Sodium desulfurization ash resourceful treatment system and treatment method

Abstract

The invention discloses a sodium desulfurization ash resourceful treatment system and treatment method, and the treatment system comprises an ash pretreatment device, an ammonium bicarbonate preparation device, and a double decomposition reactor, a first-stage cooling crystallizer, a second-stage cooling crystallizer, an ammonia still and an evaporation crystallizer which are sequentially communicated through pipelines; and a gas outlet of the ammonia still is communicated with a feeding hole of the double decomposition reactor. The method comprises the following steps: performing double decomposition reaction on ash and ammonium bicarbonate to obtain sodium bicarbonate, sequentially performing primary cooling crystallization, distillation, secondary cooling crystallization and evaporation concentration on reaction mother liquor to obtain ammonium sulfate, returning double salt obtained by the primary cooling crystallization to the double decomposition reaction, returning ammonia gas and carbon dioxide obtained by the distillation to the double decomposition reaction, returning the double salt obtained by the second-stage cooling crystallization to the first-stage cooling crystallization, and returning the crystallization mother liquor to the second-stage cooling crystallization. According to the method, the total yield of sodium bicarbonate, the total conversion rate of ammonium bicarbonate and the total nitrogen content of ammonium sulfate are improved, and resource reutilization of the sodium-process desulfurization ash is realized.

Description

technical field [0001] The invention belongs to the technical field of flue gas treatment, and in particular relates to a sodium method desulfurization ash treatment system and treatment method. Background technique [0002] my country's iron and steel plants, coal power plants, and coking plants emit a large amount of flue gas containing dust, sulfur dioxide, nitrogen oxides and other pollutants, which is an important source of environmental pollution. In the past 10 years, many measures have been taken to control them, and remarkable results have been achieved. It has basically reached the emission standards set by the state and fundamentally improved the atmospheric environment. [0003] In the prior art, due to the low sulfur content of these flue gases, they are very suitable for dry desulfurization by sodium bicarbonate method, and the desulfurization ash after sodium bicarbonate desulfurization is solid waste. The problem encountered in sodium desulfurization is that ...

AI Technical Summary

Problems solved by technology

However, the problem encountered in sodium desulfurization is that the market price of sodium bicarbonate is high, resulting in high desulfurization costs; the glauberite generated after desulfurization still forms ash accumulation

At present, there is no good way to deal with the accumulated ash, which can only be used for landfill, resulting in waste of resources and environmental pollution

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