Fused Cast AZS Exudation And Glass Defects

Fused cast AZS block is the most widely used refractory material in the dem anding areas. It is thought as the leading cause of knot and cord defects. Fused cast AZS exudation in glass contact is the main cause of impaired per formance of AZS under particular working conditions.

The main crystal phase of Fused cast AZS consists of corundum, baddeleyite and glass phase. The glass phase can reduce the expansion or shrinkage of Z rO2 within the above temperature range and prevent cracking. However, the g lass phase is easy to be corroded and cause corrosion of the fused cast AZS and glass defects.

Fused cast AZS exudation exhibits a shiny "wet looking" appearance at the s urface of blocks during heat-up process and beginning of a furnace campaign . This situation tends to stabilize all along the campaign life, with a gen erally moderate dripping of a viscous glassy phase into the smelted glass.

Fused cast AZS exudation at high temperatures, can lead to the formation of defects in the glass, especially during furnace start-up. It is only a sho rt-term cause of glass defects. Fused cast AZS exudation from a glass conta ct surface is not very visible than that in the superstructure.

In the glass furnaces, a portion of the glass phase of fused cast AZS block exudes onto the superstructure surface during furnace heat-up, until the f urnace has achieved stable temperature profile. The exuded glass, often con taining small zirconia crystals, tends to run down into the glass bath. Thi s is a major concern to glass producers since this glassy phase often cause s defects, such as viscous knots and stones.

To solve this problem, low exudation fused cast AZS has been developed. Wit h modification of chemical compositions and glass phase, it offers low exud ation level and maintains all other positive characteristics of fused cast AZS.

Sunrise offers various refractory materials for glass furnaces including fu sed cast AZS, silica brick, fireclay brick, high alumina brick, silimanite brick, mullite brick, etc..

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