What are the key risks in the antimony trisulfide supply chain for Chinese buyers?

What are the key risks in the antimony trisulfide supply chain for Chinese buyers?
China dominates global antimony processing, holding about 71% of refining capacity and 78% of mine ore treatment capacity, but domestic ore supply is tightening. Mines in Hunan, Guangxi and Gansu face declining grades, rising costs and strict environmental inspections, while Beijing has capped mining and suspended new exploration permits since 2009. As a result, China imports concentrate from Australia, Tajikistan and Russia—yet overseas supply is also constrained, with projects delayed and new smelters in Oman and Central Asia competing for feedstock. For antimony trisulfide specifically, most product comes from processing natural stibnite ore, so any disruption in concentrate supply or quality directly affects availability and pricing for downstream fireworks, rubber and semiconductor buyers.