钢渣粉低液固比固碳工艺及固碳钢渣粉对水泥基材料性能的影响  

Low Liquid-Solid Ratio Carbon Fixation Process with Steel Slag Powder and the Effect of Carbon Fixation Steel Slag Powder on the Properties of Cement-based Materials

作　　者：伍勇华[1] 匡玉峰 易昂 何娟 原毅冰 WU Yonghua;KUANG Yufeng;YI Ang;HE Juan;YUAN Yibing(College of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《材料导报》2024年第13期155-162,共8页Materials Reports

基　　金：陕西省自然科学基础研究计划项目(2021JM-353)。

摘　　要：矿物固碳进行CO_(2)捕集是减少温室效应的重要途径,钢铁生产企业利用钢渣与带有余热和CO_(2)的废气反应可以达到协同处置的效果。本工作研究了低液固比(润湿状态)条件下钢渣固碳的最佳工艺,确定出最佳固碳反应参数为反应温度100℃、液固比9%、反应时间60 min、CO_(2)压力0.4 MPa。该工艺条件下,钢渣粉固碳率可达119.1 g CO_(2)/kg,固碳产物主要为方解石型碳酸钙。在此基础上,研究了掺入固碳钢渣粉对水泥净浆体积安定性、标准稠度需水量、凝结时间、胶砂强度和水化热的影响。结果表明:钢渣粉固碳后,体积安定性明显改善;固碳钢渣粉对水泥净浆标准稠度需水量无不利影响;与未固碳钢渣相比,固碳钢渣对水泥凝结硬化的延缓作用有所减弱,且随固碳率增大减弱效果增强;固碳钢渣粉在低掺量(10%)时,能提高水泥胶砂的3 d、7 d和28 d抗压强度,但掺量过高(>30%)时,会显著降低水泥胶砂的3 d、7 d和28 d抗压强度。XRD测试表明CaCO_(3)能够水化生成单碳型水化碳铝酸钙(C_(3)A·CaCO_(3)·11H_(2)O)和半碳型水化碳铝酸钙(C_(3)A·0.5CaCO_(3)·0.5Ca(OH)_(2)·11.5H_(2)O)。低液固比固碳有助于钢铁企业实现碳中和,也可以改善钢渣体积安定性,使钢渣粉得到更有效的利用。The mineral carbon sequestration for CO_(2)absorption is crucial for reducing the greenhouse effect.Steel production enterprises can achieve synergistic disposal by reacting steel slag with exhaust gas CO_(2)and waste heat.In this paper,the optimum process of steel slag carbon sequestration under low liquid-solid ratio(wetting state)was studied.The optimum carbon fixation reaction parameters were determined as follows:reaction temperature 100℃,liquid-solid ratio 9%,reaction time 60 min,CO_(2)pressure 0.4 MPa.Under this process condition,the carbon fixation of steel slag powder can reach 119.1 g CO_(2)/kg,and the carbon fixation product is mainly calcite calcium carbonate.On this basis,the effects of carbon-fixing steel slag powder on cement stability,standard consistency water demand,setting time,hydration heat release and mortar strength were studied.The results showed that the volume stability of steel slag powder is significantly improved after carbon fixation.Compared with uncarbon-fixing steel slag powder,there is no adverse effect on the water demand of cement paste standard consistency.The retarding effect of carbon-fixing steel slag on cement setting and hardening is weakened,and the weakening effect is enhanced with the increase of carbon fixation rate.Carbon-fixing steel slag powder can improve the 3 d,7 d and 28 d compressive strength of cement mortar at low content(10%),but when the content is too high(>30%),it will significantly reduce the 3 d,7 d and 28 d compressive strength of cement mortar.XRD test shows that CaCO_(3)can hydrate to form single-carbon hydrated calcium carboaluminate(C_(3)A·CaCO_(3)·11H_(2)O)and semi-carbon hydrated calcium carboaluminate(C_(3)A·0.5CaCO_(3)·0.5Ca(OH)_(2)·11.5H_(2)O).Low liquid-solid ratio carbon fixation is helpful for iron and steel enterprises to achieve carbon neutralization,and can also improve the volume stability of steel slag,so that steel slag powder can be used more effectively.

关 键 词：钢渣 矿物固碳 固碳率 体积安定性 水化碳铝酸钙 

分 类 号：TU528[建筑科学—建筑技术科学]