Harmless and efficient resource recovery method for waste aluminum electrolysis cell linings and waste cathodes

Abstract

The invention belongs to the technical field of chemical engineering, and particularly relates to a harmless and efficient resource recovery method for waste electrolytic cell linings and waste cathodes. The method comprises the following steps: charging crushed waste electrolytic cell lining blocks, waste cathode blocks, a furnace core material, a heat preservation material and a carbon-silicon ratio reaction material into a direct-current resistance furnace, electrifying the direct-current resistance furnace, conducting heating to 2800-3000 DEG C, carrying out anaerobic combustion for 35-38 hours, conducting cooling for 144 hours, and conducting discharging to obtain silicon carbide blocks and graphitized cathode carbon blocks; and subjecting fluoride flue gas generated in the anaerobic combustion process of the direct-current resistance furnace to defluorination and dust removal treatment. The ultrahigh-temperature anaerobic combustion process and the defluorination recovery process are adopted, toxic components in the waste electrolytic cell lining can be completely discharged and subjected to innocent treatment, and meanwhile other impurities and harmful substances are discharged together.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for harmless and efficient resource recovery of waste aluminum electrolytic cell liners and waste cathodes. Background technique [0002] The waste aluminum electrolytic cell lining is an inevitable waste in the electrolytic aluminum industry. Among the dismantled waste cell lining materials, carbonaceous materials account for about 70%, in addition to containing fluoride, aluminum oxide, aluminum-iron alloy and other elements; waste The fluoride in the tank lining is NaF, CaF 2 and Na 3 AIF 6 form, where NaF is easily leached in water F - , extremely harmful; CaF 2 It is a stable and insoluble compound, harmless to the environment; Na 3 AIF 6 Easily decomposed by heat to generate NaF and AIF 3 , so Na 3 AIF 6 Has a certain degree of danger. [0003] The flotation method is a separation method that uses a specific flotation agent to select...

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Problems solved by technology

[0004] However, the flotation method has the disadvantages of complex process and high cost: in order to increase the output, the enterprise increases the corresponding saline-alkaline agent to remove fluorine, and the result is that the toner powder produced by the output effect has large impurities, low carbon content, and chemical components appear in it. , the output of calcium fluoride has large impurities and low calcium fluoride content, and the extracted cryolite has carbon and chemical components; although the purpose of harmless treatment of waste electrolytic aluminum linings has been achieved, resources cannot be recycled efficiently

[0005] It can be seen that although the flotation method can achieve harmless treatment, turn toxic and hazardous waste into general solid waste, prevent and reduce environmental pollution, but it cannot effectively solve the problem of resource reuse

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