Novel electrolytic bath for aluminum electrolysis and electrolysis technology thereof

Abstract

The invention discloses a novel electrolytic bath for aluminum electrolysis and an electrolysis technology thereof. A plurality of anodes and cathodes, which are perpendicular to the bottom of the bath, are parallelly arranged in the bath body, thus a multi-chamber electrolytic bath is formed, and the bath body contains some electrolyte. The electrolytic bath is characterized in that: the cathode is a composite of TiB2 and Al, and has the advantages of low cost, strong wet-ability to liquid aluminum, and no expanding and dropping off in a high-temperature electrolysis environment; the anode comprises following components: Fe, Cu, Ni, and Sn, wherein Fe and Cu is the main components, and the anode has the advantages of low overvoltage, high electric conductivity, low cost, strong oxidation resistant ability, and corrosion resistance; the low-temperature electrolyte is composed of following components in percentage by weight: 30 to 38 wt% of NaF, 49 to 60 wt% of AlF3, 1 to 5 wt% of LiF, 1 to 6 wt% of KF, and 3 to 6 wt% of Al2O3, wherein the mole ratio of NaF to AlF3 is 1.0 to 1.52. The multi-chamber electrolytic bath enlarges the area where electrodes carry out electrolysis reactions, so the yield can be increased by many times compared to that of an industrial single-chamber electrolytic bath if the two kinds of electrolytic baths have the same occupied area.

Description

Technical field [0001] The invention relates to a novel electrolytic cell for electrolytic aluminum and its electrolytic process, belonging to the non-ferrous metal smelting industry. Background technique [0002] Industrial electrolytic aluminum is usually electrolyzed by cryolite-alumina molten salt in a pre-baked carbon anode electrolyzer, that is, cryolite Na 3 AlF 6 The fluoride salt melt is used as a flux, and Al 2 O 3 Dissolve in cryolite, insert the carbon body as the anode vertically into the electrolytic cell, and use the carbon body covered with molten aluminum as the cathode at the bottom of the electrolytic cell. After applying a strong direct current, under the high temperature condition of 940-960℃, Electrochemical reactions are carried out at the two poles of the electrolytic cell, and the produced aluminum liquid product covers the cathode at the bottom of the electrolytic cell. However, the generally used carbon element cathode has poor wettability to the alumin...

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Problems solved by technology

[0008] The second technical problem to be solved by the present invention is that the alloy anode composed of metal components in the prior art has high overvoltage, the power consumption of the process is large, and the cost of the anode material used is high; in addition, the surface of the alloy anode in the prior art is oxidized The oxide film has low oxidation resistance and is easy to fall off, resulting in poor corrosion resistance of the alloy anode and being continuously consumed, and the corroded or fallen oxide film enters the liquid aluminum and reduces the purity of the final product aluminum; and then proposes a used The anode material has low overvoltage and low price, and the oxide film formed on the surface has strong oxidation resistance, strong stability, and electrolytic corrosion resistance. Electrolytic cell for electrolytic aluminum

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