METHOD FOR PRODUCING POLYSULFIDE BY ELECTROLYTIC OXIDATION

摘要

It is an object of the present invention to produce a cooking liquor containing polysulfide sulfur at a high concentration from white liquor in a pulp production process with a high selectivity at a low electric power with very little production of thiosulfate ions as by-product. The present invention provides a method for producing polysulfides, which comprises introducing a solution containing sulfide ions into an anode compartment of an electrolytic cell comprising the anode compartment provided with a porous anode, a cathode compartment provided with a cathode and a diaphragm partitioning the anode compartment and the cathode compartment, for electrolytic oxidation to obtain polysulfide ions, wherein at least the surface of said anode is made of nickel, and the porous anode has a physically continuous three-dimensional network structure.