Relationship between pore structure and hydration activity of CaO from carbide slag

作     者：Junqiang Zhang Shu Zhang Mei Zhong ZhiWang Guoyu Qian Junhao Liu Xuzhong Gong 

作者机构：Key Laboratory of Green Process and EngineeringNational Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China Key Laboratory of Coal Clean Conversion&Chemical Engineering Process(Xinjiang Uyghur Autonomous Region)College of Chemistry and Chemical EngineeringXinjiang UniversityUrumqi 830046China University of Chinese Academy of SciencesBeijing 100190China 

出 版 物：《Chinese Journal of Chemical Engineering》 (中国化学工程学报（英文版）)

年 卷 期：2019年第27卷第11期

页      面：2771-2782页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：Supported by the National Natural Science Foundation of China(U1610101 51422405) 

主　　题：Carbide slag CaO Hydration activity Sintering Pore volume fraction 

摘      要：CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride(PVC) industry was utilized as precursor for preparing high activity CaO. The roles of crystallite grain, average pore diameter(APD) and volume fraction of pore b 200 nm in diameter(VF200) in hydration activity of CaO from carbide slag(CS-CaO)were respectively investigated. The hydrolysis kinetics model of CaO shows a three-dimensional spherically symmetric diffusion model(D4), which suggests that hydration activity was mainly associated with APD and VF200 of CS-CaO with limited correlation to the crystal size. Specifically, the hydration activity of CS-CaO is increased with increasing VF200, while decreased with increasing APD. Under the invariable calcination temperature,the core–shell structure formed by the addition of graphite or Ca CO3 to CS effectively inhibits the sintering of CS-CaO and improves VF200. Consequently, the hydration activity of CS-CaO increased from 22.79 ℃·min^-1 to27.19 ℃·min^-1 and to 29.27 ℃·min^-1, with addition of 5% graphite or 5% CaCO3 into carbide slag, respectively.