Desulfurization slurry ion removal and concentrated solution low-temperature flue gas direct injection curing method

Abstract

The invention discloses a desulfurization slurry ion removal and concentrated solution low-temperature flue gas direct injection solidification method, which comprises the following steps: carrying out pretreatment, ultrafiltration filtration, IRCT system concentration and low-temperature flue gas direct injection evaporation treatment on desulfurization slurry to realize zero emission of the desulfurization slurry, and realizing effective removal of suspended matters in the desulfurization slurry by an ultrafiltration system in the zero emission process of the desulfurization slurry. High-power concentration of softening agent consumption, generation of softened sludge, generation of crystalline salt solid waste and coordination of desulfurization slurry desalination and gypsum output are avoided, a spray gun is directly installed on a flue by adopting a direct spraying process, the amount of contacted flue gas is large, the liquid evaporation drying and solidification effects are good, the structure is simple, operation and maintenance are convenient, the investment cost is low, and the occupied space is small. Construction is convenient, low-temperature flue gas is directly injected to utilize waste heat of the flue gas, the waste heat of the flue gas is consumed, waste heat recycling is achieved, the influence on power generation fire coal consumption is small, the influence on boiler efficiency is small, and economical efficiency is better.

Description

technical field [0001] The invention belongs to the technical field of water purification, and in particular relates to a method for ion removal of desulfurization slurry and low-temperature flue gas direct injection solidification of concentrated liquid. Background technique [0002] In order to effectively solve the problem of air pollution in my country, the application of flue gas desulfurization in thermal power plants has progressed rapidly in recent years. The limestone-gypsum wet desulfurization process is widely used because of its mature technology, high desulfurization efficiency, wide distribution of absorbents and easy availability. However, the existing wet flue gas desulfurization technology has problems such as difficulty in effectively utilizing desulfurization by-products, and easy pollution of desulfurization wastewater. A perfect wet flue gas desulfurization process should include efficient flue gas desulfurization technology, comprehensive utilization t...

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Problems solved by technology

[0008] At present, whether it is the concentration + evaporation crystallization process or the flue gas evaporation process, it mainly focuses on the solidification treatment of power plant desulfurization wastewater to achieve zero discharge of power plant wastewater. The treatment of products after solidification treatment of wastewater is very difficult, and it is easy to cause secondary pollution. Form an effective synergy with the operation of the desulfurization system. At present, the power plant lacks an effective adjustment method for the impact load of the chloride ion concentration in the desulfurization slurry that changes with the seasons. It fluctuates greatly with the seasons, mainly because in winter, in order to prevent the coal fired for power generation from freezing, a large amount of deicing agent (mainly composed of calcium chloride and sodium chloride) needs to be sprayed into the coal, resulting in a very high chloride ion content in the coal, and the coal carried by the coal Chloride ions will be trapped in the desulfurization treatment along with the flue gas after boiler combustion, and enter the desulfurization slurry in the desulfurization tower. Exceeding the concentration of chloride ions in the desulfurization slurry will lead to adverse conditions such as foaming of the desulfurization slurry and a decrease in desulfurization efficiency. The concentration of chloride ions fluctuates greatly, which will increase the design redundancy of the zero-emission system (design based on the maximum value of chloride ions), which will increase the construction scale of the zero-emission system, the one-time investment remains high, and the operation and maintenance costs are expensive. To a large extent, it limits the implementation of zero discharge projects for desulfurization wastewater

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