Determination of titanium, tantalum and niobium by precipitation from homogeneous solution

Abstract

A method of precipitation from homogeneous solution has been developed for the gravimetric determination of titanium, by thermal decomposition of soluble peroxytitanate from either an alkaline or a slightly nitric acid medium. Recoveries are better than 99.6%. Coprecipitation of tungsten and manganese are reduced to a considerable extent. Furthermore, tantalum and niobium can be precipitated with highly satisfactory recoveries from a homogeneous nitric acid-hydrogen peroxide solution. Coprecipitation of titanium is investigated and corrections for Coprecipitation calculated. The earth acids can also be precipitated from a homogeneous ammonia-hydrogen peroxide solution, the coprecipitation of tungsten being almost negligible. A study of the Coprecipitation process of tungsten on tantalum and niobium shows that the distribution coefficients follow a linear pattern on both carriers. The method has been tested on a number of synthetic mixtures of the oxides, corrections for incomplete precipitation and Coprecipitation being applied on the basis of the experimental values.