Dispersant for concrete mixtures of high salt content

In a cement or concrete system comprising cement and water containing from 2% up to a saturated solution of a dissolved mineral salt the improvement comprising an effective amount to disperse the cement of a dispersant comprising a condensation product of an acyclic ketone selected from the group consisting of acetone, diacetone alcohol, methyl ethyl ketone, methoxyacetone and mesityl oxide, an acyclic aldehyde selected from the group consisting of formaldehyde, acetaldehyde, methoxyacetaldehyde, aldol, acrolein, crotonaldehyde, glyoxal and glutaraldehyde and an alkali or alkaline earth salt acid-group-introducing compound consisting of an acid selected from the group consisting of sulphurous acid, 2-aminoethanesulphonic acid and aminoacetic acid or wherein said acid-group-introducing compound is a sulfite addition product of the ketone or aldehyde, wherein the molar ratio of ketone:aldehyde:

• acid introducing compound components is 1:1 to 18:0.25 to 3.0 and said condensation product is formed by a condensation reaction of these compounds at a temperature in the range of about 60.degree. C. to about 85.degree. C.