How much does China's pyrite supply depend on a handful of integrated miners?

How much does China's pyrite supply depend on a handful of integrated miners?
Concentration is the defining feature of China's pyrite sector. One operator holds proven reserves above 200 million tonnes at roughly 31 percent average sulfur grade, described as 85 percent of national rich-ore reserves, with about 3 million tonnes annual ore capacity and 1.4 million tonnes concentrate capacity, equal to around 16 percent of national output. Two other listed producers, Jiangxi Copper and Guangxi-based GuangSheng, match it on volume but only as by-product of copper and rare earth operations, so their pyrite output is not price-responsive. That leaves genuinely merchant, pure-play supply thin. For buyers, this means contract availability tightens first when downstream acid and phosphate demand spikes, and spot premiums widen before any new capacity arrives. Reserve depletion at high grades adds a structural constraint beyond this cycle.