GB308725A - Improvements in or relating to the manufacture of titanium compounds - Google Patents

Abstract

308,725. Titanium Pigment Co., Inc., (Assignees of Ryan, L. W.). March 27, 1928, [Convention date]. Titanium sulphate and oxide.-The precipitation by hydrolysis of titanium compounds from aqueous mineral acid titaniferous solutions by addition thereof to a hot aqueous bath is effected in the presence in the hydrolysis liquor of an organic acid, for instance tannic, citric, oxalic, or gallic acids. Phosphoric acid may also be present, and the acids may be added in the form of their salts, for instance as sodium oxalate or tartrate, as ammonium citrate, or as a phosphate Hydroylsis may be effected by gradually bring- ing together, preferably with continuous agitation, the titaniferous solution and a body of hot water whilst maintaining the mixture at the initial temperature, say 90-98‹ C., of the hot water, and the organic acid, with or without phosphoric acid, may be present either in the titaniferous solution or in the body of hot water; preferably the titautiferous solution is added to the hot water. The solution to be hydrolyzed may be obtained by digesting a titaniferous ore or commercial titanium dioxide with concentrated sulphuric acid, extracting the mass so obtained with water, reducing iron, if present, to the ferrous state as by means of zinc, and carrying the reduction so far that the, solution contains a small proportion of trivalent titanium. The hydrolysis product may be calcined at say 700- 1000‹ C. to obtain a white pigment of titanium oxide which may contain for example, 0.6-1.30 per cent of P2O5.