E-waste — a mine in the drawer

Metals, boards, screens, batteries, repair, export and recycling. Theory, formulas, worked examples and applications.

The stored-away phone still contains a mine

A single device packs in half the periodic table

A relatively small mobile phone or laptop packs, into a very small space, a surprising variety of materials: extraordinarily pure silicon for the chips, copper for the internal wiring, gold and silver in tiny but present amounts in the highest-quality electrical contacts, tin for solder joints, tantalum in capacitors, several rare earths in screens and magnets, glass in the display, aluminum in the casing, various plastic polymers, and a battery with its own internal chemistry. Extracting, refining and purifying all these materials, and then using them to manufacture chips in absolutely dust-free clean rooms, requires supply chains that stretch across the entire planet, considerable consumption of ultrapure water, and a level of industrial precision only achieved in recent decades. A very substantial share of that specific device's total environmental impact has, in fact, already happened before its user turns it on for the first time.

When it fails, it's not always repairable even though almost everything still works

When an electronic device stops working correctly, the real problem is almost never that all its components failed simultaneously: very often, a single specific component — a degraded battery, a broken screen, a damaged charging port — is the only faulty part, while the rest of the device remains perfectly functional. However, design decisions such as gluing components instead of screwing them, using proprietary parts hard to obtain outside the original manufacturer, or discontinuing software updates for models no longer recent can, in practice, prevent a repair that would in principle be technically simple. Storing a no-longer-used device in a drawer, while not the ideal solution, at least physically retains those materials in a known place; throwing it directly into ordinary household trash, by contrast, exposes its battery to fire risk from mechanical damage and definitively loses the chance to recover its materials. Informal export of electronic waste to countries with weaker environmental controls can end up, in the worst case, in manual dismantling with no protection whatsoever for the people doing it, or in the open burning of wiring to recover the copper, releasing toxic substances into that community's air, soil and water in the process.

A licensed recycler doesn't recover everything, but it recovers a lot

A properly licensed electronic-waste recycling center follows an orderly process: first it safely removes the battery, which requires separate handling due to fire risk; then it sorts the equipment by type and composition; and finally it recovers the highest-value metals through specific metallurgical processes, while also managing the glass and various plastics separately. Even so, not every chemical element present in an electronic device is recovered in practice: some are present in such tiny amounts, or so mixed with other materials, that the cost of separating them individually far exceeds the economic value that would be recovered by doing so, so that specific material is effectively lost, even when the overall recycling process was done correctly. Reusing a device that still works safely, giving it a second life through another person, in practice preserves far more of the material and energy work already invested than shredding it directly for recycling, even when that recycling is carried out in the most correct way possible.

Extending service life before replacing the device

Physically protecting the device with a suitable case, repairing it when reasonable instead of replacing it at the first fault, replacing only the battery when that swap pays off against buying an entirely new unit, keeping it updated with the available software, and selling or donating it with a secure wipe of personal data when it is no longer needed are decisions that, together, substantially extend an electronic device's real service life. When buying a new unit, prioritising brands and models with a commitment to long-term technical support and spare parts genuinely available on the market makes it easier for that life-extension decision to remain possible in the future. And it's worth remembering that a new device's energy efficiency has to pay off, over its service life, the cost already invested in manufacturing it: not every incremental efficiency improvement on its own justifies prematurely replacing a unit that still works reasonably well.

Extend before replacing

  • Protect the device with a suitable case or cover; many failures start with avoidable physical damage.
  • Repair when reasonable: almost always a single component fails, not the whole unit.
  • Replace only the battery when that pays off against buying a whole new unit.
  • Keep the software updated for as long as the manufacturer allows it.
  • Sell or donate with a secure data wipe when you no longer need it; a second life preserves far more than shredding it.
  • Always use official e-waste collection, never ordinary household trash: a damaged battery is a fire risk.
  • When buying, prioritise long-term technical support and spare parts genuinely available.

Keeping it in a drawer isn't ideal, but it's better than throwing it away badly

A stored device retains its materials in a known place; taking it to an official collection point is even better, because it allows a real share of those materials to actually be recovered instead of leaving them indefinitely idle.

The numbers, with their source

A tonne of discarded phones can contain more gold than a tonne of mine ore

A tonne of discarded mobile phones can contain on the order of 140 grams of gold, while a tonne of ore extracted from an active gold mine typically contains between 5 and 20 grams. This means electronic waste concentrates precious metals at 40 to 100 times higher levels than natural ore extracted directly from the ground, a concept that gave rise to the term "urban mining" as an alternative to conventional mining.

Sources: C&EN — Electronic waste is a gold mine waiting to be tapped; Statista — Electronic Waste (value and volume of raw materials in global e-waste).

$91 billion in metals, and only a fraction gets recovered

The electronic waste generated in 2022 contained valuable metals worth an estimated 91billion∗∗,butcurrente−wastemanagementeffectivelyrecoversonlyaround∗∗91 billion**, but current e-waste management effectively recovers only around **28 billion in secondary raw materials — less than a third of the total potential value available. In gold and silver alone, annual high-tech product manufacturing incorporates more than 16billionand16 billion and 5 billion respectively, a total of about $21 billion a year "locked away" in new electronic devices.

Sources: UNEP — UN report: Time to seize opportunity, tackle challenge of e-waste; ScienceDaily (2012) — E-waste: Annual gold, silver 'deposits' in new high-tech goods.

What this table is missing

These global figures do not distinguish between formal recycling, with proper environmental and worker-safety controls, and informal dismantling in countries with weaker controls, which can recover a similar fraction of metals but at a far greater environmental and human cost for the people doing it.

Sources