Limestone flux (L.D., below 1% SiO2)
Limestone flux, low-silica grade (below 1% SiO2)
HSN 2521 00 10 (Limestone flux, low-silica grade — below 1% SiO2) is not covered by a Bureau of Indian Standards Quality Control Order and carries no Partner Government Agency clearance requirement at the tariff-line level. Import follows the standard customs procedure: Importer-Exporter Code (IEC), bill of entry, commercial invoice, packing list. Calcareous stones from the same heading used for lime or cement manufacture may attract compliance under adjacent tariff lines or under Chapter 25 notifications governing construction materials.
The absence of compliance at this tariff line turns on the product's specific description: low-silica limestone flux used in steelmaking. A consignment reclassified by customs as limestone for cement manufacture, or as a calcined or processed lime product under Chapter 25, attracts a different compliance posture and can result in detention pending re-classification. Verify the SiO2 content certificate, end-use declaration, and processing state against the customs tariff before shipment.