Fast heating, long service life, and low budget. For kilns with these requirements, choose clay refractory bricks for the lining first. This will save a lot of trouble later.
1. Stable clay brick material – safe kiln walls
Clay refractory bricks have an Al₂O₃ content of approximately 30%–48% and a SiO₂ content of approximately 50%–65%. The main crystalline phase, mullite, has a volume change of less than 0.3% below 1200℃. Therefore, the heating section will not suddenly expand, minimizing stress on the furnace shell.
Simultaneously, clay bricks have an Fe₂O₃ content of less than 2%, preventing low-melting eutectic formation when laid adjacent to silica bricks, high-alumina refractory bricks, or magnesia-alumina spinel bricks. This means that maintenance only requires partial replacement, not complete demolition.
Furthermore, the material is not sensitive to CO and H₂ reducing atmospheres and will not decarburize and become porous like magnesia-carbon refractory bricks. Therefore, clay bricks are used as a “buffer layer” in blast furnace throats, hot blast stove partitions, and lime kiln preheating zones.
In short, when building a kiln, lay a layer of clay bricks first, followed by high-load high-alumina refractory bricks or corundum refractory bricks for a more stable overall structure.
2. Clay bricks are more affordable – flexible budgeting
Clay bricks are generally cheaper than high-alumina bricks and magnesia-carbon bricks. If calculated based on the 1200℃ zone of the kiln’s cold side, combining 75% clay bricks with 25% high-alumina bricks can reduce the total cost of refractory materials by about 20%.
Furthermore, clay brick grades range from N-1 to N-6, with flexible selection of bulk density and apparent porosity. Simply tell the clay brick manufacturer the maximum temperature and mechanical wear index, and they can provide the corresponding grade, avoiding unnecessary expenses.
3. Choosing a clay brick manufacturer
Clearly specify the Al₂O₃ content, room temperature compressive strength, and reheat line variation in the technical agreement.
Next, have the supplier provide refractory brick specifications for the same batch to avoid mixing grades.
Finally, include after-sales brick replacement clauses in the contract for easy future maintenance.
Only by comprehensively evaluating quality, delivery time, and service can you select a truly suitable refractory brick supplier.
Henan Ruitai Lianxin Refractory Materials Co., Ltd. has focused on refractory materials for 20 years. It not only provides customers with high-quality refractory bricks that meet quality standards, but also offers the most suitable kiln operating conditions solutions.
Choosing Ruitai Lianxin means choosing strength.