METHOD OF PRODUCING ANHYDROUS HYDROGEN FLUORIDE WITH LOW ARSENIC AND SULFUR DIOXIDE CONTENTS Russian patent published in 2005 - IPC

FIELD: industrial inorganic synthesis.

SUBSTANCE: method comprises treatment of fluor-spar with sulfuric acid, condensation if crude hydrogen fluoride and rectification thereof, treatment of resulting hydrogen fluoride with salt mixture of potassium permanganate and potassium bifluoride and rectification of treated mixture. More specifically, sulfuric acid used for treating fluor-spar is preliminarily treated with hydrogen and aforesaid salt mixture is added in amount providing residual content of potassium permanganate 22-30 and potassium bifluoride 33-44 g per 1 t starting HF. Invention enables development of anhydrous hydrogen fluoride production technology ensuring As and SO₂ levels in HF product, respectively, below 1 ppm and no higher than 0.001%.

EFFECT: reduced As and SO₂ levels, reduced loss of product, and increased process output.

5 cl, 3 tbl