摘要 |
A process for the production of ferrochromium by smelting chromite ore and in which ferrochromium fines may form a part of the feed materials, or for the further treatment of ferrochromium fines alone, in each case in the presence of a limited amount of carbonaceous reductant, is provided. The amount of reductant is generally limited to a maximum of 150% of the stoichiometric amount required for reduction of all the chromium and iron to metal or carbide form and to produce the required level of silicon in the product (normally 2 to 4%). The process is carried out by feeding the preferably premixed feed materials to a liquid slag phase in the bath of the furnace at a rate chosen to maintain the molten state and temperature of such material. Oxygen is substantially excluded from the reaction zone which is heated by a transferred arc thermal plasma. The feed materials generally include slagging agents chosen to ensure that the slag liquidus temperature and metal liquidus temperature are roughly the same or that of the slag is less than that of the metal, but in any event such that the slag phase remains liquid throughout the process. |