Extraction and Separation of Indium and Iron Ions from Synthetic Sulphuric Acid Leaching Solution of Blast Furnace Sludge by Ultrasonic Methods

Probe ultrasound and vibrating-plate ultrasound methods were used to enhance the extraction and separation of indium and iron ions from synthetic sulphuric acid leaching solution of blast furnace sludge. Compared with traditional solvent extraction method, the ultrasonic methods could obtain higher extraction and back-extraction rates of indium ion, shorten extraction and back-extraction time, and improve the efficiency. The results showed that vibrating-plate ultrasound method was suitable for extraction process of indium ion, and probe ultrasound method was appropriate to the back-extraction process. The optimal conditions with two ultrasonic methods to extract and separate indium and iron ions from the synthetic solution were 1 mol/L sulphuric acid and vibrating-plate ultrasound extraction for 1 min, which resulted in 96.5% and 8.5% extraction rates of indium and iron ions, and 2 mol/L hydrochloric acid and probe ultrasound back-extraction for 2.5 min, which resulted in 71.0% and 3.8% back-extraction rates of indium and iron ions, respectively.