Study On Crystallization Behavior In Direct Fibrosis Process Of Blast Furnace Slag

Blast furnace slag is the main industrial waste produced by the metallurgical industry.Aimed at the condition of lower slag sensible heat recovery in water quench process,large water consumption and low utilization of high value-added.It can change the condition when using slag with amount of modification agent produce the slag wool directly.However,in the process of direct fibrosis will lead to crystallization,decreasing the fiber fracture and strength of the effect of physical and chemical properties of fiber.This paper is based on the SiO₂-CaO-MgO-Al₂O₃ of slag system.Blast furnace slag as the main raw material,around directly in the fibrosis process,analyzing the effect of slag,different Mk and MgO/Al₂O₃ ratios on crystallization behavior.By using Fact Sage and XRD,SEM and other devices in the system of crystallization,influence the evolution of phase transformation and microstructure.Combined with DSC,Tp was studied by different heating rates.On this basis,Kissinger method was calculated E,which reveals the crystallization mechanism of slag.Fact Sage shows that the blast furnace slag will have crystals at 1425.9?,the crystal area is located in melilite.Verified by Fact Sage and XRD,the crystal is the main type of akermanite and gehlenite,using SEM to observe the micro morphology of melilite as columnar crystals.The activation energy of slag is 416.08 k J/mol by Kissinger.In different Mk,through Fact Sage and XRD,crystallization phase is akermanite and gehlenite mainly,with Mk from 1.1 to 1.4,SEM showed that the morphology from thick rough to smooth.Tp of the sample increased gradually?1139.2¹200.8K?,E increased gradually?457.82⁴65.01 k J/mol?,inhibiting the crystallization in different extents.Under the condition of different MgO/Al₂O₃ ratios,Fact Sage and XRD showed that,in cooling crystallization process,akermanite and gehlenite are main crystalline phases.The activation energy of different MgO/Al₂O₃ slag is 432.76⁵00.35 k J/mol by Kissinger method.By general analysis,ensuring the fiber quality,the optimum Mk of slag in 1.3¹.4,the best around 0.6 MgO/Al₂O₃ ratio is more appropriate.