METHOD FOR PREPARING HYDROGEN FLUORIDE Russian patent published in 2004 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: invention is designated for using in chemical and miming industries and can be used in isolation of hydrogen fluoride from mineral fluorite and other fluorine- containing materials. Mineral fluoride concentrate with content of CaF₂ 99.8% is granulated with 96% H₂SO₄ taken in the stoichiometric ratio = 1:(1-1.1), respectively, at temperature 95-250 C. Granulated charge is fed to the tube rotating roasting furnace and roasted to the complete decomposition of mineral fluorite. Exhausting gases are fed to the gas scrubbing system and hydrogen fluoride is separated. Calcium sulfate granules are treated with milk of lime, separated from pulp and dried. Invention provides converting 95-99% of fluorine to hydrogen fluoride, to prepare calcium sulfate granules with the content of fluoride ions 0.9-4.3% and 0.5% of free sulfuric acid. Granules are resistant to the moisture effect. Deposits in tube furnace are absent. EFFECT: improved preparing method. 1 dwg, 4 ex