SU1154202A1 - Method of extracting bromine from brine - Google Patents

Abstract

A METHOD FOR EXTRACTING BROMINE FROM A BALANCE, which includes treating the latter with chlorine and desorption of bromine with air, characterized in that, in order to reduce chlorine consumption and reduce its content in the bromo-air mixture, the treatment is carried out repeatedly, supplying chlorine in an amount that ensures its concentration in the solution after each treatment equal to 0.04-0.28 eq. Ct2 / 3KB. Wg, in the desorption of bromine by air after each chlorination.

Description

SP

4 th to

.four

This invention relates to a process for the recovery of bromine from brine from various bromine-containing waters.

A known method for the extraction of bromine from brine, including the chlorination of its desorption of bromine with air. Chlorine is served together with air at a ratio of 1: 3-5 in an amount according to the height of the desorber, respectively 200, 400 and 200 kg D

The disadvantages of this method are the production of a bromide mixture containing up to 30% chlorine, which leads to the need for its purification and increased consumption of chlorine. The degree of extraction of bromine is 97.6%, the loss with the spent brine is 15-40 g / m.

The closest to the invention to the technical essence and the achieved result is a method of extracting bromine from brine, which includes treating it with chlorine with the subsequent desorption of bromine with air. , which allows reducing the chlorine content in the airborne mixture by 10-15 times, i.e. to 2.04, 5 wt.% and reduce the consumption of chlorine by 10% 2.

However, the theoretical chlorine consumption is 0.445 kg per 1 kg of bromine, and in the known method the chlorine consumption is 0.7 kg per 1 kg of bromine, which is 57% higher than the theoretical one.

The aim of the invention is to reduce the consumption of chlorine and reduce co54202

keep chlorine in the air-beer mixture.

This goal is achieved by the fact that according to the method of extraction of bromine from brine, including its repeated treatment with chlorine, supplied in an amount that ensures its concentration in the solution after each treatment, equal to 0.04-0.28 eq. suekv. Br at the desorption of bromine by air after each chlorination.

Sequential chlorination and desorption of bromine and mode

15 chlorination makes it possible to reduce the consumption of chlorine by 9–25 times in comparison with the known methods and to obtain a bromide – air mixture containing 0.01–0.035 wt.% Of chlorine at a content of 20 research institutes of bromine in the spent brine of 0.001–0.078 g / l B

When choosing the optimal chlorine consumption in the proposed method, each step requires the minimum chlorine content in the bromide-air mixture, the minimum value of the final content of Br in the spent brine, the maximum oxidation depth of the bromine, the decrease

30 consumption of chlorine for the oxidation of Br and an acceptable (not too large) number of steps for the extraction of bromine.

Considering these requirements, there were

35 selected optimal ratios of consumable chlorine for each stage for all the brines studied and temperatures given in Table. one.

Table 1

36 29

0,69

25 45 0,69

48

0.38

10850

25.6 10990 26.0

9555

22,6

Continued table. As follows from Table 2, only the indicated chlorine consumption ensures the optimal conditions for carrying out the process. Example 1. The installation is a section of the apparatus with a diameter of 0.4 m and a height of 1 m. Chlorine is supplied to the reactor, which is evenly distributed in the brine flow. Having passed the height of the section, which is determined by the optimal contact time of the phases for 0.5 s, the oxidized stream enters the desorber, from which bromine, which is part of the same section, is extracted with compressed air. Bromine is extracted from the desorber with compressed air and fed to the outlet of the section. The amount of air at a 2-fold excess for the extraction of 1 kg of bromine from the stage is 1.4 m. The results of the operation of the sectional apparatus for the Sivash brine, pr (the initial bromine ion in the brine is 0.69 g / l) are given in Table. The chlorine consumption per stage is 0.04 eq. C12 / EQ. BG To extract bromine to a final content of Br in a brine of 0.058 g / l, 108 sections are required in the apparatus. Such sections may be sequentially assembled units either in one or several sections operating in circulation. At the first 96 steps (sections), bromine is extracted, where the chlorine content in the bromo-air mixture reaches 0.013% by weight. In the last 12 stages, we get a bromo-bleached mixture with a chlorine content of 4.4 May. Thus, the oxidation depth in this case is 91.6%. The consumption of chlorine for the oxidation of 1 ton of bromine is equal to

Table 1 is a continuation of the table of 483 kg, which is 8.5% higher than the theoretical one. Example 2. Bromine is extracted at the same plant on a Cuxuc (February) brine at t. The initial Br in this brine is equal to 0.38 g / l; therefore, the number of stages (sections) in the apparatus varies accordingly. At a chlorine consumption of 0.05 eq, Clj / eq. Wg per step requires 48 steps. The chlorine content in the bromo-air mixture reaches 0.08 wt.%, The oxidation depth is equal to 98%, the final content of Br in the spent brine reaches 0.008 g / l and the chlorine consumption for oxidation of 1 t of Br is 455 kg, which is only 2.2% above tereticheskogo. Example 3. The extraction of bromine is carried out in the same plant. on a kuchukek (July) brine at t 30 ° С. The initial brine is 0.38 g / l. Chlorine consumption for each stage is equal to 0.28 eq. Ct2 / / eq. Vg The required number of stages for the extraction of bromine to a final content of 0.0312 g / l is equal to 9. The chlorine content in the bromine truck. an air mixture of 6.7% by weight and an oxidation depth of 91.8%. The consumption of chlorine for the oxidation of 1 ton of bromine is 491 kg, which is 10.3% higher than the theoretical one. The implementation of the proposed method allows reducing the chlorine content in the bromo-air mixture to 0.0010, 035% when it reaches 0.001-0.078 g / l in the spent brine. Air supply at each stage allows refusing further purification of the air-to-air mixture into chlorofluid 7115A2028

titeltin bain x. As a result, in addition, the consumption is reduced

the release of waste air is significantly reduced by 14%, and the capacity of the plant to the environment. Which increases by 1-9%.

The proposed method is achieved when using the proposed - Mogo

With a more complete oxidation of Br with chlorine, the method increases the possibility of increasing the yield of the product and reducing the use of the raw material base for the content of hlrr in the bromine-carcass of bromine from much less

stuffy mixture. concentrated brines.

Claims (1)

METHOD FOR EXTRACTION OF BROMINE FROM THE BRANCH, including treating the latter with chlorine and desorption of bromine with air, characterized in that, in order to reduce the consumption of chlorine and reduce its content in the bromine-air mixture, the treatment is carried out repeatedly, supplying chlorine in an amount ensuring its concentration in the solution after each treatment equal to 0.04-0.28 equiv. SS ^ / equiv. W ’, during the desorption of bromine by air after each chlorination. Joint venture About u>