摘要
为有效消纳大量堆放的锂渣,提升锂渣的资源利用效率,以锂渣、矿粉、水泥熟料为原料,制备三元复合胶凝材料,考察了锂渣和矿粉的掺量变化对三元复合体系凝结时间、抗压强度及水化性能的影响,并揭示其机理。结果表明,较矿渣复合水泥,三元复合体系的干缩率降低,水化诱导期显著延迟,凝结时间大幅延迟。掺入10%锂渣和35%矿粉的三元复合体系,较矿渣复合水泥,初凝和终凝时间分别延长151.9%和58.6%,72 h水化放热总量增加4.4%,3 d、7 d抗压强度分别增加47.5%、14.7%,28 d抗压强度相近,56 d干缩率降低5.4%。这是因为锂渣中含大量石膏及氟盐,延缓复合胶凝体系水化。锂渣中石膏与铝酸盐反应生成钙矾石,一方面具有一定膨胀效应,降低了三元体系干缩率,另一方面提高三元体系早期水化程度,增加抗压强度。但由于锂渣活性相对较低,掺入大量锂渣导致水化后期强度显著下降。
In order to effectively utilize a large amount of lithium slag,enhance the resource utilization efficiency of lithium slag,the ternary composite cementing material was prepared with lithium slag,granulated blast furnace slag,and cement clinker as raw materials.The effect of the content of lithium slag and granulated blast furnace slag on the setting behavior,compressive strength and hydration properties of ternary composite system was investigated,and the mechanism was revealed.The results showed that compared with the granulated blast furnace slag-cement composite binder,the dry shrinkage rate of ternary composite system was reduced,the hydration induction period was significantly delayed,and the setting time was delayed sharply.The initial setting time and final setting time of the ternary composite system with 10%lithium slag and 35% granulated blast furnace slag were increased by 151.9% and 58.6%,respectively.The total amount of 72 h hydration heat release was increased by 4.4%.The compressive strength of 3 d and 7 d were increased by 47.5% and 14.7%,respectively,and the compressive strength of 28 d was close.The dry shrinkage rate of 56 d was decreased by 5.4%.This might be the large amount of gypsum and fluorine salts in lithium slag,resulting in the delay of hydration of the composite gelling system.The reaction of gypsum and aluminate in lithium slag to produce ettringite had a certain expansion effect on the one hand,which reduced the dry shrinkage of ternary system.The early hydration degree and mechanical strength of the ternary system were increased.Because of the relatively low activity of lithium slag,adding a large amount of lithium slag led to a significant decrease in the strength of the hydration stage.
作者
张国强
何燕
Zhang Guoqiang;He Yan(School of Civil Engineering,Suzhou University of Science and Technology,Suzhou,Jiangsu 215011)
出处
《非金属矿》
2024年第6期42-44,47,共4页
Non-Metallic Mines
基金
国家自然科学基金(51808369,51890911)
长江科学院开放研究基金资助项目(CKWV20221020/KY)
江苏省研究生科研与实践创新计划项目(SJCX22-1577,SJCX23-1722)。
关键词
水泥
锂渣
矿粉
力学强度
凝结时间
cement
lithium slag
granulated blast furnace slag
mechanical strength
setting time
作者简介
通信作者:何燕,E-mail:hey1019@sina.com。
