High-Purity Fluorspar (Over 97% Calcium Fluoride)

Acid-grade fluorspar — defined by a calcium fluoride content exceeding 97% by weight — is the critical feedstock for hydrofluoric acid production, which in turn underpins refrigerant, aluminum, and semiconductor manufacturing. A single 10-digit tariff line (2529220000) covers all US imports at this purity threshold, simplifying classification but not necessarily duty exposure, as fluorspar from certain origins has drawn trade-remedy scrutiny in the past. Mexico leads US supply, followed by South Africa and Mongolia, reflecting the geographic concentration of high-grade fluorspar deposits worldwide. Importers should verify origin documentation carefully given the mineral's designation as a US critical mineral.