A PROCESS FOR PRODUCING ALUMINIUM HYDROXYCARBONATE GEL

摘要

A process for the continuous production of aluminium hydroxycarbonate gel is disclosed, in which aluminium salt solution is continuously reacted with mixed alkaline carbonate and bicarbonate solution under homogeneous conditions in a relatively small reaction vessel. The reaction is continued in a subsequent reaction vessel under controlled pH. The product gel is separated from the non-aluminium cation containing reaction mixture within less than about 6 hours, whereby formation of poorly soluble addition reaction products such as dihydroxy aluminium sodium carbonate, which contribute undesired non-alumium cations to the gel product, is reduced. The aluminium salt solution is adjusted in pH by adding to it a portion of the mixed carbonate and bicarbonate solution to obtain a clear solution of pH 3.5 to 4.0. This results in a smooth, creamy gel with a less objectionable chalky mouth feel.