Editorial Article
Two Point Four Times the Price for the Same Molecule
On the 100 per cent H3PO4 basis that the contained-phosphorus ladder in this segment is built on, a tonne of thermal acid carries 0.316 tonnes of phosphorus. Assessed at the 2025 yellow phosphorus price of RMB 24,324 a tonne of contained phosphorus, that phosphorus is worth RMB 7,688. The acid is assessed at RMB 6,760.
So the product sells for RMB 928 less than the element inside it — a discount of 12.1 per cent, taken before a single one of the 4,109 kilowatt-hours the furnace burns has been paid for. On the contained-phosphorus ladder this research series uses, with elemental phosphorus indexed at 1.00, thermal acid sits at 0.88.
That is a strange result, and the temptation is to read it as a cost problem. It is not. Every input in thermal acid is globally traded at essentially one price: the ore, the coke, the electrode, the electricity, the yellow phosphorus itself. What is not globally traded is the permission to sell the finished tonne into a particular customer’s specification. The 12 per cent sits on the wrong side of the furnace to be a cost.
Where the acid sits on the ladder
| Product | RMB/t product | P content | RMB per tonne of contained P | Index (element = 1.00) |
|---|---|---|---|---|
| Phosphate rock | 1,020 | 13.1% | 7,783.9 | 0.32 |
| Dicalcium phosphate (feed grade) | 3,060 | 18.0% | 17,000 | 0.70 |
| Thermal phosphoric acid | 6,760 | 31.6% | 21,386 | 0.88 |
| Monocalcium phosphate | 4,850 | 22.0% | 22,045.5 | 0.91 |
| Yellow phosphorus (the element) | 24,324 | 100% | 24,324 | 1.00 |
| Phosphorus trichloride | 5,773 | 22.55% | 25,601 | 1.05 |
| Sodium tripolyphosphate | 8,100 | 25.3% | 32,066 | 1.32 |
| Glyphosate | 24,850 | 18.32% | 135,645 | 5.58 |
Only two products in this chain sell their phosphorus for less than the price of the element they were made from: feed-grade dicalcium phosphate at 0.70 and thermal acid at 0.88. Both, and only these, are what the chain produces when it has not yet paid for purification. Everything from 1.00 upwards — the chloride at 1.05, the salt at 1.32, the herbicide at 5.58 — carries a qualification of some kind.
A basis question the market does not settle
The Chinese assessments the parent report cites — Hubei RMB 6,500 to 7,000, Yunnan around 6,600, Sichuan RMB 6,300 to 6,800 in June 2025 — are quoted for 85 per cent product. The ladder above is on the 100 per cent basis. If those assessments are taken at face value as per-tonne-of-product prices, a tonne of acid carries 0.269 tonnes of phosphorus rather than 0.316, the acid’s phosphorus costs RMB 25,158 a tonne rather than 21,386, and its index is 1.03 — a marginal premium to the element rather than a discount to it.
Nothing else in this article turns on which convention is correct: the 2.4 times trade gap, the 1.79 Mt of idle capacity and the mechanism behind both are unaffected. It is flagged because it is the largest definitional sensitivity in the market — a 15 per cent swing in the acid’s implied value per tonne of phosphorus, produced entirely by whether a quoted price is converted to a 100 per cent basis or taken as sold.
Two point four times, same molecule
The trade reconstruction in the parent report puts non-Chinese thermal phosphoric acid at roughly 2.4 times the Chinese assessment for material of the same P2O5 content. No mining-cost difference explains that. Rock moves at one price and the energy content of the molecule is identical wherever it is oxidised. What differs is that the Western tonne arrives with a file attached — a battery, food or electronics customer who has qualified that plant, that lot and that impurity profile, and who cannot substitute on price without repeating the qualification.
This is the whole of the margin in thermal acid, and it is not in the acid. It is in the paragraph of the specification that says which plant made it.
One point seven nine million tonnes that cannot be exported
Chinese capacity in this market includes roughly 1.79 Mt that is not running. The furnaces exist, the ore is domestic, the power is contracted. What cannot be shipped is the qualification, because it attaches to a line and a customer rather than to a commodity. You can export the acid. You cannot export the fact that a specific automotive or semiconductor buyer signed off on the plant that produced it.
So the surplus sits. It sits through the years when acid is cheap, and it comes back when the spread between what the element costs and what the acid fetches is wide enough to pay for 4,109 kWh and leave something behind. That is swing capacity behaving as swing capacity, not a growth industry waiting for demand.
What would actually close the gap
Not a cheaper furnace — the furnace is already at the bottom of its cost curve and its marginal cost is a power contract. The gap closes when a Chinese purification line completes a qualification at a customer that currently pays 2.4 times the Chinese price: a multi-year file, plant by plant, grade by grade, with the first lot of every change re-tested.
The mirror image is worth stating, because the same segment contains it. In phosphite fertilisers, the European barrier is an authorisation the Commission has been unable to finalise since 2013; in thermal acid, the Chinese barrier is a customer file. In both cases the chemistry is a commodity and the permission is not.
The tell
Watch the contained-phosphorus index rather than the acid price. If thermal acid’s 0.88 moves toward 1.00 without yellow phosphorus falling, a qualification has been completed somewhere. If it falls further while the element holds, another tonne of capacity has been started in a jurisdiction that cannot sell it into the market that pays 2.4 times.