To add Mg into molten iron at a low cost, to finely granuate the oxide contained in the iron and to improve the quality by reducing the oxide consisting essentially of MgO with Al and making a specified composition consisting essentially of Mg-Al alloy, Al2O3.MgO and MgO.
A metallic reducing agent consisting essentially of Al is blended into the oxide consisting essentially of MgO, desirably at 0.2-1.5 kg ratio of Al to 1 kg of MgO, formed as a briquette, and burnt at 900-1200°C under inert gas atmosphere of Ar gas, etc. In this way, an Mg additive for molten iron, consisting essentially of Mg-Al alloy, Al2O3.MgO and MgO, is obtd. at a low cost. At this time, this Mg-Al alloy is desirable to be 10-70 wt.% the ratio of Mg therein and 10-65% content in the Mg additive. This Mg additive can be added into the molten iron in good yield and the coarsening of the oxide of Al2O3, etc., in the molten iron is prevented at a low cost.
SASAI KATSUHIRO
YAMAMURA HIDEAKI
FUJI TAKEHIKO
