METHOD OF CLEANING HYDROGEN FLUORIDE-INHIBITED NITRIC ACID-NITROGEN OXIDES MIXTURES Russian patent published in 2006 - IPC C01B21/46 C06B47/04 

FIELD: inorganic compounds technologies.

SUBSTANCE: invention relates to processing of nitric acid-nitrogen oxides mixtures containing hydrogen fluoride as corrosion inhibitor, which mixture are mainly used as liquid oxidants rocket fuel oxidants. Title mixtures are treated with a silicon-containing compound, namely alkali metal silicate, preferably liquid soda glass, wherein hydrogen fluoride is directly converted into corresponding metal hexafluorosilicate insoluble in nitric acid-nitrogen oxides mixture. Cleaning is carried out in one stage at temperature ranging from 20°C to boiling point of the mixture depending on content of nitrogen oxides, preferably at 40-45°C, while silicon-containing compound is delivered into mixture in amount close to stoichiometric amount.

EFFECT: increased productivity of process and reduced corrosion-caused wear of equipment.

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