Method and apparatus for producing desulfurizing agent, and method for removing sulfur dioxide from cement kiln exhaust gas

Abstract

[Problem] To provide a method and an apparatus for producing a desulfurizing agent, and a method for removing sulfur dioxide from cement kiln exhaust gas, enabling good handleability, easy adjustmentof water content, and small fluctuations in the modulus of slaking of CaO when powdered. [Solution] An apparatus 1 for producing a desulfurizing agent, etc. is provided, the apparatus comprising: a fractionation device 2 for fractionating a cement raw material R5 discharged from a lowermost cyclone 12D of a preheater 12 of a cement firing device 11, or a preheated raw material having a calcium oxide (CaO) content of at least 40 mass% and discharged from a preheater cyclone of the cement firing device; a separation means 3 for dividing the fractionated cement raw materials R7; a dissolution tank 4 in which water W is added to one R8 of the divided cement raw materials and the mixture is cooled and slurried; and a mixing dryer 5 for mixing the slurry discharged from the dissolution tank withthe other R9 of the divided cement raw materials, and drying slaked cement raw materials while promoting the slaking of calcium oxide in the cement raw materials in a water-evaporated water vapor atmosphere.

Description

technical field [0001] The present invention relates to a method and device for producing a desulfurizing agent from cement raw materials and a method for desulfurizing cement kiln exhaust gas by using the produced desulfurizing agent. Background technique [0002] SOx produced by combustion of fossil fuels containing sulfur (S) reacts with calcium (Ca) contained in cement raw materials, and is fixed in the clinker as clinker minerals, so preheater exhaust and chimney exhaust The emission of SOx in the gas is extremely small. [0003] However, in order to further reduce the amount of SOx emission in the gas discharged from the chimney, calcium oxide (CaO) in the cement raw material is digested (digested) and used as a desulfurizing agent. At this time, there is a method of making the cement raw material into a slurry and spraying it to the exhaust gas of the cement kiln, but there are problems such as clogging of the spray nozzle. [0004] In addition, there is also a meth...

AI Technical Summary

Problems solved by technology

At this time, there is a method of making the cement raw material into a slurry and spraying it to the exhaust of the cement kiln, but there are problems such as clogging of the spray nozzle.

[0004] In addition, there is also a method of adjusting the water content so that the cement raw material used as a desulfurizing agent becomes powdery, but the adjustment of the water content is not easy

In addition, there is also a problem that the digestibility of CaO changes when it is made into a powder, and the handling property deteriorates.

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