WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
28.20 - Manganese oxides. 2820.10 2820.90 - Manganese dioxide - Other (1) Manganese dioxide (manganous anhydride) (MnOz). The most important manganese oxide. Prepared by the action of a slightly nitric solution of potassium permanganate on a manganous salt e.g., the sulphate). Brown or blackish masses or powder (specific gravity about 5), insolub e in water. \ A ve powerfid oxidising agent. Uses include pyrotechnics, organic synthesis (preparation of hy oxyanthraquinones, aminoanthraquinones, etc.), in gas-masks, as a depolmsing agent in batteries, in the ceramics indus , in the manufacture of driers, printers' mk (manganese black), colours (brown pigments%own as mineral bistre, manganese bitumen), certain mastics, and synthetic semi-precious stones (artificial garnet). It is also used in the glass industry (glassmakers' soap) generally to correct the yellow tint of glass. 7r This oxide has the character of an anhydride from which the manganites of heading 28.41 are derived. This heading does not include the anhydrous natural manganese dioxide (pyrolusite) and hydrated natural manganese dioxide (psilomelane) (heading 26.02). (2) Manganese oxide (MnO). Greyish or greenish powder, insoluble in water. Specific gravity about 5.1. Used in textile printing. Manganous hydroxide is excluded (heading 28.25). (3) Diman anese trioxide basic. rown or include : in textile driers (manganese acid) or organic. % , the manufacture of of nitric The heading does not include natural manganic oxide (braunite - heading 26.02), nor manganic hydroxide (heading 28.25). (4) Manganomanganic oxide (manganese saline oxide) (Mn304).Resembles saline iron oxide in some respects. Natural saline oxide of manganese (hausmannite) is excluded (heading 26.02). (5) Permanganic anhydride (Mn207). Dark brown liquid which absorbs moisture and detonates towards 40 "C. This anhydride gives the pamanganates of heading 28.41. Permanganic acid is excluded (heading 28.25).
1.- Except where the context otherwise requires, the headings of this Chapter apply only to : (a) Separate chemical elements and separate chemically defined compounds, whether or not containing impurities; (b) The products mentioned in (a) above dissolved in water; (c) The products mentioned in (a) above dissolved in other solvents provided that the solution constitutes a normal and necessary method of putting up these products adopted solely for reasons of safety or for transport and that the solvent does not render the product particularly suitable for specific use rather than for general use; (d) The products mentioned in (a), (b) or (c) above with an added stabiliser (including an anti-caking agent) necessary for their preservation or transport; (e) The products mentioned in (a), (b), (c) or (d) above with an added anti-dusting agent or a colouring substance added to facilitate their identification or for safety reasons, provided that the additions do not render the product particularly suitable for specific use rather than for general use.