Comprehensive recovery and treatment method for electrolytic chlorine-containing waste gas

Abstract

The invention provides a comprehensive recovery and treatment method for electrolytic chlorine-containing waste gas. The method comprises steps as follows: solid particles such as carried dust and the like in the electrolytic chlorine-containing waste gas collected by a tail gas recovery device are removed, a NaOH solution with the weight percentage concentration being 29%-35% is sprayed to the chlorine-containing waste gas to wash the chlorine-containing waste gas, and pH value of the mixed solution is regulated to 1-2; the mixed solution is heated and subjected to vacuum pumping, and chlorine-containing steam is separated out; the chlorine-containing steam is introduced into a concentrated acid drying tower for drying treatment to prepare a finished chlorine gas product or pure chlorine gas is introduced into an anode chamber of an electrolytic cell through backflow, so that content of HClO in an acidic electrolyte solution is increased, and sterilization and disinfection effects of the acidic electrolyte solution are improved. With the implementation of the technical scheme, chlorine gas in the electrolytic chlorine-containing waste gas is recovered and treated with lower cost, chlorine gas is recycled, and economic and environmental benefits are good.

Description

technical field [0001] The invention relates to the technical field of recovery and utilization of electrolysis waste gas, in particular to a method for comprehensive recovery and treatment of electrolysis chlorine-containing waste gas. Background technique [0002] In recent years, through the electrolysis of chloride and its aqueous solution (such as NaCl, MgCl2), a large amount of electrolytic chlorine-containing tail gas will be generated in the anode chamber of the electrolytic cell. For example, with the continuous expansion of the application range of titanium metal, the number of sponge titanium enterprises is gradually increasing. , the magnesium electrolysis process has become an important part of the process flow of each sponge titanium production enterprise. In the 18000t / a sponge titanium production line, the chlorine content in the tail gas produced by the electrolysis of MgCl2 in the anode chamber of the electrolytic cell is about 5000t / a, accounting for the an...

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Problems solved by technology

[0003] At present, in the prior art, by recovering chlorine-containing waste gas through lye, and using a catalyst decomposition method to generate NaClO, a qualified NaCl solution is obtained, and the NaCl electrolyte is recycled. However, the above-mentioned technical solution has the following disadvantages: 1. The use of catalyst is complicated, the dosage is large, the composition is uncontrollable, and the cost of chlorine gas recovery is high; 2. The recovered chlorine gas contains a large amount of hydrogen chloride gas, and the impurities contain high chlorine. It needs to be washed and dried in multiple stages to elute hydrogen chloride gas, which increases the recovery. Cost, not conducive to economic and environmental protection

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