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...

Examples

Embodiment Construction

[0022] Harmless treatment and resource recovery of waste electrolyzer linings include the following steps:

[0023] Furnace loading of DC resistance furnace: the bottom layer of the furnace is covered with quartz sand, and the upper layer is covered with carbon-silicon ratio reaction material, which is paved and compacted. The thickness of the quartz sand layer is 600mm, and the mass ratio of silicon to carbon in the carbon-silicon ratio reaction material is 40:60 The separation plates are respectively arranged on both sides of the furnace head to form a furnace core, and the furnace wall is fixed externally; a 150mm thick coke grain bedding layer is laid on the bottom of the furnace core; waste cathode block layers are laid layer by layer in the center of the furnace core from bottom to top, The periphery of the furnace core is surrounded by the waste cathode block layer by layer from bottom to top, and each layer of waste cathode block layer and waste electrolyzer liner layer...

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...

Examples

Embodiment Construction

[0022] Harmless treatment and resource recovery of waste electrolyzer linings include the following steps:

[0023] Furnace loading of DC resistance furnace: the bottom layer of the furnace is covered with quartz sand, and the upper layer is covered with carbon-silicon ratio reaction material, which is paved and compacted. The thickness of the quartz sand layer is 600mm, and the mass ratio of silicon to carbon in the carbon-silicon ratio reaction material is 40:60 The separation plates are respectively arranged on both sides of the furnace head to form a furnace core, and the furnace wall is fixed externally; a 150mm thick coke grain bedding layer is laid on the bottom of the furnace core; waste cathode block layers are laid layer by layer in the center of the furnace core from bottom to top, The periphery of the furnace core is surrounded by the waste cathode block layer by layer from bottom to top, and each layer of waste cathode block layer and waste electrolyzer liner layer...

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