Method and device for preparing sodium nitrite by utilizing mother solution

Abstract

The invention relates to a method and a device for preparing sodium nitrite by utilizing a mother solution. The device comprises a crystallizer, a thickner, a centrifugal machine, a mother solution absorption tower, a circulating pump and a storage tank, wherein a converted gas pipeline is connected to a converted gas inlet of the mother solution absorption tower; a mother solution tank outlet and a mother solution outlet of the mother solution absorption tower are connected to an inlet of the circulating pump; an outlet of the circulating pump is divided into two paths, one path is connectedto a mother solution inlet, and the other path is connected to the storage tank; the mother solution contacts converted gas reversely in the mother solution absorption tower, so that the content of Na2CO3 is reduced; the absorbed mother solution flows to the storage tank by the mother solution outlet and the circulating pump; and the absorbed mother solution which is deviated from the storage tank is mixed with a raw material solution and is evaporated, crystallized and subjected to centrifugal separation to obtain a sodium nitrite product. According to the method, the raw materials of the sodium nitrite is enlarged and a nitrous ratio of the product is improved by reducing the content of Na2CO3 in the mother solution; and the sodium nitrite can be produced by reducing the content of Na2CO3 in the mother solution according to market demands, and the mother solution also can be conveyed to a conversion tower to produce sodium nitrate.

Description

technical field [0001] The invention belongs to the technical field of inorganic chemical product production and relates to NaNO 2 Mother liquor reabsorption reduces Na 2 CO 3 The method of content, be specifically related to a kind of method and device that utilize mother liquor to prepare sodium nitrite. Background technique [0002] Currently, sodium nitrite (NaNO 2 ) and sodium nitrate (NaNO 3 ) (referred to as "two sodium"), the raw material solution contains a large amount of NaNO 2 with NaNO 3 In addition, it also contains 3~5g / l Na 2 CO 3 , NaNO is produced by evaporation, crystallization and centrifugation 2 Na in the mother liquor 2 CO 3 If the content is increased to 10~15g / l, if it is directly used for secondary evaporation to produce sodium nitrite products, there will be product moisture, Na 2 CO 3 High content, not up to the quality requirements of sodium nitrite, etc. At the same time, Na 2 CO 3 When the content is high, it is easy to mix with t...

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Problems solved by technology

"But this patent application does not address the NaNO 2 Na in mother liquor 2 CO 3 Problems with high content and increasing product nitrous ratio

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