A method for the production of manganese dioxide, in particular for electrochemical generators, and manganese dioxide produced by means of the method

摘要

1,199,309. Manganese dioxide. SOC. LES PILES WONDER. 21 Dec., 1967 [23 Dec., 1966], No. 58230/67. Heading C1A. Manganese dioxide (MnO 1 . 5 -MnO 2 ) is manufactured by adding a manganese salt solution to an aqueous alkali metal or ammonium hydroxide solution at between 15‹ and 30‹ C. whilst bubbling an oxidizing gas through the solution. The product may be treated with an acid to give manganese dioxide having a degree of oxidation up to MnO 1 . 95 . The manganese salt may be manganese sulphate; the alkali metal hydroxide may be sodium or potassium hydroxide and the oxidizing gas may be air or oxygen. As illustrated in Fig. 1 (not shown) the gas is admitted to the reactor through a base made of sintered glass, sintered metal or sintered porcelain, or a screen of an artificial or natural textile having a very fine mesh and a stirrer is provided. The acids used may be sulphuric, nitric or acetic.