Ecole des Mines de Paris, Mines Paris Tech, Centre de Géosciences, Fontainebleau, France.
Waste Manag. 2011 Feb;31(2):225-35. doi: 10.1016/j.wasman.2010.05.018. Epub 2010 Jun 19.
Reusing steel slag as an aggregate for road construction requires to characterize the leaching kinetics and metal releases. In this study, basic oxygen furnace (BOF) steel slag were subjected to batch leaching tests at liquid to solid ratios (L/S) of 10 and 100 over 30 days; the leachate chemistry being regularly sampled in time. A geochemical model of the steel slag is developed and validated from experimental data, particularly the evolution with leaching of mineralogical composition of the slag and trace element speciation. Kinetics is necessary for modeling the primary phase leaching, whereas a simple thermodynamic equilibrium approach can be used for secondary phase precipitation. The proposed model simulates the kinetically-controlled dissolution (hydrolysis) of primary phases, the precipitation of secondary phases (C-S-H, hydroxide and spinel), the pH and redox conditions, and the progressive release of major elements as well as the metals Cr and V. Modeling indicates that the dilution effect of the L/S ratio is often coupled to solubility-controlled processes, which are sensitive to both the pH and the redox potential. A sensitivity analysis of kinetic uncertainties on the modeling of element releases is performed.
将钢渣再利用作为道路建设的骨料需要对浸出动力学和金属释放进行特征描述。在这项研究中，碱性氧气转炉（BOF）钢渣在液固比（L/S）为 10 和 100 的条件下进行了为期 30 天的批量浸出试验；定期随时间采集浸出液的化学成分。从实验数据中开发并验证了钢渣的地球化学模型，特别是渣矿物组成和痕量元素形态随浸出的演变。动力学对于模拟主要相的浸出是必要的，而对于次生相沉淀则可以采用简单的热力学平衡方法。所提出的模型模拟了主要相的动力学控制溶解（水解）、次生相（C-S-H、氢氧化物和尖晶石）的沉淀、pH 和氧化还原条件以及主要元素以及金属 Cr 和 V 的逐渐释放。模拟表明，L/S 比的稀释效应通常与溶解度控制过程相关联，而这些过程对 pH 和氧化还原电位都很敏感。对元素释放的动力学不确定性对模型的影响进行了敏感性分析。
