煤气化细渣综合利用与碳灰分离技术现状

Comprehensive utilization of coal gasification fine slag and carbon ash separation technology

介绍了煤气化细渣的产生机制及主要特性,综述了近年来细渣用于建材、高附加值材料、掺烧等方面的研究进展,明确了细渣中残碳和无定形硅铝氧化物等是煤气化细渣资源化利用和高附加值利用的物质基础,进而分析了预先进行碳灰分离对细渣高值化、深度化加工利用的价值和重要性,讨论了目前泡沫浮选法、重选法、筛分(分级)法等对细渣进行碳灰分离的效果,指出了粒度分布细、孔结构发达,以及残碳与灰渣间相互嵌布、熔融、包覆等是造成细渣综合利用困难、加工成本高、难以规模化利用的主要因素。基于现有研究及应用实践水平,提出优化煤气化工艺过程和相应设备,尽可能提高碳转化效率,减少残碳在固体残渣中的富集是从本质上解决煤气化细渣处理处置难题的途径,而对存量问题宜采用清洁、环保、低成本的填埋技术、土壤修复技术和制备建材技术等已经过规模化验证的方法,并对高效率分离技术、高性能材料制备技术等应通过进一步的科学研究和示范验证,通过政策、市场引导的方式拓展其利用范畴,从而实现相关优势技术从实验室走向产业化发展之路,最终解决煤气化细渣的处理处置难题。

The production mechanism and main characteristics of fine slag are introduced.The research progress of fine slag in building materials,high value-added materials and combustion are reviewed.It is pointed out that the residual carbon and the amorphous silicon and aluminum oxides in fine slag are the material basis for resource utilization and high value-added utilization of fine slag,and then the value and importance of pre-carbon ash separation for high value and deep processing and utilization of fine slag are analyzed.The effects of foam flotation,gravity separation and sieving(classification)on carbon-ash separation of fine slag are discussed,and it is pointed out that the fine particle size distribution,high porosity structure,and the mutual intercalation,melting and coating between residual carbon and ash are the main factors leading to the difficulty of comprehensive utilization,high processing cost and large-scale utilization difficulty of fine slag.Based on current research and application,it is put forward that optimizing the coal gasification process and corresponding equipment,improving the carbon conversion efficiency and reducing the enrichment of residual carbon in solid residue are essentially the ways to solve the problem of treatment and disposal of fine slag.For the stock problem,it is appropriate to adopt clean,environmentally friendly,low-cost landfill technology,soil remediation technology,building materials technology and other large-scale verification methods.In addition,the high efficiency separation technology and the high performance materials preparation technology should be verified by further scientific research and demonstration,and their utilization scope should be expanded by means of policy and market guidance,so as to develop and industrialize the superior technology,and finally appropriately treat and dispose the fine slag.