Effect of alkali-activation conditions on microstructure and heavy metal solidification of alkali-activated converter steel slag and municipal solid waste incineration fly ash
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引用次数: 0
Abstract
Alkaline-activation technology was an effective means of disposing of low-activity and heavy-metal-containing industrial solid wastes. In this paper, alkali-activated converter steel slag and municipal solid waste incineration fly ash (MSWIFA) were prepared by modulating alkali-activation conditions. The effect of alkali-activation conditions on microstructure of C-(A)-S-H and leaching of lead and zinc, pore solution pH, and the correlation among them were revealed. The results showed that low modulus Na2SiO3 and highly Na2O dosage facilitated the substitution of Al for Si in C-S-H gels and produced C-(A)-S-H exhibited a decreased Ca/Si ratio and an increased proportion of Q3 in Si-O-T chain. The leaching of lead was mainly dependent on Na2SiO3 modulus, and high Na2SiO3 modulus facilitated solidification of lead. The stabilization of zinc was largely affected by pore solution pH, leading to larger leaching in the matrix with high pore solution pH. Higher dosages of Na2O significantly increased compressive strength but were detrimental to stabilization of lead and zinc. The study provided some guidance for selection of alkali-activation conditions for harmless treatment of steel slag and MSWIFA.
碱活化技术是处理低活性、含重金属工业固体废物的有效手段。通过调节碱活化条件,制备了碱活化转炉钢渣和城市生活垃圾焚烧粉煤灰。揭示了碱活化条件对C-(A)- s - h微观结构和铅锌浸出、孔液pH的影响及其相关性。结果表明,低模量Na2SiO3和高Na2O用量有利于C- s - h凝胶中Al取代Si,生成的C-(A)- s - h表现出Ca/Si比降低和Si- o - t链中Q3的比例增加。铅的浸出主要依赖于Na2SiO3模量,高的Na2SiO3模量有利于铅的凝固。孔隙溶液pH对锌的稳定性影响较大,孔隙溶液pH越高,基质的浸出量越大。Na2O的添加量越大,抗压强度越高,但不利于铅锌的稳定。该研究对钢渣无害化处理和MSWIFA碱活化条件的选择具有一定的指导意义。
期刊介绍:
The Environmental Research journal presents a broad range of interdisciplinary research, focused on addressing worldwide environmental concerns and featuring innovative findings. Our publication strives to explore relevant anthropogenic issues across various environmental sectors, showcasing practical applications in real-life settings.