Fused Cast Bricks For The Glass Industry

Fused cast bricks have contributed significantly to increasing glass production, glass quality and service life of the glass furnaces. They are featured with good resistance to glass and slag corrosion and abrasion resistance.

Fused cast bricks are made by melting pure and relatively fine grain raw materials in an electric arc furnace. Next the materials are poured into sand or graphite molds and in specific cases into metal molds if the products have thin walls. The shapes range from small components to large blocks.

 

Fused cast bricks are featured with a dense structure without open pores with intercrystalline bonds and with intensive interlacing of the crystals. The dense crystalline structure gives the bricks superb strength, corrosion resistance and erosion resistance up to high temperatures. 

 

There are generally 5 basic types of fused cast bricks for the glass industry: 

 

Fused cast Alumina block 

Fused cast Alumina block according to its crystal phase, can be divided into alpha-beta-Al2O3, beta -Al2O3 and alpha-Al2O3. Alpha-beta-Al2O3 block is comprised essentially of alpha alumina and beta alumina crystals in a most ideal proportion which is approximately 50% and 50% respectively. This materials exhibits excellent high temperature strength retention and creep resistance due to its essentially biphasic crystalline nature. Beta-Al2O3 block consists of large plate beta-Al2O3 crystals and are relatively soft and sensitive to hydration. It has an especially good resistance to alkali oxide vapors. Upon attack by batch dust there is a slow conversion of beta -Al2O3 to alpha-Al2O3. 

Applications: Refining and cooling down area, working end and forehearth areas of soda lime and lead crystal tanks, burner parts and superstructure sidewalls. 

 

Fused cast AZS block

Fused cast AZS block is mainly composed of Al2O3, ZrO2 and SiO2. According to the ZrO2 content, fused cast AZS block can be divided into AZS 33#, 36# and 41#. The corrosion resistance increases with growing ZrO2 content. During cooling of the brick melt, baddeleyite and corundum precipitate at the same time so that both crystal phases are interpenetrated. In the glassy solidified residual melt there are round and dendritic ZrO2 crystals. The ZrO2 crystals protect the less resistant corundum from attack by the glass melt. 

Applications: in glass contact and superstructure areas of melting/working tanks and forehearths, upper area of regenerator casing and as cruciforms in the checkers. There is slow dissolution of the bricks (premature wear at the surface level of the glass melt) upon contact with glass melt. Nepheline can form in the checkers upon attack by alkali oxide vapors and batch dust. After a longer period of time this effects crack formation. 

 

Fused cast AZSC block

By adding chromium oxide the corrosion resistance of alumina-Zirconia-silica-chromium oxide block is substantially improved due to the formation of chrome corundum. 

Applications: In tank areas which are subjected to high wear in place of AZS blocks, specially in hollow ware, fiber and opal fluoride glass tanks. 

 

Fused cast high zirconia block

Fused cast high zirconia block is made of artificial synthesis high purity raw materials through special casting process. The crystalline texture consists of baddeleyite and with the characteristics of excellent high temperature & corrosion resistance, low blister and stoning potential. These advantages can prevent liquid glass from pollution effectively. 

Applications: In sidewall, throat cover, throat support, electrode block, dam block parts of high quality and special glass furnaces such as TV glass, Borosilicate glass, Alumina silicate glass, Halogen lighting glass, Opal glass and Fiber glass.  

 

Alumina-chromium-oxide-spinel brick

Alumina-chromium-oxide-spinel brick is composed of Al2O3, Cr2O3, MgO and Fe2O3 (FeO).

Applications: Melting of glasses with high alkali oxide content or alkali oxide/earth alkali oxide content as basalt melts, for example. These brick grades have a very high corrosion resistance. 

 

Sunrise supplies various kinds of fused cast bricks for glass furnaces, including fused cast AZS block, fused cast alumina block and fused cast high zirconia block. Our fused cast bricks have been used in various glass furnaces and proved to improve the service life of glass furnaces effectively.