SU1106529A1 - Method of removing arsenic from gases - Google Patents

Abstract

A METHOD FOR CLEANING MOUSEHOLD-CONTAINING GASES by irrigation with a solution of sulfuric acid followed by isolation of arsenic trioxide, characterized in that, in order to improve working conditions, a mixture of mono- and dialkylphenyl ethers of polyethylene glycol in an amount of 0.2-0.5 tons is introduced into the irrigation solution.

Description

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The invention relates to the purification of process gases from a mouse and can be applied in non-ferrous metallurgy, chemical and other industries.

A known method of cleaning arsenic trioxide gases by washing them with a liquid that dissolves AsgOs. From the obtained solution, AzgOz was isolated by crystallization 1.

The disadvantage of this method is the multi-stage process.

Closest to the invention is a method for purifying waste gases from the mouse-containing component by irrigation with a solution of sulfuric acid. The resulting mouse trioxide is removed from the system, and the diluted sulfuric acid is fed back to the scrubber 2.

The disadvantage of the known method is that during the cleaning of arcuate-containing gases in scrubbers in collection tanks for solutions, the formation of stable foam containing up to 70% of arsenic in the form of AsgOj is observed in the solid phase. The cause of foaming is the hydrophobicity of arsenic trioxide and its high dispersion. The resulting foam is not broken up by mechanical action. Abundant foam concentration of mouse, mg / m

Solution Logout

59.44 41.32 82.64 53.71 24, 79 28.93 26.86 41.01

Razozhenie prevents the normal course of the process and is unacceptable from the point of view of safety, as it can cause burns with trioxide mouse attendants.

The purpose of the invention is to improve working conditions by preventing foaming.

This goal is achieved by adding a non-ionic surfactant (surfactant) to the gas-irrigating solution of sulfuric acid, which is a mixture of mono- and dialkylphenyl ethers of polyethylene glycol in an amount of 0.2-0.5 g / l.

The method is carried out as follows.

A surfactant solution is dispensed from the container to the surface of the irrigating solution, which is located in the collection tank, through a distribution comb. The solution thus treated, after separating the solid particles AsjOs from it, is taken up by pumps and re-directed to the irrigation of the cleaned gases.

Results of gas cleaning from mice

when irrigated with their solutions without additives and with the addition of non-ionic surfactants, are given in table. one.

Table 1

Degree of cleaning,%

94 95 98 97

95 96 92 100 tweeting

Thus, the addition of a non-ionic surfactant does not reduce the degree of gas purification from the mouse.

Example. In a cylinder with a capacity of 100 ml, mouse is placed on the foam-containing foam formed during the purification of gases containing surfactant consumption, g / log O, 1 To, 2

The height of the foam layer, cm (after 5 minutes of settling)

trioxide mousta, in scrubbers irrigated with a weak sulphate solution (pH 1.5). To this solution, a different amount of surfactant is added in the form of a 1% aqueous solution. The results of the experiments are shown in table 2.

table 2

2.5 1.5 1 0.25 0.30.4 0.5 0.6

Additive surfactant less than 0.2 and more than 0.5 g / l leads to an increase in foaming.

As follows from the table. 2, the addition of surfactant in the amount of 0.2-0.5 g / l destroys the foam, transferring the arsenic trioxide to the precipitate, which is easily separated by filtration. At the same time, the mouse trioxide is prevented from contaminating the production area and conditions are created for the safe operation of the staff.

Claims (1)

METHOD FOR CLEANING MOUSE-CONTAINING GASES by irrigation with a solution of sulfuric acid followed by separation of arsenic trioxide, characterized in that, in order to improve working conditions, a mixture of mono- and dialkylphenyl ethers of polyethylene glycol in an amount of 0.2-0.5 g / l is introduced.