Steelmaking slag and steel pickling waste liquor (SPWL) are two kinds of by-products in steel plants. The existence of phosphorus (P) in steelmaking slag is the main factor affecting its reuse within the steelmaking process. To remove P from steelmaking slag with a low-cost method, selective leaching was proposed by using SPWL as a leaching agent. SPWL generally contains a small amount of Fe3+ ions, and thus the effect of Fe3+ content in SPWL on the dissolution behavior (especially P element) of steelmaking slag was investigated, as well as the pH value and steelmaking slag type. The dissolution ratios of P from various slags in the SPWL containing 500 ppm Fe3+ exceeded 95 % at pH 1.5 while those of Fe, Mn, and Al were very low, exhibiting satisfied selective leaching of P. Increasing pH value and Fe3+ content (in SPWL) resulted in a decreasing P dissolution ratio while exerting an insignificant effect on the dissolution of other elements. The FeHPO4+ was predicted as the predominant species during leaching and the transformation of FeHPO4+ to FePO4 could be present. When the SPWL containing 800 ppm Fe3+ was used, FePO4 was observed in the residues after leaching at pH 2.0, resulting in a worse removal of P from slag. However, the residues including massive valuable components had an extremely low P content after leaching in the SPWL containing 500 ppm Fe3+ at pH 1.5, which can be used as a flux in the metallurgical process. To ensure a high P removal rate from steelmaking slag and to prevent FePO4 precipitation during leaching, a relatively low pH and Fe3+ content in the SPWL are necessary.

中文翻译：

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通过在钢酸洗废液中选择性浸出从炼钢渣中去除磷


炼钢渣和钢铁酸洗废液 （SPWL） 是钢厂的两种副产品。炼钢渣中磷 （P） 的存在是影响其在炼钢过程中再利用的主要因素。为了以低成本的方法去除炼钢渣中的 P，提出了使用 SPWL 作为浸出剂的选择性浸出法。SPWL中一般含有少量的Fe3+离子，因此研究了SPWL中Fe3+含量对炼钢渣溶解行为（尤其是P元素）的影响，以及pH值和炼钢渣类型的影响。在 pH 值为 1.5 时，含 500 ppm Fe3+ 的 SPWL 中各种炉渣中磷的溶解率超过 95%，而 Fe、Mn 和 Al 的溶解率非常低，表现出令人满意的磷选择性浸出。增加 pH 值和 Fe3+ 含量（在 SPWL 中）导致 P 溶解率降低，而对其他元素的溶解影响不显著。预测 FeHPO4 + 是浸出过程中的主要物质，可能存在 FeHPO 4 + 向 FePO4 的转化。当使用含有 800 ppm Fe3+ 的 SPWL 时，在 pH 2.0 下浸出后残留物中观察到 FePO4，导致渣中 P 的去除效果较差。然而，在 pH 值为 1.5 的 Fe3+ 含量为 500 ppm 的 SPWL 中浸出后，包括块状有价组分在内的残留物具有极低的 P 含量，可用作冶金过程中的助熔剂。为了确保炼钢渣中的高 P 去除率并防止浸出过程中 FePO4 沉淀，SPWL 中需要相对较低的 pH 值和 Fe3+ 含量。