Refractory raw materials determine the main performance of refractory products, which is why they can operate stably in high-temperature environments. Refractory raw materials form the foundation of the refractory industry. This article provides a systematic introduction to the commonly used refractory raw materials.
Siliceous Refractory Raw Materials
Siliceous refractory raw materials are the primary raw materials for producing acidic refractories. Their main component is silicon dioxide (SiO₂), with a required SiO₂ content of more than 93%.
These raw materials mainly come from natural quartz ores. Common types include quartzite, vein quartz, crystalline silica, cemented silica, and quartz sand.
Siliceous refractory raw materials are mainly used to manufacture silica bricks and siliceous unshaped refractories. They are suitable for acidic environments, such as glass melting furnaces and coke ovens.
Clay-Based Refractory Raw Materials
Clay-based refractory raw materials are the most basic raw materials for making clay bricks and clay-based unshaped refractories. They are the most commonly used raw materials in the aluminosilicate refractory system.
These raw materials mainly come from natural refractory clay deposits. Industrially, they are divided into two types:
- Hard clay: hard in texture, used as clinker after calcination.
- Soft clay: mainly used as a binder because of its good plasticity.
Clay-based refractory raw materials are primarily used to produce clay bricks and clay-based fire mortar. They are economical and practical for areas with relatively lower operating temperatures.
High-Alumina Refractory Raw Materials
High-alumina refractory raw materials are important for producing high-alumina bricks and high-alumina unshaped materials. Their Al₂O₃ content is generally above 48%. They offer higher performance among aluminosilicate refractories and are the most widely used category.
These raw materials mainly come from natural bauxite and synthetic corundum materials. Common types include:
- High-alumina bauxite: natural raw material, used after calcination.
- Brown fused alumina: made by electro-fusing bauxite.
- White fused alumina: made by electro-fusing industrial alumina, with higher purity.
- Tabular alumina: sintered alumina with well-developed crystals.
- Mullite: natural or synthetic.
Thanks to their excellent overall properties, high-alumina refractory raw materials have become the most important category in the aluminosilicate system. They feature high refractoriness, good slag resistance, and a wide range of applications. They are particularly suitable for industrial kilns operating at medium to high temperatures or with large temperature fluctuations.
Magnesia Refractory Raw Materials
Magnesia refractory raw materials are the main raw materials for producing basic refractories. Their primary component is magnesium oxide (MgO). They are typical basic refractory raw materials.
These raw materials mainly come from natural magnesite ore and are processed by calcination or electro-fusion. Common types include:
- Sintered magnesia: produced by high-temperature sintering of magnesite.
- Fused magnesia: made by melting magnesite or light-burned magnesia in an electric arc furnace. It has higher purity and larger crystal grains.
- Dolomite: a composite raw material containing MgO and CaO, commonly used for dolomite bricks.
Magnesia refractory raw materials are mainly used to manufacture magnesia bricks, magnesia chrome bricks, magnesia alumina spinel bricks, and basic unshaped materials. At JHYRef, we use high-quality magnesia raw materials to produce magnesia refractories of excellent quality.
Chrome Refractory Raw Materials
Chrome refractory raw materials are important auxiliary raw materials for producing basic refractories such as magnesia-chrome bricks. Their main component is chromium oxide. They are often combined with magnesia raw materials to improve the performance of refractories.
Chrome refractory raw materials mainly come from natural chromite ore. In actual use, attention must be paid to the formation and treatment of hexavalent chromium.
Zirconia Refractory Raw Materials
Zirconia refractory raw materials are important special raw materials for producing high-performance refractories. The products made from them are often used in harsh environments.
They are particularly suitable for applications involving contact with molten glass or requiring ultra-high temperatures and strong corrosion resistance.
Conclusion
Each type of refractory raw material has its own characteristics and suitable applications. Understanding these raw materials also helps in understanding refractories as a whole.
At JHYRef, we use high-quality refractory raw materials and are a trustworthy manufacturer of refractory materials.
