利用工业固废煅烧制备天然水硬性石灰的实验及应用研究

Experiments and Applications on Preparation of Natural Hydraulic Lime by Calcination of Industrial Solid Waste

天然水硬性石灰(NHL)兼具气硬性和水硬性成分,被广泛应用于历史建筑砌体墙墙面的修复。工业固废含有一定的Ca、Si元素,满足制备NHL的矿物元素要求。本研究以石灰石、矿渣、粉煤灰和硅灰为原材料,控制不同的钙硅比参数煅烧制备NHL。利用XRD、TG、抗压抗折试验、SEM-EDS、维卡仪等测试了NHL的成分、产物的组成、微观形貌、力学性能、凝结时间等,并开展工程应用。结果表明:工业固废煅烧制备NHL具有可行性,所制得NHL主要由氢氧化钙和硅酸二钙组成,28 d水化碳化产物包括水化硅酸钙、CaCO_(3)和Ca(OH)_(2)。钙硅比为4.6时可以制备出符合欧洲标准的NHL2,对砖石风化表面的修复结果满足可逆性与兼容性要求。本文响应了国家对历史建筑遗迹保护和生态环境保护的号召,有助于创造更好的经济效益与环境效益。

Natural hydraulic lime(NHL)has both pneumatic and hydraulic components,so NHL can be widely used in the restoration of historic building masonry walls.Industrial solid waste contains certain elements of Ca and Si,meeting the mineral element requirements for the preparation of NHL.In this study,limestone,slag,fly ash and silica fume were used as raw materials to prepare NHL by calcination with different calcium-silicon ratio parameters.The composition,product composition,microstructure,mechanical properties,and setting time of NHL were tested using XRD,TG,compressive and flexural tests,SEM-EDS,and Vicat apparatus.Meanwhile carry out engineering applications.The study shows that it is feasible to prepare NHL by industrial solid waste calcination.The prepared NHL is mainly composed of calcium hydroxide and dicalcium silicate.The 28 d hydration carbonization products include hydrated calcium silicate,CaCO_(3),and Ca(OH)_(2).NHL can be prepared by calcium-silicon ratio at 4.6 that meets European standards.The repair results of the weathered surface of masonry meet the requirements of reversibility and compatibility.The article responds to the call of national policies for the protection of historical architectural relics and ecological environment,which is conducive to protecting historical culture and creating better economic benefit and environmental benefit.