{"title":"Degradation of alkali-activated Fe-rich slag in sulfuric acid","authors":"Nana Wen , Arne Peys , Tobias Hertel , Ziyou Yu , Dimitrios Sakellariou , Yiannis Pontikes","doi":"10.1016/j.cemconres.2024.107523","DOIUrl":null,"url":null,"abstract":"<div><p>Alkali-activated Fe-rich non-ferrous metallurgical slag (AA-NFS), within the FeO<sub>x</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-CaO-MgO system, were tested in 2 wt% sulfuric acid for 6 months. Corrosion depth and rate were measured non-destructively by micro X-ray computed tomography. Both intact and corroded areas were characterized by XRD, FTIR, SEM-EDX and NMR. AA-NFS with higher Ca/Si showed a higher resistance to sulfuric acid. The presence of Mg negatively affected the resistance, whereas higher Al concentrations slightly enhanced the resistance in the investigated chemical composition range. The corrosion degree is closely related to the NFS reaction extent in AA-NFS, and this corrosion process is diffusion-controlled. Leaching of the elements (Al, Ca, Mg, Fe and Na) leaves behind mostly silica-rich gels, causing the failure of the framework structure after long-term exposure. The leached Ca<sup>2+</sup> reacted with SO<sub>4</sub><sup>2−</sup> in acid solution and formed expansive sulfate products, which possibly clog pores and offer an additional protective barrier for AA-NFS against sulfuric acid.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"181 ","pages":"Article 107523"},"PeriodicalIF":10.9000,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement and Concrete Research","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0008884624001042","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Alkali-activated Fe-rich non-ferrous metallurgical slag (AA-NFS), within the FeOx-SiO2-Al2O3-CaO-MgO system, were tested in 2 wt% sulfuric acid for 6 months. Corrosion depth and rate were measured non-destructively by micro X-ray computed tomography. Both intact and corroded areas were characterized by XRD, FTIR, SEM-EDX and NMR. AA-NFS with higher Ca/Si showed a higher resistance to sulfuric acid. The presence of Mg negatively affected the resistance, whereas higher Al concentrations slightly enhanced the resistance in the investigated chemical composition range. The corrosion degree is closely related to the NFS reaction extent in AA-NFS, and this corrosion process is diffusion-controlled. Leaching of the elements (Al, Ca, Mg, Fe and Na) leaves behind mostly silica-rich gels, causing the failure of the framework structure after long-term exposure. The leached Ca2+ reacted with SO42− in acid solution and formed expansive sulfate products, which possibly clog pores and offer an additional protective barrier for AA-NFS against sulfuric acid.
期刊介绍：
Cement and Concrete Research is dedicated to publishing top-notch research on the materials science and engineering of cement, cement composites, mortars, concrete, and related materials incorporating cement or other mineral binders. The journal prioritizes reporting significant findings in research on the properties and performance of cementitious materials. It also covers novel experimental techniques, the latest analytical and modeling methods, examination and diagnosis of actual cement and concrete structures, and the exploration of potential improvements in materials.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
