GB754915A - Improvements in or relating to the production of titanium tetrachloride - Google Patents

Abstract

<PICT:0754915/III/1> Titanium tetrachloride is prepared from titaniferous materials containing substantial amounts of alkali or alkaline earth metal impurities by chlorinating the material in the presence of a carbonaceous reducing agent such as coke in a bed fluidized by a gaseous chlorinating agent, preferably chlorine and maintaining the resulting water soluble alkali or alkaline earth metal chloride content of the bed at not more than 7 per cent by weight thereof, by intermittently or continuously withdrawing a portion of the bed, leaching it to wash out the water-soluble content thereof, drying the residue and recycling it to the reaction zone. The invention is particularly applicable to titaniferous oxidic slags obtained by smelting an ore to remove iron values therefrom, which slags may contain 60 to 80 per cent titanium dioxide and 10 to 20 per cent of iron as well as calcium, magnesium and sodium compounds in amounts up to 10 per cent. The preferred mode of operation is shown in the Figure and the amount of material withdrawn from the reactor and passed through the leaching filtration and drying stages prior to re-cycling may amount from 0.2 to 7 parts by weight of the titaniferous material initially fed. The reaction may be effected at 500 to 1250 DEG C., preferably 800 to 1100 DEG C., heat being supplied if necessary by pre-heating of reactants or other means. A solid reducing agent such as coke is preferred and may constitute 15 to 35 per cent of the ore fed. The chlorinating gas may be pure chlorine but recovered chlorine containing oxygen and nitrogen may be used, for example a gas containing 30 per cent chlorine resulting from the oxidation of the titanium tetrachloride in the prohuction of titanium oxide pigment. Depending upon the operating temperature and chlorine concentration ferric or ferrous chloride may be formed, it being preferable to provide sufficient chlorine for ferric chloride formation which is volatilized with the titanium tetrachloride and separated therefrom for example by cooling the product gases to a point such that spray cooling with liquid titanium tetrachloride will condense the ferric chloride as solid.