引用格式：

DOI：10.13732/j.issn.1008-5548.2025.04.017

收稿日期：2024-06-18， 修回日期： 2024-09-21，上线日期： 2024-04-03。

基金项目： 国家自然科学基金项目， 编号： 52378263、 52178254； 四川省自然科学基金项目，编号： 2024NSFSC0914； 西南科技大学研究生创新基金， 编号： 24ycx2031。

第一作者简介： 刘继浩（2001—），男，硕士生，研究方向为超高性能混凝土。E-mail：3032347065@qq.com。

通信作者简介： 刘来宝（1978—）， 男， 教授， 博士， 四川省学术与技术带头人后备人选， 博士生导师， 研究方向为固废资源化利用。E-mail：liulaibao@swust.edu.cn。

摘要： 【目的】 为了实现硝酸加压提锂渣微粉（lithium slag，LS）在绿色建筑材料中的资源化利用，研究不同颗粒状态的LS对水泥水化反应和性能的影响。【方法】 采用机械研磨得到不同粒径的LS，并通过激光粒度仪和扫描电子显微镜（SEM）观察其颗粒状态变化，测试不同颗粒状态LS对水泥砂浆力学性能的影响；通过X射线衍射分析（XRD）、水化热分析、红外光谱分析（FTIR）、压汞分析（MIP）评价颗粒状态对水泥水化反应的影响。【结果】 随着球磨时间的延长，LS粒径逐渐减小，LS比表面积逐渐增大，颗粒逐渐趋于细化和球形化； 随着LS粒径的减小，掺入LS的水泥浆体流动度逐渐减小，凝结时间缩短； 掺入质量分数为30%的LS的砂浆抗压强度在龄期为56、 90 d时比纯水泥砂浆的高6%~29%，且LS粒径越小，抗压强度增长越快； 通过水化产物和孔隙结构结果也证明，粒径越小的LS在反应时消耗的氢氧化钙越多，在水化后期掺入LS颗粒的水泥浆体凝胶孔体积分数大于纯水泥浆体的，更多的水化凝胶填充了颗粒间的孔隙，使其微观结构更致密，后期抗压强度增长越显著。 【结论】 LS的火山灰活性随着粒径的减小而增强，在合适的掺量下可以有效促进水泥砂浆长期强度的发展。

关键词： 硝酸加压提锂渣微粉； 颗粒状态；水泥； 火山灰活性

Abstract

Objective Cement production is known for its high energy consumption and significant environmental pollution. Reducing cement usage in construction industry is key to minimize pollution. Lithium slag （LS）， a solid waste generated during the extraction of lithium carbonate from spodumene ore through nitric acid pressure leaching， contains 96.9% of alumina and silicon oxide， displaying potential pozzolanic activity. LS can be used as a mineral admixture in cement-based materials to reduce cement consumption. However， the particle size of mineral admixtures affects their pozzolanic activity and the performance of blended cement. This paper studies the effects of LS particle sizes on the pozzolanic activity and the performance and mechanical properties of the blended cement.

Methods After drying LS at （105 ± 2） ℃ for 24 h， LS powders with different particle sizes were prepared through ball milling for 20， 40， 60， 80， 100， and 120 min. The specific surface area of the resulting LS powders was measured， and four samples with distinct particle size distributions were selected for further experiments. These samples were named as LS1， LS2， LS3， and LS4 from smallest to largest particle size. Their particle size distribution and microstructure were analyzed using laser particle size analyzer and scanning electronic microscope （SEM）. P·O 42.5R cement， LS1~LS4， and standard sand were used as the main materials. The water-binder mass ratio was 0.5， the mortar mass ratio was 1：3， and the relative cement mass was 30%. LS with different particle sizes was blended to prepare standard mortar test blocks of 40 mm×40 mm×160 mm. The pure cement paste and LS1~LS4 composite pastes with 30% relative cement mass were named as A0， A1， A2， A3， and A4， respectively. The cement mortar and paste test blocks were cured with specified duration under conditions of （20±2） ℃ and 90% relative humidity， and their compressive strength was measured at 3， 7， 28， 56， and 90 d. The mix ratio of the cement paste was the same as that of the mortar， with the standard sand removed. Based on the mix ratio of cement paste， the effects of different LS particle sizes on the fluidity， setting time， and water requirement for normal consistency were assessed. Hardened cement paste specimens were prepared and cured for 28 and 90 d. The effects of LS on the hydration products and pore structure of the cement with different curing days were tested using X-ray diffraction （XRD）， Fourier transform infrared spectrum （FTIR）， and mercury intrusion porosimetry （MIP）. The hydration heat release rate and hydration heat release of A0， A1~A4 pastes within 72 h were measured using hydration heat analyzer.

