煤气化渣理化特性及其所含重金属迁移规律综述  

Review of physical and chemical characteristics and heavy metal migration rules of coal gasification slag

作　　者：廖昌建 王晶 金平 刘志禹 徐婉怡 王坤 LIAO Changjian;WANG Jing;JIN Ping;LIU Zhiyu;XU Wanyi;WANG Kun(Dalian Research Institute of Petroleum and Petrochemicals,Dalian 116045,China)

机构地区：[1]中石化(大连)石油化工研究院有限公司,辽宁大连116045

出　　处：《煤炭科学技术》2025年第2期426-443,共18页Coal Science and Technology

基　　金：中国石油化工股份有限公司资助项目(CHG23085)。

摘　　要：煤气化渣的资源化利用现已成为煤基固废的研究热点,气化渣的理化特性及其所含重金属迁移规律对其资源化利用至关重要。首先介绍并对比了气流床、流化床与固定床3种煤气化技术,然后总结了煤气化渣的理化性质,包括气化粗渣与细渣的粒度组成、表观形貌与微观形貌、无机物与晶相矿物组成和残炭的含量等,最后分析了气化粗渣与细渣中重金属的迁移行为、风险评估指数及浸出行为。气化粗渣与细渣的理化特性及重金属迁移规律均具有一定的差异,从理化特性来看:细渣粒径远低于粗渣粒径,约60%以上细渣的粒径小于0.250 mm,约50%以上粗渣的粒径大于0.500 mm;细渣的比表面积大于粗渣,平均孔径小于粗渣;粗渣与细渣的无机组分均以SiO_(2)、Al_(2)O_(3)、CaO与Fe_(2)O_(3)为主,其中酸性氧化物占总组分的35%~80%,碱性氧化物占总组分的20%~65%,且粗渣具有较多的碱性氧化物,细渣具有较多的酸性氧化物;粗渣与细渣中的晶相矿物质与非晶态物质并不是简单的煤气化残留物,而是在气化过程中经历了一系列复杂的物理化学反应后形成的,粗渣与细渣的主要晶相矿物均为石英、方解石和莫来石,但其他晶相矿物的种类与含量差别较大,这主要受煤种与气化温度等因素的影响;粗渣中的残炭量多为3%~20%,而细渣中的残炭量多为20%~40%,粗渣中的残炭含量低于细渣,但粗渣的反应活性高于细渣;不同粒径气化粗渣或细渣中的残炭含量分布不均,0.250 mm左右的中等粒度级粗渣具有较高的残炭含量,而细渣中最高残炭含量对应的粒度级为0.125~0.250 mm或大粒径,且细渣中的残炭量多随粒度级的增大而增加;气化渣中的残炭为多孔结构,具有较多且连通性较好的大孔结构,气化粗渣中的残炭多是无定型态,而气化细渣中的残炭具有明显的芳香结构、具有较多的芳香族C—C键或C—H键。在重金属迁移The resource utilization of coal gasification slag research focus in the field of coal-based solid waste.The physic-al and chemical characteristics and the heavy metal migration rules of coal gasification slag are very important for its resource utilization.Firstly,three coal gasification technologies of entrained flow,fluidized-bed and fixed-bed gasification were introduced and compared.Then,the physical and chemical characteristic of coal gasification slag,including particle size composition,apparent and microscopic mor-phology,inorganic and crystalline mineral composition and carbon residue content,were summarized.Finally,the migration behavior,risk assessment code and leaching behavior of heavy metals in coal gasification slag were analyzed.The physical and chemical characteristics of coarse slag and fine slag are different to some extent.From the perspective of physical and chemical characteristics,the differences of fine slag and coarse slag are as follows.The particle size of fine slag is much lower than that of coarse slag,about 60%of fine slag is less than 0.250 mm,and about 50%of coarse slag is more than 0.500 mm.The specific surface area of fine slag is larger than that of coarse slag,and the average pore diameter is smaller than that of coarse slag.The inorganic components of coarse slag and fine slag are mainly SiO_(2),Al_(2)O_(3),CaO and Fe_(2)O_(3),in which the acid oxides account for about 35%-80%of the total components,the basic oxides account for about 20%-65%of the total components,and the coarse slag has more basic oxides,and the fine slag has more acidic oxides.The crystal-line minerals and amorphous substances in coarse slag and fine slag are not simple coal gasification residues,but formed after a series of complex physical and chemical reactions in the gasification process.Both of the main crystalline minerals of coarse slag and fine slag are quartz,calcite and mullite,but the types and contents of other crystalline minerals are very different,which is mainly affected by factors such as co

关 键 词：煤气化渣 理化特性 重金属 迁移规律 环境风险 

分 类 号：TQ536[化学工程—煤化学工程] X7[环境科学与工程—环境工程]