Urban Mining of Gold

🌱 Can gold be recovered through urban mining?

Through urban mining, gold can be reclaimed from urban waste, such as old circuit boards. A ton of circuit boards entails about 100 times the amount of gold found in a ton of newly mined gold ore. It is estimated that globally there are precious metals worth $55-$60 billion inside old circuit boards. Japan alone is believed to have accumulated 5300 tonnes of gold, or around 10% of global gold reserves, through products and waste products. Japan's Environment Ministry estimates that approximately “280 grams of gold can be recovered from 1 tonne of, or around 10,000, mobile phones”. The Ministry says this is 56 times the amount found in newly mined gold ore.

🌱 Is the recycling profitable?

In conventional e-waste recycling, there is a large focus on recovering gold and other metals. Despite this, “some recycling processes [still] require a lot of energy and are technically complex, leading to additional costs and environmental impacts”. This typically means that the recycling is not that profitable. Generally, “printed circuit boards and other components are shredded, sorted, and then separated”. Overall, “efficiently filtering out specific metals remains tricky and adds to the cost of recycling”.

🌱 What opportunities are there for urban mining?

Recycled gold currently makes up under 30% of the global supply. As the prices and demand for gold have risen, there is however a new market for recovering gold from e-waste. As the gold output from mines is beginning to decline, recovering gold from e-waste is becoming more relevant. While the increase in gold from mine productions was only roughly 3% in January to September 2023 compared to the previous year, the global supply of recycled gold in this timeframe increased by roughly 10%. Many startups are now trying to tap into the potential that the urban mining of e-waste presents. In line with this, some startups have reported “making as much as $85,000 per day recycling old electronic circuit boards”.

🌱 What are the impacts of recycling gold from e-waste?

A large part of the problem when recycling e-waste lays in its diverse mix of materials. Removing materials such as gold from e-waste typically requires either brute force or an acid bath. Notably, the conventional methods used to recover the valuable metals “often rely on synthetic chemicals that can damage the environment”. Therefore, “[t]he common methods for recycling electronic waste [also] have several disadvantages, including environmental pollution, health risks from hazardous materials and inefficient recovery of valuable resources”. Several startups and research institutes are currently working to make the process of recovering gold from e-waste more efficient, safe, and environmentally friendly.