Method for removing lithium from lithium-contained electrolyte in Hull cell

Abstract

The invention relates to a separation process of a nonferrous metal, in particular to a method for removing lithium from a lithium-contained electrolyte in a Hull cell. The method is characterized inthat the electrolyte in the Hull cell is transferred to a delithium molten salt electrolyzer to be subjected to electrolysis, wherein the cathode of the delithium molten salt electrolyzer is a graphite cathode, so that lithium ions in an electrolyte melt are inlaid in the graphite cathode preferentially, and then removing of lithium in the electrolyte is conducted. According to the method, the lithium ions in the electrolyze melt can be selectively inlaid in the graphite cathode, when the content of the lithium in the cathode meets the requirement, the cathode which is subjected to lithium removing and full of the lithium serves as an electrolytic anode of magnesium chloride fused salt in an another magnesium chloride fused salt electrolyzer, the lithium in the graphite anode can enter themagnesium chloride fused salt and magnesium metal in the electrolysis process of the magnesium chloride fused salt, the lithium entering the magnesium electrolyzed fused salt can improve the electrical conductivity of the electrolyte, and the lithium-contained magnesium metal obtained through electrolysis can be used for preparing a magnesium lithium alloy. The method can reduce the lithium content of the lithium-contained electrolyte in the Hull cell, and provide conditions for effective utilization of the lithium.

Description

technical field [0001] The invention discloses a method for removing lithium in a Hall cell lithium-containing electrolyte, relating to a non-ferrous metal separation process, in particular a method for removing lithium in a Hall cell lithium-containing electrolyte. Background technique [0002] In recent years, due to resource reasons, the lithium content in some domestic alumina has increased. After the electrolytic cell has used this alumina for a long time for electrolytic production, the lithium salt content in the electrolyte has increased significantly, resulting in low electrolysis temperature, more precipitation on the bottom of the furnace, and If it is empty, the stability of the electrolytic cell is poor, the current efficiency is reduced, the energy consumption is high, and even the phenomenon of rolling aluminum occurs. About half of the electrolytic aluminum enterprises in Henan, Shanxi, Shaanxi, Gansu, Qinghai, and Inner Mongolia have encountered similar prob...

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Problems solved by technology

[0003] The influence of lithium fluoride on the electrolyte has two main aspects. On the one hand, it improves the conductivity, which is beneficial to energy saving. However, the disadvantage is that the concentration of lithium fluoride is too high, which significantly reduces the primary crystal temperature of the electrolyte.

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