Recycle method of water recycled from overhaul slot slag of electrolytic cell

Abstract

The invention discloses a recycle method of water recycled from overhaul slot slag of an electrolytic cell. The recycle method is characterized by comprising the following steps of: carrying out water leaching on the overhaul slot slag of the electrolytic cell, so as to enable sodium fluoride in the overhaul slot slag of the electrolytic cell to be dissolved in water to remove fluorine in the overhaul slot slag of the electrolytic cell, recovering the water in the treatment by a reverse osmosis water treatment system, recycling separated clean water, and producing a metallurgical slag former by using obtained high-fluoride residue, so that the recycle of production water can be realized. According to the recycle method, fluoride salt which is hard to remove in the overhaul slot slag of the electrolytic cell can be separated, and the recycle value of the overhaul slot slag of the electrolytic cell can be improved, so that a waste material can be recycled, the overhaul slot slag of the electrolytic cell can be economically recycled without pollution, and the pollution hidden danger can be basically eliminated.

Description

[0001] technical field [0002] The invention relates to a method for recycling water for recovering slag from overhauled electrolytic cells, and belongs to the technical field of slag treatment from overhauled electrolytic cells. Background technique [0003] Aluminum electrolytic cells generally need to be overhauled after 4 to 5 years of use. The average cell life of most enterprises in my country is about 1500 days. The waste lining removed during the overhaul is the overhaul slag of the electrolytic cell, which contains soluble fluoride. Overhaul slag mainly includes waste cathode carbon blocks, waste refractory bricks, paste, waste insulation bricks, refractory powder, refractory mortar and waste insulation boards, etc. The production amount is about 30kg / t·Al (relative number, which varies with the age of the tank). At present, the national electrolytic aluminum production capacity exceeds 9 million t / a, and the overhaul slag production is about 270,000 t / a. [0004]...

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Problems solved by technology

However, the disadvantages of this method are also very obvious: fluorine is harmful to refractory bricks, and fluorine is easily discharged into the air with flue gas to cause air pollution; the sodium content in waste cathode carbon blocks is extremely high, which will affect the later strength of cement

[0009] 3. As early as 1982, Shandong Aluminum Plant began to use waste carbon blocks to add alumina clinker to kilns to replace part of anthracite coal. Although it has passed the national appraisal and achieved good results, it cannot achieve large quantities and high added value. use

[0010] 4. Research on waste SiC-Si3N4 waste refractory brick treatment technology is basically blank at home and abroad

[0011] 5. Research on the recycling of production water for electrolytic aluminum fluorine-containing waste treatment is basically blank at home and abroad

[0012] The above-mentioned methods for dealing with electrolytic cell overhaul slag cannot be used in large quantities and with high added value, so there are not many industrial applications. As a result, most of the aluminum electrolytic cell overhaul slag is still discarded

[0013] Whether the slag from the overhaul of the electrolytic cell is stored or landfilled, huge investment costs and operation and management costs will be invested, and there will be long-term potential pollution hazards

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