Patent ID: 7214296

Claim:
An anode for chlorine evolution in a mercury cathode chlor-alkali electrolytic cell comprising a current-distributing frame and a grid array of titanium or titanium alloy or other valve metal or valve metal alloy comprising a multiplicity of generally parallel blades fixed to a multiplicity of supporting elements, the blades having a thickness between 0.2 and 1.0 millimeters and a height of 8 to 20 millimeters, the distance between one blade and the next being between 1.5 and to 2.5 millimeters wherein at least the main vertical surfaces of the blades are provided with an electrocatalytic coating for chloride evolution and wherein the surfaces facing the mercury cathode of the terminal longitudinal parts of the blades are mechanically machined to define a plane having a tolerance not higher than 0.2 millimeters.