Method for producing granular diammonium phosphate with low concentration of nutrients by tailings

Abstract

The invention discloses a method for producing granular diammonium phosphate with low concentration of nutrients by tailings, comprising the following steps: (1) adding solid diammonium phosphate, tailings and powdery ammonium sulfate into a mixing tank based on the mass ratio of 100:10:3, adding diluted phosphoric acid, and evenly mixing while stirring to obtain a mixture; (2) pumping the above mixture in a reactor, and introducing ammonia gas in the reactor for neutralization reaction; (3) pressurizing the reaction slurry by a pump, spraying the slurry in a granulation dryer after pressurizing and atomizing by a nozzle, and coating or caking into granules to obtain a granular diammonium phosphate dry material with low concentration of nutrients; and (4) feeding the dry material in a sieving machine, and sieving to obtain the granular diammonium phosphate product with the granule size of 2-4mm. The method in the invention can consume the tailings, enables the phosphorite tailings to be digested in enterprises or prolongs the stockpiling term of a tailing storehouse and is suitable for enterprises producing phosphorite tailings and monoammonium phosphate tailings, and the producedgranular diammonium phosphate with low concentration of nutrients has the advantages of better market, reduced production cost and obvious profits.

Description

【Technical field】

[0001] The present invention relates to phosphate fertilizer, further specifically, relates to diammonium phosphate, specifically, relates to the production of diammonium phosphate. 【Background technique】

[0002] Phosphate ore tailings are mainly produced in the grinding system of phosphate ore concentrators and phosphoric acid production units. They are the residues after phosphate ore flotation. Because of their low phosphorus content, they are usually treated as waste and disposed of by stockpiling. How to recycle it and turn waste into treasure is one of the problems in reducing consumption and emission.

[0003] In the Chinese patent database, applications involving the utilization of phosphate rock tailings include No. 200610018780.8 "Method for producing phosphoric acid and by-product building bricks from phosphorous tailings after phosphorous ore dressing" and No. 200810046713.6 "Using alkali slag from soda plant , Method for making engineering so...

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