What are the ladle castables ?
As a ladle castable, there are many binders (additives), such as: pure calcium aluminate cement, oxide ultrafine powder, silica sol, aluminum sol, phosphate, ρ- Al2O3 or a combination of several, etc. More pure calcium aluminate cement, polyphosphate and oxide ultrafine powder. The ratio of pure calcium aluminate cement combined with castable is the same as that of ordinary calcium aluminate water castable, except that the calcium aluminate cement used is of high purity, the chemical composition is mainly Al2O3 , CaO , and the impurity content is very small. The pure calcium aluminate cement is synthesized by using industrial alumina and pure limestone or calcite or industrial calcium phosphate as a raw material, and mixing and grinding in a certain ratio, and then synthesizing by sintering or electrofusion. Its mineral composition is mainly calcium aluminate ( CaO.2Al2O3 ) and a small amount of calcium aluminate (CaO.Al2O3) . The condensation rate is normal, the initial setting time is about 1h , and the final setting is 6 to 8h . Sodium polyphosphate is a commonly used binder for alkaline refractories. It is characterized by a very strong bond, and the formed phosphate conjugate has less invasiveness when in contact with molten slag and molten metal, and has good heat. Earthquake stability.
The theoretical basis of the properties of oxide (silica ash, Al2O3) ultrafine powder is the theory of surface phenomena. Due to the presence of surface energy, the fine powder has a dispersion-coacervation effect.
