95% Calcium Carbonate

I. Molecular Formula: CaCO₃

II. Molecular Weight: 100.09

III. Physical and Chemical Properties:
Gray powder, odorless, tasteless. No change when exposed to air, specific gravity 2.71. Melting point 825°C (decomposition). Almost insoluble in water, insoluble in alcohol.

IV. Characteristics and Uses
Limestone powder is mixed with water to form a slurry as an absorbent, which is pumped into the absorption tower to fully contact and mix with the flue gas. Sulfur dioxide in the flue gas reacts with calcium carbonate in the slurry and air blown from the lower part of the tower through oxidation to form calcium sulfate. When calcium sulfate reaches a certain saturation, it crystallizes to form dihydrate gypsum. The gypsum slurry discharged from the absorption tower is concentrated and dehydrated to reduce its moisture content to less than 10%, then conveyed by a conveyor to a gypsum storage silo for stacking. The desulfurized flue gas passes through a demister to remove mist droplets, is heated by a heat exchanger, and is then discharged into the atmosphere through the chimney. Since the absorbent slurry in the absorption tower is repeatedly circulated through the circulation pump to contact the flue gas, the absorbent utilization rate is high, the calcium-to-sulfur ratio is low, and the desulfurization efficiency can be greater than 95%. Rotary Spray Dry Flue Gas Desulfurization Process The spray drying desulfurization process uses lime as the desulfurization absorbent. The lime is slaked and mixed with water to form lime milk, which is pumped into the atomization device inside the absorption tower. Inside the absorption tower, the absorbent is atomized into fine droplets and mixed with the flue gas, where it chemically reacts with SO2 in the flue gas to form CaSO3, thereby removing SO2 from the flue gas. At the same time, the moisture brought in by the absorbent is rapidly evaporated and dried, and the flue gas temperature decreases accordingly. The desulfurization reaction products and unused absorbent are carried out of the absorption tower in the form of dry particles with the flue gas and are collected by the dust collector. The desulfurized flue gas is discharged after dust removal by the dust collector. To improve the utilization rate of the desulfurization absorbent, part of the collected material from the dust collector is generally added to the slurry preparation system for recycling.

V. Main Control Indicators