1988 Volume 74 Issue 5 Pages 801-808
Reduction of sintered manganese ore in stirred bath was investigated with a 70 kg scale induction furnace and with a 600 kg scale top and bottom blowing converter.
(1) The change of total manganese content in slag, (T. Mn) is expressed by a first order rate equation. The rate constant, k1 and final manganese content in slag, ( T. Mn) f are affected by CaO/SiO2 ratio, temperature, manganese content in metal, the amount of coke and the condition of bottom blowing. k1 and (T. Mn) are almost constant with [Mn] over 25%. In such a condition, it is shown by X-ray transmission method that reduction site is limited to the coke-slag boundary.
(2) Bottom blown oxygen gas accelerates the reoxidation of manganese and dust formation in the present case, contrary to the case of chromium smelting reduction.
(3) Top blowing oxygen must be blown softly over thick slag layer in order to keep the metal bath away from oxygen jet.
It is concluded that the smelting reduction with top and bottom blowing converter is applicable to the production of ferromanganese.
