Selection and building of refractory materials for glass furnace

Selection and building of refractory materials for glass furnace

1. Dense chrome brick

It has the best resistance to high temperature E glass erosion performance, and its corrosives basically do not cause pollution to the glass liquid, so it has become the first choice for high-quality refractory bricks for E glass unit kilns.

Dense chromium oxide is formed by isostatic pressing method, and its density is very high. The main technical indicators are Cr2O3 content>94%, porosity <15%, bulk density>4.24g/cm3, and erosion loss is only 1/10 of that of compact zirconium bricks. . It is used in E glass furnace unit kiln that directly contacts the wall of the melting part of the high temperature molten glass, the bottom of the high temperature part of the melting part, the wall and bottom of the main passage, the wall of the transition passage, etc.

The dense chromium oxide brick grades commonly used in the world include C-1215, C-1215Z, CR-100 produced by CORHARP in the United States, GR95WA produced by VGT-DYKO in Germany and UC-PC-95 produced by Shinagawa Co., Ltd. in Japan.

2. Dense Zirconia Brick

The brick’s resistance to high temperature & molten glass corrosion is slightly lower than that of compact chromium oxide bricks, and it is also formed by isostatic pressing. Its technical indicators are ZrO2>65%, apparent porosity<2.0%, and bulk density about 4.25g/cm3. In E glass, the temperature exceeds 1370°C, there is corrosion. It is used in the bottom of the melting part where the temperature of the molten glass is slightly lower in the E glass unit kiln, the transition channel, the bottom of the forming channel, the flow groove of the forming channel and the slat bracket. In addition, dense zirconia bricks are also used as backing bricks for dense chrome bricks.

Commonly used international brands include ZS-1300, ZS-1500, ZS-835 and ZS-78 produced by American CORHARP Company, ZS65WA produced by German PGT-DYKO Company, and UC-Z, UC-CZ, UC produced by Shinagawa Corporation of Japan. -CZB etc.

In recent years, many refractory companies in my country have successively introduced foreign technology and equipment, and have also produced sintered dense zirconium bricks formed by isostatic pressing, which have been partially used in domestic glass and fiberglass kilns.

The German KGT-DYKO company has developed a new type of dense zirconia brick with a coarse grain structure, which greatly improves the internal structure of the brick, and further improves the brick's resistance to rapid cold and heat. Its bulk density is 3.75g/cm3 and its porosity is 17%. The brick grade is ZS65AR, which has good thermal shock resistance, and is most suitable for drawing liquid troughs and slab holding bricks.

3. Standard zirconia brick

The ZrO2 content of the brick is about 66%, the bulk density is 3.7g/cm3, and it has good thermal stability and peel resistance. It is used in the breast wall and back wall of the feeding port area where powder erosion is serious, the breast wall and roof brick of the furnace observation hole brick and the passage flame space, and the burner brick. But there are also burner bricks using AZS, mullite bricks as transition bricks, and gap bricks on both sides of the kiln.

4. Sintered mullite bricks

The brick chemical composition is Al2O3>74%, SiO2 2.2%. The bulk density is 2.5g/cm3, the main purpose is standard chromium backing bricks, melting part breast wall and front wall bricks, passage flue lining bricks, large chute foot and discharge port outer bricks, heat exchanger entrance flue outer wall bricks Wait. There is also a kind of mullite bricks that are sintered after forming mullite crystals by the melting method; they have better resistance to high temperature creep and thermal shock resistance, and can be used as kiln towers and flame space breast walls. The effect is very good, and the localization has been successful.

5. Fused zirconia corundum brick (AZS brick)

The brick chemical composition is ZrO2 34%, Al2O3 49.2%, and SiO2 15.9%. The bulk density is 3.85g/cm3, and the main uses are the burner bricks of the melting part and the bricks of the feeding port.

6. Fused chrome corundum brick

The brick chemical composition is 28.3% Cr2O3, 58.3% Al2O3, 5.2% MgO and Fe2O3. The bulk density is about 3.4g/cm3. Mainly used in the flue interface bricks at the entrance of the heat exchanger.