A method for treating mother liquor after ammonia desulfurization and centrifugal separation of ammonium sulfate

Abstract

The invention relates to a novel treatment method for mother liquor obtained after centrifugal separation of ammonium sulfate in ammonia-process desulfurization. The method comprises the following steps: pumping 20-40% ammonium sulfate mother liquor from an ammonium sulfate centrifugal mother liquor tank to a stripping tower for vacuum concentration, introducing 0.2-0.5Mpa steam into a jacket of the stripping tower to heat, connecting a vacuum system inside the stripping tower, and improving the concentration of the ammonium sulfate solution to 60-70% so as to obtain ammonium sulfate slurry; and conveying the ammonium sulfate slurry to a rake type drier by virtue of a sludge pump, drying for 4-6 hours in the rake type drier to obtain an ammonium sulfate finished product with the water content of 5%, and conveying to a packaging workshop by virtue of a screw conveyor to package. Under the premise of not reducing the quality of the ammonium sulfate product, the problem that a crystallizer in ammonium sulfate production is excessively fast corroded is solved, ammonium sulfate wastewater is comprehensively used, the centrifugal waste liquid is treated, the energy is comprehensively utilized, the energy consumption for by-producing ammonium sulfate in ammonia-process desulfurization is reduced, and the economic benefit is improved. Meanwhile, the method provided by the invention can be used for projects such as ammonium chloride, ammonium nitrate and the like and has a wide application prospect and good economic and social benefits.

Description

technical field [0001] The invention relates to a process for ammonium sulfate evaporation and crystallization process in the preparation of ammonium sulfate by ammonia desulfurization or ammonium sulfate by other methods. It is mainly used for the concentration and crystallization of the by-product ammonium sulfate project in the flue gas desulfurization industry and other single-production ammonium sulfate projects. Finally, the centrifuged mother liquor after centrifugation and drying is processed in a new method. Background technique [0002] Industrial coal combustion flue gas contains a large amount of SO 2 , SO 2 The emission of the flue gas will bring many environmental problems. Over the past few decades, scientific research and engineering technology units around the world have researched and developed more than 200 flue gas desulfurization technologies. At present, the best commercialization is the flue gas desulfurization technology after coal burning ), accord...

AI Technical Summary

Problems solved by technology

[0016] At present, domestic solutions to the crystallizer corrosion problems of industrial salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate are mainly in two aspects. First, change the operating conditions and reduce the crystallization temperature as much as possible. The higher the temperature, the more corrosion the equipment will cause Fast, lowering the crystallization temperature can indeed slow down the Cl - , NO 3 - , S 2- The speed of enrichment corrosion of equipment, but at the same time brings a problem, the quality of industrial salt crystallized by lowering the temperature may decrease, and the particle size of industrial salt will decrease, thereby reducing product quality

Second, improve the material of the crystallizer, from the initial austenitic stainless steel 304 steel to 316L steel, and even start to use dual-phase steel 2205 steel, so as to improve the corrosion resistance of the equipment, but it will increase the cost of the equipment, and It also cannot fundamentally solve the problem of equipment corrosion, which reduces the economic benefits of the project and is not conducive to the overall social benefits of the project.

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