Eco-friendly Selective Synergistic Extraction Rare-Earths from Waste CRT Phosphor Powder Sulfuric Acid Leachate with Imidazolium-Based Ionic Liquid [OMIm] [PF6] and Extractant Cyanex272

Abstract

Considering the benefits of resource, environment and economy, recycling secondary rare earth resources is becoming an extremely significant resource regeneration way. In this paper, we reported a novel synergistic extraction system combining ionic liquid [OMIm] [PF6] and extractant Cyanex272 to separate and purify the REE from the leachate of waste CRT phosphor powder. Some extraction parameters were studied including extraction acidity, the ratio of organic phase to aqueous phase, the ratio of Cyanex272 and [OMIm] [PF6], extraction time and extraction temperature. The optimal parameters of the extraction process was obtained as extraction acidity 0.2 mol/L, the ratio of organic phase to aqueous phase 1:5, the ratio of Cyanex272 and [OMIm]PF6 X-C = 0.4, extraction time 10 min and extraction temperature 25 degrees C. Under these conditions, REE is successfully and efficiently extracted and separated with zinc and aluminum, which revealed a potential application for REE separation and purification from electronic waste.