METHOD OF PREPARING SODIUM FLUORIDE FROM FLUOSILICATE COMPOUNDS Russian patent published in 2001 - IPC

FIELD: technology of extraction of fluorine in the form of sodium fluoride from fluosilicate compounds. SUBSTANCE: method comprises preparing sodium fluoride at elevated temperature by mixing sodium hydroxide with fluosilicate compound in amount that maintains temperature of the resulting suspension within 80-90 C and pH is adjusted to 10.05-10.9, and sodium fluoride residue is then separated from mother liquor of sodium metasilicate by filtration and washed with saturated solution of sodium fluoride to give readily filterable sodium fluoride salt having low moisture content and reduce sodium fluoride losses in washing stage. EFFECT: more efficient preparation method. 3 cl, 4 ex, 4 tbl