SU66409A1 - Method for electrolytic production of chlorine and alkali - Google Patents

Description

Chlorine production is currently conducted by an electrolytic method - by electrolysis of sodium chloride, with iron or mercury at the cathode and platinum, magnetite or graphite at the anode being used as electrodes. Due to its high cost, platinum and magnetite, due to their low electrical conductivity and low mechanical strength, are not used in new advanced electrolyzers, where graphite electrodes have monopolized chlorine electrolysis.

In the process of electrolysis, the discharge of C1 and (OH) ions occurs at the anode.

2C1 + 2F 2Cl2

4 (OH) + 4F - 2H2O + Og

The oxygen released by the discharge of ions (OH) oxidizes the carbon of the graphite electrode to CO2, with the result that the chlorine gas is contaminated and the anode gradually deteriorates. In order to avoid wear of the graphite anodes, the latter are impregnated with flax oil and then chlorinated first in a cold and then in a hot form. However, despite this, in the anode product, chlorine gas, along with chlorine, in normal operation of electrolyzers, contains 1-2% of CO2 (carbon dioxide).

It is proposed to use carborundum instead of graphite anodes, "which are prepared by heating carbon electrodes, poured with quartz sand with a slight addition of coal, in a resistance furnace for 36 hours.

The electrodes obtained after carborundum have a solid continuous layer of carborundum up to 2.5 mm thick on the surface.

Such anodes were tested in experienced electrolyzers with both vertical and horizontal diaphragms. As a result of a series of experiments performed in the range of anodic current densities from 500 to 2000 a / w, the presence of carbon dioxide was not detected in the resulting anode gas.

Subject invention

A method for the electrolytic production of chlorine, characterized in that carborundum or surface-carborundum carbon electrodes are used as anodes, due to which chlorine without CO2 impurity can be obtained.