| abstract |
A process for the isolation of aromatic sulfonic acids in the form of the free acid or in the form of their alkali metal salts from aqueous solution or suspension, the aqueous solution or suspension in which the aromatic sulfonic acids or their alkali metal salts are contained being mixed with water which is immiscible or only to a limited extent extracted organic solvents from the class of alcohols, ketones or carboxylic esters, separating the organic phase, optionally converting the free aromatic sulfonic acids contained therein into their alkali metal salts and then removing the organic solvent. |