Fused cast refractories are materials that are produced by melting the raw material of the desired composition and then casting molten refractories in molds. They are widely known for having high corrosion resistance which ar e entirely different in the crystalline structure and the process for their preparation from fired or unfired bonded refractories due to closed pores.
Fused cast refractories are manufactured by melting mixtures of raw materia
the melt into molds of prescribed shapes. Finally cool and solidify them u nder thermal insulation in many cases. High density, small or large shapes are obtained. When appropriate, a finish work of drilling or cutting(to get different shapes) is made by grinding with diamond tools.
The dense crystalline structure provides the fused cast bricks with superb strength, corrosion and erosion resistance at very high temperatures. They are quite stable against aggressive melts such as glass and molten metal ox ides, but their thermal stability is usually not very high. Fused cast refr actories always have a very low and closed porosity but contains voids.
Fused cast refractories are the preferred refractories in contact with glas s melts, due to the chemical stability, impermeability, and resistance to c orrosion and erosion at the working temperatures in the glass melting furna ces. Therefore, used cast refractories are widely used in the glass industr y as a lining for glass melting furnaces. They are also used in various oth er industries such as iron & steel, aluminum, petrochemistry industries.
Fusion cast refractories are normally formed from alumina usually along wit h zirconia and silica. Proportions of other minerals such as calcia, chromi a and magnesia may be added to control the crystalline structure and physic al properties of the end products. Based on the mineralogical composition, fused cast refractories can be divided into:
Fused Cast AZS Block
Fused cast AZS block is abbreviated as AZS because it contains Al2O3? ?ZrO2?SiO2. Based on the zirconia content which basically defines their corrosion resistance, fused cast AZS blocks can be divided into Fuse d Cast AZS?33# (33% ZrO2), Fused Cast AZS?36# (36% ZrO2) an d Fused Cast AZS?41# (41% ZrO2). The corrosion resistance increases with growing ZrO2 content. They are the most widely used materials both in glass contact and superstructure of glass melting furnaces due to the very high glass and vapor resistance.
Fused Cast Alumina Block
Fuse cast alumina block contains over 90% Al2O3 and are a kind of pure alum ina block which has excellent resistance against acid slag and chemical cor rosion. Thanks to their high purity, they are perfect complements to the AZ S blocks for sensitive applications. According to the crystallographic anal ysis, Fuse cast alumina block can be divided into alpha Fuse cast alumina b lock (almost 100% alpha alumina crystal), beta Fuse cast alumina block (alm ost 100% beta alumina crystal) and alpha-beta Fuse cast alumina block (appr oximately 50% alpha and 50% beta respectively). Its neutrality against alka li vapors makes it the best choice for the downstream part of superstructur es in demanding applications.
Fused Cast High Zirconia Block
The Fused Cast high zirconia block contains at least 80% of ZrO2 with parti cularly excellent corrosion resistance against molten glass and low contami nation properties. Therefore, it has been widely employed as refractory mat erials in contact with molten glass in a glass melting furnace.
Fused Cast Skid Rail Block
Fused cast skid rail blocks are mainly made from alumina and zirconia. They are of various types including steel discharging platform brick,skid rail block and iron discharging tank blocks. They feature great strength,good we ar and fused slag corrosion resistance as well as long service life. It is mainly used in areas that require high abrasion and temperature resistance, such as gliding rail bricks in steel pusher metallurgical furnaces, the ta pping platform style walking beam furnaces, and also as the interior for de structors.
Fused Cast Mullite Block
Fused Cast Mullite blocks is characterized by high resistance to acid corro sion and erosion, good high temperature resistance and good thermal shock r esistance. It shows high performance on reheating furnaces' beds, skid rail s, and for the linings of industrial waste incinerators. It is widely used in the metallurgical industry, glass industry, ceramic kiln, and cement ind ustry,etc.
Sunrise is a refractory material supplier from China. The main products of Sunrise include fused cast AZS block, fused cast alumina block, mullite bri ck, zircon brick, alumina bubble brick, sillimanite brick, corundum brick, low porosity fireclay brick, high alumina brick, all kinds of glass furnace ramming masses, etc..