Fly ash ceramsite is made of fly ash as the main raw material (about 85%), mixed with an appropriate amount of lime (or calcium carbide slag), gypsum, admixtures, etc. An artificial lightweight aggregate made from natural hydraulic reaction. Ceramsite has excellent properties, such as low density, high cylinder compressive strength, high porosity, high softening coefficient, good frost resistance, and excellent alkali-resistant aggregate reactivity. Especially due to the low density of ceramsite, the internal porousness, the uniform shape and composition, and the certain strength and firmness, it has the advantages of light weight, corrosion resistance, frost resistance, earthquake resistance and good insulation (heat preservation, heat insulation, sound insulation, insulation, etc.). tide) and other multifunctional features. Using these excellent properties of ceramsite, it can be widely used in building materials, horticulture, food and beverage, refractory insulation materials, chemical industry, petroleum and other sectors. At the beginning of the invention and production of ceramsite, it was mainly used in the field of building materials. Due to the continuous development of technology and people's deeper understanding of the properties of ceramsite, the application of ceramsite has already exceeded the traditional scope of building materials, and its application has been continuously expanded. field. Now the application of ceramsite in building materials has dropped from 100% to 80%, and the application in other aspects has accounted for 20%. With the continuous development of new uses of ceramsite, its proportion in other aspects will gradually increase. Properties of fly ash ceramsite The reason why fly ash ceramsite has developed rapidly all over the world is that it has many excellent properties that other materials do not have. This excellent property makes it irreplaceable by other materials. These excellent properties have the following aspects. 1. Low density and light weight. The bulk density of fly ash ceramsite itself is less than 1100kg/m3, generally 300-900kg/m3. The density of concrete made with fly ash ceramsite as aggregate is 1100-1800kg/m3, and the corresponding concrete compressive strength is 30.5-40.0Mpa. The biggest feature of ceramsite is that it is hard on the outside, and there are many micropores inside. These micropores give ceramsite its light-weight properties. The density of No. 200 fly ash ceramsite concrete is about 1600kg/m3, while the density of ordinary concrete with the same label is as high as 2600kg/m3, and the difference between the two is 1000kg/m3. 2. Insulation and heat insulation. Because of its porous interior, fly ash ceramsite has good thermal insulation properties. The thermal conductivity of concrete prepared with it is generally 0.3 to 0.8 W/(m·k), which is 1 to 2 times lower than that of ordinary concrete. Therefore, ceramsite buildings have a good thermal environment. 3. Good fire resistance, ceramsite has excellent fire resistance. Ordinary fly ash ceramsite concrete or fly ash ceramsite block integrates thermal insulation, earthquake resistance, frost resistance, fire resistance and other properties, especially the fire resistance is more than 4 times that of ordinary concrete. For the same refractory period, the thickness of ceramsite concrete is 20% thinner than that of ordinary concrete. In addition, fly ash ceramsite can also prepare refractory concrete with refractoriness below 1200℃. At a high temperature of 650 ° C, ceramsite concrete can maintain 85% of the strength at room temperature. Ordinary concrete can only maintain 35% to 75% of its strength at room temperature. 4. Good seismic performance. Ceramsite concrete has good seismic performance due to its light weight, low elastic modulus and good deformation resistance. 5. Low water absorption, good frost resistance and durability. The acid, alkali corrosion and frost resistance performance of ceramsite concrete is better than that of ordinary concrete. For No. 250 fly ash ceramsite concrete, the strength loss of 15 freeze-thaw cycles is not more than 2%. Ceramsite concrete is an excellent building material and should be vigorously promoted and used.