4293 International Standard (iso) INTERNATIONALORGANIZATION FOR STANDARDIZATIONMEXAYHAPOAHAA OPTAHM3ALMR O CTAHAAPTM3ALMMORGANISATION INTERNATIONALEDE NORMALISATION Manganese ores and concentrates -- Determination of phosphorus content - Extraction-molybdovanadate photometric method Minerais et concentres de manganese - Dosage du phosphore -- Methode photometrique au molybdovanadate avec extraction First edition - 1982-08-15 UDC 553.32 + 553.461 : 543.4 : 546.18 Ref. No. ISO 4293-1982 (E) 4293-1982 ( Descriptors : magnese ores, tests, determination of content, phosphorus, spectrophotometric analysis. Copyright International Organization for Standardization Price based on 3 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 4293 was developed by Technical Committee ISO/TC 65, Manganese and chromium ores, and was circulated to the member bodies in June 1981. It has been approved by the member bodies of the following countries : France Austria Romania Brazil India South Africa, Rep: of China Italy Spain Czechoslovakia Philippines United Kingdom Egypt, Arab Rep. of Poland USSR The member body of the following country expressed disapproval of the document on technical grounds : Germany, F.R. @ International Organization for Standardization, 1982 Printed in Switzeriand Copyright International Organization for Standardization Not for Resale INTERNATIONAL STANDARD ISO 4293-1982 (E) Manganese ores and concentrates -- Determination of phosphorus content -- Extraction-molybdovanadate photometric method 1 Scope and field of application acid and combination of the solution obtained with the main solution. Evaporation of the solution to fumes of perchloric This International Standard specifies an extractionmolyb- acid. Conversion of the phosphorus to phosphovanadomolyb- dovanadate photometric method for the determination of the date complex, phosphorus content of manganese ores and concentrates. Elimination of the interference by iron and arsenic by addition The method is applicable to products having phosphorus con- of citric acid. Extraction of the phosphovanadomolybdate into tents from 0,02 to 0,5 % (m/m). isobutyl methyl ketone with citric acid present to complex arsenic and iron. This International Standard should be read in conjunction with ISO 4297. Photometric measurement using a spectrophotometer or a photoelectric absorptiometer. 2 References 4 Reagents IsO 4296/1, Manganese ores -- Sampling - Part 1 : Incre- 4.1 Sodium carbonate, anhydrous. ment sampling.1) IsO 4296/2, Manganese ores - Sampling - Part 2 : Prepara- 4.2 2 Hydrochloric acid, g 1,19 g/ml. tion of samples.1) 4.3 Hydrochioric acid, diluted 1 + 1. Iso 4297, Manganese ores and concentrates -- Methods of chemical analysis - General instructions. 4.4 Hydrochloric acid, diluted 1 + 50. 3 Principle 4.5 Nitric acid, g 1,40 g/ml. Decomposition of a test portion by treatment with hydrochloric 4.6 Perchloric acid, @ 1,51 g/ml. and nitric acids. Separation of silicon by evaporation to fumes of perchloric acid. Dissolution of the salts in water, separation of the insoluble residue by filtration, the filtrate being reserved Sulphuric acid, diluted 1 + 1. 4.7 as the main solution. Hydrofluoric acid, 1,14 g/ml. Ignition of the filter with the residue and treatment with sulphuric and hydrofluoric acids. Fusion of the ignited residue 4.9 Ammonium vanadate (NH4VO3), 2,50 g/I solution. with sodium