锂渣水泥土无侧限抗压强度及抗剪强度特性

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关键词：锂渣；水泥土；无侧限抗压强度；抗剪强度；微观机理中图分类号：S26 文献标志码：A 文章编号：1674-8530（2025）12-1245-09DOI：10.3969/j.issn.1674-8530.24.0101

Abstract：The effcts of lithium slag replacement rate and curing age on the strength of cement-soil were studied through unconfined compressve strength tests and direct shear strength tests. Scanning Electron Microscopy（SEM） was used to analyze the strength development mechanism of lithium slag cement-soil. The test results show thatthe unconfined compressve strength and shear strength of lithium slag cement-soil first increase and then decrease with the increase of lithium slag replacement rate， reaching an optimal replacement rate of 18.75% . At 7days of curing，compared to pure cement-soil， the unconfined compressive strength and shear strength（normal stress of 400kPa ）of lithium slag cement-soil with a replacement rate of 18.75% increase by 37.76% and 9.26% ，respectively. The curing age has a significant effect on the unconfined compressive strength and shear strength of lithium slag cement-soil.At a replacement rate of 18.75% ，the unconfined compressive strength and shear strength （normal stress of 400kPa ）at 28 days are 80.26% and 34.22% higher than those at 7 days，respectively.The cohesion shows a significant trend of first increasing and then decreasing with the increase of lithium slag replacement rate，whereas the internal friction angle changes little with the increase of lithium slag replacement rate.The SEM analysis well explains the conclusions of the strength tests from a microscopic perspective.At an appropriate lithium slag replacement rate，the secondary hydration reaction between the hydration products Ca（OH）2 and calcium aluminate（C-A-H）of lithium slag and cement increases，resulting in more cementitious substances and calcium，thereby optimizing and improving the microscopic structure of lithium slag cement-soil. The research results can provide a reference for the application of lithium slag cement-soil in high way engineering.

Key words： lithium slag;cement-soil; unconfined compression strength;shear strength; microscopicmechanism

“双碳”背景下，中国新能源汽车产业发展迅猛，锂电池及其重要原料锂已成为近年来需求极高的商品之一.由此引发锂矿的开采呈爆发式增长，进一步导致锂渣堆放带来的环境污染问题也愈发严重.锂渣是对富锂资源进行提锂之后所产生的废渣的统称，据估计，生产1t碳酸锂可产生 9～10t 锂渣[1-2]，因锂渣化学成分与性质均一、稳定，含有较高的 Al2O3 和 SiO2 ，且与黏土相似[3-5]，常被用于制备增稠剂、填充剂、吸附剂等材料[.当前全球锂渣年排放量超过400万t，中国年排放量超过200万t.然而，中国的锂渣综合利用率低于 10% ，大部分被储存或填埋，对锂渣的资源化利用还远不能解决大量锂渣堆放的问题。（剩余11424字）