The raw materials of activated carbon for desulfurization and denitrification are bituminous coal, coke powder, coking coal, tar, asphalt and various raw materials. Bituminous coal, coking coal and coke powder are transported in from the coal plant, and tar is transported in from the coking plant. Due to the sufficient supply and low price of pulverized coal in the market, pulverized coal can be used as raw material, with the particle size below 30mm. First of all, bituminous coal, coking coal, coke powder and asphalt solid raw materials are stored in closed material shed, batching is measured through pit, iron removal, belt and bucket are transported to mixed grinding raw material silo, and the time of materials in raw material silo is about 5 hours.
1) tar preparation process
The coal tar is sent to the tar unloading tank, and then it is sent to the tar tank with the coke oil pump for heating (lower part) storage. When necessary, it is sent to the low tar tank and the high-level coal tar tank in the pelletizing and forming workshop by the coke oil pump, and then it is prepared for standby.
2) pulverizing process
The mixed coal is continuously metered into a complete set of pulverizing equipment, and then it is grinded into fine pulverized coal with a particle size of 200 mesh screen and a passing rate of 95%. The milled fine powder is collected by the powder collector and then sent to the powder bin by the screw machine of the pulverizer.
3) granulation process
Ingredients
Before pelletizing, the coal powder is made into coal paste, the coal powder, coal tar and moisture shall be continuously measured and sent to kneader. The coal powder is measured by weight-loss scale, the proportion of ingredients is measured based on the coal powder, and the coal tar and water are measured by volume.
Kneading
Three kinds of raw materials are metered and continuously enter the kneading equipment, and are evenly mixed and kneaded into slime paste after kneading.
Granulation
The slime paste is continuously sent to the flat die rolling pelletizing equipment through mixing and conveying for pelletizing and forming. The formed materials fall into the roller screen under the pelletizing equipment. The granulated debris smaller than the sieve hole is the under screen material, which is lifted to the mixing and conveying equipment through the bucket lifting equipment for recycling and pelletizing. The cylindrical particles on the screen are the granulated material (wet).
④ granulating and air drying
The wet pelletizing material is transported to the settling material shed by belt for settling and natural drying; the dry pelletizing material (screen material) is sent to the buffer bin in front of the carbonization furnace for the carbonization furnace. The pulverized coal and dry slime debris formed in the granulation and drying process are sent to the raw material storage yard.