采用掺入电石渣并在850℃高温条件下煅烧石英岩尾砂1 h,对石英岩尾砂进行表面改性,利用X线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱仪(EDS)对改性石英岩尾砂的矿物组成和化学成分进行表征,并测定掺入改性石英岩尾砂的水泥浆体的干燥收缩和抗压强度。结果表明:改性石英岩尾砂颗粒表面生成了具有水化活性的β-C2S,水化生成水化硅酸钙(CSH)凝胶,改善了复合水泥浆体中石英岩尾砂颗粒与水泥浆体的界面黏结,提高了水泥浆体的强度,降低了干燥收缩。
The surface of quartz tailings was modified through mixing with carbide slag and calcining at850 ℃ for 1 h.The microstructure,mineral phases and chemical compositions of the modified quartz tailings were analyzed by using X-ray diffraction( XRD),scanning electron microscopy( SEM) and energy dispersive spectrometer( EDS).In addition,the effects of modified quartz tailings on the drying shrinkage and compressive strength of cement pastes were investigated. Results showed that the β-C2 S phases were formed on the surface of the modified quartz tailings. Due to the hydration of the β-C2 S,calcium silicate hydrate( CSH) gel was generated,the interface between hydrated cement matrix and quartz tailings was densified,and therefore the strength of the blended cement paste was improved,and the drying shrinkage of the cement paste was reduced.