The phone and the mine

Somewhere in the phone you are holding is a few grams of cobalt, a bluish metal that helps a rechargeable battery store energy without overheating. Most of it began its journey in the south of the Democratic Republic of Congo, which produces well over half of the world's supply. Demand has risen sharply as electric cars have joined the phone and the laptop. Cobalt is not, strictly speaking, mined for its own sake: it is largely a by-product of copper and nickel, so the world's supply rises and falls with the price of other metals.

Most Congolese cobalt comes from large industrial mines, run by international companies with machinery, security and payrolls. A smaller share is dug by hand. Artisanal miners, who work in pits and tunnels with hand tools, sell their ore to traders, and the traders sell it on. The work is dangerous, tunnels collapse, and in 2016 Amnesty International published a report documenting children working in such mines. The people at the bottom of this chain are not criminals. They are, for the most part, farmers and labourers who have found that a day in a mine pays better than a season in a field.

What happens next is where the story becomes hard to follow. The ore, from both kinds of mine, is shipped to refineries, most of them in China, where it is processed together and turned into the chemicals that go into batteries. At that point a gram from a well-run industrial site and a gram from a muddy pit are chemically identical and physically mixed. Nobody, not the refinery, not the battery maker and not the phone company, can look at a finished battery and say where its metal came from.

Technology companies respond that they audit their suppliers and have joined industry schemes that promise 'responsible sourcing'. Some of this effort is real. But an audit can only inspect a link in the chain, and a certificate on paper is not the same as a clean supply. Critics add that the system rewards companies for avoiding the worst mines rather than for improving them, which leaves the miners no better off. Several large firms have also tried to reduce their dependence on cobalt altogether, by switching to battery chemistries that use none.

There is a harder question about who should pay for a cleaner supply. Mines that meet decent standards cost more to run than those that do not, and the extra cost has to land somewhere. If it falls on the miners, it means lower pay for people who have little; if on the companies, it means profits a little smaller; if on the buyer, a phone that costs more. Few firms like to say which they prefer, and fewer still have shown the arithmetic.

Some governments are beginning to force the issue. The European Union has adopted rules that require makers of batteries to document where their raw materials come from, with penalties for firms that cannot. Whether paperwork alone can reach a pit in Katanga is another matter, but it shifts the burden. Until now, campaigners had to prove that a supplier was dirty; soon, the supplier will have to prove that it is clean.

None of this makes a simple moral for the person holding the phone. Boycotting Congolese cobalt would cost many of the poorest people in the region their income without ending the demand. The more honest conclusion is that a modern device is the end of a very long supply chain, and that the companies at the top of it have the means to see far more than they have chosen to show.