NaHCO3 synergistic electrokinetics extraction of F, P, and Mn from phosphate ore flotation tailings

Abstract

In this study, the NaHCO3 synergistic electrokinetic method was used to remove F, P, and Mn from phosphate ore flotation tailings (PTs). First, using PHREEQC simulation calculations, the occurrence forms of P, F, and Mn in the PTs were determined. Thereafter, under various electrokinetic treatment conditions, the variation trends between pH and the different forms of various elements in interstitial solutions of the PTs were analyzed. The influence of various electrokinetic treatment methods on conductivity and pH distribution was thoroughly investigated. The difference in P concentration between the cathode and anode chambers was 21.42 mg/L, the removal efficiency of Mn was 71.43 %, and the leaching of F was inhibited. Dissolved impurities migrated to the electrode chamber during electrokinetic treatment primarily because of electromigration and electro-osmotic flow. During the 1.00 M NaHCO3-enhanced electrokinetic treatment in the cathode chambers, in 360 min, P and F concentrations increased from 3.51 mg/L to 57.28 mg/L and 2.073 mg/L to 29.38 mg/L, respectively. Solution-precipitation of hydroxide or carbonate minerals was determined to be an important mechanism for P, F, and Mn stabilization. This study demonstrated that the NaHCO3 synergistic electrokinetic method is suitable for removing F, P, and Mn from PTs. The findings of this study provide insights for developing novel technologies for the clean treatment and high-value utilization of PTs.