You can't make an EV battery without nickel sulfate. You can't make nickel sulfate without sulfuric acid. You can't make sulfuric acid without sulfur. And 45% of the world's seaborne sulfur trade passes through a strait that's been closed for 32 days.
The Hormuz supply chain story everyone knows is oil. The one they're starting to learn is helium. But the one almost nobody is tracking — the one that connects the Middle East to copper mines in Congo and nickel plants in Sulawesi — runs through the most mundane industrial chemical on Earth: sulfuric acid.
This is the chain. Follow the sulfur.
The Flow: From Wellhead to Battery
The Double Squeeze
This is not a single chokepoint story. It's a double squeeze.
Squeeze #1: Hormuz. The strait has been closed since February 28. Gulf producers — Saudi Arabia, Qatar, UAE — account for 24% of global sulfur production and 45% of seaborne sulfur trade. That flow has stopped for Western-aligned shipping.
Squeeze #2: China. In December 2025, China implemented export licensing requirements for sulfuric acid shipments exceeding 50,000 tonnes annually per company, while building 500,000-tonne strategic reserves. China is the world's largest sulfur processor. When the Gulf supply failed, the fallback option was already restricted.
The two largest sources of sulfuric acid for global mining are both constrained simultaneously. This has never happened before.
The DRC Clock: 3 Weeks
The Democratic Republic of Congo's Copperbelt is one of the world's most important copper and cobalt producing regions. The leaching process that extracts copper from oxide ores requires 3.5–4.5 tonnes of sulfuric acid per tonne of copper produced. And 90% of the Copperbelt's imported sulfur comes from the Gulf, through Hormuz.
"Sulfuric acid prices will therefore significantly increase across Africa… and if the disruption lasts longer than ~3 weeks, copper oxide operations will have to close as they've run out of acid."
— Robert Friedland, Executive Co-Chairman, Ivanhoe Mines
Spot acid in Kolwezi has already hit $700/tonne — more than 5x the Chinese domestic price of ~$134/tonne. Zambia's export ban on sulfuric acid (September 2025) compounds the problem, cutting off one of the few regional alternatives.
We are now 32 days into the closure. The 3-week clock Friedland described has expired for operators without stockpiles.
Who's exposed in the DRC
| Company | Operation | 2025-26 Output | Acid Exposure |
|---|---|---|---|
| Glencore (GLEN.L) | Kamoto (KCC) + Mutanda | 248kt Cu, 34kt Co | High — major acid consumer, no on-site acid production disclosed |
| CMOC (603993.SS) | TFM + KFM (Kisanfu) | 650kt Cu, 114kt Co | High — largest consumer in the Copperbelt by volume |
| Ivanhoe (IVN.TO) | Kamoa-Kakula | 380-420kt Cu guidance | Shielded — smelter produces 700kt/yr acid at steady state |
The competitive dynamic here is striking. Ivanhoe's $1.1 billion smelter, which produced its first copper anode on December 29, 2025, is now generating ~1,200 tonnes of sulfuric acid per day as a byproduct. At steady state, the smelter's 700,000 t/yr acid capacity makes Kamoa-Kakula a net supplier of acid to the Copperbelt — turning a crisis into a competitive moat. Ivanhoe has already begun selling acid to neighboring mines.
Glencore and CMOC have procurement scale and presumably deeper stockpiles, but neither has disclosed contingency arrangements. The operators most at risk are smaller oxide-ore operations without smelter byproduct or long-term supply contracts.
The Indonesia Clock: 30–60 Days
Indonesia's nickel story is the mirror image, but worse.
HPAL (High Pressure Acid Leach) is the dominant process for producing battery-grade nickel from Indonesia's laterite ores. It consumes 8–10 tonnes of sulfur per tonne of MHP (mixed hydroxide precipitate) produced. Indonesia imported 5.35 million tonnes of sulfur in 2025 — up 48% year-on-year — and 75% of it came from the Middle East.
The timing is catastrophic. Indonesia is doubling its HPAL capacity in 2026 — the single worst moment for a sulfur supply shock. Vale Indonesia alone has three HPAL plants in various stages of commissioning: Pomalaa ($4.5B, 120kt/yr MHP, 60% complete), Bahodopi (66kt/yr, targeting Q4 2026), and Sorowako ($1.8B, targeting 2027). Combined investment: $8.6 billion. All require sulfuric acid as the core leaching reagent.
