Influence of Raw Material Type on Heat Transfer and Structure of Mould Slag

Abstract

The effect of the raw materials and mixing ratio on the heat transfer and structure of mould slag was studied in the present paper. Three groups of mould slag with identical chemical composition were designed by various raw materials and mixing ratio. The result indicates that the raw material has minor effect on viscosity, melting point and crystalline phase of the mould slag; whereas, it affects the formation and size of crystal. The wollastonite in slag has higher crystallization capacity; therefore, it promotes the formation of thicker solid slag film with higher porosities and consequently prevents the strong heat flux through the slag film. Compared with wollastonite, prefused material in the slag has capability to restrain the crystallization process; hence, the thinner solid slag film with uniform size and finer grain is formed. The experiment proves that prefused mould powder has good performance on heat transfer.