%A Shejiang Liu, Hongyang Yang, Yongkui Yang, Yupeng Guo, Yun Qi %T Novel coprecipitation–oxidation method for recovering iron from steel waste pickling liquor %0 Journal Article %D 2017 %J Front. Environ. Sci. Eng. %J Frontiers of Environmental Science & Engineering %@ 2095-2201 %R 10.1007/s11783-017-0902-1 %P 9- %V 11 %N 1 %U {https://journal.hep.com.cn/fese/EN/10.1007/s11783-017-0902-1 %8 2017-02-25 %X

Coprecipitation–oxidation method was developed to recover the iron from wastewater.

Fe3O4 nanoparticles were well synthesized from steel waste pickling liquor.

Promoters greatly improved the properties of synthesized Fe3O4 nanoparticle.

Real-time control of the Fe2+/Fe3+ molar ratio was achieved by ORP monitoring.

Waste pickling liquors (WPLs) containing high concentrations of iron and acid are hazardous waste products from the steel pickling processes. A novel combined coprecipitation–oxidation method for iron recovery by Fe3O4 nanoparticle production from the WPLs was developed in this study. An oxidation–reduction potential monitoring method was developed for real-time control of the Fe2+/Fe3+ molar ratio. The key coprecipitation–oxidation parameters were determined using the orthogonal experimental design method. The use of promoters greatly improved the Fe3O4 nanoparticle crystallinity, size, magnetization, and dispersion. X-ray diffraction patterns showed that the produced Fe3O4 nanoparticles were single phase. The Fe3O4 nanoparticles were approximately spherical and slightly agglomerated. Vibrating sample magnetometry showed that the Fe3O4 nanoparticles produced from the WPLs had good magnetic properties, with a saturation magnetization of 80.206 emu·g−1 and a remanence of 10.500 emu·g−1. The results show that this novel coprecipitation–oxidation method has great potential for recycling iron in WPLs.