Studying the Link between the Potential of a Metal-Oxide Anode, the Current Efficiency for Chlorate, and the Current Losses for the Oxygen and Chlorine Evolution in a Wide Range of the Chlorate Electrolysis Conditions

Abstract

Dependences of the current efficiency for chlorate and current losses for the oxygen evolution on the anode potential are studied. The study is performed in a cell without directed electrolyte circulation during the electrolysis of chloride–chlorate solutions of various compositions at the ORTA and ORTA-I1 anodes, at different current densities, temperatures, and solution pH. At identical temperatures, the dependences have extremums. The anode potentials corresponding to extremums coincide with critical potentials (found in a polarization study) for anodes covered with coatings containing ruthenium dioxide. The current efficiency for chlorate at ORTA-I1 is higher than that at ORTA, while the extremum region is less pronounced. The problem of how to substantially decrease the specific power consumption in the chlorate production by simultaneously increasing the anodic current density and the electrolysis temperature is considered.