Method for producing granular monoammonium phosphate with diammonium phosphate device

Abstract

The invention discloses a method for producing a granular monoammonium phosphate with a diammonium phosphate device. The method comprises the following steps: (1) adopting over 48 percent phosphoric acid with a solid content below 3 percent as a raw material, wherein the raw material phosphoric acid singly enters a feeding trough for a preneutralization reactor and a tubular reactor; (2) controlling the technical index of the tubular reactor and the trough for the preneutralization reactor by a positive and negative drop method, namely, using a material with neutralization slightly over 1 in the tubular reactor to neutralize a spraying product with the neutralization below 1 in the trough for the preneutralization reactor to ensure that the neutralization of the total products reach about 1; (3) controlling the pH value of materials at an outlet of a pelletizer to about 4; and (4) using water sealed by a pump, previous washing liquid of an underground collecting tank and process water to supplement washing liquid of each washing tower, and using the washing liquid to regulate the density and the neutralization of slurry in the trough for the preneutralization reactor so as to realize the grade use of the washing liquid of a system. The method can be used for producing the granular monoammonium phosphate with the diammonium phosphate device, which realizes the development requirement of diversified production of devices.

Description

technical field [0001] The invention relates to phosphate fertilizers, and furthermore, to ammonium phosphate fertilizers, especially diammonium phosphate and monoammonium phosphate. Background technique [0002] Traditional DAP plants are equipped with tubular reactors, pre-neutralization tanks, and even double-tubular reactors. However, only one product, diammonium phosphate, can be produced, and the requirements for raw materials are not very strict. Generally, after the concentration of wet-process phosphoric acid, as long as the acid content is above 46%, qualified diammonium phosphate products can be produced. In other words, the most important thing in the production of diammonium phosphate is to control the degree of neutralization of the product. In addition, the diammonium phosphate plant, which was reformed from the heavy calcium plant, also added tubular reactors and secondary ammonia supplement pipes in the drum granulator, increased the high plate of the reta...

AI Technical Summary

Problems solved by technology

However, under these conditions, only diammonium phosphate can be produced, and granular monoammonium phosphate cannot be produced.