Method for co-producing industrial grade diammonium phosphate during production of industrial grade monoammonium phosphate of phosphoric acid by wet process

Abstract

The invention discloses a method for co-producing industrial grade diammonium phosphate during the production of industrial grade monoammonium phosphate of phosphoric acid by a wet process. The method comprises the steps of: making filtrate obtained after carrying out desulfurization on calcium hydrophosphate and wet-process phosphoric acid neutralize with ammonia gas or ammonia water to obtain ammonium phosphate slurry, making ammonium sulfide react with the ammonium phosphate slurry, and concentrating, crystallizing and drying the filtrate to obtain an industrial grade monoammonium phosphate product; secondly, making a primary mother solution obtained through filtering after crystallizing secondarily neutralize with the ammonia gas or ammonia water; and finally, concentrating, crystallizing and drying the filtrate obtained through secondary neutralizing to obtain an industrial grade diammonium phosphate product, and returning a secondary mother solution obtained through filtering after crystallizing to a concentrating tank and continuously concentrating. The method is used for co-producing the diammonium phosphate during the production of the monoammonium phosphate, has the advantages of saving production cost, reducing energy consumption, reducing pollution and ensuring quality of the monoammonium phosphate and the diammonium phosphate through effective impurity removal, and has good economic benefits.

Description

technical field [0001] The invention relates to a method for producing industrial-grade monoammonium phosphate by wet-process phosphoric acid and co-producing industrial-grade diammonium phosphate. Background technique [0002] Industrial grade monoammonium phosphate and diammonium phosphate are widely used in fire protection, drip irrigation fertilizer, medicine and food. At present, the production of industrial grade monoammonium phosphate and diammonium phosphate generally adopts thermal phosphoric acid or purified phosphoric acid process. The disadvantages are high production cost, complicated process, high energy consumption and large pollution. Some manufacturers also adopt the wet-process phosphoric acid production process, but there are certain problems in the impurity removal process, such as high metal content in the product, which will change with the quality of phosphoric acid, making it difficult to guarantee product quality. In the prior art, the production eq...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for wet-process phosphoric acid to produce industrial-grade monoammonium phosphate and co-produce industrial-grade diammonium phosphate, so as to solve the problem of high production cost, high energy consumption, large pollution, and poor product quality in the production of monoammonium phosphate and diammonium phosphate in the prior art. unstable problem

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