How is the sulfur price surge reshaping the yellow phosphorus vs. wet-process phosphoric acid cost landscape?

How is the sulfur price surge reshaping the yellow phosphorus vs. wet-process phosphoric acid cost landscape?
The 172% surge in domestic sulfur prices since early 2025 has upended the competitive balance between thermal and wet-process phosphoric acid routes. Wet-process acid, which consumes about 1.29 tonnes of sulfur per tonne of product, has seen production costs jump by roughly 3,319 yuan per tonne. This has forced major wet-process purification plants, including Wengfu's facilities in Sichuan and Fujian, to halt or cut production. Meanwhile, thermal phosphoric acid made from yellow phosphorus has gained a cost advantage, as yellow phosphorus prices have been relatively stable and low. This dynamic has boosted yellow phosphorus consumption, with thermal phosphoric acid now accounting for 33% of demand. The sulfur shock is effectively subsidizing the thermal route, at least until sulfur prices normalize.