Method for producing monoammonium phosphate and magnesium ammonium phosphate by using wet concentrated phosphoric acid residues

Abstract

The invention provides a method for producing monoammonium phosphate and magnesium ammonium phosphate by using wet concentrated phosphoric acid residues. According to the method, concentrated phosphoric acid residues are adopted as raw materials and sodium fluorosilicate, industrial monoammonium phosphate and magnesium ammonium phosphate are respectively obtained through the processes of dilution and sedimentation, defluorination, fractional multistep neutralization, concentration and crystallization, primary mother liquor pH value adjustment, size mixing of filter cake and secondary mother liquor, magnesia powder neutralization and the like. The method is little in equipment investment, low in production cost and good in product quality and has the advantages that the problem that acid residues of ammonium phosphate plants can be only used for producing low value-added products is solved and the low-cost industrial monoammonium phosphate slow release fertilizer magnesium ammonium phosphate with high quality and inexpensive can be obtained.

Description

technical field [0001] The invention relates to a method for producing monoammonium phosphate and magnesium ammonium phosphate, in particular to a method for producing industrial grade monoammonium phosphate and industrial grade and agricultural grade ammonium magnesium phosphate by using wet concentrated phosphoric acid residue, belonging to the technical field of chemical industry. Background technique [0002] In the production process of using the concentration method to produce ammonium phosphate, a considerable amount of concentrated phosphoric acid residue will be produced. The residue content of this phosphoric acid residue is relatively high, and the water-insoluble phosphorus is also very high. Therefore, most of the prior art can only use phosphoric acid. The use of residual acid to produce low-value conventional fertilizers such as heavy superphosphate, superphosphate-rich or agricultural grade ammonium nitrate in the market not only produces low economic value, b...

AI Technical Summary

Problems solved by technology

[0002] In the production process of ammonium phosphate produced by the concentration method, a considerable amount of concentrated phosphoric acid slag acid will be produced. The slag content of the phosphoric acid slag acid is relatively high, and the water-insoluble phosphorus is also very high. Therefore, most of the existing technologies can only use phosphoric acid Using slag acid to produce low-value conventional fertilizers such as heavy superphosphate, rich superphosphate or agricultural grade ammonium nitrate, not only produces low economic value, but also causes a large backlog of such conventional products

If the phosphoric acid slag acid is used to directly produce ammonium phosphate with the existing technology, the quality of the product will be seriously affected

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