Method for preparing low-polymerization-degree ammonium polyphosphate aqueous solution

Abstract

The invention belongs to the technical field of phosphate production in inorganic chemical industry and discloses a novel method for producing a low-polymerization-degree ammonium polyphosphate aqueous solution by using low-temperature methods. Commonly-used ammonium polyphosphate production methods are mainly high-temperature thermal polymerization methods, and methods capable of producing ammonium polyphosphate by using the low-temperature methods do not exist at home and abroad. According to the method, polyphosphoric acid with the concentration of 100% to 120% serves as a main raw material, is adjusted by adding an appropriate amount of water and is mixed with ammonium bicarbonate under a natural, low-temperature and normal-pressure condition, stirring and reacting are carried out, and then, the low-polymerization-degree ammonium polyphosphate aqueous solution with the nitrogen content higher than 11%, the phosphorus pentoxide content higher than 37% and the main content of a dipolymer (ammonium pyrophosphate) is produced in batches, is widely used as a fireproofing flame retardant, a plant nutrient solution (liquid fertilizer) and the like and has high practical values. The method is simple in production operation, high in yield and low in energy consumption, is safe and environmental-friendly and does not need high temperature, the requirements for the performance of equipment and materials are lowered greatly, and the large-scale continuous production is easy to realize.

Description

technical field [0001] The invention belongs to the technical field of phosphate production in the inorganic chemical industry, and is a brand-new production technology of ammonium polyphosphate aqueous solution with a low degree of polymerization. Background technique [0002] Ammonium polyphosphate is also called ammonium polyphosphate or polycondensed ammonium phosphate (abbreviated as APP), and products with different degrees of polymerization can be produced according to different specific usage requirements. Ammonium polyphosphate is a kind of polyphosphate containing N and P. According to its degree of polymerization, it can be divided into three types: low polymerization, medium polymerization and high polymerization. The higher the degree of polymerization, the lower the water solubility, and vice versa, the greater the water solubility. According to its structure, it can be divided into crystalline form and amorphous form. The crystalline ammonium polyphosphate is ...

AI Technical Summary

Problems solved by technology

Due to its slow reaction process, difficult production control, low yield and high energy consumption, it has affected the implementation and promotion of its industrialization

There are other production methods such as gaseous P 2 o 5 , NH 3 Reaction with water vapor; heating and dehydration of low-grade ammonium phosphate, etc., but these methods are less industrially adopted due to their own defects

[0006] So far, no ammonium polyphosphate can be produced by low temperature method at home and abroad, so the present invention just creates a new method of producing low polymerization degree ammonium polyphosphate aqueous solution by low temperature method

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