The special water glass for vermiculite materials is usually made of potassium silicate and sodium silicate as binder. Potassium silicate is preferred for high-quality vermiculite plate or other vermiculite products. Because potassium silicate is an important raw material for environment-friendly building and decoration materials. The potassium content can not only act as a binder, but also inhibit harmful bacteria and insects. Potassium silicate plays an important role in vermiculite products, such as adhesion, increasing strength, fire resistance and high temperature resistance. The second choice is sodium silicate, which is used in the production of general vermiculite products. But its overall function is inferior to that of potassium silicate.
Vermiculite is a kind of secondary metamorphic mineral of magnesium containing aluminosilicate with layered structure, which is like mica in shape. It is usually made of black (gold) mother through hydrothermal alteration or weathering. It has the advantages of non burning, smokeless, non-toxic and tasteless at 1200 ℃, and the fire resistance limit is up to 4 hours, which is considered as one of the better fire insulation materials. When vermiculite is heated, the volume of vermiculite can be increased by 8-15 times, and the height can reach 30 times. Expanded vermiculite is a good heat preservation material because of its advantages of fire prevention, light weight, sound absorption, antibacterial and low thermal conductivity.
Vermiculite board is made of expanded vermiculite and a certain amount of potassium silicate or sodium silicate as adhesive, which is dried after hot pressing or cold pressing. It has the characteristics of heat preservation, heat insulation and fire prevention. It can be used in fire door core, fireplace lining, wall materials, building pipe fittings and other fields.
Vermiculite board has long been widely used in construction, shipbuilding, metallurgy, electric power, aerospace and other fields abroad. At present, vermiculite board is mainly used in China: fire door core; kitchenware, furniture; hull board, new energy automobile interior board; fire passage, ventilation system; wall partition, wall decorative ceiling; furnace, fireplace insulation. When the vermiculite board is laid on the top of the building, it can play a good effect of heat insulation, making the building warm in winter and cool in summer; when the vermiculite board is used as the partition board and ceiling of the building, it can play the role of heat insulation, sound insulation, fire prevention and moisture-proof, and reduce the load of the building.
The potassium silicate in vermiculite board can not only strengthen the basic adhesioni, but also has tasteless, non-toxic and conducive to the body of environmental friendly board adhesive. It is the best raw material for vermiculite products.
Generally the potassium silicate is used as binder for the high-end vermiculite materials, and sodium silicate is used as binder for the common vermiculite products.
The difference between the two products is the performance of potassium silicate is better than sodium silicate, such as the molding strength, anti-corrosion, anti-mildew as well as the potection of human safety.
