煤气化细渣炭灰分离研究进展

Research progress of the separation of carbon and ash in coal gasification fine slag

煤气化技术作为煤炭清洁高效利用的核心技术应用广泛,煤气化细渣是煤气化过程产生的一种由铝硅酸盐等灰成分和残炭组成的固体废弃物。目前对气化细渣的处理方式主要为堆存和填埋,不仅污染环境,还造成资源浪费。炭灰分离是实现气化细渣分质高值利用的基础,而物理分选是实现炭灰分离的重要途径。在对气化细渣组成及结构特性分析总结的基础上,综述了当前对气化细渣进行炭灰分离的研究进展,总结了各分选技术的优点及存在的主要问题,展望了未来气化细渣炭灰分离的发展方向。具体地,浮选法在气化细渣炭灰分离中的研究最广泛,但存在药剂消耗量大、新型浮选药剂成本高等缺点;重选法对细粒级气化细渣的分选效果不佳;电选法对气化细渣样品含水率要求苛刻;干法分选技术对气化细渣的炭灰分离效果较好,但受制于其脱水困难而未能推广;疏水-亲水双液分离方法的分选效果优于浮选,但其分选成本高且潜在危害性较大。在未来对气化细渣炭灰分离的研究中应加强气化细渣组成结构性质的基础研究,加强新型浮选药剂及浮选技术的研发,探讨通过多场多工艺耦合提高炭灰分离的实现路径,构建气化细渣分选产品的新型分类标准,为其精细化分质高值利用提供借鉴。

Coal gasification technology is widely used as the core technology for clean and efficient utilization of coal.Coal gasification fine slag(CGFS)is a solid waste consisting of ash components such as aluminosilicate and residual carbon produced by coal gasification process.At present,the treatment method of CGFS is mainly to stockpile and landfill,which not only pollutes the environment,but also causes waste of resources.The separation of carbon and ash is the basis for realizing the fractionated and high-value utilization of CGFS,and physical sorting is an important way to realize the separation of carbon and ash.Based on the analysis of the composition and structural characteristics of CGFS,the current research progress of carbon and ash separation of CGFS was reviewed,the advantages and main problems of each separation technology were pointed out,and the future development direction of carbon and ash separation of CGFS was prospected.Specifically,flotation has been most widely studied in carbon-ash separation of gasification fine slag,but there are drawbacks such as high consumption of chemicals and high cost of new flotation chemicals.The gravity separation method is not effective in separating fine-grained gasification slag.The electrical separation method is demanding on the water content of gasification slag samples.Dry separation technology has a better effect on the separation of carbon and ash from gasification slag,but it has not been promoted due to the difficulty of dehydration of gasification slag.The hydrophobic-hydrophilic two-liquid separation method is superior to flotation,but it is costly and potentially hazardous.In the future research on the separation of carbon and ash from gasification slag,it is very important to strengthen the basic research on the composition and structure of gasification slag,strengthen the research and development of new flotation chemicals and flotation technology,explore the realization path to improve the separation of carbon and ash through the multi-field and multi-process coupling,and construct a new type of classification standard for the separation of gasification slag products,so as to provide reference for the fine classification and high-value utilization of gasification slag.