| abstract |
A process for preparing a sulphonated dispersant from a petroleum asphalt fraction, comprising:n establishing contact between the asphalt fraction dissolved in an inert solvent and liquid or gaseous sulphur trioxide at a temperature equal to or less than 60°C, to obtain a sulphonated asphalt fraction; salifying the sulphonated asphalt fraction thus obtained by contact with an aqueous solution of a hydroxide of an alkaline metal, alkaline earth metal or ammonium and recovering the sulphonated salt from the reaction mixture. n This process provides water-soluble sulphonated salts of petroleum asphalt fractions, which can be used as fluidifying and stabilizing agents for aqueous dispersions of solids, such as aqueous dispersions of coal or cement. |