Metallurgical-grade silicon typically contains 98–99% silicon and is used in aluminum alloys and chemical synthesis. Polysilicon (polycrystalline silicon) is refined to semiconductor or solar grade (often 99.9999%+ purity) and is classified separately in HTS. The distinction matters because different duty rates, trade remedy orders, and supply chains apply to each grade.

Yes. The US has imposed antidumping and countervailing duty orders on silicon metal from multiple countries at various times. Importers should consult the current USITC and Commerce Department order lists to determine whether their supplier country and product specification are covered before finalizing purchase agreements.