Selective extraction of Zn from blast furnace dust can be achieved by the ammonium sulfate roasting-water leaching process. An innovative method for effective separation of Zn, Fe, and Mn from roasting-water leaching solution of blast-furnace dust by precipitation-solvent extraction process is proposed in this research. The Fe of leaching solution was selectively converted into FePO₄·2H₂O precipitate by using Na₂HPO₄ as precipitant. The precipitation efficiency of Fe reached 99.17%, while that of Zn was only 0.20% under the solution pH of 2.2, molar ratio of Na₂HPO₄ to Fe of 1.2:1, reaction temperature of 30 °C, and reaction time of 50 min. The zinc in the filtrate was extracted with Cyanex 302, and Zn (99.94%) was extracted through two-stage countercurrent extraction under initial pH of 3.4, Cyanex 302 concentration of 25%, and O/A of 2:1. Subsequently, Zn (99.96%) of the organic phase was stripped using 0.75 mol/L sulfuric acid by one-stage countercurrent stripping. Furthermore, according to thermodynamic calculation, it is proved that extracting Zn from sulfuric acid solution with Cyanex 302 is an exothermic reaction. The proposed process flowsheet may be used to efficiently recover Zn and Fe from blast-furnace dust.

硫酸铵焙烧-水浸工艺可实现高炉粉尘中锌的选择性提取。本研究提出了一种采用沉淀-溶剂萃取工艺有效分离高炉粉尘焙烧水浸出液中锌、铁和锰的创新方法。以Na ₂ HPO ₄为沉淀剂，将浸出液中的Fe选择性转化为FePO ₄ ·2H ₂ O沉淀。_{在溶液pH为2.2、摩尔比为Na 2} HPO ₄时，Fe的沉淀效率达到99.17%，而Zn的沉淀效率仅为0.20%Fe 为 1.2:1，反应温度为 30 °C，反应时间为 50 分钟。滤液中的锌用Cyanex 302萃取，在初始pH为3.4、Cyanex 302浓度为25%、O/A为2:1的条件下，通过两级逆流萃取，得到Zn（99.94%）。随后，使用 0.75 mol/L 硫酸通过一级逆流汽提将有机相的 Zn (99.96%) 汽提。此外，根据热力学计算，证明用Cyanex 302从硫酸溶液中提取锌是一个放热反应。所提出的工艺流程可用于有效地从高炉粉尘中回收锌和铁。