Method for desulfurizing sintering machine flue gas by magnesium strengthened line-gypsum

Abstract

The invention discloses a method for desulfurizing sintering machine flue gas by magnesium strengthened line-gypsum, comprising the following steps of: purifying the sintering machine flue gas by an electric precipitator and importing the sintering machine flue gas into an absorption tower by a draught fan; causing the flue gas to make reverse convection contact with the atomized desulfurization liquid sprayed by a nozzle in the tower to form a favorable atomized absorption area and complete the desulfurization absorption of the flue gas; demisting the desulfurized flue gas by a demister at the top of the tower and then directly discharging the flue gas from a chimney at the top of the tower; and prolonging the contact time between the flue gas and the slurry by adopting secondary impact technology in the absorption tower so as to improve the desulfurization rate. Lime slurry and MgO slurry are mixed in the desulfurization liquid, and MgO occupies 1-3% of the weight of the lime slurry; and the absorption tower is internally provided with a tower kettle agitator. In the invention, 1-3% of lime slurry is replaced by magnesium hydroxide solution, and the magnesium salt has stronger dissolubility to ensure that the alkalinity of the solution is 10-15 times higher than calcium-based technology; therefore, the desulfurization rate is as high as 95% when the gas-liquid interface is relatively faster in equivalent gas to liquid ratio.

Description

technical field [0001] The invention relates to a method for desulfurizing flue gas of a sintering machine by adding magnesium to strengthen the lime-gypsum method. Background technique [0002] Sintering machine flue gas has the following characteristics: [0003] 1. Flue gas SO 2 The concentration varies greatly, at 400-4000mg / m 3 above. [0004] 2. Flue gas temperature can vary greatly, from 80°C to 180°C. [0005] 3. The flue gas flow rate varies greatly, up to 40%. [0006] 4. The moisture content of flue gas is high, between 10% and 13%, and it is unstable. [0007] 5. The oxygen content of flue gas is high, between 15% and 18%. [0008] 6. Flue gas contains a variety of pollution components, in addition to sulfur dioxide and dust, it also contains [0009] Heavy metals, dioxins, nitrogen oxides, etc. [0010] Domestic commonly used sintering machine flue gas desulfurization methods mainly include: lime-gypsum method, limestone-gypsum method, ammonia method, ci...

AI Technical Summary

Problems solved by technology

[0005] 3. Flue gas flow rate changes greatly, up to 40% or more

[0006] 4. The moisture content of flue gas is high, between 10% and 13%, and it is unstable

[0007] 5. The oxygen content of flue gas is high, between 15% and 18%.

[0008] 6. Flue gas contains a variety of pollution components, in addition to sulfur dioxide and dust, it also contains

[0011] In engineering practice, when the calcium method is applied to the desulfurization project of the sintering machine, due to reasons such as poor design and operation management and fluctuations in working conditions, it often causes process problems such as scaling and blockage, which affects the stable operation of the system and desulfurization efficiency.