PROCESS FOR THE PREPARATION OF SOLID WHITE SODIUM STANNATE FROM TECHNICAL SODIUM STANNATE LIQUOR

摘要

1,220,009. Sodium stannate. TH. GOLDSCHMIDT A.G. 23 Sept., 1969 [2 Oct., 1968], No. 46875/69. Heading C1A. Solid white sodium stannate is prepared from technical sodium stannate liquor, by treating the liquor at a temperature above 40‹ C. with either potassium permanganate, 80-70% w./w. of the permanganate number of the liquor where the permanganate number is the number of milligrams of KMnO 4 which are reduced by one litre of sulphate solution to be treated, or an oxidation-equivalent amount of sodium hypochlorite. Solid material is separated from the liquor, and to the remaining liquor is added up to 0À1% w./w. of a mixture containing at least one sulphated oleic acid amide and one non- sulphated oleic acid amide, whereafter sodium stannate is precipitated by the addition of sodium hydroxide. Suitable sulphated oleic acid amides are the methylanilide of sulphated oleic acid and the dibutylamide or sulphated oleic acid, in each ease in the form of the corresponding sodium salt.