Fused cast alumina block is mainly composed of Al2O3 whose contents is more than 94 percent. It is produced by melting and casting high purity alumina in electric furnace at 2000℃.
The producing process of fused cast alumina block includes mixing the raw material, melting it in the electric furnace, casting, annealing, machining and then getting the final products.
In the manufacturing process of fused cast alumina blocks, first melt the raw materials in an electric arc furnace. When the material has become molten and its chemical and physical characteristics have been adjusted to the desired condition, pour the molten material into a mold.
The mold is commonly made of graphite or other suitable materials. The mold is provided with a riser or header of ample size to enable complete filling of the mold without interference by material freezing in the headers. The cast material is left in its respective mold for heat treatment, or removed from the mold after the outer walls of the casting have solidified and then annealed without other than its own support. The cast parts are generally packed closer together, thereby allowing them to anneal by virtue of their own heat.
After the blocks have cooled, similar to fused cast AZS block, the cast parts are inspected and finished by diamond cutting and/or grinding. The header may be removed shortly after casting or after annealing. The amount of material in the header is often about equal to the amount of material in the desired finished refractory piece. Header material is commonly recycled, but at considerable expense.
Fused cast alumina block has excellent endurance to strong alkali. Under 1350℃, it has strong corrosion resistance and almost does not contaminate to glass melting liquid. Because it does not contain impurities such as Fe2O3 and TiO2, when it comes into contact with glass liquid, air bubbles are rarely found. Therefore, this product has the special characteristic of minimizing contamination to glass liquid.
Sunrise Refractory offers high quality fused cast alumina block including fused cast alpha alumina block, fused cast beta alumina block and fused cast alpha-beta alumina block at competitive prices.