Study On Preparation And Properties Of High Cementitious Activity Steel Slag Of Excellent Soundness

The mineral composition of steel slag is similar to that of cement,however,the large fluctuation of chemical composition,low cementitious activity and poor volume make the use of steel slag seriously restricted.At present,online reconstruction of steel slag is a hotspot research.The formation mechanism and the effect of different process parameters on the reconstructed steel slag in the laboratory were studied by using the Fact Sage thermodynamic software calculated,finally the excellent steel slag was obtained,which provide a theoretical basis for online reconstruction.The results showed when the ratio of S/A is contant,the cementitious activity was better with the increase of C/S ratio.When the ratio of C/S is constant,the cementitious activity was better with the decrease of S/A ratio.When the ratio of C/S and S/A were different,the cementitious activity was better with the decrease of S/A ratio.The cementitious activity increased with the increase of calcination temperature and the water quenching.The cementitious activity first increased and then remained a constant with the increase of soaking time.And all the reconstructed steel slag meet the national standard GB/T 20491-2006.The mineral composition and microstructure of reconstructed steel slag was studied by X-ray diffraction and metalloscope,it showed when the ratio of S/A is constant,the amount of ?-C2 S,C3S,C2F,MgFe2O4 increased with the increase of C/S.While the ratio of C/S is constant,the amount of C3S and C4AF increased with the decrease of S/A,meanwhile,the liquid phase in the steel slag increased.Moreover,with the increase of calcination temperature,the amount of ?-C2 S,C3S would increase.The hydration heat was studied,it showed that the more of total heat release,the better of cementitious activity was.The dynamic analysis was studied,it showed that the reactions about minerals of RO,C2F,C2S,C3S all meet the first order reaction model.Under the same C/S,the liquid phase would increase with the decrease of S/A,which can provides a good dynamic condition for the reconstruction.It showed the apparent activation energy of RO,C2F,C2S,C3S decreased.