铅锌渣生态胶凝材料的制备及水化特性研究

Study on the preparation and hydration characteristics of lead-zinc slag ecological cementitious material

铅锌冶炼渣经高温熔融,水淬急冷会形成玻璃形态物料,在碱性条件下具有一定的活性,可用于生产建材掺合料和胶凝材料。以铅锌渣为主原料,添加少量水氯镁石、钙基固废和水泥作为激发剂,成功制备了铅锌渣生态胶凝材料。通过电子万能试验机、X射线衍射仪(XRD)分析了胶凝材料的力学性能和水化产物特征;通过正交试验的方法研究了胶凝材料力学性能的变化;并通过扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、压汞仪(MIP)等方法分析了胶凝材料水化产物的微观形貌及结构特征。结果表明,当水氯镁石掺量为3%(质量分数),固废总掺量为70%(质量分数),水灰比为0.4,钙基固废掺量为16%(质量分数)时,制备出的铅锌渣生态胶凝材料性能最优,其28 d抗压强度达到9.73 MPa,且水灰比为影响抗压强度的第一因素;XRD分析表明,胶凝材料发生了聚合反应,生成了-Si-O-Si-的结构;SEM分析表明,胶凝材料水化产物微观下呈现蜂窝状结构,这种结构激发了其潜在水化活性,提升了材料的力学性能;FT-IR分析表明,Si-O键逐渐聚合为Si-O-Si键,C-S-H中硅氧四面体聚合度增加;MIP分析表明,胶凝材料的孔径较小,硬化体结构密实,强度较大。

Aftermelting at high temperature and water quenching and quenching,lead-zinc smelting slag will form glass form materials.It has certain activity under alkaline conditions and can be used to produce building material admixtures and cementing materials.Lead-zinc slag ecological cementitious material is successfully prepared by using lead-zinc slag as main raw material with a small amount of bischofite,calcium based solid waste and cement as activator.The mechanical properties and hydration products of cementitious materials are analyzed by electronic universal testing machine and X-ray diffraction(XRD).The mechanical properties of cementitious materials are studied by orthogonal test.The microstructure and morphology of the hydration products are analyzed by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR)and mercury porosimetry(MIP).The results show that when the content of bischofite is 3 wt%,the total content of solid waste is 70 wt%,the water cement ratio is 0.4,and the content of calcium based solid waste is 16 wt%,the prepared lead-zinc slag ecological cementitious material has the best performance.The 28 d compressive strength of cementitious material reaches 9.73 MPa,and the water cement ratio is the first factor affecting the compressive strength.XRD analysis shows that the cementitious materials are polymerized to form the structure of-Si-O-Si-.SEM analysis shows that the hydration products of cementitious materials present honeycomb structure,which stimulates the potential hydration activity and improves the mechanical properties of the materials.FT-IR analysis shows that the Si-O bond is gradually polymerized into Si-O-Si bond,and the degree of polymerization of silicon oxygen tetrahedron in C-S-H increases.MIP analysis shows that the pore size of cementitious material is small,and the structure of hardened body is dense and the strength is high.