SU763251A1 - Method of purifying hydrogen halide from sulfur-containing impurities - Google Patents

Description

one

The invention relates to methods for purifying gaseous hydrogen halide used to produce acids and salts, which are used in various sectors of the technology, mainly in the electrical and electronic industries.

A known method of purifying hydrogen fluoride from impurities of sulfur compounds by washing the gas with liquefied hydrogen fluoride, which circulates until the contaminant particles increase to 100-150 fu c. Upon reaching the specified particle size, the impurities are removed mechanically, for example by filtration. .

The disadvantage of this method is a shallow degree of purification. The concentration of impurities in the purified gas is found at a level of X1.10%.

There is also known a method for purifying hydrogen fluoride from impurities of sulfur-containing compounds by contacting liquefied hydrogen fluoride with concentrated sulfuric acid containing potassium permanganate (3-fold excess relative to the content of impurities of sulfur-containing compounds in the gas to be purified) with stirring and at a temperature of 12-15 ° C subsequent distillation of 2J.

The disadvantages of the method are low degree of purification from sulfur impurity 5 (up to 1 ..%), as well as a multistage process due to the need for gas liquefaction and distillation.

The purpose of the invention is to increase the degree of purification of hydrogen halide from sulfur-containing compounds and simplify the process by reducing the number of stages.

This goal is achieved by the described method of purification of halogen-prenatal from sulfur-containing impurities by treating it with concentrated mineral halide-acid, containing bismuth nitrate in an amount of 0.1-1 wt.%.

20

The essential difference of the proposed method is the use of the corresponding hydrohalic acid containing as the reagent nitrogen bismuth nitrate as well as the amount of reagent used for the purification of hydrogen halide.

This difference allows to achieve the degree of purification of hydrogen halide from sulfur-containing impurities to

Yu mass.%.

Claims (2)

30 5 The amount of bismuth nitrate added is optimal. Reducing the bismuth nitrate content in the acid solution leads to an increase in the concentration of sulfur impurities in the purified product. With an increase in the content of nitric acid bismuth, the degree of purification does not decrease, but the consumption of the added salt increases, which is irrational; Example 1 Hydrogen fluoride with a concentration of sulfur-containing compounds of 3-10 wt.% Is passed through a fluoroplast-4 bubbler, the dimensions of which are H 100 cm, D 25 cm with a linear velocity of 12 m. The bubbler is filled with 70% hydrofluoric acid mixed with bismuth nitrate. The gas is contacted with the reaction mixture at room temperature. To 25 g of hydrofluoric acid, bismuth nitric acid is added in the amount of 0.025 kg as a solid salt to maintain its content in acid at 0.1%. After purification, the concentration of impurity, sulfur is 5-10%. The purified gas enters the collection of the finished product. Example 2 Hydrogen fluoride with a concentration of sulfur-containing compounds of 3-10 wt.% Is bubbled at room temperature at a speed of 12 m / h through 70% hydrofluoric acid in the presence of bismuth nitrate, the content of which in an acid solution is 1 wt.%. For this, 0.25 kg of bismuth nitrate is added to 25 kg of hydrofluoric acid. The purified product contains an admixture of sulfur compounds wt.%. The resulting gas enters the collection of the finished product. Example 3 Hydrogen fluoride with a content of impurities of sulfur compounds, wt.%, Is bubbled at a speed of 12 m / h at room temperature through 70% of hydrofluoric acid in the presence of bismuth nitrate, the content of which in solution is 0.5 wt.%. To this end, 0.125 kg of bismuth nitrate is added to 25 kg of hydrofluoric acid. In the purified product, the concentration of impurities of sulfur compounds. The purified gas is fed into the collection of the finished product. Example 4 Hydrogen chloride with a content of impurities of sulfur compounds of 1-10 wt.% Is bubbled at a speed of 12 m / h at room temperature through 30% hydrochloric acid and bismuth nitrate, the content of the latter in the solution is 0.5 wt.%. For this, 0.12 kg of bismuth nitrate is added to 24 kg of hydrochloric acid. The concentration of impurities of sulfur compounds in the purified product is " 5%. The purified gas enters the collection of the finished product. Claim 1. The method of purification of hydrogen halide from sulfur-containing impurities by treating it with a concentrated mineral acid in the presence of a reagent, characterized in that, in order to increase the degree of purification and simplify the process, by reducing the number of stages, hydrochloric acid is used as the acid, and as a reagent-bismuth nitrate. e 2. The method according to claim 1, characterized in that the nitrate ismut is introduced in an amount of 0.1-1 wt.% t by weight of acid. Information sources taken into account in the examination 1. UK patent 1,421,646., Cl. C 1 A, 01.21.76. 2. The patent of Germany No. 1.144.698, l. From 01 6 7/22, 22.11.63 (prototype).