METHOD OF OBTAINING SODIUM SILICON FLUORIDE

摘要

FIELD: chemistry. ^ SUBSTANCE: present invention relates to chemical industry. Fluorine-containing gases from wet-process production of phosphoric acid and fertiliser are absorbed in water. The obtained silicon hydrofluoric acid is neutralised with soda in the presence of sodium bicarbonate at pH 0.2-3 for a period of 0.25-1 hour. Mass ratio soda:sodium bicarbonate equals 1:1 - 4. ^ EFFECT: increased rate of settling sodium silicon fluoride crystals to 8 - 10 m/h due to increase in percentage of crystals with size of 60-70 mcm to 80-85%. ^ 6 ex