Desulfurization system and desulfurization process based on calcium cycle of cement clinker production line

Abstract

The invention discloses a desulfurization system and a desulfurization process based on a calcium cycle of a cement clinker production line, and belongs to the technical field of flue gas desulfurization. The system comprises a decomposition unit, a desulfurization unit, a dust collection unit and a desulfurizer preparation unit. The desulfurizer preparation unit is connected with the decomposition unit and the desulfurization unit, and comprises a cooling unit and a digestion unit, wherein the cooling unit is connected with a discharge outlet of the decomposition unit, and the digestion unitis connected with a discharge outlet of the cooling unit. A discharge outlet of the digestion unit is connected with a feed inlet of the desulfurization unit, and a discharge outlet of the desulfurization unit is connected with a feed inlet of the dust collection unit. A discharge outlet of the dust collection unit is connected with the feed inlet of the desulfurization unit and a feed inlet of the decomposition unit. According to the process, self-made active heat raw materials are cooled by the cooling unit, digested by the digestion unit to prepare desulfurizers, and fed into the desulfurization unit for desulfurization; generated desulfurized slags return to a decomposing furnace and enter a rotary kiln for calcination. The desulfurization system and the desulfurization process have the advantages that self-sufficiency of the desulfurizers is achieved, the problem of SO2 emission of flue gases is solved, the cost of purchased desulfurizers is saved, and the treatment problem of semidry-desulfurized slags is solved.

Description

technical field [0001] The invention relates to the technical field of flue gas desulfurization, in particular to a calcium circulation desulfurization system based on a cement clinker production line and a desulfurization process. Background technique [0002] Cement raw materials are mainly composed of calcareous raw materials, silicon-aluminum raw materials, iron raw materials, etc. Among them, calcareous raw materials are the main ones, generally accounting for about 80%. During the production of cement clinker, when the raw materials contain more low-valence sulfur such as organic sulfur or sulfide, the low-valence sulfur will be oxidized at high temperature in the preheater to release SO 2 gas, resulting in SO in the flue gas 2 If the concentration exceeds the standard, desulfurization treatment is required to meet the environmental protection emission targets. [0003] The existing cement kiln flue gas desulfurization methods mainly include dry desulfurization, wet ...

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Problems solved by technology

[0012] (1) There are disadvantages in dry desulfurization or wet desulfurization of cement kiln flue gas desulfurization. The former has low desulfurization efficiency, while the latter has problems such as gypsum rain, white smoke, water consumption, and wastewater treatment.

[0013] (2) Cement kiln flue gas desulfurization adopts semi-dry desulfurization technology, and quicklime or slaked lime desulfurization agent needs to be purchased from outside. Carbonization will occur during transportation and storage, and lime will be converted into calcium carbonate, reducing the activity of desulfurization agent.

[0014] (3) Cement kiln flue gas desulfurization adopts semi-dry desulfurization technology. The desulfurization agent using quicklime or slaked lime for flue gas desulfurization needs to be purchased from outside. Pollution, consumption of limestone mineral resources

[0015] (4) Cement kiln flue gas desulfurization adopts semi-dry desulfurization technology, and the main component of the desulfurization slag produced is calcium sulfite, which is difficult to recycle and dispose of

[0016] Semi-dry desulfurization technology is the development direction of flue gas desulfurization technology due to its high desulfurization efficiency and no problems such as white smoke and gypsum rain. desulfurization residues are difficult to deal with, and the semi-dry desulfurization system has relatively high power consumption in operation; the dry desulfurization system is simple and low in power consumption, but the desulfurization efficiency is often low, and desulfurization agents need to be purchased, which is not suitable for Cement production line with high sulfur dioxide emission value

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