According to the different parts of the glass kiln, the refractory bricks used are also different. If the refractory is improperly selected, the glass defects produced by the
refractory bricks may have the following types:
1. Stones
When the larger particles of refractory brick fall off into the glass melt and cannot be completely dissolved by the melt, "stones" will appear in the glass. The particles with a large specific gravity will settle to the bottom of the pool. Insoluble materials such as ZrO2 can also be dispersed. The small particles do not cause harm.
The alkali in the glass will react with alumina-containing refractory bricks to form feldspar-like substances. Due to the difference in thermal expansion, the flakes fall off. After falling off, new flakes are generated to cause harm. Those unsintered solid particles in the ramming material may also enter the glass and form stones.
2. Bubbles
All organic impurities attached to the surface of the refractory bricks will be burned to produce bubbles. Certain inorganic building materials also have a tendency to generate bubbles at the beginning. In addition, the air discharged from the holes of the refractory bricks can also cause bubbles. Carbon-containing impurities are always the source of bubbles.
Metal iron itself has no tendency to generate bubbles, but the carbon contained therein has such a tendency. Substances with redox potential will also produce bubbles due to changes in the oxidation conditions in the melt. Zirconium bricks also tend to generate bubbles in the early stages of use. But through the action of alkali in the glass, the quality is improved, and no more bubbles are produced.
3. Defects formed indirectly
The alkali in the glass and the material containing Al2O3 combine with granite. In a certain temperature range, this substance cannot be completely dissolved and leaves "stones". The effect of KZ-brick is similar. Alumina may dissolve or semi-dissolve, leaving ZrO2 as a "stone". The aggressive components of the glass may dissolve the SiO2 in the zircon product and leave ZrO2 stones. If the particles are large enough, stones will appear in the glass. These particles will also be produced on the corroded checker bricks. When the combustion-supporting air passes through the checker brick masonry, it may blow them (part of the checker brick, damaged refractory brick or their components) into the melt and cause it. The formation of "stones". The refractory bricks falling from the upper structure of the kiln or the roof may also form stones.
Refractory bricks for glass kilns are often divided into the following types:
1. Rectangular bricks, standard refractory bricks, ordinary wall bricks;
2. Plug the head brick. Small sheet;
3. Large standard refractory bricks and rectangular bricks;
4. Thin plate;
5. Vault bricks: full bricks, double-layer full bricks, combined with full bricks, flat bricks, horizontal bricks, buns bricks, semicircular bricks;
6. Arch-foot bricks: pointed wedge bricks, pillars. Corner brick;
7. Melting pool tiles: integral pool wall tiles. Round bricks.
