Fluosilicates

Fluosilicates

 

salts of fluosilicic acid, H2SiF6. They decompose upon heating—for example, CaSiF6=CaF2 + SiF4. The sodium, potassium, rubidium, cesium, and barium salts are only slightly soluble in water; the characteristic crystals formed are used in quantitative and microchemical analysis. Sodium fluosilicate has found widest practical application, particularly in the manufacture of acid-resistant cement and enamel. A substantial proportion of Na2SiF6 is converted into NaF. Sodium fluosilicate is produced from the waste products of superphosphate plants containing SiF4. Fluosilicates of magnesium, zinc, and aluminum (industrial name, Fluoate) are used to waterproof building stone, since they are readily water-soluble. All fluosilicates, as well asH2SiF6, are toxic.

References in periodicals archive ?
In 1823, he succeeded in preparing amorphous silicon by the same general method as used earlier, but he purified the product by removing the fluosilicates by repeated washings.