GB743735A - Improvements in or relating to a method for the purification of titanium tetrachloride - Google Patents

Abstract

Crude titanium tetrachloride is treated to remove a major portion of the impurities therein by refluxing in the presence of a non-drying vegetable oil of the olive oil type, namely almond, apricot kernel, date kernel, hazel nut, peach kernel, peanut, plum kernel. and olive oils. The amount of oil employed is suitably 0.1 to 0.2 per cent. The treatment may suitably be carried out in a unit comprising a still having a fractionating column, a reflux return and a condenser and the tetrachloride oil mixture may be heated to a temperature and for a period of time such that all the tetrachloride as vapour is circulating through the fractionating column and reflux return; thereafter the vapour is allowed to pass to a condenser where the tetrachloride is condensed and collected leaving a hard granular still residue comprising rutile, anatase, free carbon and vanadium in the form of its chloride or oxychloride, which may be recovered from the residue by water leaching. Impurities referred to include vanadium, silica, alumina, niobium and tungsten and the vanadium content of the final condensate may be reduced to from 0.0001 to 0.0003 per cent by weight of the tetrachloride. Examples relate to the addition of 1 part of olive or peanut oil respectively to 1000 parts of crude tetrachloride at room temperature and the subsequent refluxing of the mixture at 136 DEG C. for about 2 hours, followed by distillation to obtain water-white titanium tetrachloride condensate.