提取钛的尾矿渣(TETS)具有较高的活性,但是氯离子的含量很高。为了有效地结合氯离子,CaO被用来激活TETS,制备了CaO活化TETS固化胶凝材料。研究了CaO含量和固化龄期对固化试样强度的影响,氯化物结合能力,并对氯化物结合机理进行了研究。通过XRD,FTIR,SEM,和EDS,水合反应产物,微观结构,形态学,并对固化样品的微观成分进行了表征。结果表明,利用CaO活化具有较高机械强度的TETS能有效结合氯离子。当CaO含量为10重量%时,28天固化体的强度可以达到20MPa以上,氯离子结合量为38.93mg/g,氯化物结合率高达68%。固化样品的新产品相主要是弗里德尔盐(FS)和方解石,其中FS产量和晶体发育程度受CaO含量和固化龄期的影响。固化样品中的氯离子结合离子主要是FS的化学键合。FS衍射峰强度随CaO含量和固化龄期的增加而增加,但方解石衍射峰强度受它们的影响较小。FS主要在固化样品的孔中积累和生长。它可以优化固化样品的孔结构,并在结合氯离子的同时提高固化样品的强度。研究结果可为含氯TETS的资源化利用提供有用信息,提高海工混凝土的耐久性,以及海砂在混凝土中的应用。
Titanium-extracted tailing slag (TETS) has high activity, but the content of chloride ions is high. To effectively bind the chloride ions, CaO was used to activate the TETS, and the solidified cementitious material of CaO-activated TETS was prepared. The effects of CaO content and curing age on the strength of solidified samples, chloride binding capacity, and chloride binding mechanism were studied. By means of XRD, FTIR, SEM, and EDS, the hydration reaction products, microstructure, morphology, and micro-components of the solidified sample were characterized. The results show that the chloride ions can be effectively bound by using CaO to activate TETS with higher mechanical strength. When the CaO content is 10 wt%, the strength of the 28-day-cured body can reach more than 20 MPa, the chloride ion binding amount is 38.93 mg/g, and the chloride binding rate is as high as 68%. The new product phases of the solidified sample are mainly Friedel\'s salt (FS) and calcite, in which the amount of FS production and the degree of crystal development are affected by the CaO content and curing age. The chloride binding ions in the solidified sample are mainly the chemical binding by FS. The FS diffraction peak strength increases with the increase of CaO content and curing age, but the calcite diffraction peak strength is less affected by them. FS mainly accumulates and grows in the pores of the solidified sample. It can optimize the pore structure of the solidified sample and improve the strength of the solidified sample while binding chloride ions. The results can provide useful information for the resource utilization of chlorine-containing TETS, the improvement of durability of Marine concrete, and the application of sea sand in concrete.