When manufacturing the insulation brick, the most common and convenient method is the bubble method and the method of burning the additive.
There are 2 methods to inject air into the mud:
1. First, mechanically inject air into the suspension, and then use stabilizer to stabilize the bubbles in the mud;
2. Add a foaming agent to the suspension, this agent generates gas after interaction, and the gas makes the mud material to form a porous structure, and finally stabilize the porous structure with a stabilizer.
To preserve the air bubbles in the mud, it is necessary to reduce the surface tension of the suspension, for which a foaming agent is generally added. The foam can be stabilized by adding a large amount of materials that can absorb moisture, such as clinker, or adding crystals containing a large amount of hydration water into the mud.
In order to make the mud fluffy, carbonic acid and acids or aluminum, metals and other reagents are added to the suspension, and bubbles are generated by their chemical reaction. In order to achieve this purpose, dolomite and sulfuric acid are often used abroad, because they are the cheapest industrial raw materials. Hemihydrate gypsum and other hydraulic substances are used as stabilizers. The mud of thermal insulation bricks is quickly dried and fired after solidification. The fired product is then machined to give it the desired shape and size.
