锂渣基碱激发胶凝材料的制备及性能

Preparation and properties of lithium slag-based alkali-activated cementitious materials

目的:针对锂渣活性差、堆积量大、利用率低的难题,提出以锂渣为主要原料、矿粉为硅铝矫正料制备碱激发胶凝材料的技术研究。方法:通过正交试验探究各影响因素对胶凝材料抗压强度影响,得到最佳原料配比;通过机械活化和热活化得到锂渣最佳活化条件,采用XRD、SEM对锂渣基胶凝材料的微观结构进行表征。结果:结果表明:当机械活化60 min、650℃热活化1 h的锂渣掺量60%、水玻璃模数1、水玻璃掺量12%、液固比0.4、养护温度20℃、搅拌时间10 min,胶凝材料28 d强度可达45.52 MPa;胶凝材料主要水化产物为钠沸石、C-S-H凝胶、白榴石等,凝胶填充孔隙,增加致密性,提升胶凝材料性能。意义:为锂渣的综合利用提供了新的思路。

Purpose:To solve the problem of poor activity,large accumulation and low utilization rate of lithium slag,a technical study on the preparation of alkali-activated cementitious materials with lithium slag as the main raw material and mineral powder as silicon-aluminum corrective material was proposed.Method:The influence of various influencing factors on the compressive strength of cementitious materials was explored by orthogonal experiments to obtain the optimal raw material ratio;the optimal activation conditions of lithium slag were obtained by mechanical activation and thermal activation,and the microstructure of lithium slag-based cementitious materials was characterized by XRD and SEM.Result:The results show that when the lithium slag is mechanically activated for 60 min utes and thermally activated at 650℃for 1 hour with a content of 60%,a water glass modulus of 1,a water glass content of 12%,a liquid-solid ratio of 0.4,a curing temperature of 20℃,and a stirring time of 10 minutes,the 28-day strength of the cementitious material can reach 45.52 MPa;the main hydration products of the cementitious material are sodium zeolite,C-S-H gel,leucite,etc.The gel fills the pores,increases the density,and improves the performance of the cementitious material.Significance:It provides a new idea for the comprehensive utilization of lithium slag.