Dept. of Environmental Engineering, Karabuk University, Karabuk 78050, Turkey.
Dept. of Civil and Environmental Engineering, Univ. of Maryland, College Park, MD 20742, USA.
Waste Manag. 2019 Feb 1;84:1-12. doi: 10.1016/j.wasman.2018.11.018. Epub 2018 Nov 17.
Aged steel slag has a potential use as a highly durable aggregate in roadway construction; however, its high capacity for creating alkaline leachates (pH > 12.4) poses a severe environmental risk. In batch and column leach tests, 10% alum-based water treatment residual (WTR) addition to aged steel slag resulted in a 67% decrease in acid neutralizing capacity of steel slag and leachate alkalinity, but this alkalinity mitigation effect was accompanied with markedly increases in dissolved Al concentrations in the leachates (<4.6 mM) compared to steel slag-only samples. Measurements of dissolved ions, saturation index evaluations, and results of geochemical modeling analysis indicated that ettringite and monosulfate formations were favored and that it is probably the responsible mechanism for the observed mitigation of alkalinity and Ca release under alkaline conditions.
老化钢渣具有作为道路建设中高耐久性骨料的潜力；然而，其高碱性浸出物（pH 值>12.4）的能力构成了严重的环境风险。在批量和柱浸试验中，将 10%基于铝的水处理残渣（WTR）添加到老化钢渣中，导致钢渣的酸中和能力和浸出液碱度降低了 67%，但这种碱度缓解效果伴随着浸出液中溶解 Al 浓度的明显增加（<4.6mM）与仅含钢渣的样品相比。溶解离子的测量、饱和度指数评估以及地球化学模拟分析的结果表明，形成了钙矾石和单硫酸盐，这可能是在碱性条件下观察到的碱度和 Ca 释放缓解的原因机制。
