摘要 |
Magnesium is produced by the metallothermic reduction of MgO in a molten slag bath comprised of MgO, Al2O3 and CaO together with oxide formed from the reducing metal. The composition of the slag is controlled during at least a first stage of the reduction so that it is wholly within the periclased region of its phase diagram and, at least in the surface region, has a substantially constant liquidus temperature. The surface region of the slag is maintained by direct heating (e.g. by a plasma) at or close to the liquidus temperature. |