Stability Transformation Mechanism of Steel Slag Aggregate with Autoclaved Carbonation  

作　　者：HU Chenguang SU Hang FU Jiawei LI Enshuo DING Feng FENG Xiaoxin 胡晨光

机构地区：[1]College of Materials Science and Engineering,North China University of Science and Technology,Tangshan 063210,China [2]Laboratory of Inorganic Material of Hebei Province,Tangshan 063210,China [3]Tangshan Transportation Bureau,Tangshan 063000,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2025年第2期412-426,共15页武汉理工大学学报(材料科学英文版)

基　　金：Funded by the Natural Science Foundation of Hebei Province(No.E2020209010);the Science and Technology Plan Project of Tangshan(No.19150225E);the Key R&D Projects of North China University of Science and Technology(No.ZD-ST-202301)。

摘　　要：In view of the volume instability of steel slag aggregate leading to the quality problem of expansion damage in asphalt road construction,the 4.75-9.5 mm steel slag particles were treated by autoclaved carbonation technology,and the effects of the carbonation system(temperature and time)on the autoclaved pulverization rate,f-CaO content,and the relationship between them for the carbonated steel slag were investigated.In addition,the microstructure of the carbonated steel slag was analyzed by X-ray diffractometer(XRD),scanning electron microscope and energy dispersive spectrometer(SEM-EDS),metallographic microscope and X-ray fluorescence imaging spectrometer(XRF).The experimental results indicate that,under the initial CO_(2)pressure of 1.0 MPa,increasing the carbonation temperature leads to the increase in the crystal plane spacing of Ca(OH)_(2)that was generated by the hydration of minerals in steel slag,and promotes the transformation of carbonated CaCO_(3)from the orthorhombic system to the hexagonal system,resulting in the increase of the crystal planes spacing of them,meantime,accelerates the decomposition of RO phases and also the outward migration of Ca^(2+),Fe^(2+),and Mn^(2+)ions to cover and coat on the Si^(4+),Al^(3+)ions,and impels the formation of hydroxides such as Fe(OH)_(3)and the formation of carbonates such as Ca(Mg)CO_(3),FeCO_(3)and MnCO_(3).Carbonation at the temperature of 90℃for 3 h can reach the center of 4.75-9.5 mm steel slag particles.Meanwhile,the increase of temperature can promote the mineral reaction in steel slag,resulting in the fuzzy interface between mineral phases,increase of burrs,dispersion,crossover,reduction of grain size,and rearrangement of mineral particles.

关 键 词：volume stability of steel slag carbonation system f-CaO content autoclaved pulverization rate MICROSTRUCTURE 

分 类 号：TG1[金属学及工艺—金属学]