A treatment method for unorganized emission of fluorine-containing gas during aluminum electrolysis production process

Abstract

A method for controlling the unorganized emission of fluorine-containing gas during the aluminum electrolysis production process, which is carried out according to the following steps: (1) Set up multi-layer staggered nozzles at the emission skylight of the aluminum electrolysis plant, and spray alkaline sodium metaaluminate through the nozzles Solution, alkaline sodium metaaluminate solution absorbs unorganized emission of fluorine-containing gas to form an absorption liquid containing cryolite, gaseous hydrogen fluoride and alkaline sodium metaaluminate form cryolite; (2) After collecting the absorption liquid containing cryolite Filter, and the solid phase is cryolite; the filtrate is added to sodium metaaluminate for recycling; (3) the scrubbing gas is discharged into the atmosphere after defogging. The method of the invention has the advantages of simple process, convenient operation, low energy consumption, and good pollutant removal effect.

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...