悬浮态快速煅烧煤系高岭岩新方法的基础研究

To resolve the problems of high energy consumption, poor reactivity, fluctuating whiteness, as well as limited capacity of single facility, which are existing in traditional calcining technology, High Solid Gas Mass Ratio (HSGR) suspension preheating and precalcining technology, which has been successfully implemented in cement industry, was creatively adopted to coal-bearing kaolinite(CBK) calcination. Microstructure characterization, thermal analysis, thermodynamics calculation, numerical simulation and suspemsion calcining experiment will be employed to identify the formation of hydroxyl and carbon existed within CBK, to make sure the mechanism of de-hydroxylation, de-carbonation and phase transition during the process of CBK calcination, to ascertain the shortest residence time for CBK particles to de-hydroxylating and de-carbonating completely, and to investigate the effects of particle size, calcination temperature and time on the properties of calcined kaolin, i.e., the quality of calcined kaolin in whiteness, reactivity and oil-absorption value. All of these will clearify the reaction model of CBK calcinations, explore the process mechanism of de-hydroxylation, de-carbonation and phase-transformtion during calcining CBK, the formation.mechanism of microporous inside calcined kaolin, and the effective measures for modifying the performance of calcined kaolin. This study will offer theoretical guidance for profound understanding the basic law of CBK calcination and developing new method of flash calcining CBK with high efficiency and energy saving.

本研究针对传统窑炉煅烧煤系高岭岩过程单位能耗高、煅烧产品活性低和白度指标不稳定.、单机产量低等问题，创造性地提出将在水泥工业成功应用的高固气比悬浮预热分解技术用于煤系高岭岩的煅烧。用微观表征、热分析、热动力学计算、数值模拟和热态悬浮煅烧实验等方法系统研究煤系高岭岩中羟基、有机碳的赋存形态和脱羟、脱碳机理、悬浮态下完全反应所需的最短时间以及原料细度、煅烧温度和煅烧时间对煅烧高岭土性能（白度、活性、吸油值等）的影响规律，阐明煤系高岭岩煅烧反应的动力学模型，探索煤系高岭岩煅烧过程脱碳-脱羟-相变复合反应的机理、煅烧高岭土的孔结构形成机理和改善煅烧高岭土性能的有效途径。本研究工作将为深刻揭示煤系高岭岩煅烧过程的基本规律，开发高效节能的煤系高岭岩煅烧新方法奠定理论基础。

传统煤系高岭岩煅烧工艺存在单位能耗高、煅烧产品活性低或白度指标不稳定、单机产量低、难以大型化等问题，采用悬浮态煅烧工艺有望突破这些问题。本项目以内蒙煤系高岭岩为主要原料，对煤系高岭岩脱羟-脱碳-相变复合反应过程机理、反应热动力学、影响悬浮煅烧反应的关键因素及煅烧产品微观孔结构的形成机理进行研究，建立脱羟-脱碳-相变复合反应过程机理模型、煤系高岭岩脱碳-脱羟反应热动力学模型，以及煅烧高岭土孔结构形成机理模型，确定悬浮态下煤系高岭岩完全脱羟、脱碳所需的最短反应时间、最佳工艺参数（原料细度、煅烧温度、煅烧时间等）、影响煅烧高岭土性能的关键因素和改进方法，为悬浮态煅烧煤系高岭岩反应器和工业系统的设计与开发提供理论依据和技术参数支持。. 项目取得的重要成果及关键数据如下：（1）系统深入地阐述了煤系高岭岩中羟基和碳的赋存形态，硅、铝氧的配位结构及在煅烧中的演变机制；（2）提出了基于气体产物定量解析表征复杂反应中基元反应的方法，首次得到分别描述煤系高岭岩中脱羟基和脱碳反应特征的动力学方程；（3）基于结构特征和非稳态方法建立了煤系高岭岩颗粒反应模型，开发相应的计算软件，模拟了不同条件下煤系高岭岩的反应历程，预测脱羟基和脱碳反应时间；（4）自主设计开发用于煤系高岭岩悬浮态煅烧的半工业化系统，并成功制备出高品质的煅烧高岭土产品，提出产品质量调控方法和理论。. 项目的研究成果丰富了煤系高岭岩煅烧的机理、动力学、悬浮态煅烧控制理论和基础数据，提出的基于产物定量解析的动力学新方法为复杂反应机理研究提供了新途径，基于自主开发的悬浮态系统获得的煤系高岭岩煅烧参数和产品调控方法为进一步的技术开发和工业化应用奠定了基础。