The mineral is an essential component of batteries for smartphones and laptops, making billions for multinationals such as Apple and Samsung, yet many of those working to extract it are earning as little as 8p a day in desperately dangerous conditions.
With little regulation requiring companies to trace their cobalt supply lines, and most of the world’s cobalt coming from the Democratic Republic of Congo, the chances are your smartphone contains a battery with cobalt mined by children in the central African nation.
The Sky News team visited a string of mines in the DRC’s former Katanga Province and found children working at all of them.
Eight pence a day for backbreaking work
At one cobalt mine, children toiled in the drenching rain carrying huge sacks of the mineral.
Dorsen, eight, had no shoes and told us he hadn’t made enough money to eat for the past two days – despite working for about 12 hours a day.
His friend Richard, 11, talked about how his whole body ached every day from the tough physical work.
The mine tunnels are dug by hand by miners who have no protective equipment. The tunnels have no supports and are prone to collapse, especially in the rain.
At one mine we travelled to, workers had downed tools in support of a fellow miner who had died after one such collapse.
There are thousands of unofficial, unregulated, unmonitored mines where men, women and children work in what can only be described as slave conditions.
In one group, we found a circle of children with a four-year-old girl picking out cobalt stones.
Other children younger than her were sitting among the mineral or playing nearby. A pregnant woman already carrying a toddler on her back was also in the group.
None of them wore gloves or masks, yet the World Health Organisation says exposure to cobalt and breathing in its dust fumes can cause long-term health problems.
Certainly, many of those involved in the mining industry believe they’re suffering poor health as a result.
Makumba Mateba has a huge tumour on his throat which he believes has grown because the water in his village is contaminated by cobalt mining.
He said: “We only drink the water which comes from the mining sites after all the minerals have been washed in it.
“It comes right through our village and I drink it and I’m sure it’s that which has made me sick.”
Becha Gibu, a doctor in the village of Kimpesa, said many of the babies he delivered had mysterious illnesses.
“There are lots of infections they’re born with, sometimes rashes, sometimes their bodies are covered in spots,” he said.
“The mothers are also just not strong when giving birth – this is all a consequence of the mining.”
The DRC sits on one of the richest mineral deposits in the world, with huge amounts of gold, tin and cobalt underneath its soil.
It produces 60% of the world’s cobalt – a fifth of which is extracted by hand or artisanal miners known locally as creusseurs.
Cobalt collected by small mining operations is sold to mostly Chinese traders, who we filmed secretly.
They don’t ask questions about where their cobalt comes from or who has worked to extract it – they just want the best price.
Traders then sell it mostly to exporter Congo Dongfang International, a subsidiary of Zhejiang Huayou Cobalt, which supplies most of the world’s largest battery makers.
The supply line is chaotic, informal and unregulated, with unofficial, non-standardised prices paid out to groups, individuals and larger networks.
The cobalt supply line
In 2016, Amnesty International found that no country legally requires firms to publicly report their cobalt supply chains – allowing multinationals easy deniability.
And it has been reported that Donald Trump is set to issue a new executive order that would reverse regulatory controls designed to prevent US companies profiting from “conflict minerals” mined in the DRC and neighbouring countries.
A number of tech and automotive firms Sky News contacted said they would review their protocols, but would rather improve conditions than make a clean break from established supply chains.
Apple, whose response referenced the specific mine in our report, said it told one of its smelters, Huayou Cobalt, to suspend sourcing from artisanal mines.
But it said it would not sever all ties with artisanal mines as that “would be harmful to communities who rely on this mining for their income”.
An Apple spokesperson added: “Apple is deeply committed to the responsible sourcing of materials for our products and we’ve led the industry in establishing the strictest standards for our suppliers.
“We know our work is never done, and we will continue to drive our standards deep in our supply chain. If our suppliers are unable or unwilling to meet our standards then we suspend or terminate business with them.”
Speaking to Sky News, a Huayou spokesperson said the firm “pays attention” to child labour issues and was “monitoring” its supply chain.