A kind of preparation method of large particle sodium bifluoride

Abstract

The invention provides a preparation method of large-particle sodium bifluoride. The method comprises the following steps: (1) preparing a sodium carbonate solution dissolving sodium carbonate in water to obtain the sodium carbonate solution; (2) carrying out a synthesis reaction on the sodium bifluoride: adding an appropriate amount of sodium bifluoride seed crystals into a reactor, adding the sodium carbonate solution, obtained in the step (1), and hydrofluoric acid into the reactor at the same time while stirring, and continuously stirring for carrying out a reaction after the end of feeding so as to obtain suspension; (3) filtering: filtering the suspension obtained in the step (2) so as to obtain a sodium bifluoride filter cake; (4) drying: drying the sodium bifluoride filter cake obtained in the step (3) so as to obtain the large-particle sodium bifluoride product. The method provided by the invention solves the problems that the sodium bifluoride product prepared by the traditional preparation method is fine in particles, high in drying difficulty and poor in operating environment.

Description

technical field [0001] The invention relates to a preparation method of sodium hydrogen fluoride, in particular to a preparation method of large particle sodium hydrogen fluoride. Background technique [0002] Sodium bifluoride is white crystal or powder, mainly used as food protectant, animal and plant specimens and anatomical specimens preservative and preservative, also used in acid-resistant cement, masonry cleaner, disinfectant, glass etchant, leather treatment agent, welding , Brazing flux, starch protective agent, stainless steel pickling, tinplate production and textile processing, etc., are widely used. [0003] At present, the preparation method of sodium bifluoride is mostly to add hydrofluoric acid solution in the reactor, then add a theoretical amount of sodium carbonate solution under stirring to obtain sodium bifluoride slurry, and then filter and dry to obtain sodium bifluoride product. This preparation method of sodium bifluoride has an obvious shortcoming,...

AI Technical Summary

Problems solved by technology

Although this method can produce large-particle sodium bifluoride products, it also has obvious disadvantages: first, anhydrous hydrogen fluoride is a highly dangerous material, and special protective measures need to be taken during transportation, storage and use, which greatly increases the difficulty of operation and production costs

In addition, because the reaction is carried out at high temperature, the energy consumption of the preparation process is high; and sodium bifluoride has a large solubility at high temperature, in order to reduce material loss, the material must be cooled after the reaction is completed

However, sodium bifluoride solution at high temperature is very corrosive, and it is difficult to find suitable cooling equipment

Therefore, this method is more difficult to produce in large quantities in industry.

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