利用选择性浸出和沉淀从高磷钢渣中提取磷

摘要：使用高磷铁矿石冶炼所产生的高磷钢渣被视为一种磷资源。为了回收高磷钢渣中的磷，研究采用了选择性浸出和沉淀的方法，对不同P2O5含量的高磷钢渣进行了研究。结果表明：高磷钢渣中P2O5主要富集在2CaO·SiO2-3CaO·P2O5固溶体中；pH值为5.0时高磷钢渣中大部分固溶体被溶解分离，磷溶出率超过81.0%，而铁溶出率低于6.0%，实现了选择性浸出；浸出后的低磷残渣可作为冶金熔剂循环使用；升高浸出液pH值后，磷酸根离子形成沉淀；回收的沉淀物中P2O5质量分数达到23.9%，可作为磷肥使用。通过本工艺，高磷钢渣中磷能被有效分离及提取，实现了资源化利用。

Extraction of phosphorus from high-P2O5 steelmaking slag using selective leaching and precipitation

The high P2O5 steelmaking slag generated from utilization of high P iron ore is considered as a phosphorus resource. To recover phosphorus from high P2O5 steelmaking slag, a process of selective leaching and precipitation was adopted, and steelmaking slags with various P2O5 contents were investigated. The results show that P2O5 is mainly concentrated in the 2CaO·SiO2-3CaO·P2O5 solid solution. Most of the solid solution from high P2O5 steelmaking slag is dissolved at pH 5. The dissolution ratio of P exceeds 81%, and that of Fe is less than 6%, achieving selective leaching. After leaching, the low P residue can be reutilized as a metallurgical flux. When the pH increases, the phosphate ions in the leachate form precipitates. The obtained precipitate containing 23.9 mass% P2O5 can be used as a fertilizer. Through this process, the phosphorus in high P2O5 steelmaking slag can be effectively separated and extracted, realizing its resource utilization.