A process for preparing sodium

A method for producing sodium persulfate comprising the steps of: (1) electrolysis of a cathode output solution having a 20 to 80% by weight aqueous solution of sulfuric acid contains, and an anode output solution containing 5 to 18Gewichts-% sodium sulfate, 21 to 38% by weight ammonium sulfate and 0.1 to 2% by weight contains sodium persulfate, to produce a product and a cathode anode product, (2) reaction of the anode product with sodium hydroxide in a reaction crystallizer to produce a reaction mixture, (3) Crystallization of sodium from the reaction mixture by concentration to produce a Natriumpersulfatschlamms, (4) separation of the Natriumpersulfatschlamms in Natriumpersulfatkristalle and mother liquor to isolate the Natriumpersulfatkristalle, (5) crystallization of sodium sulfate from the mother liquor to produce a sodium sulphate slurry, (6) Separation of sodium sulfate crystals from the sodium sulfate slurry, (7) recycling in step (2) in the released ammonia gas in step (1) obtained cathode product, (8) neutralization of the resulting cathode product with sodium hydroxide and / or ammonia to produce a neutralized product and cathode (9) recycling the neutralized cathode product ...