Zircon-Mullite Refractory Block
Zircon-mullite refractory blocks are fired ceramic construction blocks blending zircon and mullite for glass furnace crowns and regenerators. They resist alkali corrosion and thermal cycling. HTS 6902.90.50.20 applies to these other refractory ceramic blocks.
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Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If alumina content >50% with specific bonding
Alumina refractory bricks have dedicated subheadings under 6902.20.
If sold as individual components for assembly
Non-constructional refractory ceramic goods or parts classify in 6903.
If containing graphite or carbon additives
Carbon or graphite-enhanced refractories move to Chapter 68 articles.
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Import Tips & Compliance
• Submit mineralogical analysis to prove inorganic nonmetallic fired composition per Chapter 69 notes
• Ensure blocks are not cermets (8113) by confirming no metallic binders
• Pair with end-use declarations for furnace construction to prevent reclassification as parts
Related Products under HTS 6902.90.50.20
High-Alumina Refractory Firebrick
High-alumina refractory firebricks are dense ceramic bricks composed primarily of alumina and silica, fired at high temperatures to withstand extreme heat above 1500°C. They are used in furnace linings and kilns for their excellent thermal shock resistance and corrosion resistance. Classified under HTS 6902.90.50.20 as refractory ceramic constructional goods other than siliceous fossil meals, due to their fired ceramic composition for high-temperature industrial applications.
Magnesia-Chrome Refractory Brick
Magnesia-chrome refractory bricks are fired ceramic blocks made from magnesia and chromite for superior resistance to basic slags in steelmaking furnaces. They maintain structural integrity at temperatures exceeding 1700°C. This product fits HTS 6902.90.50.20 as 'other' refractory ceramic constructional goods, distinct from siliceous types.
Silicon Carbide Refractory Tile
Silicon carbide refractory tiles are high-fired ceramic tiles with exceptional wear resistance for use in blast furnace hearths and incinerators. They offer high thermal conductivity and resistance to abrasion. Classified in HTS 6902.90.50.20 as other refractory ceramic constructional tiles, excluding siliceous fossil meals.
Chromite-Magnesite Constructional Block
Chromite-magnesite constructional blocks are refractory ceramic blocks fired for rotary cement kilns, offering resistance to chemical attack. They serve as durable lining materials. Classified as other refractory ceramic constructional goods in HTS 6902.90.50.20.
Fireclay Refractory Tile
Fireclay refractory tiles are fired high-alumina clay tiles for boiler walls and incinerator floors, providing good abrasion resistance. They are constructional elements in high-heat environments. HTS 6902.90.50.20 covers these as other refractory ceramic tiles.
Insulating Refractory Brick
Insulating refractory bricks are lightweight, fired ceramic bricks with porous structure for furnace back-up insulation, reducing heat loss. They have low thermal conductivity while refractory. Fits HTS 6902.90.50.20 as other refractory constructional bricks.