Refractory Plastic

Refractory plastic is made up of 70~80% granular and powdery materials, plus 10~25% plastic clay and other binder and plasticizer. It is an amorphous refractory which is in the shape of hard mud paste and maintains high plasticity for a long time.

Refractory plastic is mainly used in various heating furnaces which are not in direct contact with melting material. The material is mostly clay and high aluminum, but also silicon, magnesium, chromium, zirconium and silicon carbide. If press binder classification, have clay to combine, water glass to combine, phosphate to combine, the plastic that sulfate combines to wait.

What basic properties should refractory plastics have?
To ensure the smooth construction and at high temperature can normal use, should possess the following basic properties: (1) has certain plasticity, so that the construction: (2) has certain storage life, to ensure that the specified storage period forming performance remains the same: (3) have a certain strength after the room temperature curing, to facilitate the construction can be dismantled after framework or quotation: today have set the volume stability of high temperature and to prevent the furnace lining structure caused by deformation of a big damage.

How to control the plasticity of plastic?
The plasticity of plastic has direct influence on the properties and addition of clay. It also has to do with the amount of water. Plasticity increases with the amount of water added. But cannot be too high, it is 5~10% commonly. To improve plasticity is to control the amount of clay in the plastic and the amount of water can be added, can be added plasticizer.

Plasticizer in the role of refractory plastic: (1) to improve the moisture absorption of clay particles, so that the clay particles dispersed and covered by water film: (2) to make the clay particles sol; (3) to increase the electrostatic repulsion between clay particles, stable sol; (4) to block the solarization of the ions as insoluble salt excluded from the system; ) to increase the viscosity of the water in clay to form a strong water film. Common plasticizers mainly include pulp waste liquid, naphthenic acid, lignin sulfonate, lignin phosphate, lignin chromate and so on.

The choice of binder also has some influence on the plasticity of plastic. Do not use water hard binder, can choose hot hard or gas hard binder. If gas hard binder is used, sealing measures should be taken when storage. Long-term storage, but also to take measures to slow coagulation.