Process Optimization of Steel Pickling Waste Liquor Treated by Electrochemical Synthesis of Fe_3O_4

摘要

A simple electrochemical method is proposed for recovering iron from steel pickling waste liquor with graphite plates as electrodes. In this study, response surface methodology (RSM) was used to optimize the experimental conditions and assess the effect of the process variables, including initial pH, reaction temperature (T), current density (J), and reaction time (t), on total iron (TFe) removal. The model obtained by analyzing data with Design Expert 8.0.6 was very significant, and pH had the most significant effect on TFe removal. The optimum reaction conditions were pH = 9, T=35 ℃, 7=20.07 mA/cm~2, and t=30 min, under which conditions the removal rate was more than 99.99%, the residual TFe = 0.28 mg/L at the initial TFe of 10 g/L, and the obtained product had strong magnetism. Therefore, the method of electrochemical synthesis of Fe_3O_4 is promising in the treatment and recycling of steel pickling waste liquor.