Chapter 2518 — Customs Tariff Headings
Products classified under Tariff item 25.18
Dolomite Block for Lime Production
Large rectangular dolomite blocks in their natural, unsintered state, intended for use as feedstock in the production of dead-burned lime. These blocks have not undergone calcination or sintering, and are classified under tariff item 2518.10.00 as dolomite, not calcined or sintered.
2518.10.00Industrial Dolomite Lump for Refractories
Lump dolomite in sizes of 2-6 inches, used as feedstock for refractory brick production. The product is not calcined or sintered, and is presented in its natural, unprocessed form, qualifying for tariff item 2518.10.00.
2518.10.00Natural Dolomite Quarry Stone
Naturally quarried dolomite stone blocks extracted directly from deposits, without any calcination or sintering. These blocks are in their crude state, as permitted by Chapter 25 notes, and are classifiable under tariff item 2518.10.00.
2518.10.00Quarried Dolomite for Glass Manufacturing
High-purity dolomite blocks for flat glass manufacturing, delivered raw and uncalcined. The product is not sintered and meets the definition of dolomite in its natural state under tariff item 2518.10.00.
2518.10.00Raw Dolomite Slab for Flooring
Dolomite slabs saw-cut into rectangular dimensions from quarry blocks, intended for further processing into flooring tiles. The slabs are merely cut by sawing and not calcined or sintered, falling under tariff item 2518.10.00 as dolomite in a minimally processed state.
2518.10.00Rough Trimmed Dolomite Boulder
Dolomite boulders roughly trimmed into rectangular shapes for dimension stone applications, remaining unsintered and uncalcined. The product is minimally processed and qualifies for tariff item 2518.10.00 as dolomite roughly trimmed or merely cut into blocks or slabs.
2518.20.00Calcined Dolomite Aggregate for Asphalt Mix
Coarse calcined dolomite aggregate used in hot mix asphalt for road construction, valued for its polished stone value resistance. The calcination process imparts chemical stability beyond natural dolomite, qualifying it under tariff item 2518.20.00.
2518.20.00Calcined Dolomite Filler for Polymer Composites
Micronized calcined dolomite used as a functional filler in polypropylene and PVC compounds to improve stiffness. It is a processed mineral powder in its raw state, not yet incorporated into plastics, so it belongs under tariff item 2518.20.00.
2518.20.00Calcined Dolomite Powder for Refractories
Finely ground calcined dolomite produced by heating dolomite rock to high temperatures to remove volatiles, creating a stable refractory material. This calcined form is distinct from raw dolomite and falls under tariff item 2518.20.00.
2518.20.00Dead Burned Calcined Dolomite for Steel Flux
High-purity calcined dolomite dead-burned at 1700°C+ for use as a fluxing agent in basic oxygen steelmaking converters. The sintering process differentiates it from raw dolomite, placing it under tariff item 2518.20.00.
2518.20.00High Reactivity Calcined Dolomite for Animal Feed
Fine calcined dolomite powder used as a magnesium supplement in ruminant livestock feed. It is a calcined mineral product, not yet formulated as a Chapter 30 medicament or Chapter 31 fertilizer, so it falls under tariff item 2518.20.00.
2518.20.00Magnesia-Dolomite Sinter for Cement Rotary Kilns
Sintered blend of magnesia and calcined dolomite for transition zones in cement kiln linings. The dolomite component is in a calcined/sintered state, and the product is not yet assembled into a refractory article, so it falls under tariff item 2518.20.00.
2518.20.00Sintered Dolomite Blocks for Kiln Linings
Rectangular blocks of dolomite sintered at high temperatures to achieve a dense, heat-resistant structure for industrial furnace linings. The sintering process and rectangular shape place it under tariff item 2518.20.00, as it is not yet shaped into a specific refractory article.
2518.20.00Sintered Dolomite Slabs for Glass Furnace Crowns
Large rectangular slabs sintered from dolomite for crown construction in soda-lime glass melting furnaces. These roughly cut, thermally processed slabs are covered by tariff item 2518.20.00 before final refractory shaping.