Explanatory notes
… chemically defined. 2849.10 ‑ Of calcium 2849.20 ‑ Of silicon 2849.90 ‑ Other This heading covers : (A) Binary … lumps or shapeless masses, crushed or in grains. Fusible only with difficulty; resists chemical reagents; has a … the form of grinding wheels, hand sharpening or polishing stones, etc. ( heading 68.04 ). (3) Boron carbide …