Study On The Basic Performance And Application Of Blast Furnace Bag Dust

Cyclic economy,energy saving and emission reducing are important in iron & steel enterprises.Due to the practical situation of Guangfu Company, this paper has developed a new kind of coating based on blast furnace(BF) bag dust which is used in pig-machine casting.This method developed a new way to reuse this kind of Metallurgical solid waste.Thermal performance,microstructures,composition distribution were studied by TG-TSC,SEM,XRD.The composition of Zn in BF bag dust was studied,and the corresponding mathematical model had been built.The properties of BF bag dust used in pig-machine coating which is used as substitution of slime were systemically studied.Furthermore,property improvements experimental were carried out and the best processing parameters were established.The results showed that the BF bag dust of Guangfu Company contains 25 to 35 percent Fe,20 to 28 percent C,the accumulation quantity of Zn was serious,particles were fine,this material was consists by Fe₂O₃,Fe₃O₄,SiO₂, ZnO and partial extraneous phases.Fe spread in most particles and represented little variance,Partial particles contain great amount of Si,Zn was accumulated in fine partials.The quantity of Zn and particle size had reverse relationship by the result of composition distribution of Zn mould. Phases change in high temperature,Fe₃O₄ was the main phase at 800℃,The coating could prevent cracking caused by suddenly heating better,but the property of mould release and suspension is not good.The experiment study on modification showed that the property of coating strength and suspension become better along with rolling,screen separation could improve the property of suspension but there is no significant change in coating strength, the property of coating strength and suspension improve along with the add in of bentonite.Thermal conduction in pig-machine mould was calculated according to Beckley equation,The result showed that the mould using BF bag dust based coating had thermal conduction speed ratio of Q₁=4.25×10⁵W/m²,and Q₂=7.65×10⁵W/m² when slim was used.The heat shock of mould was weakening obviously when use BF bag dust,could protect the mould.Determine the best match and technology of coating by the results: 10%bentonite,1%CMC,89%BF bag dust(under 300 mesh),rolling 30 minute under wet point,rolling 1 hour under flow point.Mould release experiment shows the coating is suit to work.This technology could bring great benefit to iron & steel enterprises,take Guangfu Company as an example,it could save 16.65 million Yuan and dispose 59%BF bag dust in 2007.Release the pressure under environment. This technology was worth popularization.