GB697673A - Process for the production of rutile - Google Patents

Abstract

In the production of rutile by hydrolysis of a titanium sulphate solution, without the addition of nucleating agents, and by subsequent calcination of the hydrolysate at 700-950 DEG C, the solution, containing 180-260 grms./litre Tio2 is first heated until it becomes strongly turbid due to the formation of colloidal titanium hydrate, and hydrolysis is initiated by mixing with an aqueous liquid, e.g. water or ferrous sulphate solution, or 5N caustic soda solution, or 5N sulphuric acid solution, which can be hot or cold, and which may be added in amounts equal to 10-100 per cent of the volume of the titanium sulphate solution. After the addition, the solution may be boiled, preferably for an hour at the most, and the hydrolysate is then advantageously cooled within the mother liquor to below 95 DEG C by adding colder water or aqueous solution; alternatively, the hydrolysate is separated rapidly from the mother liquor. Prior to or during heating of the solution before the addition of the aqueous liquid, there may be added water or an aqueous solution, e.g. ferrous sulphate, 5N caustic soda, or 5N sulphuric acid solution, provided that the titanium sulphate solution is not diluted below the limit specified above. A solid alkaline substance, e.g. sodium hydroxide or calcium oxide, may alternatively be added.