Computers and other electronic equipment contain precious metals. Recycling could yield more gold than mining, and do no harm to the environment.
• A tonne of gold-bearing ore could yield 0.3 to 5 grams of gold.
• A tonne of old cellphones can yield as much as 280 grams of gold, about 140 grams of platinum and palladium, and 140 kilograms of copper. There’s also plastic and glass that can be recycled from used cell phones.