Carbazole–Phosphazene Based Polymer for Efficient Extraction of Gold and Precious Elements from Electronic Waste

Abstract

The continuous advancement of industry and technology has significantly increased electronic waste, which contributes to the depletion of valuable metal reserves. Therefore, it is crucial to recycle precious metals in electronic waste effectively and sustainably. This study introduces a novel approach by applying a carbazole–phosphazene-based polymer, EBE-06, in a two-stage leaching method for efficient metal extraction. In the first leaching stage, tin is selectively separated using an acid solution at a controlled pH. In the second stage, valuable metals such as gold are recovered through adsorption onto EBE-06. The polymer exhibited a 99% gold adsorption rate within 1 h, independent of pH, and a maximum adsorption capacity of 1.787 g of gold per gram of polymer. The desorption process yielded 95% efficiency, with the polymer maintaining 94% efficiency over three cycles of use.