Regeneration treatment method for waste cathode carbon blocks of aluminum electrolytic cell

Abstract

The invention discloses a regeneration treatment method for waste cathode carbon blocks of an aluminum electrolytic cell and belongs to the technical field of solid waste treatment in the aluminum electrolysis industry. The main treatment process comprises the steps of crushing, screening, toxicity inhibition, batching and pressure-controlled heat treatment. After waste cathode carbon block materials of the aluminum electrolytic cell are crushed and screened, toxic inhibitors of hydrogen peroxide, potassium permanganate, hypochlorite and the like are added, then carbonaceous materials of anthracite, calcined petroleum coke, waste anode carbon blocks, anode scraps and the like are blended to serve as furnace-in raw materials, and the furnace-in raw materials are placed in a resistance furnace to be subjected to heat treatment at the ordinary pressure (1200-1800 DEG C) or the control pressure (1000-1600 DEG C and 0.01-0.5 atm). Fluoride volatilized from flue gas can be used for producingfluoride salt electrolytes after being cooled and crystallized, treated materials do not contain any contaminant, the carbon content is up to 99%, the conductivity is good, the specific surface areais large, the treated materials can be used for producing various carbon products, waste is turned into wealth, and environment-friendly resource application of overhaul of the waste cathode carbon blocks of the aluminum electrolytic cell is achieved.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment in the aluminum electrolysis industry, and in particular relates to a treatment and regeneration technology of a waste cathode carbon block material of an aluminum electrolysis cell. technical background [0002] In the production of aluminum electrolysis, large prebaked anode electrolytic cells are commonly used, and the bottom cathode uses carbonaceous graphite materials. In aluminum electrolysis production, the graphite cathode will absorb a large amount of fluoride salt when it is eroded by electrolyte and aluminum metallurgy, and a small amount of cyanide will be generated near the steel rod. At present, the life of the electrolytic cell is about 6 to 8 years. During the overhaul, the lining of the electrolytic cell needs to be replaced, and a large amount of solid waste including cathode carbon blocks will be produced, which contain about 10 to 30% of fluoride, Spent cathode c...

AI Technical Summary

Problems solved by technology

However, this kind of treatment method needs to be filtered and washed many times during the treatment process, resulting in a large amount of cyanide-containing and fluorine-containing wastewater, causing secondary pollution. At the same time, the fluoride salt content in the treated carbon residue is still as high as 6-8%. The harmless treatment and recycling of such solid waste have not been truly realized