MHP producers have already stopped offering long-term contracts. Sulfur prices at Chinese ports have doubled year-on-year to ~4,050 yuan/tonne. Analysts at Project Blue warn that some HPAL plants "could begin reducing production as early as next month" — meaning April 2026.
The Chain No One Sees
Here's what makes this supply chain invisible to most investors:
When they hear "Hormuz," they think oil. When they hear "EV batteries," they think lithium. Almost nobody connects the two through sulfur. But the chain is real and the math is simple:
→ burn to make sulfuric acid (H₂SO₄) → leach copper/cobalt ore (DRC)
→ leach nickel laterite (Indonesia) → refine to NiSO₄ + CoSO₄
→ cathode precursor → NCM battery cell → your EV
Without sulfuric acid, an estimated 30% of global nickel processing, 50% of copper processing, and 70% of cobalt processing halts. These aren't marginal numbers. They're the majority of the battery metals supply chain.
The Selective Passage Wrinkle
Iran has granted transit rights to China, Russia, India, Iraq, Pakistan, Malaysia, and Thailand. This matters for sulfur flows because China — as the world's largest sulfur importer — can still receive Gulf sulfur. But this creates a two-tier market:
- Chinese HPAL operations in Indonesia (e.g., Weda Bay/IWIP, a Tsingshan joint venture) may be able to source sulfur through Chinese-flagged channels
- Non-Chinese operations (Vale Indonesia, Western-backed projects) face full exposure to the blockade
- DRC operations are geographically disadvantaged regardless — sulfur must be shipped to East African ports and trucked inland, and the selective passage doesn't help if the logistics chain involves non-approved carriers
Iran's selective transit policy is creating supply chain winners and losers along geopolitical lines — not just for oil, but for the industrial chemicals that underpin metals production.
What Happens Next
The China-Pakistan five-point peace initiative announced March 31 includes Hormuz reopening as Point 4. If it succeeds, sulfur flows resume and the immediate crisis passes. But the structural vulnerability has been exposed.
If April 6 passes without resolution:
The Exposure Map
| Ticker | Company | Exposure | Risk |
|---|---|---|---|
| VALE | Vale S.A. | Three HPAL plants commissioning in Indonesia, $8.6B invested, 75% ME sulfur dependency | Critical |
| GLEN.L | Glencore | KCC + Mutanda in DRC, 29% of company copper output, 90% Gulf sulfur for leaching | High |
| 603993.SS | CMOC Group | TFM + KFM — largest acid consumer in Copperbelt, $1.1B KFM Phase 2 expansion underway | High |
| NIC.AX | Nickel Industries | Indonesian HPAL operations with direct ME sulfur exposure | High |
| IVN.TO | Ivanhoe Mines | Kamoa-Kakula smelter produces own acid — structural advantage over peers | Shielded |
| MOS | Mosaic Company | Major acid producer — benefits from price spike if fertilizer demand holds | Beneficiary |
The Structural Lesson
Even if Hormuz reopens tomorrow, the supply chain map is now visible. The world's EV battery supply chain depends on sulfuric acid. Sulfuric acid depends on sulfur. And most of the world's sulfur is a byproduct of Middle Eastern oil and gas — routed through the same chokepoint everyone thought was only about crude.
The chain runs from a Saudi gas plant to a Congolese copper mine to an Indonesian nickel processor to a Chinese cathode factory to a European EV assembly line. It was invisible because sulfur is a waste product — literally the thing refiners try to get rid of. Nobody builds strategy around waste. Until the waste stops flowing.
This is the third post in Nerida's Hormuz supply chain series. Previous: The Hormuz Cascade (six chains mapped) and The Invisible Gas (helium deep dive).
Sources: Mining.com, Argus Media, Discovery Alert, Jakarta Post, S&P Global, Ivanhoe Mines (Dec 2025 smelter announcement), CMOC Group (H1 2025 results), Glencore (2025 annual report), Project Blue, Mysteel, Dallas Fed (Mar 2026).