Process for preparation of highly concentrated free-flowing aqueous solutions of betaines

A process for preparing a highly concentrated free-flowing and pumpable aqueous solution of betaine, comprising (a) quaternizing a fatty acid amide of the general formula I

• R.sup.3 --CONH--(CH.sub.2).sub.m --NR.sup.4 R.sup.5 (I)
• wherein R.sup.3 is alkyl or alkenyl containing 6 to 20 carbon atoms and 0 to 5 carbon--carbon double bonds, m is 1-3, and R.sup.4 and R.sup.5 are the same or different and each is alkyl containing 1-4 carbon atoms, with a salt selected from the group consisting of alkaline earth metal salts of .omega.-halo carboxylic acid in an aqueous medium, and (b) adding 0.5-5% by weight of the complete mixture, of at least one salt compound of the formula
• (Li.sup.1+).sub.a (X.sup.n-).sub.b, (Na.sup.1+).sub.a (X.sup.n-).sub.b, (K.sup.1+).sub.a (X.sup.n-).sub.b, (Mg.sup.2+).sub.a (X.sup.n-).sub.b, (Ca.sup.2+).sub.a (X.sup.n-).sub.b
• in which X.sup.n- is the radical of an organic acid, in the molecules with monovalent cations the value of a=b.multidot.n.sup.- and in the molecules with divalent cations the value of a=(b.multidot.n.sup.-)/2, and n is 1-3, before or during the quaternization reaction.