Carbon capture has become an important technology to mitigate ever-increasing CO₂ emissions worldwide, and alkali waste is a potential source of CO₂ capture material. Slagging-gasification is a novel technology for treating municipal solid waste (MSW), and the gasification fly ash (GFA) is the only solid residue that is not reused at present due to its high heavy metal content. GFA contains high amounts of Ca(OH)₂ and Ca(OH)Cl, making it protentional for CO₂ capture. In this study, GFA and washed gasification fly ash (WGFA) were treated with CO₂ for different treatment periods. Weight changes of samples were recorded to evaluate the efficiency of CO₂ capture. To assess the properties of treated GFA, pH value, leached heavy metal concentration, mineral composition, and microscopic morphology were studied. The results revealed that GFA and WGFA could adsorb 18.8% and 23.7% CO₂ of their weights, respectively. Carbonation could immobilize heavy metals including Pb, Zn, and Cu when a proper treatment period was applied. An excessive treatment period decreased the efficiency of heavy metal immobilization. Pre-washing is recommended as a pre-treatment method for GFA carbonation, which increased the efficiency to adsorb CO₂, improved the pH of carbonated GFA, and enhanced the effect to immobilize heavy metals.

碳捕集已成为缓解全球不断增加的CO ₂排放的重要技术，碱废物是CO ₂捕集材料的潜在来源。造渣-气化是一种处理城市固体废物（MSW）的新技术，而气化飞灰（GFA）是目前唯一没有被回收利用的固体残渣，因为它的重金属含量很高。GFA 含有大量的 Ca(OH) ₂和 Ca(OH)Cl，使其有利于捕获CO _{2 。}在这项研究中，GFA 和洗涤气化飞灰 (WGFA) 用 CO ₂处理不同的处理时间。记录样品的重量变化以评估 CO _2的效率捕获。为了评估处理过的 GFA 的性质，研究了 pH 值、浸出的重金属浓度、矿物成分和微观形态。结果表明，GFA 和 WGFA 可以分别吸附其重量的 18.8% 和 23.7% 的 CO ₂。当应用适当的处理时间时，碳化可以固定包括 Pb、Zn 和 Cu 在内的重金属。处理时间过长会降低重金属固定的效率。推荐采用预洗作为GFA碳化的前处理方法，可提高CO ₂的吸附效率，改善碳化GFA的pH值，增强固定重金属的效果。