2367 NTERNATIONAL STANDARD (TSO) INTERNATIONAL ORGANIZATION FOR STANDARDIZATION -MEKAYHAPOJHA OPTAHH3ALIH IIO CTAHIAPTH3ALIMH·ORGANISATION INTERNATIONALE DE NORMALISATION Cryolite (natural and artificial) -- Determination of aluminium content - 8-hydroxyquinoline gravimetric method First edition-1972-12-15 2367-1972 (E) UDC661.8:553.634:546.621:543.21 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 OSI 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, 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 Council. International StandardiSO 2367wasdrawnupbyTechnical Committee ISO/TC 47,Chemistry. It was approved in November 1971 by the Member Bodies of the following countries : Austria Israel Switzerland Belgium Italy Thailand Canada Netherlands Turkey Egypt, Arab Rep. of New Zealand United Kingdom France Portugal U.S.S.R. Germany Romania Yugoslavia Hungary South Africa, Rep. of Ireland Spain Member Bodies the following The of countries expressed disapproval of the document on technical grounds : India Poland International Organization for Standardization,1972 Printed in Switzerland ISO 2367-1972 (E) INTERNATIONALSTANDARD Cryolite (natural and artificial) - Determination of aluminium content -- 8-hydroxyquinoline gravimetric method 1 SCOPE 5.5 Ammonia,p0,97g/mlapproximately,6,7%(m/m) solution. This International Standard specifies a gravimetric method using 8-hydroxyquinoline, for the determination 5.6 Reducingbuffer 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 ml of glacial FIELDOFAPPLICATION acetic acid, p approximately 1,05 g/ml, dilute to 1000m! 2 and mix. The method can be applied to the determination of the aluminiumpresent in natural and artificial cryolite, 5.7Ammoniumbenzoate,100g/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. 3REFERENCE Dilute 100 ml of the ammonium benzoate solution (5.7) ISO/R1619,Cryolite(natural andartificial)--Preparation with 900 ml of water, add 20 ml of glacial acetic acid, p andstorageoftestsamples. approximately 1,05 g/ml, and mix. 5.9 Hydrochloric acid, approximately 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 5.11Ammonia,p0,90g/mlapproximately,27,8% (m/m) ammoniumbenzoate,inan acetic reducing medium solution. Dissolution of the precipitate and reprecipitation of aluminium as aluminium tri(quinolin-8 oxide) in an acetic 5.12Acetic acid,p 1,01 g/ml (1,7 N approximately) buffer medium. Filtration, washing, drying the precipitate at a temperature of 130 c and weighing. Dilute 100mi of glacial acetic acid, p approximately 1,05 g/ml, with water, dilute to 1 000 ml and mix. 5REAGENTS 5.13 8-hydroxyquinoline (quinolin-8-ol), 20 g/l