Steel slags are generally alkaline with a high calcium content and are viewed as a potential feedstock for carbon dioxide sequestration and utilization, mostly through aqueous mineral carbonation routes. For recovery of multiple metals such as Ca, Fe, Mg, and Si, and generation of value-added products by dissolution and precipitation reactions in aqueous media, enhancing the metal selectivity and extraction efficiency are important. However, there is limited understanding of independent parameters that influence these important characteristics. In this work, a systematic attempt was made to correlate these key dissolution characteristics of basic oxygen furnace slag in acidic media with its mineralogical and physical characteristics, the changes in aqueous chemistry, and the role of potential secondary precipitates. The findings from this study substantiate that steel slag is a potential feedstock because of the calcium being mainly present as orthosilicates, which were found to leach congruently without forming a leached layer that might hinder calcium extraction. The leaching of Fe(II) from the slag is the main source of impurity and its slow oxidation-precipitation leads to a pH plateau at the end of the dissolution step. Oxidation-precipitation of Fe(II) is controlled by hydroxyl concentration in the aqueous solution, which necessitates a pH-swing step by addition of a base after dissolution. Use of surface complexing agents, such as sodium molybdate, can significantly reduce iron impurity in the leachate and obtain an iron-rich slag residue for recycle to iron and steel industry.

钢渣通常是碱性且钙含量高的钢渣，被视为潜在的二氧化碳封存和利用原料，主要通过含水矿物碳酸化途径。对于回收多种金属（例如Ca，Fe，Mg和Si）以及通过在水性介质中进行溶解和沉淀反应生成增值产品，提高金属的选择性和提取效率至关重要。但是，对影响这些重要特征的独立参数的了解有限。在这项工作中，进行了系统的尝试，以将碱性氧气炉渣在酸性介质中的这些关键溶解特征与其矿物学和物理特征，水化学变化以及潜在的二次沉淀物的作用联系起来。这项研究的结果证实了钢渣是一种潜在的原料，因为钙主要以原硅酸盐的形式存在，发现钙的浸出程度一致，而没有形成可能妨碍钙提取的浸出层。从炉渣中浸出的Fe（II）是杂质的主要来源，其缓慢的氧化沉淀在溶解步骤结束时导致pH值稳定。Fe（II）的氧化沉淀受水溶液中羟基浓度的控制，这需要在溶解后添加碱来进行pH波动步骤。使用表面络合剂（例如钼酸钠）可以显着减少渗滤液中的铁杂质，并获得富铁渣残留物，以循环回钢铁工业。