利用钢渣磁选尾渣制备加气混凝土砌块的研究

Preparation of autoclaved aerated concrete block by the residue from the magnetic separation of steel slag

钢渣湿法磁选过程中产生的磁选尾渣由于含水量较高,利用困难,通过将其代替部分石灰和水泥用于制备加气混凝土砌块,研究了配合比、原料细度等对砌块强度的影响,并用X射线衍射(XRD)和扫描电镜(SEM)等分析方法对蒸压过程中的水化产物进行了研究。结果表明,尾渣可以代替部分水泥和石灰用于制备加气混凝土砌块,其掺量高达38%时,砌块抗压强度可达4.1 MPa,适当降低尾渣及河砂细度有利于提高砌块强度。XRD和SEM分析表明,蒸压过程中的主要产物为托贝莫来石、水化硅酸钙(B)和硬硅钙石。片状的托贝莫来石和纤维状的水化硅酸钙(B)、硬硅钙石交织生长,使加气混凝土砌块具有较高的强度。

It is difficult to reuse the residue from the magnetic separation of steel slag for its high water content. In this manuscript,the residue was reused to prepare the autoclaved aerated concrete（AAC） block in replace of lime and Portland cement. The influence of the ratio and the fineness of raw materials on the compressive strength was investigated and the autoclaved products were detected by XRD and SEM. The results show that the residue can partly replace lime and Portland cement in preparation of AAC block and the residue content can reach 38%. The compressive strength of the AAC block achieves 4.1 MPa and the finer residue and sand is benefit to increase the compressive strength. XRD and SEM results show that the main autoclaved products of the AAC block were the plate tobermorite,fihroid hydrated calcium silicate（B） and xonotlite,which mixed grow, making the AAC block have higher strength.