Tearing apart sulphuric acid

Sulphuric acid.

Bloomberg framed it as China weaponizing another export. CNBC ran a chyron about trade war escalation. Both are reading the wrong diagram. This is not about copper. This is not about the US. This is about a Chinese phosphate fertilizer plant that needs to keep running through the summer planting cycle, and a government that just watched sulphur imports get strangled in a shipping lane four thousand miles away.

Sulphuric acid is the most-produced industrial chemical on the planet. 260 million tonnes a year. Nobody writes about it because nobody can make it sound interesting — it's a clear liquid that fertilizes your food, leaches copper out of Chilean rock, and cleans silicon wafers in Taiwanese fabs. It has no ticker. It has no ETF. It is the kind of input that only gets mentioned after it's already broken something.

On April 10, Beijing told its smelters exports stop May 1. That's eight days from this morning. The ban covers acid that comes out of copper and zinc smelters as a by-product — which is, conveniently, most of the acid China exports. 2.7 million tonnes a year vanishes from the global pool next week.

Nobody on the sell-side has moved their copper cost models. I've checked.

Alright. Story off. Numbers on.

China runs more than 40% of global sulphuric acid capacity — roughly 177 million tonnes. Exports run about 2.7 million tonnes a year. Chile alone imports over a million tonnes annually, about a third of the acid used in its SX-EW copper leaching. The math from here writes itself.

Start upstream. The Middle East supplies about a third of global sulphur and roughly half of the seaborne trade. Every ton of it moves through the Strait of Hormuz. That strait has been functionally shut since late February — Iran's navy is boarding tankers, insurance premiums on Gulf transits are a multiple of pre-conflict levels, and flows are running significantly below normal. Sulphur prices are up around 70% since the conflict started.

Sulphur is the feedstock for sulphuric acid. You can't make one without the other. Chinese domestic acid prices ran from roughly 464 yuan a tonne a year ago to about 1,045 yuan in January. That's before the ban. Export-quality realized prices at CESCO Week last week were quoted at $400 to $500 a tonne. One European smelter told Fastmarkets they had none to sell at any price.

Chilean import acid prices jumped 44% in a single month. That is not a market in equilibrium finding a new clearing level. That is a system in redistribution failure.

Fertilizer is the demand engine the metals desks keep forgetting. Roughly 54% of global sulphuric acid feeds phosphate fertilizer production. Mining and metals take about 10%. When Beijing has to choose between its spring planting season and its copper-importing customers, that is not a close call.

Here is the part the algorithms haven't figured out yet.

The COT data on COMEX copper shows speculators net long and pressing. Copper posted four consecutive weekly gains into this week, flirting with $13,500 a tonne on the spot rally. The positioning is priced for the supply story. Nobody is positioned for the cost-curve story.

Those are not the same trade.

SX-EW — solvent extraction and electrowinning — is the low-cost processing route for oxide copper ores. It is also entirely dependent on cheap sulphuric acid. Goldman puts the production-at-risk number at 200,000 tonnes for Chile and 125,000 tonnes for the DRC, where stockpiles run out in May or June. That is before you get to Indonesian HPAL nickel, which is in the same queue for the same dwindling acid supply and nobody has modeled it properly.

I've been on the wrong side of one of these cost-shock trades before. It doesn't show up in price the first week. It shows up two quarters later when the C1 cost guidance gets revised on an earnings call, and suddenly the sell-side models that had a mine earning $4,000 a tonne of margin have one earning $3,100. The stock drops 18% in a morning. The copper price doesn't have to fall for this to hurt. The margins collapse anyway.

The machines see rising copper. They buy more. They have never, to my knowledge, sat through an Antofagasta operations call and heard the words "acid availability constraint."

The cascade runs on a calendar, not a chart.

May 1: Chinese acid exports stop. Chilean and African buyers with inventory on water are fine for four to eight weeks. After that, they're paying spot, and spot is already $500 a tonne and rising. By mid-June, the first pure-play SX-EW producers will begin quietly revising production guidance — not dramatically, just enough to get the analyst community to sharpen pencils. H1 earnings season in late July and August is when the full impact hits the tape.

Then the dispersion opens up. And that is where the trade is.

Where the capital goes: integrated producers who smelt their own concentrate and therefore generate their own acid. Ivanhoe's Kamoa-Kakula smelter in the DRC produced 117,871 tonnes of high-strength acid in Q1 and sells the surplus to other DRC miners. They are long the tightness. So is anyone running an integrated Chilean or Peruvian complex where the smelter sits next to the leach pads.

Where the capital does not go: pure-play oxide producers running imported acid on thin margins. The mid-cap Chilean SX-EW names. The small African copper-cobalt operations buying Chinese acid on spot. Indonesian HPAL nickel projects — Tsingshan-feeding, Lygend-feeding names — are in the same exposure bucket and trading as if they're not.

One honest caveat. A Hormuz ceasefire that actually holds, one where insurance rates normalize and Saudi and Qatari sulphur starts moving again, unwinds half of this setup inside a month. I don't think the ceasefire holds. But I have been wrong about this before, and if I'm wrong again, you'll read it here in two sentences.

The paper market is trading the headline. The physical market is trading the pH of a leach pad in Antofagasta. Pick your layer.