Process for producing urea ammonium sulfate by using by-product of ammonium sulfate from flue gas desulfurization with ammonia process

Abstract

The invention discloses a process for directly producing long-acting large-particle urea ammonium sulfate by using the by-product of ammonium sulfate from the flue gas desulfurization. Solid urea is measured and added to a urea quick melting device, and then liquid urea is added to a urea and ammonium sulfate mixer; one part of ammonium sulfate crystal from the flue gas desulfurization and drying is added to the urea and ammonium sulfate mixer to be pulped, and the other part is delivered to a rotary drum coating granulator so as to be used as seed crystal; the mixed pulp from the urea and ammonium sulfate mixer is sprayed on small ammonium sulfate particles through an air atomizing spray nozzle; the small ammonium sulfate particles are cooled by a rotary drum cooler; the cooled small ammonium sulfate particles are added into a vibrating screen so as to be screened; and the qualified small ammonium sulfate particles are added into a packaging belt. The large-particle urea granulating technology is adopted by the process, thus the external material return is reduced in the production process, and the consumption is lowered. The urea and the ammonium sulfate are combined, thus the defect of signal product is overcome. The proportion of nitrogen to sulfur can be adjusted according to the crop or market demand. The urea ammonium sulfate can prevent the soil hardening and increase the crop yield and can take effect quickly for a long term.

Description

Technical field: [0001] The invention relates to desulfurization of air pollution in the field of environmental protection and chemical fertilizer production in the field of chemical industry, in particular to a new process for producing high-quality fertilizers by using the by-product ammonium sulfate generated by ammonia flue gas desulfurization. Background technique: [0002] The current ammonia-based flue gas desulfurization technology mainly subcontracts the by-products generated by desulfurization directly into ammonium sulfate fertilizer, and the urea produced by chemical enterprises is also a separate product. [0003] The ammonia-ammonium sulfate fertilizer desulfurization technology uses ammonia water as a desulfurizer, and the by-product is ammonium sulfate. After the ammonium sulfate solution in the desulfurization tower is discharged, it is filtered, evaporated, centrifuged, and dried to produce ammonium sulfate crystals, which are packaged and put into storage t...

AI Technical Summary

Problems solved by technology

The nitrogen content is 20-21% (generally used as a standard nitrogen fertilizer). After the ammonium sulfate is applied to the soil, it will quickly dissolve in the soil water and dissociate into NH 4 + and SO 4 2- , is a physiologically acidic fertilizer, while SO 4 2- with Ca in soil 2+ CaSO 4 (Gypsum), it is easy to block the soil pores and cause soil compaction; because ammonium sulfate contains sulfur, it is beneficial to the root development of seedlings, so it is often used as mouth fertilizer and seedling fertilizer; because of low nitrogen content, ammonium sulfate is a low-concentration nitrogen fertilizer; because of the above The reason also limits the large-scale use of ammonium sulfate

[0006] Urea is a high-nitrogen fertilizer, suitable for any soil. When urea is applied to the soil, the amide in it must be converted into ammonium nitrogen under the action of microorganisms in the soil before it can be absorbed by the root system of the plant, and the effect is slow. , generally takes about 3 to 5 days, and it is difficult to dissolve. Once it encounters heavy rain, it is very easy to be wet in the deep layer of the soil, leaving the absorption range of plant roots, causing losses; at the same time, the urease secreted by soil microorganisms easily hydrolyzed into ammonium carbonate, and then decomposed into NH 3 and CO 2 It also causes the loss of nitrogen; therefore, it cannot be used as seed fertilizer, but can only be used as top dressing

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