超细、低灰无烟太西煤的煤岩特性与构筑超细碳化硅粉体的关系

Development of high purity ultra-fine silicon carbide powder from coal is one of the key technical ways to improve the utilization efficiency of anthracite resources. The existing industrial production of anthracite silicon carbide has shortcoming of coarse grain, high impurities, it is difficult to obtain high quality powder product. Research of high quality anthracite base to prepare SiC powder with controlled structure, excellent quality, especially nano powder, is still an urgent subject, it has important significance for the development of deep production of high-quality anthracite coal utilization. This project combined with previous work, from the research on the construction of super, super low ash coal as the main carbon source and high reaction activity of carbon and silicon source system as a starting point, The main control start from the dispersion behavior of the carbon source in silica sol and petrology composition interaction to construct the systematic research on raw material system and reaction mechanism control, through "micro domain construction- control response of precursor system" optimization mechanism of technology system, to obtain a key technical breakthrough on modified sol-gel micro domain construction and preparation of silicon carbide directly from coal, to analyze the relationship between petrology characteristics and preparation of ultra-fine SiC powder, to reveal the structure and morphology control factors and rules, and to provide new technical ideas for realizing the precise control of structure and performance on direct obtain coal based SiC powder materials.

高纯超细煤质碳化硅粉体材料的开发是提高无烟煤资源利用效率的关键技术途径之一。现有的工业生产无烟煤质碳化硅晶粒粗大、杂质高，难以获得优质的粉体产品。深入研究优质无烟煤基制备结构可控、品质优异的SiC粉体技术尤其是纳米粉体仍是一个十分迫切的课题，对于拓展优质无烟煤的深度加工利用途径有重要意义。 本项目紧密结合前期工作，从探究超细、超低灰太西煤为主要碳源以及高反应活性的碳硅源体系的构建作为技术契入点，主要从该类碳源在硅溶胶中的分散行为调控以及与煤岩成分的相互作用入手对原料体系的构建与调控反应机制进行系统研究，明确通过"前驱体体系的微域构筑-调控反应"技术体系优化机制，获得改性的溶胶凝胶微域构筑及直接制备煤质碳化硅粉体的关键技术突破，并解析煤岩特性与制备超细碳化硅粉体的关系，揭示结构及形貌特征等控制因素及其规律，并为实现直接获得煤基碳化硅粉体材料结构和使用性能的精确控制提供新技术思路。

近年来，高纯度、形貌可控的煤质微纳米级碳化硅的制备及其功能化材料由于其原料低廉、制备成本低、易于规模化应用等独特优势，备受关注。本项目主要结合项目组前期研究工作，基于对优势特色资源无烟太西煤的深度开发利用，采用溶胶-凝胶预制前驱体技术、太西煤煤岩组份调控及结构改性技术、催化碳热还原法技术等，探究了以多种不同灰份、不同挥发份含量的细颗粒太西煤为主要碳源制备微纳米级碳化硅的工艺规律，揭示了催化碳热还原获得微纳米碳化硅时灰份、加热方式等对产物形貌、粒径大小、得率等影响规律。结果显示，太西煤是制备纳米级β-SiC颗粒的有效碳源，且溶胶凝胶法预制前驱体达到了很好的微域构筑，使得后续的热还原反应比较好地实现了对微纳米级碳化硅的形貌控制。此外还初步探究了煤基碳化硅基碳基复合固体酸材料（包括磁性碳化硅核壳碳基固体酸、异质结光电催化剂等）的制备方法。采用XRD，XPS、HR-SEM，HR-TEM和BET等分析手段对材料的结构、成分进行了表征分析；并部分关联探索了材料的催化性能等。该项目的实施为高性能、低成本微纳米碳化硅材料的制备提供了一种新思路；为太西煤资源深度有效利用、以及在资源环境保护等领域绿色化学工艺中的应用奠定了一定科学基础。