A process for decomposing zircon sand
Реферат: Zircon sand is decomposed by reaction with at least one mol., preferably 1.5 to 4 mols., of one or more alkali metal oxides per mol. of zircon sand. The reaction is initiated by heating to the igniting temperature, i.e. 100 DEG to 300 DEG C., and the mixture is allowed to react exothermically. After cooling, the mixture is worked up, preferably by suspension in softened, calcium-free, water, so that the soluble constituents are removed, and the solid zirconium hydroxide may be purified by acid-treatment, and then dried. Further, the hydroxide may be dissolved in mineral acid of concentration exceeding 10% and zirconium hydroxide or basic zirconium sulphate, each of which may be converted to the anhydrous oxide by heating, is precipitated by the addition of ammonia. When 1 to 2 mols. of alkali metal oxide are used per mol. of zircon sand, a mixture of zirconium hydroxide, sodium-zirconium silicate and unreacted zircon sand is obtained. This mixture, preferably after extraction with water, may be treated with ammonium sulphate at about 850 DEG C. to give a mixture of sodium sulphate, zirconium oxide and silica. The sodium sulphate may be removed by extraction with water to give a zirconium oxide-silica mixture, which may be used for the production of colours in ceramics.
Process for the production of zirconium sulphate
Номер патента: AU8109187A. Автор: Martin Richard Houchin,Hari Narayan Sinha. Владелец: Commonwealth Scientific and Industrial Research Organization CSIRO. Дата публикации: 1988-05-25.