System and method for zero discharge of magnesium oxide method desulfurization wastewater

Abstract

The invention discloses a system and method for zero discharge of magnesium oxide method desulfurization wastewater, and belongs to the field of environmental protection. The system comprises a magnesium oxide method desulfurization absorption tower and a hot method decrement device, flue gas generated after boiler combustion is connected with the magnesium oxide method desulfurization absorptiontower sequentially through an air preheater and a dust remover, the output end of the bottom of the magnesium oxide method desulfurization absorption tower is connected with a waste water tank, and the output end of the bottom of the waste water tank is connected with the hot method decrement device. The output end of the bottom of the thermal decrement device is connected with a sedimentation tank, the output end of the top of the sedimentation tank is connected with a spray drying tower through a clear liquid tank, and the bottom end of the spray drying tower stores a target product. The system and method have the characteristics of low system investment, high additional value of byproducts, no secondary waste and the like.

Description

technical field [0001] The invention relates to the field of environmental protection, in particular to a system and method for zero discharge of desulfurization wastewater by magnesium oxide method. Background technique [0002] Magnesium desulfurization technology is a wet desulfurization process based on active magnesium oxide, which has the advantages of environmental friendliness, resource saving, and high resource utilization rate. However, most of the magnesium sulfate and magnesium sulfite slurries after desulfurization in the existing magnesium oxide desulfurization process are directly discharged, resulting in the waste of crystalline salts such as magnesium sulfate and magnesium sulfite, and the by-products cannot be effectively used. Raw material consumption is high. High one-time investment. [0003] Some existing technologies use a dehydration system to recover crystalline salts such as magnesium sulfate, but due to the solubility of magnesium sulfate, the re...

AI Technical Summary

Problems solved by technology

[0003] Some existing technologies use a dehydration system to recover crystalline salts such as magnesium sulfate, but due to the solubility of magnesium sulfate, the recovery will be incomplete;

[0004] Some desulfurization wastewater zero discharge technologies adopt the process route of "softening + membrane concentration + evaporation crystallization". This disposal method will use sodium hydroxide + soda ash to soften and produce a large amount of mixed sludge. At the same time, the salt produced by evaporation crystallization is also mixed salt. , cannot be sold directly as a by-product, and the output value of the product is low

Images