快速煅烧条件对煤系偏高岭土性能的影响  

The Effect of Rapid Calcination Conditions on the Properties of Coal-series Metakaolin

作　　者：王磊 酒少武[1] 成思萌 王朝蓬 李辉[1] WANG Lei;JIU Shaowu;CHENG Simeng;WANG Zhaopeng;LI Hui(College of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710000,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,陕西西安710000

出　　处：《材料科学与工程学报》2022年第5期791-795,822,共6页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51672207)。

摘　　要：本研究对内蒙煤系高岭岩粉料开展快速煅烧实验,研究煅烧条件对偏高岭土性能的影响,探索快速煅烧方法的可行性。在自行设计的快速煅烧装置上,700~900℃、30 s~25 min的条件下制备煤系偏高岭土,采用X射线衍射仪(XRD)、红外光谱和扫描电镜(SEM)等技术手段判断煅烧程度,分别以氟硅酸钾容量法和比色法测定煤系偏高岭土中活性硅和活性铝的溶出活性,对最优性能的产品通过胶砂试验测定胶凝活性。结果表明:煅烧温度和时间不当会降低产品的溶出活性;最佳条件为在800℃煅烧10 min,制备的煤系偏高岭土的活性铝和活性硅的溶出量分别为86.01%和68.99%,28 d活性指数为105%,能满足高强高性能混凝土用矿物外加剂的要求。Rapid calcination experiments were carried out for Inner Mongolia coal series kaolin to study the influence of calcination conditions on the properties of metakaolin and evaluate the feasibility of the process. Metakaolin products were prepared by a self-designed rapid calcination device at a temperature range of 700-900 ℃ for 30 s to 25 min. XRD, infrared spectroscopy, and SEM were used to determine the degree of calcination. Potassium fluosilicate volumetric method and colorimetric method were used to determine the dissolution activity of active silicon and active aluminum in metakaolin. Mortar tests were carried out for the metakaolin products with the highest comprehensive dissolution rate to determine its gelling activity. The results showed that insufficient or excessive temperature and time lead to the decrease of solubility activity of metakaolin products. The best condition for the preparation of metakaolin was calcined at 800 ℃ for 10 min. Dissolution rates of active aluminum and active silicon of metakaolin prepared under the best condition were 86.01% and 68.99%, respectively. The activity index of 28 d was 105%, which could meet the requirements of mineral admixtures for high strength and high performance concrete.

关 键 词：煤系高岭岩 快速煅烧 硅铝溶出活性 

分 类 号：TU521.3[建筑科学—建筑技术科学]