AUTHOR=Jinhui Li , Ying Wang , Yudong Wang , Yang Gao , Yang Yang , Ruixiang Wang TITLE=Selective Complex Precipitation for Ferro-Chrome Separation From Electroplating Sludge Leaching Solution JOURNAL=Frontiers in Chemistry VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.592407 DOI=10.3389/fchem.2021.592407 ISSN=2296-2646 ABSTRACT=

In this paper, aiming at the problem of chrome-iron separation in electroplating sludge, the separation of ferrochrome by complexation and precipitation with benzoic acid as complexing agent is achieved. The optimal conditions consisted of a 1: 3 molar ratio of Fe3+: C6H5COOH, a reaction temperature of 30°C, a final pH of 2.5 and a reaction time of 2 min. The separation rate of the iron was 97.38% and the rate of loss of chromium was only 3.59%. The ferrochromium separation products were analyzed by XRD, fluorescence spectroscopy, infrared spectroscopy and H NMR Spectroscopy in order to study the mechanism of precipitation. The results showed that benzoic acid preferentially forms a complex with iron and iron benzoate precipitates with an increase pH. The iron benzoate crystals have a fine particle size, settle rapidly and are easy to filter. The separation of Cr 3+/Fe3+ was successful using our methodology.