What are the advantages of electric furnace ramming material compared with castable material? do you know?

Ramming materials can be prepared from refractory aggregates and powders of various materials according to the needs of use. At the same time, the appropriate bonding agent is selected according to the refractory aggregate material and use requirements. Some ramming materials do not use bonding agent but only add a small amount of flux to promote their sintering. Sodium silicate, ethyl silicate and silica gel are commonly used as binders in acid ramming materials. Alkaline ramming materials use aqueous solutions of magnesium chlorides and sulfates, as well as phosphates and their polymers as binders. It is also common to use organic substances and temporary binders that have higher carbon content and form carbon bonds at high temperatures. Glauber's salt is often used as a binder for chromium ramming materials. High-aluminum and corundum ramming materials often use phosphoric acid and aluminum phosphates, sulfates, chlorides and other inorganic substances as binders. When phosphoric acid is used as the binder, the phosphoric acid reacts with the activated alumina in the ramming material during storage to form water-insoluble aluminum orthophosphate precipitates and harden. It is difficult to construct without plasticity. Therefore, in order to extend the shelf life of ramming materials, appropriate preservatives must be added to prevent or delay the occurrence of coagulation and hardening, and oxalic acid is usually used as a preservative.

Compared with other amorphous materials, refractory ramming materials are dry or semi-dry and loose, and most of them have no cohesiveness before forming. Therefore, only strong ramming can obtain a dense structure. Compared with castables and plastics, ramming materials have higher stability and corrosion resistance at high temperatures. But it also depends on the choice of high-quality materials, and the reasonable ratio of pellets and powders also has a lot to do with.

Both electric furnace ramming materials and castable materials are refractory materials, but there are also differences between the two:

The difference in raw material composition: The ramming material is mainly an unshaped refractory material made of aggregate and powder with a certain particle gradation, plus a binder and additives, which is mainly constructed by manual or mechanical ramming. Ramming materials include corundum ramming materials, high-aluminum ramming materials, silicon carbide ramming materials, carbon ramming materials, silicon ramming materials, magnesia ramming materials, etc.

Like the electric furnace bottom ramming material, silicon carbide, graphite, electric calcined anthracite as raw materials, mixed with a variety of ultra-fine powder additives, fused cement or composite resin as a binder made of bulk materials. It is used to fill the gap between the furnace cooling equipment and the masonry or the filler for the masonry leveling layer.

Castable is a kind of granular and powdery material made by adding a certain amount of binder to refractory materials. With high fluidity, it is suitable for unshaped refractory materials formed by casting. The three major components of the castable are the main component, the additional component and the impurity, which are divided into: aggregate, powder and binder. Aggregate raw materials include silica, diabase, andesite and waxstone.

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