SU982784A1 - Method of cleaning electrolyte solutions from sulphuric acid - Google Patents

Description

The invention relates to sorption methods for purifying electrolyte solutions from sulfuric acid and can be used in chemical technologies for the processing of highly concentrated electrolytes containing sulfuric acid, salts of non-ferrous and scattered metals.

A known sorbdione method of purifying electrolytes from sulfuric acid using nitrogen-phosphorus-containing ampholyte of the type ANKF-ZG P.

The disadvantage of this method is the relatively low capacity of the used sorbents and their selectivity with respect to the AO ions in the presence of non-ferrous and rare metal ions.

Closest to the invention, the technical essence and the achieved result is a method of purifying electrolyte solutions from sulfuric acid, including contacting them with styrene-divinylbenzene anion exchangers, subsequent removal of residues of contaminated solutions from the anion exchanger by draining them and regenerating it with water.

In this case, strong base anion exchangers of the AB-17 type are used, removal of the contacting solutions is carried out, drying the sorbent layer by blowing off compressed air, after which the anion exchangers are regenerated with water G 2.

The disadvantage of this method is the low degree of extraction of sulfuric acid (about 70%).

In addition, due to the partial sorption of metals (up to 20% of the initial

10 quantity) requires additional consumption of reagents for regeneration sorbents from metals o

 The aim of the invention is to increase the degree of purification of solutions of electrolytes from sulfuric acid and to reduce the consumption of reagents during its implementation.

The goal is achieved according to the method of electrolytic purification,

20 products from sulfuric acid, including their contact with styrene-divinylbenzene anion exchanger, which is used as a low-base anion exchanger containing amino-alcoholic functional groups, specifically, di- and diethanolamine or aminotrimethylolmethane, the subsequent removal of residues of contacting solutions from the intergrain space of anion.

30 and the latter are regenerated with water, in which the contacting is carried out with a low basic anitone containing amino alcohol functional groups. In addition, a sorbent with functional groups of mono- and diethanolamine or aminotrimethylolmethane is used as a low-base anion exchanger. The technology of the proposed method is as follows. Substandard (waste) electrolytes of electrochemical production, electroplating, etching solutions, acidic solutions of hydrometallurgy of non-ferrous and scattered metals, and wash acidic water are used as initial solutions for sorption purification from acid, these solutions containing colored and scattered metal ions, prefabricated in contact with anion exchangers, with these groups (for example, AN-61, ANV-11) to a given or complete degree of purification from acid. The degree of purification (deacidification) is determined by the relative amount of contact mass of the ion exchanger and solution. The relative amounts of the contacting anion exchanger and electrolyte solution are chosen taking into account the required degree of purification and acid concentration in the solution based on the sorption capacity of anionites depending on the acidity of the solution presented in Table. 1. A-nionite, saturated with sulfuric acid, is separated from the acid-free solution, removed partially captured (from the intergranular space and from the surface of the grains) purified solution by stripping with compressed air, vacuuming or centrifuging the salts of non-ferrous metals left in the purified solution are directed to further processing carried out by known chemical and metallurgical methods. Desorption swallow. acid is carried out with water, in order to intensify the desorption process, they are conducted with hot water (60-70 ° C). This gives eluates with a concentration of sulfuric acid of 50-100% (depending on fractions) of the initial content of the latter in the purified electrolyte and achieve complete regeneration of the anion. The regenerated anion exchange resin is reused. Example 1. AN-61, ANB-11 anion exchangers and ANKF-ZG ampholyte (basic object) are listed in contact with solution. Sulfuric acid of various concentrations containing indium (III), iron (III) and chromium (III) with a concentration of metals 8, mol / l. After saturation of the ion exchangers, the ion exchanger is separated from the solution and centrifuged, partially entrained by blowing compressed air or by vacuum. sulphate solution, wire drainage of ion exchanger. Absorbed acid is desorbed with water and its content in the eluate is determined by the sorption capacity of ionites with the metal absorption capacity determined by the concentration difference in solution before and after sorption. Comparative results of sorbability and selectivity of sorption of sulfuric acid and related metals by the known and proposed methods are given in the table. 1. Example 2. Under the conditions of example 1, sorption extraction of sulfuric acid is carried out on anion exchangers AN-61, ANB-11 in comparison with the known method (sorption of acid on a strongly basic AB-17 anion exchanger) The results of the experiments are presented in tabl “2” As follows from the above data, cleaning solutions and electrolytes from sulfuric acid with the help of anion exchangers AN-61 and ANB-11 in comparison with limestone method, as well as with the basic object (sorption on Ampholite ANKF-ZG) will reduce the consumption of reagents, including ion exchanger approximately 1.2-1 / 6 times, and completely eliminate the operation of regeneration of ion exchangers from impurities of associated metals. The technical and economic effect of the proposed method is due to an increase in the degree of extraction of sulfuric acid by 1.2-1.6 times due to an increase in the exchange capacity of the anion exchanger, as well as an increase in the selectivity of sorption absorption of the acid against the background of metal impurities. Table 1

4, B4

0.0

5.26

6.28

0.0

6.98

4.38 1.96

2.1

2.82

2.4

5.73 1.58

Claims (2)

2.51 Claim D. A method for purifying electrolyte solutions from sulfuric acid, including contacting them with styrene-vinylbenzool anion nitbm, then removing residual contact solutions from. the intergranular space of the anion exchanger by drying it and regenerating the latter with water, which is the fact that, in order to increase the degree of purification of the solvents, as well as to reduce the consumption of reagents, contacting is carried out with a low basic anion exchange resin containing amino alcohol functional groups Continuation of tAL. 1 2. A method according to claim 1, characterized in that a sorbent with functional groups of a mony of diethanolamine or an aminotrimethylolmethane is used as a niacobasic anion exchange resin. Sources of information taken into account in the examination I. 1. The author's certificate of the USSR for application # 2708903 / 23-26, cl. On 01 J 41/04, 1980. 2. Bereza S.V. and others. Tsvetna metallurgists. 1974, 22, p. 28-30 (prototype).