An AF aerogel is an aerogel that uses amyloid fibrils derived from whey, as an adsorbent for gold recovery from e-waste. A study has demonstrated that AF aerogels have a high capacity for gold adsorption. Their use would have a less environmental impact than that of the conventional use of activated carbon as adsorbent.[1]
Nanofibrils of protein amyloid derived from whey is a novel (as of 2023) adsorbent for the extraction of gold from electronic waste. Prepared AF aerogels have a very high capacity for the adsorption of gold. [1]
The process begins with the separation of amyloid fibrils from waste dairy products, and their incorporation into an aerogel. The AF aerogel is then used in a solvent of dissolved computer motherboards (the main printed circuit board in a computer) to extract the gold contained. Af aerogels can convert gold (Au) ions into single crystalline flakes. The result is a yield of high purity gold nuggets, equating to around 21-22 carats, with only trace amounts of other metals present.[1]
The use of AF aerogels has a profitable profile. It costs just over one dollar to retrieve one gram of gold, and the market value of a gram of gold (as of 2023) is around 50 dollars.[1]
The use of AF aerogels compares favourably in terms of environmental impact in comparison to the conventional use of activated carbon adsorbents.[1]