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SiO₂、Al₂O₃、CaO与Fe₂O₃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。在重金属迁移规律方面：重金属在粗渣与细渣中存在不同程度的富集情况，富集因子与重金属元素的挥发性密切相关；与粗渣相比，细渣具有更大的环境风险，气化渣中的Cd、Ni、Cu、Zn、As、Co、Mo、Se、Pb与Cr等重金属存在较高环境风险，应予以重点关注；气化渣中重金属的浸出行为与浸出方案、浸出时间及气化渣颗粒尺寸因素密切相关，在强酸或/与强碱条件下大部分重金属会出现较高的浸出浓度，且重金属的浸出浓度多随时间的增加而增大直至趋于稳定，同时小尺寸气化渣中重金属的浸出浓度通常高于大尺寸气化渣。

The resource utilization of coal gasification slag has become a research focus in the field of coal-based solid waste. The physical 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 morphology, 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 SiO₂, Al₂O₃, CaO and Fe₂O₃, 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 crystalline 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 coal type and gasification temperature. The carbon residue content of coarse slag is mostly 3%−20%, while that of fine slag is mostly 20%−40%. The carbon residue content of coarse slag is lower than that of fine slag, but the reactivity of coarse slag is higher than that of fine slag. The distribution of carbon residue content in coarse slag or fine slag with different particle sizes is uneven. The medium coarse slag with about 0.250 mm has a higher carbon residue content, while the highest carbon residue content in fine slag corresponds to the particle size of about 0.125−0.250 mm or large particle size, and the carbon residue content in fine slag increases with the increase of particle size. The residual carbon in the gasification slag has a porous structure with more large pores and good connectivity. The residual carbon in the gasification coarse slag is mostly amorphous, while the residual carbon in the gasification fine slag has obvious aromatic structure and more aromatic C—C or C—H bonds. In terms of heavy metal migration, there are different degrees of heavy metal enrichment in coarse slag and fine slag, and the enrichment factors are closely related to the volatility of heavy metal elements. Compared with coarse slag, fine slag has greater environmental risk, and heavy metals such As Cd, Ni, Cu, Zn, AS, Co, Mo, Se, Pb and Cr in gasification slag have higher environmental risk, which should be paid more attention to. The leaching behavior of heavy metals in gasification slag is dependent on leaching scheme, leaching time and particle size of gasification slag. Under strong acid or/and strong alkali conditions, most heavy metals will have higher leaching concentration, and the leaching concentration of heavy metals increases with the increase of time until it becomes stable. Meanwhile, the leaching concentration of heavy metals in small-size gasification slag is usually higher than that in large-size gasification slag.