Alkaline earth metal carbonate dispersions containing organic sulfonate dispersants

摘要

1,134,608. Alkaline earth metal carhonate dispersions. CHEVRON RESEARCH CO. 27 April, 1967 [23 May, 1966], No. 19569/67. Heading C1A. An alkaline earth metal carbonate dispersion in a hydrocarbon diluent is prepared by mixing calcium or barium oxide with methanol in a hydrocarbon diluent having a boiling point above that of methanol and below 180‹ C. and present in an amount to give a 5-20 wt. per cent dispersion of the oxide, the oxide to methanol mole ratio being 1: 2 to 5, adding CO 2 to the mixture in from 10 to 50% of the amount stoichiometrically required to convert the oxide to carbonate while maintaining the temperature below the b.pt. of methanol, introducing an organic sulphonate dispersant having at least 20 C atoms, in an amount such as to have at least 8 moles of the alkaline earth metal oxide originally present in the mixture for each mole of sulphonate, continuing the CO 2 addition until it is no longer absorbed whilst maintaining the temperature below the b.pt. of methanol, treating the mixture with water at a temperature sufficient to vaporize the water, and removing substantially all the water. The treatment with water may comprise steam stripping and the mixture may thereafter be filtered. The mixture of oxide, methanol and hydrocarbon diluent typically contains at least 3 mole per cent of water (preferably 5-15 mole per cent) based on the oxide. The dispersant, which is preferably an alkaline earth metal organic sulphonate or a mahogany sulphonate, may be introduced in the form of a solution in a hydrocarbon diluent.