碱激发尾煤充填材料水化动力过程与水化机制
Hydration dynamic process and hydration mechanism of alkali excited flotation tailings filling material
樊玉萍 1李德浩 2董宪姝 1马晓敏 1付元鹏1
作者信息
- 1. 太原理工大学矿业工程学院 山西太原 030024;山西省生态矿业工程研究中心 山西太原 030024
- 2. 太原理工大学矿业工程学院 山西太原 030024
- 折叠
摘要
为了优化充填材料中胶凝材料成本和性能之间的平衡关系,用浮选尾煤替代部分水泥制备胶凝材料,研究其火山灰性质和水化动力过程变化特征.采用活性率Ka表征胶凝材料火山灰活性,通过TAM Air等温微仪测定胶凝材料水化放热速率,基于Krstulović-Dabić水化动力学模型,计算尾煤胶凝材料水化动力学参数.试验结果表明:浮选尾煤火山灰活性激发的最佳条件是,经800 ℃煅烧处理3 h后,添加w(硅酸钠)=6％的固体硅酸钠激发剂,活性率Ka最高为18.85％.浮选尾煤胶凝材料,较水泥的水化放热特征曲线的第二放热峰显著下降且前移,表现出较低的水化放热速率和水化放热量.通过水化动力过程转变特征分析,发现浮选尾煤胶凝材料结晶成核和晶体生长(NG)过程向相边界作用(Ⅰ)过程转变和Ⅰ过程向扩散(D)过程转变节点发生前移,由此建立了尾煤胶凝材料水化动力学过程描述性模型.浮选尾煤经热活化和碱激发联合处理后制备的胶凝材料表现出更快的水化速率和较低的放热量,应用于充填开采,可有效降低充填材料成本.
Abstract
Flotation tailings coal was used to replace some cement-prepared cementitious mate-rials to study the variation characteristics of volcanic ash properties and hydration kinetics process,aiming to achieve a better balance between the cost and performance of cementitious materials in filling materials,The activity rate Ka was employed to characterize the volcanic ash activity of cementitious materials,the hydration exothermic rate of cementitious materials was determined by TAM Air isothermal calorimater,and the hydration kinetic parameters of tailings coal cementitious materials were calculated based on the Krstulovic-Dabic hydration ki-netic model.The results show that the best condition for the activity excitation of volcanic ash of flotation tailings coal is to add solid sodium silicate activator with mass fraction w(sodium silicate)=6％after calcination at 800 ° C for 3 h,and the highest activity rate Ka is 18.85％.Compared with cement cementitious materials,the second peak of the hydration exothermic characteristic curve of flotation tailings coal cementitious materials decreases significantly and moves forward,showing lower hydration exothermic rate and hydration heat release.Through the analysis of the variation characteristics of hydration kinetics process,it is found that the transition nodes from NG process to Ⅰ process and from Ⅰ process to D process of the flotation tailings coal cementitious materials move forward.Therefore,a descriptive model of hydration kinetic process of tailings coal cementitious material is established.The cementitious materials prepared by the combined treatment of thermal activation and alkali excitation show faster hy-dration rate and lower heat release,which can effectively reduce the cost of filling materials when applied to filling mining.
关键词
浮选尾煤/充填开采/火山灰活性/水化放热速率/水化动力学Key words
flotation tailings/infill mining/pozzolanic activity/hydration exothermic rate/hy-dration kinetics引用本文复制引用
基金项目
国家自然科学基金重点国际(地区)合作研究项目(51820105006)
山西省重点研发计划项目(202202090301009)
出版年
2024
NETL
NSTL
万方数据