Method of preparing ammonium polyphosphate by using phosphoric acid by wet process and yellow phosphorus as raw materials

Abstract

The invention belongs to the technical field of polyphosphate production in the inorganic chemistry industry, and is a novel production technology for preparing ammonium polyphosphate by using phosphoric acid by wet process and yellow phosphorus as raw materials. According to a method innovation, a low-polymerization-degree ammonium polyphosphate product with good water solubility is prepared by adopting the phosphoric acid by wet process with converted P2O5 content of 30-50 percent, the yellow phosphorus and liquid ammonia as main raw materials. The method can be used for directly producing the product in two forms of solid and liquid, the production is easy to control, the energy consumption is low, the operation is easier, the product is easy to pack, the use is facilitated, the production cost is greatly lowered, the produced low-polymerization-degree ammonium polyphosphate product has the insoluble matter content of less than 1 percent, the polymerization degree of 2-10 and the polymerization ratio of 40-80 percent, and is suitable for making high-quality fluid fertilizers, and the fast development of modern agriculture in China can be greatly promoted.

Description

technical field [0001] The invention belongs to the technical field of polyphosphate production in the inorganic chemical industry, and is a novel production technology for preparing ammonium polyphosphate by using wet-process phosphoric acid and yellow phosphorus as raw materials. Background technique [0002] Ammonium polyphosphate, also known as ammonium polyphosphate or polycondensed ammonium phosphate (APP for short), is a polyphosphate containing N. According to the specific needs of use, it can produce oligomerization, medium polymerization and high polymerization. The higher the degree of polymerization, the lower the water solubility, and vice versa. According to its structure, it can be divided into crystalline and amorphous. Crystalline ammonium polyphosphate is a long-chain water-insoluble salt. The general molecular formula of ammonium polyphosphate is (NH 4 ) (n+2) P n O (3n+1) , when n is 2 to 20, it is water-soluble; when n is greater than 20, it is inso...

AI Technical Summary

Problems solved by technology

This method uses wet-process phosphoric acid and yellow phosphorus as the main raw materials to reduce production costs, facilitate production operations, improve the water solubility of ammonium polyphosphate products, and overcome the thermal phosphoric acid and phosphoric acid used in the existing conventional ammonium polyphosphate production technology. The production cost of phosphate as raw material is relatively high, and it is not easy to be fully soluble in water. It has broad application prospects and great commercial value for realizing low-cost large-scale continuous production of fully water-soluble ammonium polyphosphate series high-quality liquid fertilizers.

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