Weak magnetic response on radical reaction involved dissolution corrosion of lightweight magnesia with iron oxide containing steel slag

Slag corrosion of refractory lining is related to the safety of metallurgical buildings and steel quality. The dissolution corrosion behavior of lightweight magnesia in the CaO-Al 2 O 3 -SiO 2 -FeO x slag at 1600 °C under weak static magnetic field was investigated. The effects of iron oxide content in the slag on the dissolution rate of the magnesia , slag structure, weak magnetic effect and radical reaction were discussed. The results show that the dissolution rate of the magnesia in the iron oxide containing slags will be reduced, and the weak magnetic effect is still displayed. The reaction inhibition interval of magnetic flux density is 4–8 mT in the range of 0–16 mT. The iron oxide in the slag can improve the dissolution activation energy , promote the formation of original radicals, and depolymerize the slag structure. The study reveals the radical reactions between oxides and iron oxide containing molten slags. The formation pathway of radicals and the mechanism of radical reaction in the molten slag were clarified. The dissolution corrosion of the magnesia in CaO-Al 2 O 3 -SiO 2 -FeO x slag under weak magnetic field is mainly affected by two kinds of radical reactions related to magnesia oxide and iron oxide, and the latter has a larger magnetic inhibition threshold. With increasing of iron oxide content, the latter gradually dominates the effect. Thus, the increase of iron oxide will increase the magnetic inhibition threshold, the increase of temperature will gradually weaken the influence of weak magnetic field on the reaction and gradually decrease the magnetic inhibition effect and threshold. Iron oxide in the steel slag plays an important role on the weak magnetic response of lightweight magnesia dissolution corrosion with radical reactions. • The magnesia dissolution in iron oxide containing slag is controlled by radical reactions, which show weak magnetic response. • Iron oxide in the slag can promote the formation of original radicals of the slag, and reduce the dissolution rate. • The influence of iron oxide content in the slag and temperature on magnetic effect is clarified. • The mechanism of free radical reactions in dissolution of magnesia in CaO-Al 2 O 3 -SiO 2 -FeO x slag were illustrated.