Method and device for producing calcium ammonium nitrate

Abstract

The invention relates to a method for producing calcium ammonium nitrate. The method comprises the following steps: carrying out a reaction on nitric acid and calcium carbonate slag to generate calcium carbonate, water and carbon dioxide, and feeding into a filter press to filter acid non-soluble substances and particle impurities; after mixing the generated calcium carbonate liquor and calcium carbonate liquor in a certain proportion, carrying out intermediate-pressure steam distillation and concentration; and pelleting by using a disc pelleting machine, and then, cooling, screening and packaging to obtain finished-product calcium ammonium nitrate. The invention further relates to a device for producing calcium ammonium nitrate by production waste calcium carbonate slag of nitric phosphate. The device is additionally provided with a settling tank for preventing slag from entering into the system. By adopting a disc pelleting technology, continuous and stable production of excellent calcium ammonium nitrate is realized, and problems that a conventional pelleting technology is easy to agglomerate and block, and the finished product is less in particle quantity and the like are solved.

Description

technical field [0001] The invention relates to a method for producing calcium ammonium nitrate, in particular to a process for producing calcium ammonium nitrate by using calcium carbonate slag, which is waste from nitrophosphate fertilizer production. The invention also relates to a device for carrying out the method. Background technique [0002] Calcium ammonium nitrate is also known as calcium ammonium nitrate for agricultural use in the Fertilizer Registration Center of the Ministry of Agriculture. Its molecular formula is 5Ca(NO 3 ) 2· NH 4 NO 3· 10H 2 O, molecular weight 1080. The total nitrogen content is 15.5%, of which more than 90% is nitrate nitrogen, and the rest is ammonium nitrogen. Calcium ammonium nitrate is mainly used for crops and economic crops, and can be used as base fertilizer, top dressing and spray fertilizer. Because it mainly contains nitrate nitrogen, it is easy to directly absorbed by crops. Because the product contains 18% water-solubl...

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Problems solved by technology

The high-tower granulation cannot be airtight and cannot be isolated from the air, and the temperature of the granulation space will rise as the production continues, and the relative humidity will be higher, which is not conducive to granulation

If the traditional drum granulation is used, the heat of the product cannot be taken away normally. When the temperature exceeds 70°C, the product cannot be granulated, and the agglomeration is serious

Tsinghua University has used large particle fluidized bed technology to produce this product, but due to the small amount of finished product particles and easy agglomeration and blockage, it is greatly restricted in continuous production

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