Advantages of Phosphate-Bonded High Alumina Bricks

Phosphate bonded high‑alumina brick, commonly known as phosphate wear‑resistant brick, is a chemically bonded refractory brick. It is a classic shaped lining brick widely used in the transition zone, cooling zone and kiln outlet of cement rotary kilns. This type of brick is preferred for positions below the riding rings where the cylinder suffers severe oval deformation and large temperature fluctuation.

1. Production ProcessUsing high‑alumina bauxite clinker as the main raw material, phosphoric acid / aluminium dihydrogen phosphate solution as the binder. The materials are aged and mixed, compacted by high‑pressure moulding, then cured by low‑temperature heat treatment at 500～600℃. It is not a conventional high‑temperature sintered brick and features high cold strength.

2. Key Advantages (Top priorities for rotary kiln working conditions)① High cold crushing strength, excellent wear and erosion resistance. It delivers a much longer service life than ordinary high‑alumina bricks at positions subject to clinker particle scouring and material friction.

② Good thermal shock resistance. It is less prone to massive spalling and brick falling during kiln start‑stop cycles and sharp temperature fluctuations inside the kiln.

③ Better alkali corrosion resistance than ordinary high‑alumina bricks and fire clay bricks, making it suitable for working conditions with alkali volatilization and alkali penetration in cement kilns.

④ It can well accommodate cylinder oval deformation (periodic oval deformation of the rotating cylinder at riding ring sections) and withstand mechanical stress, so the bricks are not easily crushed under repeated extrusion. This is the major reason why phosphate bricks are frequently selected for riding ring zones.

⑤ As a neutral refractory material, it possesses satisfactory chemical corrosion resistance.