3.2. V–C–O and Ti–C–O system
Ao Jingqing has pointed out that VCx and TiC can be formed in steelmaking converter via reaction of V2O5 and TiO2 in slag with graphite . However, the formed VCx and TiC are not stable and will reoxidize at high oxygen partial pressure. V–C–O system diagrams at 1650 °C and 1420 °C are shown in Fig. 3. Chen Zhaoyou has indicated that in an open system, e.g. steelmaking converter, PCO=1 atm, Po2=5.6×10−16 atm . In this HU 308 case, VCx can be formed. For vanadium recovering converter, oxygen blowing time is about 3–5 min, far shorter than 30–45 min blowing of steelmaking converter. In biomass case, PCO<<1 atm and Po2>>5.6×10−16 atm. VCx and TiC are difficult to form and will quickly reoxidize at high oxygen partial pressure, that is why VCx and TiC cannot be observed and detected.
Fig. 3. V–C–O and Ti–C–O predominance area diagrams at 1650 °C and 1420 °C.Figure optionsDownload full-size imageDownload as PowerPoint slide