Phosphate bonded high alumina bricks are made of dense super or first grade high alumina bauxite clinker as the main raw material, phosphoric acid solution or aluminum phosphate solution as the binder, after being formed by a semi-dry machine and heat treated at 400-600 °C. chemically bonded refractory products. Phosphate-bonded high-alumina bricks belong to non-burning bricks. In order to avoid large shrinkage of products during high temperature use, heat-expandable raw materials, such as kyanite, sillimanite, pyrophyllite, silica, etc., should be introduced into the ingredients.
Compared with ceramic-bonded sintered high alumina, it has better spalling resistance, but lower softening temperature under load and poor corrosion resistance, so it is necessary to add a small amount of fused corundum mullite to strengthen the matrix. Phosphate bonded high alumina bricks are suitable for cement kilns, electric furnace roofs and ladles, etc.
General-purpose high-alumina bricks are made of high-quality bauxite clinker, supplemented by combined clay and additives. It has the advantages of high refractoriness, good acid and alkali corrosion resistance, high high temperature strength and good thermal shock stability. Widely used in thermal equipment in metallurgy, petroleum, chemical, building materials, machinery, processing and other industries.
