7953 (TSO International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION+MEXAYHAPOAHAR OPIAHW3ALWR NO CTAHAAPTW3AUWU+ORGANISATION INTERNATIONALE DE NORMALISATION Manganese ores and concentrates - Determination of calcium and magnesium contents - Flame atomic absorption spectrometric method Minerais et concentrés de manganese - Dosages du calcium et du magnesium - Methode par spectrometrie d'absorption atomique dans la flamme First edition -- 1985-12-15 UDC 553.32 : 543.42 : 546.41 : 546.46 Ref. No. ISO 7953-1985 (E) Descriptors : minerals and ores, manganese ores, concentrates, chemical analysis, determination of content, calcium, magnesium, atomic absorption method. 3 Price based on 4 pages without license from IHS Not for Resale Foreword iSO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with sO, 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. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 7953 was prepared by Technical Committee ISO/TC 65, Manganese and chromium ores. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. International Organization for Standardization, 1985 Printed in Switzerland d without license from IHS Not for Resale INTERNATIONAL STANDARD ISO7953-1985 (E) Manganese ores and concentrates - Determination of calcium and magnesium contents - Flame atomic absorption spectrometric method Scope and field of application 1 NOTE - If a dinitrogen oxide flame is used for the determination of magnesium, the sensitivity is decreased by a factor of about 3. This International Standard specifies a flame atomic absorption spectrometric method for the determination of calcium and/or Reagents magnesium contents of manganese ores and concentrates. All standard solutions shall be stored in polythene bottles. The method is applicable to products having calcium contents from 0,01 to 15 % (m/m) and magnesium contents from 0,01 Any slight surface oxidation on the manganese and magnesium to 4 % (m/m). shaft be removed by rinsing in dilute hydrochloric acid, distilled water and acetone prior to drying and weighing. It should be read in conjunction with ISO 4297. 4.1 Hydrochloric acid, g 1,19 g/ml. References 2 4.2 Hydrochloric acid, dituted 1 + 1. Is0 4296/1, Manganese ores -- Sampling -- Part 1 : Increment 4.3 Hydrochloric acid, diluted 1 + 50. sampling. Is 4296/2, Manganese ores - Sampling - Part 2 : Prep- 4.4Nitric acid, g 1,40 g/ml. aration of samples. 4.5 Sulfuric acid, g 1,84 g/ml, diluted 1 + 1. Iso 4297, Manganese ores and concentrates - Methods of chemical analysis -- General instructions. 4.6 Hydrofluoric acid, Q 1,14 g/ml. 3 Principle 4.7 Fusion mixture, consisting of 3 parts by mass of potas- sium carbonate and 1 part by mass of boric acid. Decomposition of a test portion by treatment with hydrochloric and nitric acids. Filtration of any insoluble residue after 4.8 Background solution. evaporation and dehydration, the filtrate being reserved as the main solution. Dissolve 12,50 g of manganese [purity 99,95 % (m/m)], 1,25 g of iron [purity > 99,9 % (m/m)], 18,75 g of potassium carbo Ignition of the filter containing the'residue. Treatment with nate and 6,25 g of boric acid by adding 625 ml of hydroc