Operating chlor-alkali cell by adding inorganic particulate material and polyphosphate

摘要

A method of operating a chlor-alkali electrolytic cell comprising a catholyte compartment containing a cathode, an anolyte compartment containing an anode, and a liquid-permeable diaphragm partitioning the catholyte and anolyte compartments comprises adding water-insoluble inorganic particulate material, e.g., clay mineral, and alkali metal polyphosphate, e.g., tetrasodium pyrophosphate, to the anolyte compartment of the electrolytic cell while the cell is operating. The water-insoluble inorganic particulate material and alkali metal polyphosphate may be added to the anolyte compartment in the form of an aqueous slurry. The diaphragm may be formed of fibrous synthetic polymeric material coated with at least one oxide or silicate of a valve metal, optionally a day mineral, and optionally a hydrous oxide of Zr or Mg.