High-Calcium Aluminate Refractory Blocks
Large refractory blocks with over 50% CaO content, fired for use in cement rotary kilns and lime kilns. These constructional goods provide thermal shock resistance and are shaped for furnace linings. Meets HTS 6902.10.50.00 as 'other' refractory goods with dominant calcium oxide.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If containing <50% Mg/Ca/Cr oxides
Lower oxide content classifies as other refractory bricks under 6902.90.
If unfired or cement clinker form
Unfired hydraulic lime or cement products excluded from Chapter 69 per notes.
If used solely for furnace linings but lower purity
Lower-spec refractory construction goods fall into 6904 if not meeting 6902 criteria.
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Import Tips & Compliance
• Provide lab analysis reports confirming CaO percentage and firing process to prevent misclassification as building bricks
• Check for proper marking of dimensions if tiles exceed 3.2cm thickness per US notes for headings 6905/6907
• Obtain end-use statements for industrial furnaces to differentiate from construction materials
Related Products under HTS 6902.10.50.00
Magnesia-Herringbone Refractory Bricks
Herringbone-patterned magnesia bricks with >50% MgO for improved gas flow in tunnel kilns and reheating furnaces. The angled design prevents brick movement under thermal cycling. HTS 6902.10.50.00 classification for magnesium refractory bricks.
Rebonded Fused Magnesia Chrome Bricks
Ultra-high purity bricks made from rebonded fused magnesia-chrome grains with aggregate >50% MgO/Cr2O3, for electric arc furnace roofs. Exceptional service life in severe conditions. Covered by HTS 6902.10.50.00 as premium refractory bricks.
High Purity Magnesia Refractory Shapes
Custom-shaped refractory components with 95%+ MgO content for specialized furnace zones like ladle impact pads. Precision fired to maintain dimensional stability. HTS 6902.10.50.00 for high magnesium oxide refractory goods.
Calcium Ferrite Refractory Bricks
Refractory bricks incorporating calcium ferrite phases with >50% CaO equivalent for waste incinerator linings. Resistant to alkali corrosion from flue gases. Classifies HTS 6902.10.50.00 for high calcium oxide refractories.
Magnesia-Dolomite Composite Refractory Blocks
Composite blocks blending magnesia and dead-burned dolomite achieving >50% combined MgO/CaO for basic oxygen furnace linings. Balanced chemistry for steelmaking slags. HTS 6902.10.50.00 classification applies.
Chromium-Corundum Refractory Bricks
High-chrome corundum bricks with Cr2O3>50% for glass furnace superstructures resisting batch carryover. Dense microstructure prevents glass penetration. Covered by HTS 6902.10.50.00 for chromium oxide dominant refractories.