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Recycling and utilization method of waste cathode carbon block of electrolytic aluminum electrolytic tank

A technology of waste cathode carbon blocks and electrolytic cells, which is applied in the direction of carbon preparation/purification, improvement of process efficiency, carbonate preparation, etc., to achieve obvious advantages, advanced technology, remarkable environmental and economic benefits

Active Publication Date: 2019-07-19
GUANGXI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This scheme combines pyrolysis and wet treatment, and aims at the characteristics of fluoride contained in waste cathode carbon blocks, and conducts harmless treatment and resource utilization of waste cathode carbon blocks in aluminum electrolytic cells, in order to achieve "zero emission" of harmful gases Under the premise of obtaining high value-added hydrofluoric acid products, further solving such solid waste environmental protection problems and generating considerable economic benefits

Method used

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  • Recycling and utilization method of waste cathode carbon block of electrolytic aluminum electrolytic tank
  • Recycling and utilization method of waste cathode carbon block of electrolytic aluminum electrolytic tank

Examples

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Embodiment 1

[0021] A method for recycling waste cathode carbon blocks of an electrolytic aluminum electrolytic cell. The processing process includes the following steps: using a crusher and a ball mill to crush the waste cathode carbon blocks to a carbon powder with a particle size of less than 45 meshes, and adding the amount of carbon powder to 10 g of carbon powder 5wt%, that is, 0.5g of 5A zeolite molecular sieve with a particle size of less than 2mm, to obtain a uniformly mixed solid powder; heat the mixed solid powder at 800°C for 30 minutes at high temperature; the CO produced by heat treatment 2 , NO x The gas is passed through 10% NaOH solution for absorption to obtain Na 2 CO 3 、NaNO 3 the salt solution and recover it; add 98wt% concentrated sulfuric acid at 80°C to the fluorine-containing solid obtained after heat treatment to obtain three products: solid, mixed salt solution and HF gas, wherein the solid product is carbon powder for recovery Reuse; the liquid is a mixed sal...

Embodiment 2

[0023]A method for recycling waste cathode carbon blocks of an electrolytic aluminum electrolytic cell. The processing process includes the following steps: using a crusher and a ball mill to crush the waste cathode carbon blocks to a carbon powder with a particle size of less than 45 meshes, and adding the amount of carbon powder to 10 g of carbon powder 20wt%, that is, 2.0g of 10X zeolite molecular sieve with a particle size of less than 2mm, to obtain a uniformly mixed solid powder; heat the mixed solid powder at a temperature of 1600 ° C for 120 minutes; the CO produced by heat treatment 2 , NO x The gas is passed through 10% NaOH solution for absorption to obtain Na 2 CO 3 、NaNO 3 the salt solution and recover it; add 98wt% concentrated sulfuric acid at 120°C to the fluorine-containing solid obtained after heat treatment to obtain three products: solid, mixed salt solution and HF gas, wherein the solid product is carbon powder for recovery Reuse; the liquid is a mixed ...

Embodiment 3

[0025] A method for recycling waste cathode carbon blocks of an electrolytic aluminum electrolytic cell, the processing process comprising the following steps: using a crusher and a ball mill to crush the waste cathode carbon blocks to a carbon powder with a particle size of less than 45 meshes, and adding carbon powder mass to 20 g of carbon powder 10wt%, that is, 2.0g of 5A-type zeolite molecular sieve with a particle size of less than 2mm, to obtain a uniformly mixed solid powder; heat the mixed solid powder at a temperature of 1000°C for 80 minutes; the CO produced by heat treatment 2 , NO x The gas is passed through 10% NaOH solution for absorption to obtain Na 2 CO 3 、NaNO 3 the salt solution and recover it; add 98wt% concentrated sulfuric acid at 110°C to the fluorine-containing solid obtained after heat treatment to obtain three products: solid, mixed salt solution and HF gas, wherein the solid product is carbon powder for recovery Reuse; the liquid is a mixed salt ...

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Abstract

The invention discloses a recycling and utilization method of waste cathode carbon block of an aluminum electrolytic tank. The method comprises the following steps: performing crushing, color selection, pulverization and ball milling on a waste cathode carbon block raw material of the aluminum electrolytic tank to obtain carbon powder, and then blending the carbon powder with a 5A or 10X type zeolite molecular sieve which accounts for 5 to 20 percent by mass of the carbon powder and has a particle size less than 2 mm, performing thermal treatment at 800 to 1,600 DEG C for 30 to 120 min, adding98 percent by weight of concentrated sulfuric acid with temperature of 80 to 120 DEG C into a fluorine-containing solid product, and introducing generated HF gas into deionized water for absorption and condensation to obtain a hydrofluoric acid product. According to the recycling and utilization method, the zeolite molecular sieve is used as a thermal treatment reaction material and also achievesthe effects of a catalyst and a dispersant; the process is advanced, and the advantages are obvious; and on the premise of realizing 'zero discharging' of harmful gas, a high-added-value hydrofluoricacid product is obtained, and the environmental benefit and the economical benefit are outstanding.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of solid waste in the electrolytic aluminum industry. Specifically, the invention relates to a method for harmless treatment of waste cathode carbon blocks of an electrolytic aluminum electrolytic cell and effective recovery of carbon and fluorine resources therein. Background technique [0002] my country's electrolytic aluminum industry has maintained a relatively high growth rate since entering the 21st century. The life of the electrolytic cell of alumina electrolysis is limited, and it needs to be overhauled every 3 to 5 years. The spent cathode carbon block is one of the main wastes generated by the overhaul of the electrolytic cell, and it is a dangerous solid waste containing fluorine generated during the electrolysis process. [0003] By 2017, my country has built an aluminum electrolytic production capacity of about 45 million tons, with an actual output of more than 3...

Claims

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Application Information

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IPC IPC(8): C01B7/19C01B32/05C01D5/06C01D7/07C01D9/06
CPCC01B7/191C01B32/05C01D5/06C01D7/07C01D9/06Y02P10/20
Inventor 罗轩秦祖赠周佐陈晓睿谢新玲苏通明何珍莉
Owner GUANGXI UNIV