Views: 111 Author: SEPPE Publish Time: 2021-08-03 Origin: SEPPE
Cenosphere is a lightweight, inert, hollow sphere filled with inert air or gas, typically produced as a byproduct of coal combustion at thermal power plants.
1、High refractoriness
The main chemical composition of cenosphere is silicon and aluminum oxide, of which silicon dioxide is about 50-65% and aluminum oxide is about 25-35%. Because the solubility point of silicon dioxide is as high as 1725 degrees Celsius, and the solubility point of aluminum oxide is 2050 degrees Celsius, both are high refractory materials. Therefore, cenosphere has a very high refractoriness, generally up to 1600-1700 degrees Celsius, making it an excellent high-performance refractory material.
2、Good Hardness and high strength
As the cenosphere are hard glass body formed by silica-alumina oxide mineral phase (quartz and mullite), the hardness can reach 6-7 grade of Mohs, the static pressure strength is up to 70-140MPa, the true density is 2.10-2.20g/cm3, which is comparable to the rock. Therefore, the cenosphere has a high strength. Light porous or hollow materials such as perlite, zeolite, diatomaceous earth, sea pumice, expanded vermiculite, etc. are poor in hardness and strength, and the thermal insulation products or light refractory products made of them have the disadvantage of poor strength. Their shortcomings are exactly the strengths of cenosphere, so they have more competitive advantages and are more widely used.
3、Fine particle size and large specific surface area
The particle size of naturally formed cenosphere is 1-250 microns. The specific surface area is 300-9000px2/g, which is similar to that of cement. Therefore, cenosphere do not need to be milled and can be used directly. The fineness can meet the needs of various products. Other light insulation materials generally have large particle size (such as perlite, etc.), and if they are milled, the capacity will be increased substantially, and the heat insulation will be greatly reduced. In this aspect, cenosphere has some obvious advantages.
4、Excellent electric insulating property
The cenosphere after the selection of magnetic beads are excellent insulating materials, which do not conduct electricity. The general insulator's resistance decreases with the increase of temperature, but the cenosphere, on the contrary, increases the resistance with the increase of temperature. This advantage is not possessed by any other insulating materials. Therefore, it can make insulating products under high temperature conditions.
