The invention relates to a method for sulfate removal from sulfate-containing carbonized products, comprising the following steps: a) allowing a compound X2CO3 and/or XHCO3, wherein X stands for NH4+ and an alkali ion, to act on the sulfate-containing carbonized product in an aqueous medium and b) separating the aqueous medium, the aqueous medium containing X2SO4, wherein X is defined as above.