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Chemical and physical analyses have shown that hydrous titanium dioxide, prepared from titanium sulfate solution, consists of flocculates of small anatase crystals. Water and sulfur trioxide appear to be present as adsorbed layers and in capillaries between and within the flocculates. During heating, loss of water occurs at about 15OoC., loss of sulfur trioxide at about 65OoC., crystallite and particle-size growth at about 600°C., and the transformation of anatase to rutile in the range 700" to 95OoC., depending on the method of preparing the samples. The kinetics of the transformation were found to be first order, following an induction time which appeared to depend on a nucleation process. Activation energies were of the order of 100 kcal. per mole and frequency factors of the order of 10" to lo2' hr.-I. Precision X-ray diffraction studies showed that the anatase lattice expanded slightly before the transformation and that the initial rutile formed was expanded.

Reduced titanium chlorides dissolved in fused alkali and alkaline earth chlorides may be electrolyzed in diaphragmed cells under an inert gas atmosphere to yield ductile titanium as adherent, crystalline deposits. The reduced titanium chlorides are prepared in situ by adding TiCl4 through a hollow cathode at a controlled feed to current ratio.