How to extract silver using used cooking oil?

Finnish scientists from the University of Helsinki and the University of Jyväskylä have developed a new method for extracting silver from waste using fatty acids contained in used vegetable oil. The research is published in the scientific journal Chemical Engineering Journal (CEJ).

Modern silver recycling technologies often require aggressive chemicals that harm the environment.

The proposed method is based on a combination of fatty acids (such as oleic or linoleic) and diluted hydrogen peroxide. This mixture effectively dissolves silver, after which the metal can be isolated in pure form using light in a special reactor.

"Our goal is to create inexpensive and sustainable methods for recycling metals, especially from complex multi-component waste," explained the authors of the development.

Silver is widely used in electronics, solar panels, and other high-tech industries, but less than 20% of its global production comes from recycled sources. At the same time, natural reserves are being depleted, and the price of the metal has increased sixfold over the past 25 years.

The new technology not only solves the problem of resource scarcity but also offers a safe alternative: fatty acids are non-toxic, biodegradable, and can be reused after silver extraction.

The method opens up possibilities for so-called "urban mining" - extracting valuable metals from waste, for example, from keyboards with silver coating or other electronic components.