Over 1 billion electronic devices could be discarded annually in the US a decade from now, but these could become a source of roughly half the amount of gold currently mined anew here. Gold holds most of the metallic value in waste electronics. These are becoming smaller and more complex, containing more gold per unit weight than previously. Over 100 tons might be recoverable from electronics discarded in 2033. Tiny protein fibers (a protein fibril sponge) derived from whey, a dairy industry side-stream, might be used to recover gold from electronic waste. It would be a highly sustainable new method.
https://ethz.ch/en/news-and-events/eth-news/news/2024/03/turning-waste-into-gold.html