Currently, there are no effective industrial technologies to return fluorine into a technological cycle. The authors have proposed a method for processing uranium hexafluoride depleted in the U-235 (DUHF) isotope in a hydrogen-oxygen flame that can be used as a basis for obtaining hydrogen fluoride and uranium oxides. Using own devising program code and complex ASTRA.4, performed thermodynamic calculations in the U-F-H-O elements system and it was shown that if the number of hydrogen atoms exceeds the number of fluorine atoms, then at temperatures above 1150 K, the only fluorine-containing substance in the thermodynamically equilibrium mixture was HF, while the main uranium-containing was UO2. The proposed method was experimentally investigated at a pilot plant and it showed that the composition of its products was close to thermodynamic equilibrium. The results can become the basis for industrial technology of the hydrogen fluoride production from DUHF.