METHOD FOR OBTAINING MAGNESIUM AND CHLORINE AND ELECTROLYZER FOR ITS IMPLEMENTATION Russian patent published in 2021 - IPC C25C3/04 

FIELD: chemistry.

SUBSTANCE: invention relates to the production of magnesium and chlorine by electrolyze from a salt melt containing magnesium chloride. A task solved by inventions is to reduce specific power consumption due to an increase in current output, reduce chlorine losses with plumbing suction gases, and increase the service life of an electrolyzer. A method is proposed for the production of magnesium and chlorine from the salt melt containing MgCl₂ using a non-diaphragm electrolyzer, including closed electrolyte circulation between an electrolyze chamber and a cell for magnesium separation due to gas filling of the electrolyte with chlorine bubbles in an inter-electrode gap equal to 6÷25, determined according to the formula:

where П is gas filling of the electrolyte with chlorine bubbles in the inter-electrode gap, A/cm²; d_k is cathode current density, A/cm²; H_k is cathode height, cm; l_av is average inter-electrode distance, cm, different in that current (kA) and electrolyte weight are set in such quantitative expression that their ratio is equal to 8-10, and an electrolyte flow from the electrolyze chamber enters the cell for magnesium separation along two directions: through upper circulation channels and additional channels located between upper and lower circulation channels, wherein the electrolyte flow speed in upper circulation channels of V shape is selected from the condition:

,

where S_u.ch. is the total area of upper circulation channels; S_ad.ch. is the total area of additional channels; and the non-diaphragm electrolyzer for the implementation of the above-mentioned method includes an electrolyze chamber with alternative anodes and cathodes, a cell for magnesium separation separated from the electrolyze chamber with a partition with upper V-shaped and lower circulation channels, different in that a ratio of the electrolyze chamber width to the width of the cell for magnesium separation is equal to 1.6÷2.7, in the partition, between upper V-shaped and lower channels, additional channels are installed, the area of passage section of which is 0.016÷0.048 from the area of upper V-shaped channels, additional channels in the partition are made of melted-casted mica crystal material – fluorophlogopite. In a new method, specific power consumption is reduced due to an increase in current output, and chlorine losses with plumbing suction gases are reduced. On a new electrolyzer, the service life of the electrolyzer is increased, chlorine losses with plumbing suction gases are reduced.

EFFECT: reduction in specific power consumption due to an improvement of conditions of magnesium separation in an assembly cell and, consequently, an increase in magnesium current output, increase in the electrolyzer efficiency, reduction in chlorine losses with plumbing suction gases, and increase in the service life of the electrolyzer.

2 cl, 3 dwg