利用选择性浸出和沉淀从高磷钢渣中提取磷

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

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。

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,aprocess of selective leaching and precipitation was adopted,and steelmaking slags with various P2O5contents 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 pH5.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 23.9mass% P2O5 can be used as a fertilizer.Through this process,the phosphorus in high-P2O5steelmaking slag can be effectively separated and extracted,realizing its resource utilization.