Efficiently managing and utilizing Cr-containing slags and wastes is a global urgency. Alkali-activated materials offer a sustainable and cost-effective solution. This study investigated eco-friendly alkali-activated blast furnace ferronickel slag (AA-BFFS) for both self-stabilization/solidification (SS) of Cr-containing BFFS and immobilization of external Cr ions. Our investigation involved comprehensive analysis, including reaction characterization, pH-dependent leaching tests, and a novel thermodynamic modeling approach to reveal the reaction process and leaching behaviors. The results indicate that AA-BFFS forms a dual-layered self-S/S barrier: reaction products, AFm and C-(N)-A-S-H, constitute the first layer at the inner pH above ∼7, while Ca/Mg phases in BFFS form a secondary layer at the inner pH above ∼5. External Cr ion immobilization involves Cr(III) precipitation and sorption, while Cr(VI) is only partially sorbed, leaving 73.2 % soluble at 7 days at the high doping level. The research provides a scientific basis for the sustainable utilization of BFFS and other Cr-containing wastes.

中文翻译：

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用于 Cr 固定化的碱激活高炉镍铁渣

有效管理和利用含铬炉渣和废物是全球的当务之急。碱激活材料提供了可持续且经济高效的解决方案。本研究研究了环保型碱激活高炉镍铁矿渣 (AA-BFFS)，用于含铬 BFFS 的自稳定/凝固 (SS) 和外部铬离子的固定。我们的研究涉及综合分析，包括反应表征、pH 依赖性浸出测试以及揭示反应过程和浸出行为的新型热力学建模方法。结果表明，AA-BFFS 形成双层自 S/S 屏障：反应产物 AFm 和 C-(N)-ASH 在内部 pH 值高于~7 时构成第一层，而 Ca/Mg 相在BFFS 在内部 pH 值高于~5 时形成第二层。外部 Cr 离子固定涉及 Cr(III) 沉淀和吸附，而 Cr(VI) 仅部分吸附，在高掺杂水平下 7 天后 73.2% 可溶解。该研究为BFFS及其他含铬废弃物的可持续利用提供了科学依据。