2367 (TSO NTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEKIYHAPOHA OPTAHH3ALIM IIO CTAHIAPTW3ALIHM.ORGANISATION INTERNATIONALE DE NORMALISATION Cryolite (natural and artificial) - Determination of aluminium content - 8-hydroxyquinoline gravimetric method First edition -- 1972-12-15 2367-1972 (E) UDC 661.8 : 553.634 : 546.621 : 543.21 Ref. No. ISO 2367-1972 (E) Descriptors : metalliferous minerals, aluminium ores, cryolite, chemical analysis, gravimetric analysis, determination of content, aluminium. Price based on 3 pages ISO FOREWORD ISO (the Internationat 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, governmentat 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 Councit. International Standard iSO 2367 was drawn up by Technical Committee ISO/TC 47, Chemistry. It was approved in November 1971 by the Member Bodies of the following countries : Austria Israe! Switzerland Belgium Italy Thailand Canada Netherlands Turkey Egypt, Arab Rep. of New Zealand United Kingdom France Portuga! U.S.S.R. Germany Romania Yugoslavia Hungary South Africa, Rep. of Ireland Spain The Bodies following countries expressed disapproval of the Member of the f document on technical grounds : India Poland @ International Organization for Standardization, 1972 Printed in Switzerland ISO 2367-1972 (E) INTERNATIONAL STANDARD Cryolite (natural and artificial) - Determination of aluminium content --- 8-hydroxyquinoline gravimetric method 5.5 Ammonia, p 0,97 g/ml approximately, 6,7 % (m/m) 1 SCOPE solution. This International Standard specifies a gravimetric method, using 8-hydroxyquinoline, for the determination of 5.6 Reducing buffer solution. aluminium content of natural and artificial cryolite. Dissolve 50 g of hydroxylammonium chloride and 50 g of ammonium chioride in a little water, add 50 mi of glacial 2 FIELD OF APPLICATION acetic acid, p approximately 1,05 g/ml, dilute to 1 000 ml and mix. The method can be applied to the determination of the aluminium present in natural and artificial cryolite, 5.7 Ammonium benzoate, 100 g/t solution. provided that the Fe203 content does not exceed 0,15 %. Dissolve 100 g of ammonium benzoate in tepid water, add NOTE - The method can also be applied to both natural and 0,001 g of thymol and, after cooling, dilute to 1 000 ml and artificial products with molar ratio of NaF to AiF3 between mix. approximately 3 and 1,7. 5.8 Ammonium benzoate, acetic acid wash solution. 3 REFERENCE Dilute 100 ml of the ammonium benzoate solution (5.7) ISO/R 1619, Cryolite (natural and artificial) -- Preparation with 900 ml of water, add 20 ml of glacial acetic acid, p approximately 1,05 g/mi, and mix. and storage of test samples. 5.9 Hydrochloric acid, approximatelyp 1,05 g/ml 4 PRINCIPLE approximately 10 % (m/m) solution. Solution of a test portion by acid fusion using potassium 5.10 Tartaric acid, 500 g/l solution. pyrosulphate and recovery by hydrochloric acid. Separation of interfering elements by precipitation of aluminium, with 5.11 Ammonia, p 0,90 g/ml approximately, 27,8 % (m/m) ammonium benzoate, in an acetic reducing medium. solution. Dissolution of the precipitate and reprecipitation of aluminium as aluminium tri(quinolin-8 oxide) in an acetic 5.12 Acetic acid, p 1,01 g/ml (1,7 N approximately). washing, drying of the buffer medium. Filtration, precipitate at a temperature of 130 °C and weighing. Dilute 100 mi of glacial acetic acid, p approximately 1,05 g/mi, with water, dilute t