Additive for processing aluminum electrolytic carbon slag by melting method and using method thereof

Abstract

The invention particularly relates to an additive used for processing aluminum electrolysis carbon slag through a melting method and a using method of the additive. The additive is characterized by comprising four components of A, B, C and D; A comprises MgF2; B comprises LiF; C comprises CaF2; D comprises AlF3; and the mass ratio of A to B to C to D is (2.5-6.0):(2.5-6.0):(3.5-7.5):(6.0-9.5). The adding amount of the additive into the carbon slag is counted as that the mass ratio of the additive to the carbon slag is (1.0-8.0):20.0. The carbon slag and the additive are ground into minus 200 meshes by 80% or above and added into a melting furnace protected by inert gas after being fully mixed and dried, the temperature is increased to 900-1300 DEG C and preserved for a period of time, then separating is conducted, and carbon particles and an electrolyte are obtained. The additive is added in the process of processing the aluminum electrolysis carbon slag through the melting method, the electrolyte and carbon particle separating effect can be obviously improved, and the electrolyte and the carbon particle products higher in purity are obtained. The obtained electrolyte can directly return to an electrolytic tank to be used, and the carbon particles can be used as thermal power plant fuel.

Description

technical field [0001] The invention belongs to the field of metallurgical solid waste recovery, and in particular relates to an additive for treating aluminum electrolytic carbon slag by a melting method. Background technique [0002] Aluminum has been widely used as a metal with superior performance, but in the process of aluminum electrolysis, due to the uneven combustion (selective oxidation) of carbon anodes, the anode carbon blocks collapse and form a large amount of carbon slag. According to statistics, every ton of primary aluminum produced will produce 3-15 kg of carbon slag. In 2016, the output of primary aluminum in my country was 32.71 million tons, and the resulting carbon slag was as high as 100,000-500,000 tons. The huge output cannot be ignored. The main components of carbon residue are 50%-70% electrolyte and 30%-50% carbon, both of which are available resources, and most of the carbon is pure oil coke and carbon blocks falling from the anode. Contains Na ...

AI Technical Summary

Problems solved by technology

[0003] As a method of comprehensive recovery of carbon residue, the melting method can simultaneously recover carbon and electrolyte in carbon residue, but the separation of carbon residue by melting method is not thorough at present, and the two are mixed with each other in the final product, and the purity is low

Among them: carbon particles contain a lot of fluoride, and direct combustion will produce a large amount of fluorine-containing waste gas, causing secondary pollution, which cannot meet the requirements of environmental protection. At the same time, high-temperature fluoride will cause corrosion to combustion equipment and affect the life of equipment

The electrolyte contains a lot of carbon, and direct return to the aluminum electrolytic cell will not only cause difficult control of the cell temperature and deterioration of the furnace, but also reduce the conductivity of the electrolyte, affecting normal production and the life of the electrolytic cell