Wet-type ammonia process three-circulation desulphurization technique suitable for sintered flue gas

Abstract

The invention provides a wet ammonia process ternary cycle desulfurization process applicable to sintering flue gas. In the process, the desulphurization of the sintering flue gas in the steel industry is realized by the methods of three-stage circulation absorption, outside tower oxidation, saturation and crystallization. The invention provides the desulfurization process for the sintering desulfurization reserved currently in the nation; the desulfurization process has low investment, low running cost and can realize resource recovery. Home grown coking waste ammonia or other ammonia of the steel industry are used for treating SO2 in the waste gas in a sintering machine so as to treat wastes with processes of wastes against one another; the absorptivity of the SO2 is high; the loss of the outlet ammonia of the system is low; in the running process, a great amount of steam is not needed and solid ammonium sulphate with fine quality is generated and sold as fertilizer. The invention belongs to the desulfurization process which changes waste into valuable, not only reduces the emission of sulfur dioxide, but also brings tremendous environmental benefits and definite economic benefit.

Description

technical field [0001] The invention relates to flue gas desulfurization technology, in particular to a wet ammonia desulfurization process suitable for sintering flue gas in iron and steel enterprises. Background technique [0002] With the rapid development of my country's economy, my country's energy consumption is also increasing, SO 2 The pollution level of acid rain and acid rain is also increasing day by day, which has become an important environmental factor restricting the coordinated and stable development of my country's economy. Currently, for sintering flue gas SO 2 The emission control methods mainly include: (1) low-sulfur raw material mixing method; (2) high chimney dilution emission; (3) flue gas desulfurization method. Both the low-sulfur raw material blending method and high stack dilution emissions are limited by energy and policies, and cannot fundamentally solve SO 2 pollution, while my country's sulfur dioxide control is a dual control of emission c...

AI Technical Summary

Problems solved by technology

[0004] First, the packed tower is used as the absorption tower. Due to the huge amount of flue gas, the manufacturing difficulties of the tower are more prominent, especially the uniform distribution of the absorption liquid in the packed tower is a difficult problem.

[0005] Second, ammonium sulfate evaporation and crystallization adopts one-effect evaporation, and the steam consumption is relatively large

[0007] Under the same total nitrite content, the higher the alkalinity of the solution, the higher the SO in the tail gas 2 The lower the equilibrium concentration, but the higher the alkalinity, the higher the equilibrium partial pressure of ammonia on the solution surface, and the greater the loss of ammonia in the tail gas, which affects the utilization rate of ammonia and causes secondary pollution of ammonia

Under acidic conditions, the circulating fluid contains para-SO 2 Ammonium sulfite with absorption function also contains a large amount of ammonium sulfate, and ammonium sulfate has a strong effect on SO 2 There is no absorption capacity, so a large amount of ammonium sulfate solution participates in the empty cycle, resulting in a large consumption of circulating pump power, increasing the cost of operation, and affecting the desulfurization effect at the same time, so the SO in the flue gas is removed 2 Reducing the loss of ammonia and preventing the formation of ammonia mist aerosol are mutually restrictive

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