Using low cement castable in blast furnace taphole can significantly improve many aspects of performance, as follows:

I. Anti-erosion and anti-scour performance

Low cement castable has the characteristics of high density and low porosity, which can effectively resist the chemical erosion and mechanical erosion of high temperature molten iron and slag. For example, the corrosion resistance of ALO-SiC-C low cement castable can be significantly improved by adding silicon carbide (SiC) and carbon.

II. High temperature strength and stability

The cement content of low cement castable is low (usually less than 8%), which reduces the formation of anorthite at high temperature, thus improving the mechanical strength at high temperature. At the same time, it has compact structure and tight connection between particles, and can maintain high strength and stability at high temperature.

III. Thermal shock stability

The low cement castable has good thermal shock stability and can adapt to frequent temperature fluctuations in the taphole of blast furnace. For example, adding a small amount of aluminum powder and organic fiber can prevent the castable from bursting during baking and improve its thermal shock stability.

IV. Antioxidant properties

The low cement castable can effectively improve the oxidation resistance of the material by adding antioxidants (such as silicon powder, iron silicon nitride, etc.). This is especially important in the high temperature oxidation environment of blast furnace taphole.

V. Extension of service life

Using low cement castable can significantly prolong the service life of blast furnace taphole. For example, after using low cement castable in the taphole of Shanghai Baosteel blast furnace, the iron flux can reach 100,000 tons at a time. In addition, the low porosity and high density of low cement castable make it more durable in high temperature environment.

VI. Convenience of construction and maintenance

The low cement castable is easy to construct, has low water demand, can be baked quickly after construction and is not easy to burst. This not only reduces the construction time, but also reduces the maintenance cost.

VII. Energy conservation and environmental protection

The low cement castable does not produce harmful gas during use, and the surface is not easy to adhere to slag iron, which reduces the workload of cleaning and maintenance. In addition, its characteristics of low water demand and rapid baking also meet the requirements of energy saving and environmental protection.

To sum up, the application of low cement castable in blast furnace taphole can significantly improve the corrosion resistance, erosion resistance, high temperature strength, thermal shock stability and other properties of refractories, and at the same time prolong the service life and reduce the maintenance cost, which has significant technical and economic advantages.