Large NaCl-effect on the Decomposition Rate of Chlorate Ions in HCl-containing Brine Solutions and Its Consequences for the Chlor-alkali Industry

The decomposition rate of chlorate (NaClO3) in aqueous solutions (brines) containing initially 6:1 mol/mol HCl:NaClO3 is studied at 90°C at various NaCl contents experimentally. A strong positive effect of NaCl addition is shown on the decomposition rate of chlorate. It is found more reasonable in the chlor-alkali industry first to saturate the brine by sodium chloride and only then to eliminate from it the chlorate by adding HCl (before the solution is transferred into the electrolysis cell to be protected from the chlorate ions).