NTERNATIONAL STANDARD (ISO) 4159 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAH OPFAHM3AUMA HO CTAHAAPTW3AUMW-ORGANISATION INTERNATIONALE DE NORMALISATION Ferromanganese and ferrosilicomanganese -- Determination of manganese content - Potentiometric method Ferro-manganese et ferro-silico-manganese - Dosage du manganese - Méthode potentiométrique First edition -- 1978-12-15 (3) 8L Ref. No. ISO 4159-1978 (E) UDC 669.15-198 : 543.257.1 : 546.711 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 International Standards is carried out through ISO technical committees. Every member 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 Standards by the ISO Council. Internationa! Standard 1sO 4159 was developed by Technical Committee ISO/TC 132, Ferroalloys, and was circuiated to the member bodies in October 1977. It has been approved by the member bodies of the foilowing countries : Iran South Africa, Rep. of Australia Itaty Austria Spain Butgaria Sweden Japan Canada Korea, Rep. of Turkey United Kingdom Czechoslovakia Mexico Norway France U.S.A. Germany, F.R. Philippines U.S.S.R. India Romania Yugoslavia The member body of the following country expressed disapprova! of the document on technical grounds : Poland @ internationat Organization for Standardization,1978 Printed in Switzerland Copyright International Organization for Standardization from IHS 1SO 4159-1978 (E) INTERNATIONAL STANDARD Ferromanganese and ferrosilicomanganese -- Determination of manganese content --- Potentiometric method 1 SCOPE AND FIELD OF APPLICATION 4.5 Hydrochloric acid, p 1,19 g/ml, diluted 1 + 4. This International Standard specifies a potentiometric method for the determination of the manganese content of 4.6 Sodium pyrophosphate, saturated solution. ferromanganese and ferrosilicomanganese. Dissolve 145 g of sodium pyrophosphate (P20,Na4.10H20) The method is applicable to alloys containing from 55 in a 2 litre conical flask, with about 1 litre of hot water; to 95 % (m/m) of manganese. heat without exceeding, even locally, the temperature 2 REFERENCE Prepare this solution at the time of use. IsO 3713, Ferroalloys - Sampling and preparation of samples -- General rules. 1) 4.7 Potassium permanganate, recrystallized. Place 50 g of pure anatytical grade potassium permanganate 3 PRINCIPLE in the conical flask (5.1), and dissolve it in 200 ml of warm distilled water (70 to 80 °C). Dissolution of a test portion with hydrochloric,hydro- fluoric and perchloric acids. Fit the reflux condenser (5.2) to the flask and boil the Potentiometric determination (see note) of manganese with solution for 20 min. Fiter the warm solution quickly under potassium permanganate in a pyrophosphoric medium at a vacuum through a sintered glass funnel (5.3). controlled pH, according to the reaction : Cool the filtrate in iced water, stirring vigorously, and 4 Mn2+ + MnO4- + 8 H+ + 15 (P20,H2)2 allow the fine, crystalline precipitate to settle for 10 min. →5 Mn(P20,H2)33- + 4 H20 Decant the solution; then, using a glass spatula, transfer the crystalline mass into a funnel with a filter piate, porosity 4, NOTE - The method may be completed by any other electrometric and place under suction for a few minutes to remove most method : amperometric titration, dead-stop, etc. of the mother liquor. Dissolve the crystalline mass in 160 ml of distilled water 4 REAGENTS (deionized water is not permitted for this phase), and repeat the recrystallization. During the analysis, use only reagents of recognized ana- lytical grade, and only distilled water or water of equivalent After filtering