Treatment method for carbon-containing solid waste in aluminum electrolysis industry

Abstract

The invention provides a method for treating carbon-containing solid waste in the aluminum electrolysis industry, which comprises the following steps: the carbon-containing solid waste is crushed and then added into a fluidized bed furnace to be roasted, boiling gas in the fluidized bed furnace is at least one of preheated air and industrial oxygen, the height of a boiling layer is 10-300cm, the temperature of the boiling layer is maintained at 500-800 DEG C, the roasting time is 0.1-10 hours, and the carbon-containing solid waste is obtained. The roasted product is electrolyte mainly containing cryolite, and the carbon content is less than or equal to 1%. According to the method, after the waste cathodes of the aluminum electrolysis cell, the aluminum electrolysis carbon residues or the electrolytes obtained through flotation of the waste cathodes and the aluminum electrolysis carbon residues are subjected to boiling oxidation roasting, products are pure electrolytes, the carbon content is reduced to 1% or below, other impurities are not added, the requirements of aluminum electrolysis can be met, and all the electrolytes are subjected to resource utilization.

Description

technical field [0001] The invention relates to the technical field of aluminum electrolysis, in particular to a method for treating carbon-containing solid waste in the aluminum electrolysis industry. Background technique [0002] The service life of the aluminum electrolytic cell is approximately 2000-4000 days. After long-term use, the lining material of the electrolytic cell will be deformed, worn and broken due to physical and chemical effects, which makes the electrolytic cell unable to continue normal production and must be overhauled. The essence of the electrolytic cell overhaul is to replace the lining. The cell lining materials eliminated during the replacement process include: waste cathode carbon blocks, waste refractory materials and anti-seepage materials. These discarded electrolyzer lining materials are also known as overhaul slag. Studies have shown that at present, for every ton of primary aluminum produced, an average of 20-30kg of aluminum electrolysis ...

AI Technical Summary

Problems solved by technology

[0004] 1) HCN is highly toxic, a small amount can cause poisoning and death in a few seconds (the lethal dose of HCN is 0.05 grams), and HCN can also be poisoned by entering the blood from skin abrasions or inhaling HCN through the respiratory tract

[0005] 2) It is harmful to the growth of animals and plants, causing animal bones / plant tissues to become black and necrotic;

[0006] 3) Affect the balance of agricultural ecology and reduce the yield of crops;

[0008] 5) After long-term storage and weathering, it is easy to form dust and pollute the atmosphere

However, because the electrolyte obtained by flotation also contains about 5% carbon, it is not suitable for use in electrolytic cells; and the carbon powder also contains more than 10% electrolyte, and the scope of use is also affected