| 摘要 |
Steel and pigment-grade TiO2 with up to 99.99 % (TiO2 + ZrO2) are produced continuously by direct smelting ilmenite or titaniferous magnetite concentrates at ultra-high temperature. Both oxidic and metal phases are independently force circulated in fully backmixed melt circulation reactors. Close proximity to thermodynamic equilibrium permits liquidus composition melts to be contained within reactors with protective linings of unmelted shells comprised of oxycarbide of the solidus composition. The unmelted shells are maintained above the critical temperature of the ductile to brittle fracture transition by supercritical steam generation, whilst the endothermic heat is supplied by electrical conductive heating. Smelting reduction with natural gas or carbon with low sulphur content, followed by in-line continuous vacuum refining makes available a continuous feed of refined melt for further in-line processing at somewhat lower temperatures using known emerging technologies for titanium metal production. |
