Six types of refractory materials commonly used in foreign glass kilns

Six types of refractory materials commonly used in foreign glass kilns

Refractory materials used in foreign glass kilns mainly fall into the following six categories:

1.AZS and high zirconia bricks

The main production process for fused AZS bricks is to improve their corrosion resistance and wear resistance. In addition to adopting oxidation method for melting to reduce the carbon content of the product to 0.005, the glass phase precipitation temperature is increased to 1450°C. The casting and annealing processes have also been improved, and now fused AZS with little or no shrinkage cavity volume has been produced. High zirconia bricks with a ZrO2 content of more than 90 have very good thermal shock properties, such as ZrO295, Si021. 4. High zirconia bricks with stabilizer 3.7 have a bulk density of 4.7g/cm3, a porosity of 18.4, and a thermal shock resistance of up to 15 to 20 times from room temperature to 1400°C (15 minute interval). Japan produces a fused-cast zirconia brick with a zirconia content of 90, called ZFC brick. Its corrosion resistance is better than AZS bricks with a ZrO2 content of 40. At 1500~1600°C, no glass phase precipitates after 16 hours, which is good for The glass has very little contamination and has no cracks after 40 thermal shock resistance tests at 800~1250C.

2.Chrome bricks and chrome-containing bricks

Dense chromium oxide bricks formed by isostatic pressing are used for side walls, necks or other severely corroded parts of E glass and C glass tank kilns, with a service life of up to 6 to 7 years. In recent years, there have been new developments in chromium-containing products, such as adding Cr203 to AZS bricks to form A1203-Zr02-Si02-Cr203 series refractory materials. At high temperatures, Cr203 forms a solid solution with A1203 on the one hand, and on the other hand, Cr203 is High melting point substances enter the glass phase of the brick and increase the viscosity of the glass phase, thereby increasing the seepage temperature of the glass phase and greatly improving the glass erosion resistance of glass products. A company in the United States has produced a recombination-cast AZS/Cr203 refractory material with superior chemical composition and physical properties. Compared with the original AI203/Cr203 material, the annual furnace period reduces power consumption by 4%, increases output by 15%, and costs . Reduced by 3.75, the glass quality is not affected. This kind of brick can be machine pressed, hand pounded or isostatically pressed, and then sintered at high temperature.

3.Alkaline bricks

High-purity directly bonded alkaline bricks fired at 1800°C are widely used in regenerator walls and bricks. Germany has launched a new material with the trade name RUBINAIEZ. Its chemical composition is MgO75, ZrO213.5, Si029.5. It is a periclase brick combined with zircon. In the early stage of sintering, the zirconium silicate in the brick structure reacts with magnesium oxide to form a protective layer of forsterite and zirconium oxide around the periclase particles. This structure greatly improves the In order to improve the alkali and sulfate corrosion resistance of bricks, the effect of making checkered bricks in the middle of the regenerator is good.

4. Olivine magnesia brick

The olivine binding phase has particularly strong corrosion resistance. By increasing the forsterite content in the binding phase of magnesia bricks, the corrosion resistance of magnesia bricks can be improved. In order to add 20% forsterite fine powder to the ingredients of magnesia bricks, a forsterite bonding matrix can be formed that can protect the magnesia particles and reduce erosion. The price of this brick is relatively cheap, and it has been widely used in the middle part of the glass kiln regenerator grid abroad.

5. Barium feldspar olivine bricks

In view of the good corrosion resistance of olivine but insufficient thermal shock resistance, the introduction of barium feldspar into its binding phase can significantly improve the thermal shock resistance of bricks. Barium feldspar is formed during firing and is only present in the bound matrix phase. When the barium feldspar content is 15, silicon has the best performance and the service temperature is about 1250'C. Research shows that barium feldspar is resistant to alkali and sulfate attack.

6. Unshaped refractory materials

The application of unshaped refractory materials in glass kilns is also a development trend. The UK uses refractory concrete prefabricated blocks to build regenerators, checkered brick floors, flues, small furnace pallets, burners, etc., which greatly reduces the joints of the kiln structure, increases the speed of furnace construction, and shortens the cold repair time. ERSOL from France Sipp is an amorphous refractory material series made of ER1681 fused particles as the main component. It is used with fused bricks at the bottom of the pool. It has excellent resistance to glass erosion and has a tendency to precipit