초록 ▼

This invention relates to a process of producing lithium metal by the electrolysis of fused mixed salts comprising electrolyzing fused mixed salts consisting of lithium chloride and potassium chloride in a diaphragmless electrolytic cell, withdrawing molten lithium metal from the cell to a receiver

This invention relates to a process of producing lithium metal by the electrolysis of fused mixed salts comprising electrolyzing fused mixed salts consisting of lithium chloride and potassium chloride in a diaphragmless electrolytic cell, withdrawing molten lithium metal from the cell to a receiver and cooling the lithium metal which has been withdrawn. To decrease the content of impurities in a continuous process, molten mixture which rises in the interelectrode space in the cell and contains lithium metal is collected in an annular zone, which surrounds the top end of the cathode adjacent to the surface level of the molten mixture, said molten mixture is withdrawn from said annular zone through a siphon pipe and is supplied from the latter to a separating chamber, which communicates with the electrolytic cell and is sealed from the chlorine gas atmosphere in the electrolytic cell, electrolyte and lithium are separated in the separating chamber under a protective gas atmosphere, lithium metal is discharged from the separating chamber into a receiver under a protective gas atmosphere, and the electrolyte is recycled from the separating chamber to the electrolytic cell. An electrolytic cell for carrying out the process is also described.

대표청구항 ▼

A method of producing lithium metal comprising the steps of: providing a ceramically unlined electrolysis cell having an upright tubular cathode separated from an anode centrally disposed within said cathode by an annular interelectrode space terminating at an upper end of said cathode in an annular

A method of producing lithium metal comprising the steps of: providing a ceramically unlined electrolysis cell having an upright tubular cathode separated from an anode centrally disposed within said cathode by an annular interelectrode space terminating at an upper end of said cathode in an annular trough for collecting a mixture of electrolyte and lithium metal, and an enclosure for said cathode forming an electrolyte space communicating with said interelectrode space near a bottom portion thereof and forming a compartment above said trough and said interelectrode space containing a chlorine gas atmosphere; introducing an electrolyte of fused lithium chloride and potassium chloride into said enclosure so that said electrolyte passes into said interelectrode space; electrolyzing said electrolyte in said cell to form a molten mixture of lithium metal and electrolyte rising in said interelectrode space and passing into said trough; withdrawing said mixture from said trough downwardly through a siphon pipe and supplying the withdrawn molten mixture to a separating chamber in said enclosure upwardly by mechanically displacing said molten member upwardly from an upwardly open end of said siphon pipe communicating with said separating chamber, said separating chamber being sealed off from the chlorine gas atmosphere in said enclosure; separating said molten mixture in said separating chamber into lithium metal and electrolyte while maintaining a protective gas mixture above the lithium metal in said chamber; discharging the separated lithium metal from said separating chamber; and discharging separated electrolyte from said separating chamber into said enclosure for recycling to said cell.