Suitable range and general requirements for refractory castable

As an amorphous refractory material, refractory castable is often used in parts with complex shape and surface, because these parts are not suitable for laying refractory bricks, and it is difficult to ensure the stability of working conditions.

The pouring material is combined with the shell by means of the grilled nail fixed on the steel shell. In the cement industry, there are two kinds of heat-resistant steel grilled nail, V type and Y type, and the commonly used materials are 1Cr18Ni19Ti and Cr25Ni20, etc.

Generally, steel grippers can be made of 1Cr18Ni19Ti steel bars. In the selection of materials, in addition to considering the high temperature strength of materials, the destructive expansion caused by oxidation and corrosion of materials under high temperature should also be considered.Although the ordinary steel bar can meet the strength requirement of working temperature in some low-temperature parts, the oxidized corrosion scale may produce great expansion stress and break the refractory castable.Especially in high temperature areas, such as coal injection pipes and kiln mouth parts, high temperature strength Cr25Ni20 grade heat resistant steel should be used to make pickles.

To avoid castable for solidification contraction and expansion caused in the process of heating in the process of the damage of the castable, for large area of the castable, masonry shall be in accordance with a certain aspect of a village, in turn, divided into (each residential area should be within 1.5 m2), application of construction joints between the village separated, and fill in it, refractory fiber forming seam in fact expansion joint and crack control.Expansion joints and cracking control joints should avoid the important or weak parts, or the main stress areas.

The refractory castable of each district should be finished once and it is difficult to guarantee the bonding strength between two layers of castable after two castings.

 The lining surface should strive to be smooth and smooth, uneven surface causes unwanted accumulation of materials and in turn cause a row of large blocks and clogging.Special attention should be paid to pyramidal parts prone to blockage.Masonry formwork should be of sufficient strength, firm support and smooth surface.Steel formwork should be coated with release agent, wood formwork should be coated with waterproof paint, or directly spread thin film.