Method for producing fire-resistant insulated castable by self-foaming thermal reaction hardened forming

Abstract

The invention discloses a method for producing a fire-resistant insulated castable by self-foaming thermal reaction hardened forming, which is characterized by comprising the following steps of: pre-mixing and stirring 60 to 70 percent of refractory aggregate with the granularity between 0.5 and 5mm, 20 to 30 percent of refractory powder with the granularity between 0 and 0.5mm and 3 to 10 percent of aluminum powder with granularity between 0 and 0.1mm, and adding 50 percent phosphoric acid solution in a certain proportion; fully stirring, injecting the castable into a specified mold so as to perform spontaneous reaction foaming forming; and after fully reacting and continuously raising the temperature to the constant temperature of over 60 DEG C for about 1 hour, and curing and hardening into a molded fire-resistant insulated material with certain intensity. The prepared fire-resistant insulated material has hardness and intensity indexes equivalent to those of the light-weight refractory brick, simple production technology, energy-saving and environment-friendly production process, and significance for industrial application.

Description

technical field [0001] The invention relates to a refractory and thermal insulation castable, in particular to a production method of a self-foaming thermal reaction hardening molded refractory and thermal insulation castable. Background technique [0002] Refractory and thermal insulation castable is a kind of amorphous refractory material, which can be poured like concrete, and it is a variety with large production volume among amorphous refractory materials. The production of castables saves the molding and firing processes, greatly simplifies the process and equipment, is conducive to increasing output and reducing costs, with greater production flexibility and less energy consumption. Since the 1970s, unshaped refractory materials have developed greatly at home and abroad. Due to the large-scale and complex shapes of industrial kilns, special-shaped bricks have become more complicated, which has brought great pressure on both brick making and furnace building. come wit...

AI Technical Summary

Problems solved by technology

Compared with fired bricks, the production of castables by this process mainly has the following three disadvantages: (1) Due to the large amount of water required during construction, the bulk density of the final product is not high; In the process of compound bonding into ceramic bonding, the strength drops greatly in the range of hydrate dehydration temperature; (3) the CaO content in the castable is very high (usually greater than 5%), which is very harmful to the high temperature performance of the material

These unfavorable factors greatly limit the application range of ordinary refractory castables, and can only partially replace fired refractory bricks.

In addition, traditional castables generally use high-alumina cement as a cement. Due to the large amount of cement added, not only will more impurities be brought in, the structure will not be dense, but the impurities brought in during use will react with refractory materials to form a low Melting point eutectic, large shrinkage at high temperature, changes in organizational structure, not resistant to corrosion