There is more gold in a ton of mobile phones than a ton of gold ore. In this episode, Jean-Marc talks about bio-leaching as the best method to recycle printed circuit boards. It involves bacteria breaking down the board or the glue that holds metal to the boards allowing for the extraction of the rare metals.
Jefferson and his organization are looking for the best way to deal with unwanted IT hardware; a way that will include reuse and recycling of these items to ensure zero percent goes to landfills. The method should maximize their life and thereby reduce the carbon footprint, therefore, supporting the planet from a sustainable perspective.
Our negative ecological impact on the planet is measured by embodied carbon dioxide (eCO2), which is related to fossil fuels and water. If unwanted hardware is managed through a proper matrix, then the eCO2 footprint extends over a longer period and obviates the requirement to create new hardware within shorter time scales. We can extend the life of technology and recycle them, then measure the impact. For example, new gold costs much more to mine from the earth than from PCBs in laptops.
There is a hierarchy of things that can be done with unwanted IT components. Reuse is better than recycle but recycle is better than landfills. The benefits of reusing and recycling can be measured in terms of water, carbon, and fossil fuels and against the UN’s 6th, 12th, and 13th SDGs, which cover clean water and sanitization, responsible consumption & production, and climate action, respectively.
About 60-80 percent of the eCO2 footprint of technology is through the manufacturing process: sourcing of raw materials and transportation, manufacturing assembly, and getting them to the market. If these aspects were measured, we could minimize negative impacts on the planet and maximize positive impacts through the reduction of our carbon footprint, water consumption, and fossil fuel use.
PCBs should be treated as hazardous waste. Many organizations deconstruct them through thermal and non-thermal means, both of which are unfriendly to the environment.
Jefferson recommends bio-leaching as the best method to recycle PCBs. It involves bacteria breaking down the board or the glue that holds metal to the boards allowing for extraction of the rare metals. For mobile phones, copper is the most dominant metal. Others include palladium, platinum, and gold. In essence, there is more gold in a ton of mobile phones than a ton of gold ore. Therefore, there is value in using bio-leaching in urban mining. Moreover, you’d need 17,900 kilograms of carbon to extract one kilogram of gold from gold ore compared to just 397 kilograms of carbon that bio-leaching would require. Therefore, bio-leaching makes both commercial and environmental sense.