2000 Volume 86 Issue 11 Pages 741-747
For accelerating the removal of copper and tin by evaporation under practical reduced pressure, 1.3×102 Pa, decarburization by weak oxidizing agents such as SiO2 and MgO has been investigated in laboratory scale experiments. The experimental results are as follows;
(1) An effective removal of copper was obtained in the order of MgO>SiO2>O2 at a given amount of decarburization. The order is the same as that of oxygen potential of those oxidizers.
(2) 50% of copper in iron melt was removed in 40 min in MgO crucible, which was reacted as an oxidizer. The rate of decopperization was 1.53 times higher than that without decarburization.
(3) The reason why the acceleration of the removal of copper was achieved is assumed to be due to the increase in reaction interfacial area obtained by turbulence with decarburization. However, low oxygen content is preferable, because oxygen is the surface active element and is assumed to retard the evaporation reaction.
(4) In high sulfur melt, 0.1 mass%, removal of copper was slightly lowered by suppresion of decarburization. However, removal of tin was accelerated. The phenomenon is considered to be caused by preferential evaporation as SnS.