Process for producing white pyruric acid

Abstract

The invention discloses a method for preparing white cyanuric acid, which comprises the following steps: (1) under stirring, adding molten urea into organic solvent, and introducing inert gas into the organic solvent at the same time to obtain hot pulp stock after condensation reaction of the molten urea, the organic solvent and the inert gas; (2) under stirring condition, adding cooling fluid into the hot pulp stock to obtain cold pulp stock after the mixture is cooled; (3) carrying out solid-liquid separation on the cold pulp stock to obtain filter cakes; and (4) drying the filter cakes under the conditions of certain temperature and flowing inert gas to obtain crystals of the white cyanuric acid. The method has the advantages that the method does not need acid cleaning and refining, isenergy-saving and environment-friendly, obtains the product of the white cyanuric acid, avoids the process of water washing, and improves yield of the product greatly.

Description

technical field The invention relates to a preparation method of white cyanuric acid. Background technique Cyanuric acid (CA) is an important fine chemical intermediate synthesized from urea, and is one of the downstream products of urea that is encouraged to be developed by the state. The production of cyanuric acid mainly has two processes: solid-phase method and liquid-phase method. The crude CA content obtained by the solid-phase method is only about 75%, and it needs to be boiled with inorganic acid to reach the level of 98.5% of superior products. High consumption, long time-consuming, serious environmental pollution and other shortcomings. There are many reports on the production process of the liquid phase method, most of which are concentrated in the laboratory stage. The current research results show that the liquid phase method can obtain products with a purity greater than 96%, does not require hydrolysis and refining, and has low energy consumption. But at the...

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Problems solved by technology

But at the same time, due to the common problem of deep color in the current liquid-phase method products, the industrial application of liquid-phase method products is greatly limited.

For this reason, there are few liquid-phase cyanuric acid industrialization devices in production at home and abroad.

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