Preparation process of new refractory materials

Phosphate and phosphate refractory castables are new refractories with good properties prepared from phosphoric acid or phosphate solutions and refractory aggregates and powders in a certain ratio.
Commonly used binders are phosphoric acid, aluminum dihydrogen phosphate, polyphosphate, and the like.

A, phosphoric acid and aluminum phosphate combined with refractory castable

According to the type of cement, it is divided into phosphoric acid bonded refractory castable and aluminum phosphate combined with refractory castable. The refractory aggregates and powders used are usually bauxite clinker, clay clinker, magnesia, waste silica brick or silica, corundum, mullite, silicon carbide, and the like. Light aggregates include expanded perlite, alumina hollow spheres, and the like. According to the aggregate types, it can be divided into high aluminum, clay, siliceous and magnesium.

B Phosphoric acid or aluminum phosphate reacts only slowly with neutral and acidic aggregates (such as waste silica brick or silica) at room temperature. In order to promote the room temperature hardening of castables, hardeners such as alumina cement and calcium aluminate cement are often used. Magnesium oxide, etc. The reaction of phosphoric acid or aluminum phosphate with the iron contained in the raw materials used affects the aging effect, and the mixing of the mud also has a corrosive effect on the kneading machine. Therefore, aging inhibitors are often added to the ingredients, such as the addition of 0.15% NH-66 inhibitor. If you do not add inhibitor, you should be trapped after stirring. In addition, phosphoric acid and phosphate combined with refractory castables are protected from water or steam.

Phosphate and phosphate refractory castables are characterized by good thermal shock resistance, high compressive strength, strong slag resistance and impact resistance, high load softening temperature and chemical stability. The temperature of use varies from 1000 to 1800 °C depending on the type and grade of the raw materials.

When magnesium material is used as refractory aggregate and powder, the reaction between the phosphoric acid and the aluminum phosphate solution and the magnesium material is fierce, the mixture is rapidly solidified, and there is no construction time, so polyphosphorus sodium is used as a binder. Commonly used are sodium tripolyphosphate, sodium hexametaphosphate and the like. Magnesia refractory castables are prone to hydration. Cracks are easily generated during the drying process. The addition of an appropriate amount of silica fine powder can overcome the hydration problem, but the temperature dependence of the silicon oxide on the material should be controlled. Alumina or alumina spinel refractory castables are castables developed for ladle www.zzyucai.com. The refractory aggregate is corundum, special grade clinker clinker, the powder is magnesia-alumina spinel powder, bauxite clinker powder, corundum powder and magnesia powder, etc., the binder is made of silica micropowder and sodium polyphosphate.