Governing method for discharging fluorine-containing gas amorphously in aluminum electrolysis production process

Abstract

The invention relates to a governing method for discharging fluorine-containing gas amorphously in an aluminum electrolysis production process. The method comprises the following steps: (1) arrangingmultiple layers of nozzles which are arranged in a staggered manner at a discharge skylight of an aluminum electrolysis plant and spraying an alkaline sodium metaaluminate solution through the nozzles, wherein the alkaline sodium metaaluminate solution absorbs an absorption liquid containing cryolite after the fluorine-containing is discharged amorphously, and gaseous hydrogen fluoride and alkaline sodium metaaluminate react to generate cryolite; (2) collecting and filtering the absorption liquid containing cryolite, wherein the solid phase is cryolite; and adding sodium metaaluminate into thefiltrate for circular use; and (3) demisting the washed gas and discharging the gas into atmosphere. The method provided by the invention has the advantages of being simple in process, convenient tooperate, small in energy consumption, good in pollutant removal effect and the like.

Description

technical field

[0001] The invention belongs to the technical field of industrial waste gas treatment, and in particular relates to a treatment method for unorganized discharge of fluorine-containing gas in the aluminum electrolysis production process. Background technique

[0002] During the aluminum electrolysis process, the air pollutants released mainly include fluorides (HF, CF 4 、C 2 f 6 etc.), SO 2 and gas particles, among which fluoride is the most harmful. According to the characteristics of the current electrolysis process, the airtight cover of any kind of electrolytic cell cannot be completely closed. During the process of anode replacement and aluminum extraction, some gas will always be emitted into the workshop and discharged into the atmosphere through the skylight of the workshop, which is called non-organization. Organize the emission of fluorine-containing gases. As far as the amount of fluoride in the smoke is concerned, the amount of fugitive emissio...