Experimental Study Of Mold Fluxes Preparation From Blast Furnace Slag

The blast furnace slag is the byproduct discharged from blast furnace. There is approximately 6×107t of blast furnace slag annually in our country, and the totally accumulation amount is over 108t by now. According to the compositional characteristics of the blast furnace slag, it can be used as the major material for developing the mold fluxes, by which it is possible to recycle and reuse in the iron and steel company and promote the utilization level.After consulting the literatures concerning the information of mold fluxes used by domestic and foreign steel plants, a datebase was established with Microsoft Visual Basic 6.0 as the compiler language. In this study, mold fluxes were prepared from the blast furnace slag of Baosteel. By using experimental apparatus of melting temperature, rotary viscometer and experimental apparatus of inclusions dissolution, the variation curves of melting temperature, viscosity, solidification temperature and Al2O3 dissolution rate etc. under different mixture ratio were investigated, then the slag composition was initially designed. Under this experiment condition, the results were shown as following.(1) With the database of mold fluxes, the information of mold fluxes used by domestic and foreign steel plants can be managed and inquiried according to steel grade, slab type, physicochemical properties and chemical composition. It also supplying the theoretical basis for development and application of mold fluxes.(2) Mold fluxes can be prepared by adding wollastonite, fluorite, soda and artificial cryolite et al into the blast furnace slag of Baosteel.(3) The melting temperature of mold fluxes decreased gradually with increasing the content of wollastonite, while the viscosity and Al2O3 dissolution rate are increased.(4) With the same flux agent content, the capacity for decreasing the melting temperature of mold fluxes is as following:cryolite> fluorite and soda> fluorite> soda; the capacity for decreasing the viscosity of mold fluxes is as following:fluorite and soda> cryolite> fluorite; the capacity for decreasing the solidification temperature of mold fluxes is as following:cryolite> fluorite> soda; the capacity for decreasing the Al2O3 dissolution rate is as following:fluorite and soda> cryolite> fluorite.