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Extending the service life of fused zirconium corundum bricks in glass electric melting furnaces

Release time:

2022-01-10 13:38

As we all know, the glass tank kiln melts horizontally, the material liquid level moves horizontally, and the erosion is serious at the three-phase interface except for the flow liquid hole, as shown in Figure 1. The glass electric melting furnace is vertical melting, most of which are cold top melting, the glass liquid surface is covered by a layer of raw material layer, and there are fewer three-phase interfaces. Because it is vertical melting, the pool wall brick erosion is no longer concentrated in the three-phase interface, but the overall erosion, so the weak link of fused corundum brick is the breakthrough of erosion.

According to the erosion mechanism of fused zirconium corundum brick, the content of Na2O in the raw material composition of fused zirconium corundum brick should be strictly controlled first. The national standard requires the content of Na2O in 33#WS to be below 1.45, the content of Na2O in 41#WS to be below 1.3, the standard of our company's electric furnace requires the content of Na2O in 33WS to be below 1.35, and the content of Na2O in 41#WS to be below 1.05.

For the erosion site, it is required that the ratio of riser to brick must reach 1.5:1. The pressure of riser can effectively reduce the residual pores in the brick, enhance the erosion resistance of the brick at the injection port, and require that there is no obvious shrinkage residue at the injection port.

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.