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Application Change of Fused-cast Zirconium Corundum Brick in Glass Furnace

Release time:

2021-11-12 11:03

The main components of fused-cast zirconium corundum bricks are alumina, zirconia and silica. The English abbreviation is AZS, which indicates the English initials of the main components. During production, alumina, zirconia and silica are placed in an electric melting furnace, melted and cooled by injection molding. The lithofacies structure consists of a eutectoid body of corundum and zirconium clinoptilite and a glass phase filled between the two crystals. Fused and cast zirconium corundum bricks are mostly used in the construction of glass furnaces, and different models and compositions are also different. They can be used for the construction of different parts of glass furnaces. The glass furnace in use will withstand a high temperature of thousands of degrees. Under the severe test, what changes will the fused-cast zirconium corundum brick have?

Melting and casting zirconium corundum material in the glass furnace will have a process of crystallization, first in the oblique zircon crystal space precipitation of a oblique zircon, then in the oblique zircon and corundum eutectoid line precipitation aluminum zirconium eutectoid, and finally the precipitation of glass phase and the remaining crystals. As one of the petrographic structures of fused-cast zirconium corundum brick, the glass phase can reduce the melting temperature, expand the casting temperature range and relax the thermal stress, but it is also the weak link of fused-cast zirconium corundum brick and reduces the corrosion resistance of the material.

Fused and cast zircon corundum bricks will be gradually eroded in the glass furnace. The glass phase will be replaced by the glass of the tank furnace first, and the corundum will begin to dissolve, slowing down the erosion rate of the brick body. After the corundum is exhausted, the fused and cast refractories begin to disintegrate, and the oblique zircon enters the kiln and becomes stones. If the refractory components are not mixed after being dissolved, stripes will be formed, and the striped components are different from the glass, which can affect the degree of dissolution of the gas and cause bubbles to precipitate, which will adversely affect the quality of the produced glass; stones and stripes will also affect the quality of the glass.

Application of fused corundum brick in float glass melting furnace

The glass melting furnace is a thermal equipment for melting glass composed of refractory materials. The service efficiency and service life of glass melting furnace depend on the variety and quality of refractory materials to a great extent. The development of glass production technology depends to a large extent on the improvement of refractory manufacturing technology. Therefore, the rational selection and use of refractory materials is a very important content in the design of glass melting furnaces. To do this, we must master the following two points, one is the characteristics and applicable parts of the selected refractory materials, and the other is the use conditions and erosion mechanism of each part of the glass furnace.

Process Improvement of Electro-fused Zirconium Corundum Pavement Brick

Electrically fused zirconium corundum brick is made of industrial alumina powder and zircon sand (containing 66% of zirconium oxide and 34% of silicon dioxide) melted at high temperature in an electric furnace. After melting, it is cast into a shape (the casting temperature is 1780-1840 ℃), injected into the model and cooled to form a solid close to white. Its petrographic structure consists of the eutectoid body and glass phase of corundum and zirconium clinite, it is a eutectoid body of corundum phase and zirconium clinoptilite phase, and the glass phase is filled between their crystals.

How to overcome the defects produced in the casting and annealing of fused zirconium corundum bricks

Electrofused zircon corundum brick in the production will produce a variety of defects, resulting in the use of poor quality products. The physical and chemical inhomogeneity of zirconium corundum bricks is often the main reason for the defects of the products. Particles that are not melted through in the batch and gas inclusions that have not been discharged from the melt in time are all physical inhomogeneities. The difference in the composition of the melt along the depth of the furnace is a chemical inhomogeneity.

Causes of Serious Erosion of Zirconium Corundum Brick in Glass Electric Melting Furnace

The erosion of fused zirconium corundum brick is mainly divided into physical action and chemical action. Physical action refers to the glass melting furnace wall in the long-term operation process, repeatedly subjected to the impact of rapid cooling and rapid heat, the surface must undergo a contraction of the expansion of the change process. Due to excessive fatigue, the structure of fused zirconium corundum brick is damaged, resulting in increased surface cracks and loose structure. Therefore, under the action of air flow, material and glass liquid washing, cracking and peeling, and this process will be repeated.