SORBENT FOR EXTRACTION OF HYDROGEN FLUORIDE FROM GASES AND METHOD FOR ITS PREPARING Russian patent published in 2003 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to sorbents used for extraction of hydrogen fluoride from gaseous mixtures and to methods for its preparing and can be used for trapping hydrogen fluoride from disposal gases or for treatment of gaseous metal fluorides (uranium, tungsten, molybdenum, sulfur, selenium, tellurium hexafluorides and others) from hydrogen fluoride. Method for preparing sorbent involves mixing lithium fluoride and calcium, magnesium or ammonium fluorides as an addition. Mixtures of fluorides is wetted and formed to granules, granules are sintered at temperature 250-500 C, treated with liquid hydrogen fluoride or hydrofluoric acid solution in the concentration above 30 wt.-% and subjected for temperature treatment to obtain sorbent containing 75-90 wt.-% of LiF and 10-25 wt.-% of CaF₂ or MgF₂. Lithium fluoride-base a sorbent in the form of granules is suitable for exploitation, it endures multifold cycles of sorption-desorption and provides effective trapping hydrogen fluoride from gases. EFFECT: improved extraction method. 3 cl, 3 tbl