METHOD OF PROCESSING AMMONIUM POLYFLUORIDE AND METHOD OF PRODUCING NITROGEN TRIFLUORIDE USED THEREIN Russian patent published in 2024 - IPC C01B21/83 C01B7/19 C01B32/10 C01B11/24 

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to methods of processing ammonium polyfluoride and producing nitrogen trifluoride NF₃ by fluorination of ammonium polyfluoride with fluorine. Method of processing ammonium polyfluoride involves fluorination of molten ammonium fluoride with fluorine, neutralization and drying of the gas stream, and removal of volatile impurities. After separating excess liquid ammonium polyfluoride from the fluorination reactor, it is directed for flaking or reacted with oxygen, or with oxygen and carbon, or with oxygen and hydrogen-containing substances, or with oxygen, and with carbon, and with hydrogen-containing substances, or with fluorine, or with fluorine and hydrogen-containing substances with separation of low-boiling substances and extraction of hydrogen fluoride or hydrofluoric acid. Method of producing nitrogen trifluoride involves fluorination of molten ammonium polyfluoride with fluorine, neutralization and drying of gas flow, removal of volatile impurities. Fluorine is fed to the fluorination step, while maintaining acidity of ammonium polyfluoride in the range from NH₄F·1,2HF to NH₄F·2HF by adding ammonia. Nitrogen trifluoride is purified from difluoroamine, tetrafluorohydrazine and dinitrogen difluoride in a thermocatalytic reactor into which a fluorine stream is fed. Nitrogen trifluoride is purified from fluorine, hydrogen fluoride, silicon tetrafluoride, sulfur-containing acid gases and carbon dioxide with an alkaline solution. Gas flow is dried by zeolite. Impurities with boiling point lower than that of nitrogen trifluoride are removed by low-temperature rectification. Carbon tetrafluoride is separated from nitrogen trifluoride by absorption.

EFFECT: invention enables to create an integrated, low-waste, explosion-proof technology of producing TPA and a group of inorganic fluorides—nitrogen trifluoride, carbon tetrafluoride, carbon difluoride-oxide, hydrogen fluoride, high-purity hydrofluoric acid.

8 cl, 1 dwg, 11 ex