Results and Discussion The results showed that as ball milling time increased， LS particle size gradually decreased， exhibiting a more spherical shape. Compared to A0， the water requirement for normal consistency increased by 1.5% for A1 and 3.5% for A4. Fluidity decreased by 16.9% for A1 and 44.6% for A4. The initial setting and final setting times for A1 decreased by 15.5% and 5.3%， respectively， and for A4， these values decreased by 27.4% and 14.3%. Hydration heat test results showed that the addition of LS reduced the heat release rate and cumulative heat release. However， with the decrease in LS particle size， both the heat release rate and the cumulative heat release increased， although the overall hydration reaction rate was lower than that of pure cement paste. The compressive strength of A1~A4 cement mortars was lower than that of A0 in the early stage of hydration （3， 7 d）. At 28 d， the compressive strength of A4 reached 122.6%， with a strength of 52.1 MPa， while other LS samples had lower strengths than A0. Beyond 56 d， the compressive strength of the mortars ranked from highest to lowest was A4， A3， A2， A1， and A0， indicating that smaller LS particle sizes promoted the long-term strength development of cement mortar. XRD analysis showed that the intensity of calcium hydroxide （CH） diffraction peak of A1~A4 was lower than that of A0 at 28 d， and decreased with smaller LS particle sizes. At 90 d of curing， the change in CH diffraction peak intensity was consistent with that observed at 28 d， but the decrease in CH peak intensity was more pronounced， This indicated that the active aluminosilicate in LS underwent a secondary hydration reaction with CH generated by cement hydration reaction， forming more calcium aluminosilicate gel. Also， the smaller the LS particle size， the more CH was consumed， resulting in a greater amount of hydrated calcium silicate gel， which promoted strength development. This trend was consistent with the compressive strength results of the mortar. FTIR and MIP analysis demonstrated that the addition of LS increased the content of calcium aluminosilicate hydrate gel， further optimized the pore structure of the hardened cement paste， and increased the volume fraction of gel pores in the test blocks. These findings confirmed that smaller LS particle sizes effectively promoted the cement hydration reaction and improved the compressive strength of the mortar.

Conclusion In this paper， the effects of nitric acid pressure leaching-extracted lithium slag powder with different particle sizes on its pozzolanic activity and the properties of the blended cement were studied. The study provides valuable insights into the use of LS in sustainable building materials.

Keywords： nitric acid pressure lithium extraction slag powder； particle state；cement； pozzolanic activity

参考文献（References）

［1］MARTIN S， VOLKER H， JOHANNES R， et al. The cement plant of tomorrow［J］. Cement and Concrete Research， 2023，173： 107290.

［2］王鑫， 李玉华， 何立环， 等. 中国水泥行业2011—2022年二氧化碳和大气污染物排放分析［J］. 中国环境监测， 2024，40（2）： 8-18.

WANG X， LI Y H， HE L H， et al. Emission analysis of carbon dioxide and air pollutants in China’s cement industry from 2011 to 2022 ［J］.Environmental Monitoring in China， 2024， 40（2）： 8-18.

［3］李联康. 集成先进低碳技术装备打造绿色智能水泥示范线［J］. 中国建材， 2024（3）： 82-85.

LI L K. Integrated advanced low-carbon technology and equipment to create a green intelligent cement demonstration line［J］.China Building Materials， 2024（3）： 82-85.

［4］张昊， 段玉凯， 王军. 生态胶凝材料研究进展与展望［J］. 科技创新与应用， 2019（20）： 38-41.

ZHANG H， DUAN Y K， WANG J. Research progress and prospect of ecological cementitious materials ［J］. Innovation and Application of Science and Technology， 2019（20）： 38-41.

［5］王浩， 黄根红， 陈瑞英， 等. 全球锂资源供需展望及锂产品价格预测［J］. 中国有色冶金， 2022， 51（6）： 1-11.

WANG H， HUANG G H， CHEN R Y， et al. Global lithium resource supply and demand outlook and lithium product price

forecast ［J］.China Nonferrous Metallurgy， 2022， 51（6）： 1-11.

［6］张苏江， 张彦文， 张立伟， 等. 中国锂矿资源现状及其可持续发展策略［J］. 无机盐工业， 2020， 52（7）： 1-7.

ZHANG S J， ZHANG Y W， ZHANG L W， et al. Status of lithium resources in China and its sustainable development strategy［J］.Inorganic Salt Industry， 2020， 52（7）： 1-7.

［7］ZHANG Y， MA B Z， LV Y W， et al. An effective method for directly extracting lithium from α-spodumene by activated roasting and sulfuric acid leaching［J］.Journal of Industrial and Engineering Chemistry， 2023， 122： 540-550.

［8］李强. 锂辉石提锂工艺方法综述［J］. 化工管理， 2022（32）： 147-149.

LI Q. Review of lithium extraction process from spodumene ［J］. Chemical Management， 2022（32）： 147-149.

［9］GU T， ZHANG G， WANG Z， et al. Review： the formation， characteristics， and resource utilization of lithium slag［J］.Construction and Building Materials， 2024， 432： 136648.

［10］ LUCIA I， JORGE A， MARIA D.Extraction of lithium from β-spodumene using chlorination roasting with calcium chloride［J］. Thermochimica Acta， 2015， 605： 63-67.

