Improving the hydration activity and volume stability of the RO phases in steel slag by combining alkali and wet carbonation treatments
Improving the hydration activity and volume stability of the RO phases in steel slag by combining alkali and wet carbonation treatments
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DOI：
10.1016/j.cemconres.2023.107236
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发表时间：
2023-06-28
影响因子：
11.4
通讯作者：
Chang, Jun
中科院分区：
文献类型：
--
作者：
Li, Wenzheng;Cao, Mingli;Chang, Jun
钢渣(SS)的体积稳定性差是由于存在游离CaO、游离MgO和RO相所致。采用碱法和湿法碳化(AWC)相结合的方法对反渗透相进行处理，以激发其水化活性。氧化镁摩尔比为0.84的AWC_RO相的水化程度从10.6%提高到57.6%。基于密度泛函理论，研究了FeO-MgO-MnO比例对反渗透相水化活性的影响。结果表明，铁对氧化镁水化的抑制作用强于锰。掺入AWCSS的砂浆28d抗压强度比掺加未处理SS提高34.4%，膨胀率由0.0447%降至0.0298%。AWC_RO相的主要产物为Mg(OH)2和Mg5(CO3)4(OH)2&Bull；4H2O，它们具有晶种效应，加速了水泥的早期水化。这种方法为解决SS体积稳定性差的有意义的解决方案提供了指导。
Poor volume stability of steel slag (SS) is due to the existence of free-CaO, free-MgO, and RO phases. Combined treatments of alkali and wet carbonation (AWC) were conducted on the RO phases to stimulate hydration activity. The hydration degree of AWC_RO phases with MgO molar ratios of 0.84 increased from 10.6 % to 57.6 %. The effects of FeO-MgO-MnO proportions on the hydration activity of RO phases were investigated electronically based on the density functional theory. Results showed that Fe imparted higher inhibition effects on MgO hydration than Mn. The compressive strength of mortar with added AWC_SS was 34.4 % higher than with added untreated SS at 28 days, with an expansion rate decreased from 0.0447 % to 0.0298 %. The main products of AWC_RO phases were Mg(OH)2 and Mg5(CO3)4(OH)2 & BULL;4H2O, which exhibited seed crystal effects, accelerating the early hydration of cement. This method provides guidance towards a meaningful solution to poor SS volume stability.