Comprehensive utilization method of waste and old cathode carbon blocks of aluminium electrolytic bath

Abstract

The invention relates to a comprehensive utilization method of waste and old cathode carbon blocks of an aluminium electrolytic bath, which is characterized in that after being treated by sorting, crushing, pulverizing, ash removing and drying, the waste and old cathode carbon blocks are used as raw materials for producing blast furnace carbon blocks, electric furnace carbon blocks, electrolytic bath cathode carbon blocks, electrolytic bath side carbon blocks, electrolytic carbon blocks, self-roasting carbon blocks or carbon paste. In the comprehensive utilization method, the recycling of dangerous waste and the cathode carbon block different for being practically disposed and applied, the harmless treatment and comprehensive utilization of the waste and old cathode carbon blocks are realized, the waste becomes valuable, simultaneously the use of anthracite, metallurgical coke, tar coke and petroleum coke is reduced, the resource is saved and the production cost is reduced.

Description

technical field [0001] The invention relates to a comprehensive utilization method of waste and old cathode carbon blocks of an aluminum electrolytic cell, belonging to the technical field of non-ferrous metallurgy and environmental protection. Background technique [0002] The waste cathode carbon block used in the aluminum electrolysis process generally contains carbon, sodium fluoride, cryolite, aluminum fluoride, calcium fluoride, alumina, etc., of which the carbon content is about 50-70%, electrolyte (including fluoride salt and alumina ) is about 50-30%, and the cyanide content is about 0.2%; the fluorine content of the leaching liquid of solid waste of electrolytic aluminum cathode furnace materials (mainly cathode carbon blocks and refractory materials) can reach 6000 mg / L, CN - The content can reach 10-40 mg / L, exceeding the standard requirements of the national "Hazardous Waste Identification Standard-Leach Toxicity Identification" (F - <50 mg / L, CN - >1 m...

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Problems solved by technology

However, it is only mentioned that the fluoride salt and alumina in the carbon material are deashed by the flotation method, and it is difficult to ensure the purity of the carbon material only by the flotation method in actual production; the other patent mentions that the obtained carbon powder is used as a powder used to produce carbon products

[0007] The article "Recycling and Utilization of Waste Cathode Lining of Aluminum Electrolytic Cells" published in the fourth issue of 2001 in "Mineral Protection and Utilization" mentioned that there are foreign attempts to use waste cathodes as anode paste ingredients in aluminum electrolysis production. Using waste cathodes as anode paste batching aggregates, waste cathode carbon blocks are directly used for anode paste batching without ash removal after crushing, and the blending ratio of waste cathodes is below 4.5% (wt), which cannot make full use of waste cathodes, and Used as aggregate, due to the large difference in activity with binder, petroleum coke, and pitch coke, the waste cathode aggregate has serious slag loss