［11］陈亚， 廖婷， 陈白珍， 等. 纯碱压煮法从锂辉石中提取锂的研究［J］. 有色金属： 冶炼部分， 2011（9）： 21-23.

CHEN Y， LIAO T， CHEN B Z， et al. Study on the extraction of lithium from spodumene by soda pressure boiling method［J］. Nonferrous Metals： Smelting Part， 2011（9）： 21-23.

［12］王奕仁. 锂渣的火山灰活性评价及其复合胶凝材料微结构特性研究［D］. 北京： 中国矿业大学（北京）， 2019.

WANG Y R. Study on the pozzolanic activity evaluation of lithium slag and the microstructure characteristics of its composite cementitious materials［D］. Beijing：China University of Mining and Technology （Beijing）， 2019.

［13］王雪， 王恒， 王强. 我国锂渣资源化利用研究进展［J］. 材料导报， 2022， 36（24）： 63-73.

WANG X， WANG H， WANG Q. Research progress on resource utilization of lithium slag in China［J］. Material Report，

2022， 36（24）： 63-73.

［14］邹晨， 吴松蔚. 锂渣粉作掺合料在混凝土中的研究［J］. 江西建材， 2023（11）： 52-54.

ZOU C， WU S W. Research on lithium slag powder as admixture in concrete［J］. Jiangxi Building Materials， 2023（11）：52-54.

［15］ZHANG G， PENG G F， ZUO X Y， et al.Adding hydrated lime for improving microstructure and mechanical properties of mortar for ultra-high performance concrete［J］.Cement and Concrete Research， 2023， 167： 107130.

［16］杨泽波， 刘勇， 陈清蓉， 等. 混凝土用矿物掺合料超细化作用机理［J］. 材料导报， 2023， 37（S1）： 151-155.

YANG Z B， LIU Y， CHEN Q R， et al. Ultrafine mechanism of mineral admixtures for concrete ［J］. Material Introduction，2023， 37（S1）： 151-155.

［17］RANGANATH R V， BHATTACHARJEE B， KRISHNAMOORTHY S. Influence of size fraction of ponded ash on its pozzo-

lanic activity［J］. Cement and Concrete Research， 1998， 28（5）： 749-761.

［18］GUZZO P L， MARINHOD B F B， DE A T A A. Effect of prolonged dry grinding on size distribution， crystal structure and thermal decomposition of ultrafine particles of dolostone［J］. Powder Technology， 2019， 342： 141-148.

［19］袁化强. 基于胶凝材料颗粒间相互作用力及骨料特性的自密实混凝土流变性及机理研究［D］. 济南： 山东大学， 2023.

YUAN H Q. Study on the rheology and mechanism of self-compacting concrete based on the interaction force between cementitious materials and aggregate characteristics ［D］. Jinan： Shandong University， 2023.

［20］SCRIVENER K L， JUILLAND P， MONTEIRO P J M. Advances in understanding hydration of Portland cement［J］.Cement and Concrete Research， 2015， 78（Pt.A）： 38-56.

［21］ZHAO Y， GAO J， LIU C， et al. The particle-size effect of waste clay brick powder on its pozzolanic activity and properties of blended cement［J］. Journal of Cleaner Production， 2020， 242（1）： 1-10.

［22］LAND G， STEPHAN D. The influence of nano-silica on the hydration of ordinary Portland cement［J］. Journal of Materials Science， 2012， 47（2）： 1011-1017.

［23］HOU P， KAWASHIMA S， KONG D， et al. Modification effects of colloidal nano SiO₂ on cement hydration and its gel property［J］. Composites Part B Engineering， 2013， 45（1）： 440-448.

［24］SAHOO B， MATTEPPANAVAR S. Observation of phase transformations in cement during hydration［J］. Construction and Building Materials， 2015， 101（Pt.1）： 122-129.

［25］MOLLAH M， YU W， SCHENNACH R， et al. A Fourier transform infrared spectroscopic investigation of the early hydration of Portland cement and the influence of sodium lignosulfonate［J］. Cement and Concrete Research， 2000， 30（2）：267-273.

［26］傅博， 马梦凡， 申旺， 等. 气化渣对硅酸盐水泥强度和微观结构的影响研究 ［J］. 硅酸盐通报， 2020， 39（8）： 2523-2527.

FU B， MA M F， SHEN W， et al. Effect of gasification slag on strength and microstructure of Portland cement ［J］. Silicate Bulletin， 2020， 39（8）： 2523-2527.

［27］WINSLOW D N， DIAMOND S. A mercury porosimetry study of the evolution of porosity in portland cement［J］. Gels， 1969.

［28］SILVA B A， FERREIRA PINTO A P， GOMES A. Natural hydraulic lime versus cement for blended lime mortars for restoration works［J］. Construction and Building Materials， 2015， 94（30）： 346-360.

［29］ZENG Q， LI K， TEDDY F C， et al. Pore structure characterization of cement pastes blended with high-volume fly-ash［J］.Cement and Concrete Research， 2012， 42（1）： 194-204.