Process for preparing sulfonated dispersants

摘要

Process for preparing water-soluble sulfonated dispersants by causing sulfur dioxide to react with aromatic fractions in a ratio, by weight, comprised within the range of from 0.8:1 to 1.5:1, in which the reaction takes place by means of: (1) a first step of prevailing sulfonation of the aromatic fractions in the presence of SO2, with a prevailingly sulfonated product being formed; (2) a subsequent step of removal of SO2 and heating of the solid sulfonated product up to a temperature comprised within the range of from 70 to 110.degree.C; with both of said steps being carried out under conditions of said solid sulfonate being crushed and kept moving.