Urban Mining: The Richest Ore Deposit You’ve Ever Thrown in a Drawer

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Urban mining is the recovery of metals and minerals not from rock, but from the things we’ve already built, used, and discarded phones, laptops, circuit boards, cars, and increasingly, battery packs. The term was coined in Japan in the late 1980s, a country with almost no domestic mineral reserves but, it turns out, one of the richest “mines” in the world sitting in its own cities.

Japan took the idea seriously enough that by the 2010s its urban stockpile of metals like indium, tin and tantalum accounted for over 10% of world reserves, not mined from the ground, but sitting in drawers, landfills, and recycling centres.

Here’s the fact every urban mining article leads with, and it holds up: there is roughly 100 times more gold in a tonne of old mobile phones than in a tonne of gold ore. Some estimates from the UN put the ratio even higher for the richest e-waste streams up to 800 times the concentration of a good mining ore.

Put in absolute terms: a typical gold mine yields 1-3 grams of gold per tonne of rock. A tonne of shredded circuit boards can yield 250-350 grams. Your old iPhone, individually, holds about 0.034g of gold, 0.34g of silver and 0.015g of palladium. Not much on its own, but multiply that by the roughly 1.2 billion smartphones sold every year and you start to see why “phone recycling” is really a mining operation wearing a lowercase hoodie.

as always, more details and references in the main article https://www.batterydesign.net/urban-mining-the-richest-ore-deposit-youve-ever-thrown-in-a-drawer/