Method for recycling ammine in ammonium paratungstate production

Abstract

The invention provides a method for recycling ammonia during the production of ammonium paratungstate. During the evaporation and crystallization of a solution for producing the ammonium paratungstate, free ammonia in the solution and ammonia released by the crystallization process can be volatilized in a gas state. Firstly, a closed vessel is used to collect gaseous ammonia; secondly, the ammonia is reclaimed through the mode of condensation and separation; and finally the reclaimed ammonia can be returned to the main production process and be used for preparing a strippant. The method reduces the consumption of liquid ammonia during the production of the ammonium paratungstate, thereby greatly reducing the production cost and having an ammonia reclamation rate of above 90 percent. Simultaneously, the method prevents the air pollution caused by a large amount of evaporated and overflowed ammonia gas; and the atmospheric emission reaches national standards. Therefore, the method reduces the corrosion of workshop equipment and realizes the reclamation of the ammonia, thereby not only realizing considerable economic benefits, but also realizing certain social and environmental benefits.

Description

technical field [0001] The invention relates to a method for recycling ammonia, in particular to a method for recycling ammonia in the process of producing ammonium paratungstate. Background technique [0002] Ammonia is very soluble in water with a solubility of 1:700. During the crystallization process of ammonium paratungstate production, most of the free ammonia in the crystallization process solution is converted into ammonia gas and chemical changes occur in the process to release ammonia gas. If the volatilized ammonia is not recycled, not only a lot of ammonia is wasted, but also Will pollute the environment. Although there is a method of reducing the pollution of gaseous ammonia through simple spraying and recovery, the concentration of the absorbed ammonia water is low, and the process of ammonia wastewater treatment is increased. Therefore, it is necessary to fully recover and comprehensively utilize ammonia to meet the requirements of energy saving, emission re...

AI Technical Summary

Problems solved by technology

During the crystallization process of ammonium paratungstate production, most of the free ammonia in the crystallization process solution is converted into ammonia gas and chemical changes occur in the process to release ammonia gas. If the volatilized ammonia is not recycled, not only a lot of ammonia is wasted, but also will pollute the environment

Although there is a method to reduce the pollution of gaseous ammonia through simple spraying and recovery, the concentration of ammonia water absorbed is low, and the treatment process of ammonia wastewater is increased.

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