Study on titanium compound in red mud

In order to find out in what form the titanium present in red mud in Bayer alumina process, various titanium oxides were treated with alkali-solution at a high temperature.The results obtained are as follows:1) When titanium dioxide is treated with caustic soda solution, it makes a precipitate and the chemical constitution of the precipitate is approximately corresponding to Na2O•6TiO2•7H2O.2) When the reaction was made in the presence of Fe2O3, the product has more Na2O than that of Na2O•6TiO2•7H2O.3) As a result of the reaction of Indian high-titanium bauxite to caustic soda solution, it was found that the titanium in the bauxite existed mainly in anhydride oxide form and when treated with less concentrated alkaline solution at a comparatively low-pressure as in the American Bayer Process, a small amount of Na2O was combined with TiO2.4) It was also found that the amount of Na2O combined with TiO2 increased with more vigorous treatment conditions, eventually up to the amount corresponding to 6Na2O•TiO2•7H2O.