Editorial Article
Ninety-Seven Per Cent of the Price Is the Element
Ninety-seven per cent of the price is the element
Thermal phosphoric acid is the only product in the phosphate chain that is, in substance, a way of shipping electricity. A tonne of 100 per cent H₃PO₄ made the thermal route carries 4,109 kWh — the oxidation of yellow phosphorus to P₄O₁₀ and its hydration to acid, counted end to end. The wet route dissolves rock in sulphuric acid and purifies afterwards; it carries a fraction of that energy. Almost everything else about this market follows from that one number.
What follows first is that the thermal route is priced off two inputs its operators do not set. In 2025 the yellow phosphorus assessment was RMB 24,324 a tonne. A tonne of acid contains 0.3161 t of P₄ — 123.9 g of phosphorus per mole against 392.0 g for four moles of acid — so it carries RMB 7,688 of phosphorus before a kilowatt hour is bought. The oxidation step earned a RMB 841.6 margin a tonne in September 2025, which at 10.6 per cent of product price works back to an acid price of roughly RMB 7,940.
The element inside the acid is 96.8 per cent of what the acid sells for. Then the furnace switches on.
The idle tonnage is a tariff, not an overhang
China produced 982.8 kt of thermal phosphoric acid in 2025 against nameplate consistent with about 2.77 Mt. Utilisation was 35.46 per cent. Read that as a capacity story and it is four decades of overbuild; read it as an energy story and it is a fleet of residual suppliers running when the grid is cheap and dark when it is not.
At 4,109 kWh a tonne, every RMB 0.10 on the industrial tariff is RMB 411 a tonne of acid — roughly half the entire oxidation margin, in a single line of a utility bill. At any plausible tariff in the provinces where the furnaces sit, power alone is a quarter to a third of the product’s price. No other input in this chain is that elastic to something a phosphate producer cannot influence.
Which reframes what the idled 1.79 Mt actually is. It is not a supply overhang waiting to be cleared by demand growth. It is optionality written against the electricity curve: capacity that exists precisely because the tariff moves, and that will produce in the months the tariff falls. A market read through capacity utilisation looks broken at 35 per cent. A market read through the power price looks rationally idle.
The chain’s first downgrade
There is a second way to see the same fact, and it runs through phosphorus rather than kilowatt hours. On a contained basis, at the 2025 industrial acid price of RMB 6,760 and a 31.61 per cent phosphorus content, thermal acid sells its phosphorus for RMB 21,386 a tonne. Yellow phosphorus, at RMB 24,324 with a nominal 100 per cent content, sells its phosphorus for RMB 24,324.
| Product | RMB/t product | P content | RMB per tonne of contained P | Index (element = 1.00) |
|---|---|---|---|---|
| Yellow phosphorus | 24,324 | 100% | 24,324 | 1.00 |
| Thermal phosphoric acid | 6,760 | 31.61% | 21,386 | 0.88 |
Thermal acid is the first product in the chain that sells its phosphorus for less than the element it was made from — at an 11.9 per cent discount, having consumed 4,109 kWh a tonne to get there. That is not a pricing failure. It is what the acid is for: the furnace exists to convert an element that is difficult to move and impossible to ship as fertiliser into a liquid that any industrial customer can meter, and the discount is the price of the conversion.
It also means the acid’s price cannot rise far above the element without the oxidation step earning an integrated return — and at 35.46 per cent utilisation, it plainly is not.
Where the same phosphorus earns 2.4 times more
Outside China, thermal acid is not priced as a commodity off yellow phosphorus. Food, pharmaceutical and electronic-grade acid carries a premium of roughly 2.4 times on identical phosphorus, because what is being bought is a certificate and a specification rather than a molecule. That is the whole of the value story in this market, and it is not available to a producer who has only built a furnace.
The implication for anyone allocating capital across this segment is uncomfortable but clear. The Chinese thermal fleet’s problem is not that it is too large. It is that 2.77 Mt of capacity is positioned at the one point in the chain where the product is a conversion service on an administered commodity, while the premium for the same element sits behind a qualification file that the fleet has not written. Utilisation will recover when the tariff allows it and fall again when it does not. The premium never arrives by itself.