Silica fire bricks are the only real choice when you need to build the crown of a glass melting furnace. The heat up in the roof area easily goes past 1600°C. Standard materials will just melt or collapse under their own weight. You need a solid silica refractory brick up there. It handles the extreme heat and holds the furnace roof up without softening.
1.Silica brick composition and specs
What makes a good silica fire brick? It is all about the silicon dioxide (SiO2) purity.
Good silicon brick composition is always above 96% SiO2. If you check a standard silica brick datasheet, you will see the silica brick density needs to be around 1.85 g/cm³ to 1.95 g/cm³. If it is too light, the brick is porous and weak against furnace gases.
The silica brick thermal conductivity is also very specific. It lets the furnace keep the heat inside where the glass actually melts.
2.Silicon firebrick uses in the furnace
The main silica brick application is in the upper structure of the glass furnace. This means the main crown, port arches, and sometimes the burner blocks.
Why use them here? Because glass melting creates a lot of alkali vapors. These vapors will eat basic bricks alive, but silica brick refractory is acidic. It resists this alkali attack very well.
Another key part of silica brick properties is high-temperature volume stability.
When the kiln heats up to working temperature, these bricks expand just a little bit. This expansion actually locks the roof arch tight. No gaps, no heat leak.
3.Sizes, prices and shipping
Furnace roofs are curved, so standard silica brick dimensions don’t always work for the whole job. You usually need specific wedge shapes or custom arch blocks.
You can look at our silica brick catalogue to see standard shapes, but most glass furnace jobs are custom made from kiln drawings.
Ruitai Lianxin is a direct refractory brick company and an experienced fire brick exporter.
Furnace roofs are curved, so standard silica brick dimensions don’t always work for the whole job. You usually need specific wedge shapes or custom arch blocks. You can look at our silica brick catalogue to see standard shapes, but most glass furnace jobs are custom made from kiln drawings.
Just send us your kiln drawings, and our engineers will check the exact shapes you need. Contact us right now to get a fast quote.