Mercury outboard aluminum anodes

Mercury outlet aluminum anodes has the advantages of good effect, energy saving and reducing the pollution of waste liquid to the environment.

The corrosion of aluminum zinc mercury anode forms local cracks. The corrosion in this state has nothing to do with the distribution of mercury, and the distribution of mercury in the formed cracks is uniform Mercury is distributed in solid solution and aluminum, iron and mercury compounds Intermetallic compounds with high mercury content do not participate in the reaction Therefore, it is considered that the local occurrence of corrosion at the crack is due to the following autocatalytic activation mechanism That is, the steel structure and anode form an electric couple in seawater, and the dissolution of aluminum and mercury in the solid solution occurs under the action of the electric couple

Because the metal is protected by oxide layer, corrosion will occur locally at weak points and form corrosion pits According to the reaction of 3hg2 ~ (2 +) + Al → Al ~ (3 +) + 6hg In the previous stage, Hg2 ~ (+ 2) ions dissolved in the corrosive medium are re deposited on the anode Metal mercury was measured in active cracks by energy spectrum analysis The deposition of metal mercury on aluminum produces the subsidiary effect of local stripping oxide layer, which makes aluminum close to its theoretical potential (- 1900mv saturated calomel electrode) The corrosion will be confined to these areas with strong anode, and other Hg2 ~ (+ 2) ions will be released in the corrosion pit to make the reaction continue A new oxide layer is quickly covered on the bare metal, and the oxide layer should be removed continuously to maintain the activity of the anode The metal mercury produced by displacement reaction forms tiny droplets on the metal surface, and the re formed oxide layer after short-time activation separates the mercury from the metal At a certain time, as long as there is a small number of very small activation points (- 1575mv saturated calomel electrode) is enough to reduce the working potential of aluminum from - 710mv to - 1050mv