This work investigates spent caustic as an alkaline activator for the consolidation of municipal solid waste incineration (MSWI) fly ash through the alkaline activation process. The effects of comparable alkalinity of NaOH solution and spent caustic, and the addition of blast furnace slag (BFS) on consolidation MSWI fly ash were investigated. Compressive strength measurement for alkali-activated MSWI fly ash-based mortars was characterized to evaluate the consolidation effect. The microstructure of mortars was characterized by XRD, FTIR, ²⁹Si NMR, and SEM measurement. It was found that the compressive strength of spent caustic-activated mortars was higher than that of NaOH-activated mortars. The formation of ettringite and more C-(A)-S-H, and the presence of carbonate and organics in spent caustic-activated mortars enhanced the compressive strength. This work found an emerging cost-efficient alkaline activator in waste management through alkaline activation and could achieve environmentally sustainable.

这项工作研究了用过的苛性碱作为碱性活化剂，以通过碱性活化过程巩固城市固体废物焚烧（MSWI）粉煤灰。研究了NaOH溶液和废碱相当的碱度以及高炉矿渣（BFS）的添加对固结MSWI粉煤灰的影响。对碱活化MSWI粉煤灰基砂浆的抗压强度进行了测量，以评估固结效果。XRD，FTIR，²⁹对砂浆的微观结构进行了表征Si NMR和SEM测量。发现废碱活化砂浆的抗压强度高于NaOH活化砂浆。钙矾石和更多的C-（A）-SH的形成以及废碱活化砂浆中碳酸盐和有机物的存在提高了抗压强度。这项工作发现了一种通过碱活化在废物管理中新兴的具有成本效益的碱活化剂，并且可以实现环境可持续性。