Process for desulfurizing flue gas of rotary kiln by utilizing high-flow slag washing water

Abstract

The invention relates to a process for desulfurizing the flue gas of a rotary kiln by using large-flow slag washing water. According to the innovative point, a calcium-sulfur ratio of materials entering the kiln is controlled through an intelligent batching system, high-concentration calcium oxide is used for dry-process pre-desulfurization in the rotary kiln, residual sulfur enters a desulfurization tower along with the flue gas, residual unreacted calcium oxide is dissolved through the large-flow slag washing water, and the residual sulfur is removed in the desulfurization tower. Desulfurization quicklime does not need to be additionally added, the process has the characteristices of low in operation cost, and meanwhile the slag washing water serves as low-concentration large-flow desulfurizing liquid, and equipment and pipelines can be effectively prevented from being blocked.

Description

technical field [0001] The invention relates to the field of iron and steel smelting production and the field of environmental protection, in particular to a process for desulfurizing flue gas of a rotary kiln by using large-flow slag flushing water. Background technique [0002] At present, due to the low sulfur content in the raw materials and the low sulfur content of the rotary kiln fire method for treating zinc-containing dust and sludge, the by-product flue gas has the characteristics of large flue gas volume and low sulfur content. Generally, the sulfur dioxide concentration of flue gas before treatment is Less than 2000mg / Nm 3 . At present, more than 80% of the desulfurization process of the rotary kiln fire method for zinc-containing dust and sludge adopts the limestone-gypsum calcium desulfurization process. It has the advantages of good desulfurization effect, stability and simple process. But there are also many problems. [0003] First of all, the gypsum slu...

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Problems solved by technology

[0003] First of all, the gypsum slurry after desulfurization is easy to precipitate and precipitate, blocking pipelines and equipment, resulting in high maintenance costs

Secondly, the cost of desulfurization agent quicklime is relatively high (about 400-600 yuan / ton), while the desulfurization product quicklime is cheap and difficult to sell, so the operating cost of the equipment is also relatively high

This also limits the further development of calcium desulfurization

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