Roasting and leaching process of iron sulfate to separate zinc and iron from blast furnace dust

다국어 초록 (Multilingual Abstract)

The physical phase analysis and thermodynamic calculations of blast furnace dust were performed using Xraydiffraction fluorescence spectrometer, X-ray diffractometer, scanning electron microscope, energy spectrometer, andFactsage software. The leaching pattern and mechanism of zinc elements were studied by a roasting-leaching method.
The results showed that the conversion of zinc ferrite to zinc sulfate could be realized when the roasting temperaturerange was 500-730 oC, which was convenient for zinc leaching. A better roasting condition could be obtained when theroasting temperature was 600 oC, roasting time was 60 min, and molar ratio of ferric sulfate was 1.2 : 1. Under theseconditions, the zinc and iron leaching rates were 84.57% and 24.51%, respectively, at a sulfuric acid concentration of110 gL1, liquid-solid ratio of 10 : 1 mLg1, leaching time of 60min, stirring speed of 400 rpm, and leaching temperatureof 80 oC. The leaching process of zinc from blast furnace dust sulfate roasting products agreed with the unreacted coremodel, and internal diffusion was the restrictive step. The kinetic equation of the leaching process was 12R/3(1R)2/3=0.47t, the apparent activation energy of the leaching reaction was 17.4 kJmol1, and the reaction order was 1.908.