Chrome corundum bricks refer to corundum refractory products containing Cr2O3. At high temperatures, Cr2O3 and Al2O3 form a continuous solid solution, so the high-temperature performance of chrome corundum products is better than that of pure corundum products. Chrome corundum bricks used in petrochemical gasifiers should be low in silicon, low in iron, low in alkali, high in purity, and have high density and strength. The Cr2O3 content of chrome corundum products, which are widely used, is mostly in the range of 9% to 15%. The main mineral composition is α-Al2O3-Cr2O3 solid solution. The secondary mineral composition is a small amount of composite spinel (or no composite spinel) and a refractory brick with a chromium oxide content of 1% to 30%. There are two types: fused cast chrome corundum bricks and sintered chrome corundum bricks. Generally, chrome corundum bricks refer to sintered chrome corundum bricks.
Chrome corundum bricks are characterized by their unique composition and properties:
1. High temperature resistance: Chrome corundum bricks have excellent thermal stability and are suitable for use in high temperature environments. They can withstand temperatures up to 1800°C, making them ideal for applications in industries such as steel, cement, glass and non-ferrous metals.
2. Chemical resistance: Chrome corundum bricks have strong resistance to chemical corrosion, especially to alkalis, slag and molten metals. This corrosion resistance allows them to maintain structural integrity and performance in harsh chemical environments, making them suitable for furnaces and kilns where corrosive materials are present.
3. Wear resistance: Chrome corundum bricks have excellent wear resistance, making them durable. They can withstand the erosion of abrasives, ensuring extended service life even in high-wear environments such as cement kilns or ladles.
4. Resistance to slag erosion: Chrome corundum bricks are almost not eroded by slag, the inner hole edge is clearly demarcated from the residue, and there is little slag penetration into the brick. Chrome corundum refractory bricks have better resistance to chemical melting and permeability of gasified slag than corundum refractory bricks.
5. High mechanical strength: These bricks have high compressive strength and structural integrity, enabling them to withstand mechanical stresses and loads. They can resist thermal shock and maintain their shape and strength even when exposed to rapid temperature changes.
6. Compressive strength: The room temperature compressive strength of chrome corundum bricks is greater than 150MPa, and the compressive strength of corundum refractory bricks is 70-100MPa, which is significantly higher than corundum bricks. During the firing process of corundum bricks and chrome corundum bricks, Al2O3-Cr2O3 solid solutions are formed between particles, between particles and fine powders, and between fine powders. The solid solution connects particles and fine powders together, which greatly improves the strength of refractory bricks.
7. Low porosity: Chrome corundum bricks have low porosity, which helps reduce thermal conductivity and prevent heat loss. This property helps improve energy efficiency and improve thermal insulation in high-temperature applications.
8. Good thermal conductivity: Although chrome corundum bricks have low porosity, they still have good thermal conductivity. This property helps to effectively transfer and distribute heat in the kiln, ensuring uniform temperature distribution and improved process control.
9. Easy to install: Chrome corundum bricks are relatively easy to install due to their standard shapes and sizes. They can be easily cut or shaped to suit specific applications, simplifying the installation process and reducing downtime during maintenance or repairs. Chrome corundum bricks are widely used in key high-temperature parts of various industries with their advantages of high temperature resistance, chemical resistance, wear resistance and mechanical strength to withstand complex working environments and ensure the stability of high-temperature kilns during operation.
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