High-alumina bricks are classified by alumina content into: Grade III (Al₂O₃: 48–65%), Grade II (Al₂O₃: 65–75%), Grade I (Al₂O₃: 75–80%), and Special Grade (Al₂O₃: ≥80%).
They are classified by the type of kiln used into: spalling-resistant high-alumina bricks for cement kilns, low-creep high-alumina bricks for hot blast stoves, and phosphate-bonded high-alumina bricks for rotary kilns (used for ceramsite, lithium oxide, or zinc oxide production).
Based on shape and dimensions, they include knife-shaped, axe-shaped, and wedge-shaped bricks, as well as high-alumina skew bricks and anchor bricks.
Categories also include standard bricks, shaped bricks, and specially shaped bricks.