Recycling method of anode carbon residues

Abstract

The invention provides an anode carbon residue recycling method, and belongs to the technical field of aluminum electrolysis solid hazardous waste disposal and utilization, the anode carbon residue recycling method comprises the following steps: S1, crushing and grinding anode carbon residues to be treated, and optionally adding an additive for mixing; s2, performing strengthened separation on the material obtained in the step S1 at the high temperature of 750-950 DEG C, wherein the strengthened separation is performed under the condition of applying a strengthening force field; and S3, cooling the material obtained after reinforced separation in the step S2, wherein the upper layer of the cooled material is carbon powder, and the lower layer of the cooled material is fluoride salt solid. According to the method, the separation of the carbon residues and the molten fluoride salt at high temperature is promoted by utilizing a force field strengthening method, the carbon and the fluoride salt in the carbon residues can be efficiently separated, the carbon powder and the fluoride salt block with relatively high purity are respectively obtained, the carbon powder can be used as a raw material for producing carbon materials such as anodes for aluminum, and the fluoride salt can be used as an electrolyte to return to an electrolytic cell for use. The treatment time is short, the separation effect is good, the carbon loss is less, and carbon dioxide is basically not discharged in the process.

Description

technical field [0001] The invention relates to the technical field of aluminum electrolysis solid hazardous waste disposal and utilization, in particular to a method for recycling anode carbon residue. Background technique [0002] The production of electrolytic aluminum in my country generally adopts large-scale pre-baked anode electrolytic cells of 400kA and above. Due to the uneven quality of the anode used, during the electrolysis process, it will lead to falling off and slag, and then it is regularly removed with part of the electrolyte to form anode carbon slag. It is estimated that my country will discharge about 400,000 tons of anode carbon residue solid waste every year. This kind of solid waste has been included in the "National Hazardous Waste List (2021 Edition)". At present, the disposal of anode carbon residue by major domestic aluminum plants And the utilization technology is not very mature, and most aluminum electrolysis enterprises store it, which leads to...

AI Technical Summary

Problems solved by technology

However, the existing wet treatment methods cannot achieve a complete separation of carbon and fluoride salts, and the two low-purity products obtained cannot be used and are still solid hazardous wastes

The fire treatment method needs to consume a relatively high amount of fuel to burn the charcoal. This part of the charcoal is not fully utilized, and the process also causes carbon dioxide emissions.

Using high-temperature static separation method, because part of the fluoride salt will be wrapped by carbon powder, unable to gather, it is difficult to quickly form a molten pool at the bottom, and the separation is slow and incomplete

[0005] In short, the existing method cannot realize the complete separation of carbon and fluoride salt in the anode carbon residue, and the purity of the separated product is low