Production method of anhydrous ammonium hydrogen fluoride

Abstract

The invention discloses a production method of anhydrous ammonium hydrogen fluoride. The production method comprises the following steps: 1, a neutralization reaction occurs between hydrous hydrofluoric acid or anhydrous hydrofluoric acid and liquid ammonia in a reaction kettle to produce a mixed solution of ammonium fluoride and ammonium hydrogen fluoride; 2, the mixed solution of ammonium fluoride and ammonium hydrogen fluoride is pumped into a concentration tower for vacuum low-temperature concentration so that the concentration of the mixed solution of ammonium fluoride and ammonium hydrogen fluoride reaches more than 70%; 3, the mixed solution of ammonium fluoride and ammonium hydrogen fluoride with the concentration more than 70% is pumped to a high-temperature transformation kettle, and ammonia gas that is decomposed during the transformation process is guided into the reaction kettle for recovery; and 4, a discharge valve of the high-temperature transformation kettle is opened so that the material flow passes through a scraping machine to produce sheet-like anhydrous ammonium hydrogen fluoride. The production method is reasonable in design, has lower requirements for equipment conditions, is easy to promote, and plays a positive role in environmental protection as well as comprehensive resource utilization.

Description

technical field [0001] The invention relates to a production method of anhydrous ammonium bifluoride, which belongs to the field of chemical production. Background technique [0002] At present, the production of anhydrous ammonium bifluoride in foreign countries uses anhydrous hydrogen fluoride and liquid ammonia as raw materials. These two raw materials are first gasified, reacted under gaseous conditions, and excess hydrogen fluoride and ammonia are removed under molten conditions, and then cooled, formed, Made into products, the chemical reaction principle is: 2AHF (gas phase) + NH 3 (gas phase)-NH 4 HF 2 . The problems of using this method are: 1. Anhydrous hydrogen fluoride must be used, which limits the source of raw materials, and the cost is high; 2. The material is gasified, reacted, defluorinated and ammonia removed, cooled, recycled, and formed, and the process is relatively long , high equipment requirements, low production capacity, correspondingly increase...

AI Technical Summary

Problems solved by technology

The problems of using this method are: 1. Anhydrous hydrogen fluoride must be used, which limits the source of raw materials, and the cost is high; 2. The material is gasified, reacted, defluorinated and ammonia removed, cooled, recycled, and formed, and the process is relatively long , high equipment requirements, low production capacity, correspondingly increased costs

The product contains 3%-5% moisture, which cannot be used in places with high requirements, and is easy to agglomerate. In order to prevent agglomeration, many domestic manufacturers add anti-agglomeration additives to the product, but it will affect the use. If the drying process is added and the temperature is not properly controlled, the product will decompose, pollute the environment and increase the cost; because the reaction end point of the ammonium bifluoride produced by the liquid phase method is indicated by the pH value, the product is a mixture of ammonium fluoride and ammonium bifluoride. The chemical reaction principle is: HF+H 2 O+NH 3 -NH 4 f 2 +NH 4 F+H 2 o