Method for utilizing kieselguhr/calcium-based composite additive for absorbing SO2 in cement kiln smoke

Abstract

The invention discloses a method for utilizing a kieselguhr / calcium-based composite additive for absorbing SO2 in cement kiln smoke, and belongs to the field of industrial kiln smoke treatment. According to the method, the kieselguhr is dried for 24 h at the temperature ranging from 60 DEG C to 105 DEG C; then, 10wt-15%wt of kieselguhr, 7%wt of CaO or Ca(OH)2 and 78%wt-83%wt of cement raw materials are mixed, the mixture is inflated with SO2 gas at the temperature ranging from 300 DEG C to 500 DEG C, the kieselguhr and the CaO or the Ca(OH)2 are utilized for absorbing SO2 gas so as to achieve the purpose of desulfurization. The kieselguhr adopted in the method has the characters of porousness and strong adsorption, and more reaction spaces and places can be provided for the cement raw materials and the CaO or the Ca(OH)2 for absorbing SO2 gas. The added kieselguhr and the added CaO or Ca(OH)2 are close to the cement raw materials in component, and therefore the final mineral composition and performance of cement clinker cannot be affected. The technology is simple, the adsorption material source is wide, and the desulphurization efficiency is high.

Description

technical field

[0001] The invention belongs to the field of industrial kiln flue gas treatment, in particular to a method for absorbing SO in cement kiln flue gas by using diatomite / calcium-based composite additives. 2 Methods. Background technique

[0002] SO in cement industry kiln tail gas 2 As one of the air pollutants, it will cause a series of environmental problems such as acid rain. Most cement enterprises are facing SO 2 emission reduction issues. Modern cement enterprises have generally used the new dry process cement production technology. The cement raw material is decomposed in the preheater and then fired in the kiln. Due to the large amount of sulfur compounds contained in raw materials and fuels, a large amount of SO will be produced during the decomposition of materials and the combustion of fuels. 2 Gas, discharged into the air will cause serious air pollution.

[0003] At present, desulfurization in the cement industry mainly includes cement process ...

Examples

Embodiment 1

[0014] First put the diatomite at 95°C and dry it for 24h, then take 15%wt (3.2g) diatomite, 7%wtCaO and 78%wt Portland cement raw meal (fineness is 0.08mm sieve residue 14 %) for grinding, and after the mixture is uniformly mixed, it is added into a tube furnace with a diameter of 3 cm. Then, O was introduced into the mixture 2 , N 2 and SO 2 (800ppm) mixed gas, O 2 and N 2 The volume ratio of the two is 1:4, and the gas flow rate through the material is 0.5L / min. Finally, at a temperature of 400°C, the mixed material is measured for SO 2 The gas removal rate was 40%.

Embodiment 2

[0016] First put the diatomite at 95°C and dry it for 24h, then take 15%wt (3.2g) diatomite, 7%wtCaO and 78%wt Portland cement raw meal (fineness is 0.08mm sieve residue 14 %) for grinding, and after the mixture is uniformly mixed, it is added into a tube furnace with a diameter of 3 cm. Then, O was introduced into the mixture 2 , N 2 and SO 2 (800ppm) mixed gas, O 2 and N 2 The volume ratio of the two is 1:4, and the gas flow rate through the material is 0.5L / min. Finally, at a temperature of 500°C, the mixed material is measured for SO 2 The gas removal rate was 57%.

Embodiment 3

[0018] First put the diatomite at 95°C and dry it for 24h, then take 10%wt (3g) diatomite, 7%wtCa(OH) 2 Grind with 83%wt Portland cement raw meal (fineness is 0.08mm sieve remaining 14%), after the mixture is evenly mixed, add it into a tube furnace with a diameter of 3cm. Then, O was introduced into the mixture 2 , N 2 and SO 2 (800ppm) mixed gas, O 2 and N 2 The volume ratio of the two is 1:4, and the gas flow rate through the material is 0.5L / min. Finally, at a temperature of 500°C, the mixed material is measured for SO 2 The gas removal rate was 51%.

technical field

[0001] The invention belongs to the field of industrial kiln flue gas treatment, in particular to a method for absorbing SO in cement kiln flue gas by using diatomite / calcium-based composite additives. 2 Methods. Background technique

[0002] SO in cement industry kiln tail gas 2 As one of the air pollutants, it will cause a series of environmental problems such as acid rain. Most cement enterprises are facing SO 2 emission reduction issues. Modern cement enterprises have generally used the new dry process cement production technology. The cement raw material is decomposed in the preheater and then fired in the kiln. Due to the large amount of sulfur compounds contained in raw materials and fuels, a large amount of SO will be produced during the decomposition of materials and the combustion of fuels. 2 Gas, discharged into the air will cause serious air pollution.

[0003] At present, desulfurization in the cement industry mainly includes cement process ...

Examples

Embodiment 1

[0014] First put the diatomite at 95°C and dry it for 24h, then take 15%wt (3.2g) diatomite, 7%wtCaO and 78%wt Portland cement raw meal (fineness is 0.08mm sieve residue 14 %) for grinding, and after the mixture is uniformly mixed, it is added into a tube furnace with a diameter of 3 cm. Then, O was introduced into the mixture 2 , N 2 and SO 2 (800ppm) mixed gas, O 2 and N 2 The volume ratio of the two is 1:4, and the gas flow rate through the material is 0.5L / min. Finally, at a temperature of 400°C, the mixed material is measured for SO 2 The gas removal rate was 40%.

Embodiment 2

[0016] First put the diatomite at 95°C and dry it for 24h, then take 15%wt (3.2g) diatomite, 7%wtCaO and 78%wt Portland cement raw meal (fineness is 0.08mm sieve residue 14 %) for grinding, and after the mixture is uniformly mixed, it is added into a tube furnace with a diameter of 3 cm. Then, O was introduced into the mixture 2 , N 2 and SO 2 (800ppm) mixed gas, O 2 and N 2 The volume ratio of the two is 1:4, and the gas flow rate through the material is 0.5L / min. Finally, at a temperature of 500°C, the mixed material is measured for SO 2 The gas removal rate was 57%.

Embodiment 3

[0018] First put the diatomite at 95°C and dry it for 24h, then take 10%wt (3g) diatomite, 7%wtCa(OH) 2 Grind with 83%wt Portland cement raw meal (fineness is 0.08mm sieve remaining 14%), after the mixture is evenly mixed, add it into a tube furnace with a diameter of 3cm. Then, O was introduced into the mixture 2 , N 2 and SO 2 (800ppm) mixed gas, O 2 and N 2 The volume ratio of the two is 1:4, and the gas flow rate through the material is 0.5L / min. Finally, at a temperature of 500°C, the mixed material is measured for SO 2 The gas removal rate was 51%.