Tap hole clay composition

Tap hole clay composition

The quality of the raw materials of the taphole mud has a great impact on the quality of the taphole clay. Now large blast furnaces basically use high-purity raw materials to improve the quality of the taphole mud, which is generally composed of the following materials:

Silicon carbide

SiC has the characteristics of corrosion resistance, high temperature resistance, high thermal conductivity, good wear resistance (hardness value up to 2500kg/mm2), high strength, and low linear expansion coefficient. It can improve the taphole mud's anti-scouring ability and anti-slag erosion ability.

Coke powder

Coke powder can not only play a role in rapid drying, but also make the iron mouth present a reducing atmosphere, which has the function of protecting carbon materials and carbonized networks.

Corundum powder

Corundum has a high density, high melting point (2050℃) and softening temperature (>1870℃), good resistance to slag iron erosion, stable chemical properties, and good wear resistance. It is a refractory material with excellent properties and is generally used in taphole mud in powder form.

Silicon nitride

Silicon nitride will react with CO to generate SiO2 and precipitate C. SiO2 has the function of preventing oxidation as a protective film. Silicon nitride is mainly used to enhance the wear resistance and corrosion resistance of cannon mud.

High-aluminum aggregate

High-aluminum aggregate is a dense refractory granular raw material with a particle size of about 3mm and a refractoriness of 1770℃. It plays a skeleton role in cannon mud. On the basis of ensuring a certain plasticity, its particle size is as small as possible.

Clay

The refractoriness of refractory clay is higher than 1580℃. The main mineral phase is kaolinite. It has good plasticity in a wet state and is an indispensable refractory material in the composition of cannon mud.

Refractory additives

Refractory additives are designed to improve the construction performance of cannon mud raw materials. Some companies use kyanite, mica and nitride as refractory additives to improve the performance of taphole clay .

Binder

Binder is an important part of the taphole clay system. The type and amount of binder often affect the strength of the taphole clay. Therefore, the selection of the type of taphole mud binder and the determination of the amount of addition have a great impact on the quality of the taphole mud. The amount of binder is generally within 20%. With the large-scale and long-life blast furnaces, the types of binders have gradually changed from water to organic binders, such as tar, asphalt, anthracene oil and resin.