THERMODYNAMIC ASPECTS OF RECOVERY WO3 TITANIUM

The paper considers the effectiveness of the technology of direct alloying with tungsten in submerged welding of powdered wires containing WO₃ tungsten oxide and reducing agents as a filler. It is shown that during electric arc discharge, tungsten and (or) chemical compounds of tungsten (carbides, silicides, borides and other compounds) can be formed during the surfacing process. In this regard, it is possible to use such powder wires: they have been tested in laboratory and semi-industrial conditions. This work is devoted to the thermodynamic assessment of the possibility of reducing tungsten oxide WO₃ with titanium. Thermodynamic calculations of reactions of recovery of tungsten oxide WO₃ using titanium to a temperature of 3000 K under standard conditions were carried out to obtain tungsten and titanium oxides TiO, Ti₂O₃, Ti₃O₅, Ti₄O₇, TiO₂.. The thermodynamic characteristics of reactions necessary for the assessment of reducing properties under standard conditions [∆_rН°(Т), ∆_rS°(Т), ∆_rG°(Т)] for substances in crystalline and liquid states are calculated in the temperature interval of the welding arc 1500 – 6000 K according to thermodynamic properties свойствам [[Н°(Т) – Н°(298.15 K)], S°(Т), ∆_fH°(298.15 K)] reagents WO₃, W, Ti, TiO, Ti₂O₃, Ti₃O₅, Ti₄O₇, TiO₂. As a result of the thermodynamic analysis of the thermodynamic characteristics of the reactions, it was determined that as a result of the reduction of WO₃ by titanium to a temperature of 2100 K, the production of TiO₂ is thermodynamically most likely, at temperatures above 2100 K, the formation of Ti₄O₇ is most likely. Thermodynamically, the production of TiO, Ti₂O₃, and Ti₃O₅ oxides is the least likely.

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