SU1366473A1 - Method of processing sulfite absorption solution - Google Patents

Abstract

This invention relates to the processing of a sulphite absorption solution of sulfuric acid production. In order to obtain a concentrated sulfur dioxide, to prevent clogging of communications and to increase the degree of utilization, the 50 sulphite absorption solution is treated with a 20–40-fold excess of concentrated sulfuric acid from the stoichiometric standard for the formation of ammonium bisulphate. The 70-80% sulphurous anhydride released during this process is used to produce sulfuric acid, and ammonia-containing sulfuric acid can be used in fertilizer production. The method provides for 100% -H5 in the degree of use of 50 °, and also eliminates the formation of crystallizing solutions and thereby prevents the clogging of communications by deposits. 1 tab. i (L

Description

with (35

four;

The invention relates to the production of sulfuric acid, in particular, to methods for processing a sulphite absorption solution obtained by purifying waste gases from sulfuric anhydride in the production of sulfuric acid.

The purpose of the invention is to increase the concentration of sulfur dioxide, as well as to prevent clogging of communications with ammonium sulfate.

80-containing waste gases in the production of sulfuric acid are washed in one or two stages with an ammonia solution of sulfite salts at pH 4.1-5.4 (up to 6.4). The sulfite solution contains ammonium sulfite and ammonium bisulfite and a small amount of sul30, NH.

five

23

9.8

SO, 3.5 to 100 g of sulphite solution is poured gradually into a test tube - a stirred reactor, sulfuric acid is supplied in excess and SO 2 is blown off to the exhaust gas. The gas released from the first reactor is absorbed by the alkaline solution into the Tish- to The solution flows into the second test tube reactor, where, with vigorous stirring, blow air is supplied to 50.2. The working capacity of each reactor is 50 ml. The residence time of the absorption sulphite solution in the first reactor is 3.2 minutes. The gas after the second reactor enters

ammonium bis, and ammonium bisulfate, forming a separate absorber-2Q. Determine

Shyes due to the oxidation of sulfite and due to the absorption of traces of SOj contained in the exhaust gases of the sulfuric acid plant. Sulfite breaker decomposed with sulfuric acid

NH HSOj + H SO - t

25

the content of sulfite and sulfate in the first absorber and the degree of removal of 80 in the first reactor. 95% of the amount of 80 in the sulfite solution. The solution after the second reactor is left for a day in a closed flask without stirring at room temperature. The visual deposition of deposits on the wall of the flask is determined. There is no precipitate. In the sulfuric acid formed, the concentration of ammonium ions is 0.58%. The results are given in the table.

(NH)

 SOj + 2H2SO - 2NH4HS04 + H20 + SO

(NH) S04 + H S04

.

In this method, the treatment of the sulfite absorption solution is carried out by a 20-40-fold amount of concentrated sulfuric acid from the stoichiometric norm per image) - ammonium bisulfite.

Due to a significant excess of sulfuric acid, the process of separating SO2 is quick and can be carried out on apparatus of any type. The resulting solutions do not crystallize and do not clog communication deposits, instruments and equipment, can be used to obtain extraction phosphoric acid.

The example of the river. The sulphite solution obtained at the ammonia plant and the sulfuric acid production of gas is subjected to processing.

5.7 21.9 14.4 53.0 main components

(NH4) 2SO

(NH4) HS03

(N11)

H, 20

, 80,

in terms of

composition of sulphite solution5

0

five

0

five

0

five

the content of sulfite and sulfate in the first absorber and the degree of removal of 80 in the first reactor. 95% of the amount of 80 in the sulfite solution. The solution after the second reactor is left for a day in a closed flask without stirring at room temperature. The visual is determined. no precipitation on the walls of the flask. There is no precipitate. In the resulting sulfuric acid, the concentration of ammonium ions is 0.58%. The results are shown in the table,

 From the table it follows that when used for processing sulfite absorption solution of concentrated sulfuric acid in a 20-40-fold excess of the stoichiometric norm for ammonia binding to ammonium bisulfite, the degree of separation 80, in the first reactor with a residence time of 5-2.5. The min is 94.5-95%. The precipitate at the specified parameters does not occur. When processing the sulphite absorption solution with less than 20 times the amount of sulfuric acid, sediment is released and the amount of precipitation decreases to 80 in the first reactor. When processing the sulphite absorption solution with more than 40-fold amount of sulfuric acid, there is a significant decrease in the degree of emission of 80. in the first reactor.

The invention makes it possible to achieve a single contact in sulfuric acid plants.

100% utilization of sulfur dioxide.,,

Claims (1)

In addition, the proposed method of processing sulphite absorption solution allows to obtain ammonia-containing sulfuric acid (1 - 0.4% NH), followed by its use in the production of fertilizers. At DK / DA installations, the stump of gas use can also be increased to 100% and the discharge of the residual amount 50 to the atmosphere is stopped. Invention Formula The method of processing sulfite absorption solution of sulfuric acid, 3 30.0 85.0 15.0 95.0 6.4 90.0 20.0 95, t 5.2 94.5 lot production, which involves treating the initial solution with concentrated sulfuric acid to produce ammonium bisulfate and a gas containing sulfuric anhydride, and feeding the latter into a system for producing sulfuric acid, characterized in that sulfuric acid for processing: sulfite solution is used in 20-40-fold excess, from the stoichiometric standard for the formation of ammonium bisulfate. 6.8 t, 2 0.88 7.2 5.4 84 3.6 2.7 t, 7 1.35 P2 1.07 25.5 4.3 3.3 2.15 P7 1.53 1.38