodium sulfate in the form of berkeyite (Na₂CO₃·2Na₂SO₄) on cooling solution to 40-60^оС.

EFFECT: reduced power consumption and created production of anhydrous berkeyite salt.

1 dwg