Other
Natural borates and concentrates thereof (whether or not calcined), but not including borates separated from natural brine; natural boric acid containing not more than 85 percent of H3BO3 calculated on the dry weight > Other
Duty Rate (from China)
Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Products classified under HTS 2528.00.00.50
Calcined Colemanite Borate Concentrate
Calcined colemanite is a naturally occurring calcium borate mineral concentrate processed by heating to remove water, used primarily in glass and ceramic manufacturing. It falls under HTS 2528.00.0050 as a calcined natural borate concentrate with less than 85% H3BO3 content on dry weight, excluding borates from brine. This classification covers unrefined mineral forms not chemically separated.
Natural Ulexite Borate Ore
Ulexite is a hydrated sodium calcium borate mineral mined as sodium borate ore, commonly used in fertilizers and fiberglass production. Classified in HTS 2528.00.0050 as a natural borate not from brine, with H3BO3 content below 85% dry weight. It remains in raw or concentrated form without chemical separation.
Anhydrous Borax Natural Concentrate
Anhydrous borax concentrate derived from natural sodium borate deposits, calcined to remove water for use in detergents and enamels. HTS 2528.00.0050 applies to this non-brine natural borate with H3BO3 under 85% on dry basis. It is supplied as powdered or granular mineral product.
Priceite Calcium Borate Mineral
Priceite, a rare calcium borate (Ca4Mg2B10O23), occurs naturally and is concentrated for specialty glass and flux applications. It qualifies for HTS 2528.00.0050 as other natural borates not from brine, maintaining under 85% H3BO3 equivalence. Supplied in ground or lump form post-mining.
Kernite Sodium Borate Concentrate
Kernite is a natural sodium borate (Na2B4O7·4H2O) concentrate from evaporated lake beds, used in welding fluxes and herbicides. HTS 2528.00.0050 covers this non-brine natural borate with H3BO3 content below 85% dry weight. Typically exported as crushed or powdered ore.
Sassolite Natural Boric Acid Crystals
Sassolite consists of natural boric acid (H3BO3) crystals from volcanic fumaroles, capped at 85% purity for this category. Used in pharmaceuticals and antiseptics precursors. HTS 2528.00.0050 includes this as natural boric acid not exceeding the purity limit, distinct from synthetic.
Hydroboracite Borate Mineral Powder
Hydroboracite, a magnesium calcium borate, is ground into powder for enamel frits and insulation compounds. Classifies under HTS 2528.00.0050 as other natural borate concentrates from solid deposits, under 85% H3BO3 dry. Non-brine origin confirmed via mining records.