Potential of polymer inclusion membrane process for selective recovery of metal values from waste printed circuit boards: A review

Abstract

Waste printed circuit boards (WPCBs) contain plethora of precious metals along with multitude of harmful materials, which are secondary resources and environmental pollutants. Researchers have developed several efficient recovery techniques such as recrystallization, chemical precipitation, ion exchange and solvent extraction but still recovery of metals in lower concentration such as gold, silver, palladium, nickel and zinc remain a global issue. This paper focuses on the hydrometallurgical route, employing Polymer Inclusion Membrane (PIMs) to separate and recover valuable metal ions of lower concentration. PIMs are one of the most promising techniques with benefits such as environmentally friendly, selective separations of metal ions, simultaneous extraction and back extraction characteristic, long-term stability with negligible carrier loss. This article also explores synthesis, mechanisms etc. involved in the extraction of metal ions from the solution obtained after leaching of WPCBs. Overall it reviews the published work from the last twenty years on recovery of lower concentration metals from aqueous solutions through PIMs to examine its suitability for WPCBs recycling. © 2020