Abstract: 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.

Abstract: The present invention provides a process plant for the production of molten steel from primary and/or secondary ferrous materials in which no free oxygen is permitted to contact directly carbon-containing iron melts, comprising:—i) at least three pairs of furnaces (1,2; 3,4;5,6), each furnace of a pair having a hearth base (36) and being interconnected so as to form a continuous flowpath loop for molten metal, the first pair (1,2) defining an iron making loop (A) and the second and third pair (3,4;5,6) defining primary and secondary steel refining loops (B,C) respectively, (ii) means (8) for transferring molten metal from the ironmaking loop (A) to the first refining loop (B) and from the first refining loop (B) to the second refining loop (C), (iii) means for controllably supplying heat to, and removing heat from metal in the furnaces (1,2,3,4,5,6), whereby, in use a central region of metal (19a) in the furnace (1,2,3,4,5,6) becomes or is maintained in its molten state and a peripheral region of the metal (2