Views: 127 Author: SEPPE Publish Time: 2021-05-07 Origin: SEPPE Technologies
Cenosphere are a kind of fly ash bead particles, which are extracted from fly ash, derived from fly ash, and have many properties of fly ash, but even so, floating beads and fly ash Ash is still different.
The difference in physical properties
1. Density
The density of Cenosphere is smaller than that of fly ash. The bulk density of Cenosphere is only 1/3-1/2 of that of fly ash. The true density of Cenosphere is also smaller than that of fly ash, only 40% of fly ash. It is also because of the lower true density of Cenosphere that Cenosphere has more unique uses than fly ash, for example, it can be configured with low-density oil well cement slurry and other materials.
2. Melting point
The melting point of Cenosphere is higher than that of fly ash. Although the melting point is a physical property, it is affected by chemical factors. In the chemical composition of Cenosphere, the oxide content of silicon and aluminum is relatively high, while the oxide content of iron, calcium, magnesium, potassium, and sodium is relatively low. Due to the high content of silicon and aluminum, the content of aluminum oxide meets the requirements of clay products in aluminum silicate refractories, and therefore its melting point is relatively high, so it is used as a raw material for lightweight refractories. The alumina content of fly ash is in the range of 15% to 30%, which meets the requirements of semi-siliceous products in aluminum silicate refractories, so its melting point is lower than that of Cenosphere.
3. Water absorption
The saturated water absorption rate of Cenosphere is lower than that of fly ash, indicating that the water demand of Cenosphere is lower than that of fly ash. Therefore, under the same water-cement ratio, Cenosphere has better flow properties than fly ash.
4. Thermal conductivity
The thermal conductivity of Cenosphere is 0.058~0.080 W/ (mK), which is much lower than fly ash, indicating that Cenosphere has better thermal insulation performance than fly ash, so Cenosphere is a good thermal insulation material. The refractoriness of Cenosphere is 1500℃, even as high as 1600℃, which is higher than that of fly ash. Therefore Cenosphere can be used as a raw material for high-temperature refractory materials.
5. Particle size range
The particle size distribution unit of Cenosphere is narrower than that of fly ash. The particle size range of Cenosphere is not fixed, but is related to the particle size of the powdered coal into the pulverized coal furnace and the combustion conditions of the furnace.
6. Specific surface area
According to statistics, the specific surface area of Cenosphere is generally between 2000 and 3000 cm2/g, and fly ash is sometimes as high as 5000 cm2/g, so Cenosphere has a smaller specific surface area than fly ash. This is not only because the particle size distribution of Cenosphere is narrower than that of original fly ash, but the average particle size is also larger than that of original fly ash.
Difference in chemical properties
1. Alkaline
The pH value of the aqueous solution of Cenosphere is 7.56, which is slightly alkaline as a whole, while the pH value of fly ash is 9.44, which is alkaline as a whole. It can be seen that the alkalinity of fly ash is significantly higher than that of Cenosphere.Therefore, the alkali resistance of the corresponding fly ash is also better.
2. Loss on ignition
The loss on ignition of Cenosphere is much smaller than that of fly ash. This is because Cenosphere contains almost no pulverized coal particles. The loss on ignition of fly ash is due to the different levels of combustion of pulverized coal, sometimes as high as 20%. Therefore, the quality loss and volume shrinkage rate of refractory insulation material products produced with Cenosphere as raw materials will also be small.
The difference in physical properties is reflected in the fact that Cenosphere has a lower density than fly ash, higher melting point, and lower water absorption. The difference in chemical properties is reflected in the fact that Cenosphere has lower alkalinity and less loss on ignition than fly ash.
Therefore, Cenosphere can be used to produce high-temperature refractory materials and lightweight materials.
