5890 (OSI) International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAH OPTAHM3AUMA IO CTAHAAPTW3AMW+ORGANISATION INTERNATIONALE DE NO RMALISATION Manganese ores and concentrates - Determination of silicon content -- Gravimetric method Minerais et concentres de manganese - Dosage du silicium - Methode gravimetrique First edition - 1981-05-15 UDC 553.32 : 543.21 : 546.28 Ref. No. ISO 5890-1981 (E) ISO 5890-1981 (E) Descriptors : chemical analysis, determination of content, silicon, gravimetric analysis. Price based on 2 pages Not for Resale Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards institutes (ISO member bodies). The work of developing Inter- body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with isO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council International Standard ISO 5890 was developed by Technical Committee ISO/TC 65, Manganese and chromium ores, and was circulated to the member bodies in February 1980. It has been approved by the member bodies of the following countries : Australia Germany, F.R. Romania Hungary Austria South Africa, Rep. of China india United Kingdom Czechoslovakia Italy USSR Egypt, Arab Rep. of Korea, Dem. P. Rep. of Poland France No member body expressed disapproval of the document. @International Organization for Standardization,1981 Printed in Switzerland d without license from IHS Not for Resale INTERNATIONAL STANDARD ISO 5890-1981 (E) Manganese ores and concentrates - Determination of silicon content Gravimetric method 4.7 Hydrofluoric acid, g 1,14 g/ml. Scope and field of application 1 This International Standard specifies a gravimetric method for 4.8 Perchloric acid, g 1,51 g/ml. the determination of the silicon content of manganese ores and concentrates. 4.9 Hydrogen peroxide, 30 g/l solution. The method is applicable to products having a silicon content greater than 0,5 % (m/ m) and a fluorine content not more than 5 Apparatus 0,1 % (m/m). This International Standard should be read in conjunction with Ordinary laboratory apparatus and ISO 4297. 5.1 Muffle furnace, capable of being controlled at a temperature between 1 000 and 1 100 °C. 2 Reference Iso 4297, Manganese ores and concentrates -- Methods of 5.2 2 Platinum crucibles. chemical analysis - General instructions. 3 Principle 6 Procedure Decomposition of a test portion by treatment with 6.1 Test portion hydrochloric, nitric and perchloric acids. Filtration of the residue containing the silicon and reservation of the filtrate as Weigh a mass of the test sample, chosen from table 1 in accor- the main solution. Ignition of the filter paper with the residue. dance with the expected silicon content. Fusion of the residue with sodium carbonate; leaching of the melt with hydrochloric acid and combination with the main Table 1 solution. Expected silicon content Mass of test portion Separation of the silica by evaporation of the solution with per- % (m/m) g chloric acid and weighing of the silica with impurities. From 0,5 to 2 2,0 Volatilization of the silica with hydrofluoric and sulphuric acids, From 2 to 10 1,0 weighing of the residue and calculation of the silica content by the difference in mass. From 10 to 20 0,5 4 Reagents 6.2 Decomposition of test portion 4.1 Sodium carbonate, anhydrous. Place the test portion (6.1) in a 250 or 300 ml beaker, moisten with a few drops of water, add 15 to 30 ml of the hydrochloric acid (4.4) and heat gently to decompose the ore. Add 2 to 3 ml 4.2 Nitric acid, @ 1,40 g/ml. of the nitric acid (4.2), heat until nitrous fumes cease to be evolved, and allow to cool. Add 10 ml of the perchloric acid 4.3