Ultrasound-Assisted Micro-Channel Extraction of Magnesium from Wet-Process Phosphoric Acid

Abstract

A new extractant PN-1 was synthesized, and an ultrasound-assisted micro-channel extraction (UAME) system was developed for the extraction of magnesium from wet-process phosphoric acid (WPA). The effects of O/A ratio, P 2 O 5 content, initial pH, ultrasound power, and aqueous phase ratio on extraction were investigated. The extraction efficiency of Mg 2+ could reach 89.09% under the conditions of 74 W ultrasound power, 4 O/A ratio, and 0.2 mL/min aqueous phase velocity. The response surface methodology (RSM) result indicated that O/A ratio and aqueous phase velocity have extremely significant influences on extraction efficiency, significant interaction existed between ultrasound power and aqueous phase velocity, and ultrasound power evidently reduced extraction time. Furthermore, the magnesium could be fully stripped by 1 mol/L H 2 SO 4 with a phase ratio lower than 2. Thus, the new extractant PN-1 and ultrasound-assisted microchannel extraction system are suitable for the extraction of magnesium from wet-process phosphoric acid.