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Congolese cobalt to a battery cathode

Custody journey · starts in Democratic Republic of the Congo

Congolese cobalt to a battery cathode

A metal almost nobody mines on purpose, carried out of a landlocked country by truck.

Cobalt (II) hydroxide in solution · Omi1103 · CC BY 4.0 · Wikimedia Commons
1,000 tonnes of copper-cobalt ore
4 tonnes of contained cobalt, about 350 electric cars' worth
Democratic Republic of the Congo → Tanzania · Truck Tanzania → China · Container ship China → South Korea South Korea → Germany Democratic Republic of the Congo — Industrial mines, and a great deal of hand digging 1 Democratic Republic of the Congo Tanzania — The long haul 2 Tanzania China — Into a battery-grade salt 3 China South Korea — Into the cathode 4 South Korea Germany — About 350 cars 5 Germany
Numbered in the order the material travels. Click a country to open its page. Equirectangular projection drawn from country centroids — the arcs show which borders are crossed, not the actual sailing route.

What is actually moving

Cobalt is a by-product: it comes up because somebody wanted the copper. It leaves the DRC as a hydroxide filter cake on a truck, crosses two borders, sails to China, and is refined into the sulfate that goes into a cathode. The route is long, and the due-diligence obligations attached to it are the strictest of any material in this atlas.

The material
Cobalt
The variety
Heterogenite, cobalt oxide ore, recovered alongside copper
Where it starts
Democratic Republic of the Congo — Kolwezi, where roughly three-quarters of the world's cobalt originates
Why this route and not another. Cobalt hydroxide is an intermediate invented to solve a freight and refining problem — it concentrates the metal enough to be worth moving, and it is refined where the sulfate and precursor plants already are.
The narrowest link. Refining. Roughly three-quarters of the world's cobalt refining is in one country, regardless of where the ore was dug.
Read the two numbers on each step: what went in, and what came out. Watching them shrink is the point. By the end you will have followed a thousand tonnes of rock down to a few kilograms of the thing that actually does the work.

Step by step, and border by border

01 Extraction 1,000tonnes

Democratic Republic of the Congo · Kolwezi and the Lualaba belt held by Industrial operators and artisanal miners (Miner)

Industrial mines, and a great deal of hand digging

Most cobalt comes from large mechanised copper mines. A material share is also dug by hand by artisanal miners and sold into the same processing plants, which is why chain-of-custody documentation matters here more than anywhere else in this atlas.

1,000 tonnesore 1,000 tonnesore to the plant

Why here: The Copperbelt. There is no comparable cobalt resource being mined at this scale anywhere else.

continuous Mutanda →
Industrial mines, and a great deal of hand digging
Steam shovel loading copper and cobalt … · Public domain via Wikimedia Commons
02 Processing 8tonnes

Democratic Republic of the Congo · Hydrometallurgical plant held by Operators (Chemical)

Leached out with the copper

Cobalt dissolves in the same acid leach as the copper, then is separated and precipitated as a hydroxide once the copper has been electrowon out.

1,000 tonnesore 8 tonnescobalt hydroxide cake

What happened to the rest: If the copper price falls far enough to close the mine, the cobalt stops too. Its supply follows copper economics, not its own.

Why here: It shares a circuit with the copper because it shares an orebody with it.

Leached out with the copper
"Mixing tanks and clarifying basins at … · Public domain via Wikimedia Commons
03 Transport 8tonnes

Tanzania · To Dar es Salaam or Durban held by Hauliers (Trader)

The long haul

Bagged hydroxide is trucked 2,000 km or more to a port, crossing at least one border. Queues at the crossings routinely add days.

8 tonneshydroxide 8 tonnesat the port

Why here: There is no railway that does this job reliably. The road IS the supply chain.

Truck · 7–14 days 7–14 days Tanzania →
The long haul
Port activities in Dar Es Salaam, Tanzania · CC BY-SA 4.0 via Wikimedia Commons
04 Refining 4tonnes

China · Zhejiang and Jiangxi refineries held by Refiner (Refiner)

Into a battery-grade salt

Redissolved, purified of nickel, copper, iron and manganese, and crystallised into cobalt sulfate heptahydrate — pink crystals to a very tight specification.

8 tonneshydroxide 4 tonnescontained cobalt as sulfate

Why here: This is the real chokepoint. Mining is spread across one country; refining is concentrated in another.

Container ship ~4 weeks in transit Huayou Cobalt Refineries →
The road not taken Another material with one refining country Different element, same shape of problem: the mine is not the bottleneck.
Into a battery-grade salt
Ammonium - cobalt sulfate.JPG · CC BY-SA 4.0 via Wikimedia Commons
05 Component 4tonnes

South Korea · Precursor and cathode plants held by Cathode manufacturers (Manufacturer)

Into the cathode

Co-precipitated with nickel and manganese sulfates into a precursor, then lithiated and calcined. Cobalt is what keeps the cathode's layered structure from collapsing as it charges and discharges.

4 tonnescobalt 4 tonnescobalt in cathode material

Why here: Cathode makers cluster near cell makers, who cluster near carmakers.

Into the cathode
NTM cathode ray tubers Kr Birkeland 189… · CC BY-SA 4.0 via Wikimedia Commons
06 End market 4tonnes

Germany · Wherever they are sold held by Drivers (End user)

About 350 cars

At roughly 13 kg per pack for a mid-nickel chemistry, 4.5 tonnes of cobalt is a few hundred vehicles — and every one of them can be traced back, on paper, to the pit it came from.

4 tonnescobalt 4 tonnesin service

What happened to the rest: Cathode chemistry has been cutting cobalt for a decade — from a third of the cathode metal to under a tenth in high-nickel designs, and to zero in LFP.

Why here: Substitution is the quiet counter-pressure on this entire route.

About 350 cars
Wallbox EV charging station at the Park… · CC BY 4.0 via Wikimedia Commons

This is a worked example. It follows a stated starting quantity through published typical yields and recoveries, so the proportions are checkable; it is not a record of a specific shipment. Route facts — which countries, which processes, and why the material cannot simply be handled somewhere else — are compiled from public reporting.

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