48519030032228 4280-77 5 H-0a-Ls INTERNATIONALSTANDARDISO4280-1977(E)/ERRATUM Iso Published1978-09-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION·MEKTYHAPOIHA OPIAHH3AUM O CTAHAAPTM3AIWM·ORGANISATIONINTERNATIONALEDENORMALISATION Cryolite, natural and artificial, and aluminium fluoride for industrial use - Determination of sulphate content--Bariumsulphategravimetricmethod ERRATUM Page 1 Clause 5, 1st line : Add "recognized"" after "of"" Page 2 Sub-clause 7.2.4, lines 12 and 13 : Replace "burning of the paper" by "igniting the paper and" COPYRIGHTInternationa Licensed by Infn 4280-77 4851903 0032229 7 S-YQ.-H NTERNATIONAL STANDARD TSO 4280 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEKIYHAPOIHAH OPFAHH3ALIH IIO CTAHIAPTH3ALIHHI.ORGANISATION INTERNATIONALE DE NORMALISATION Cryolite, natural and artificial, and aluminium fluoride for industrial use -- Determination of sulphate content - Barium sulphate gravimetric method Cryolithe, naturelle et artificielle, et fluorure d'aluminium a usage industriel -- Dosage des sulfates - Methodegravimetriquea I'étatde sulfatedebaryum First edition - 1977-11-15 UDC 661.8 : 553.634 + 661.862.362 : 546.226 : 543.21 Ref. No. 1SO 4280-1977 (E) 280-1977 Descriptors : aluminium ores, aluminium fluorides, cryolite, chemical analysis, determination of content, sulphates, gravimetric analysis. CoPYRIGHTInternational icensedby'Information'HandlingServices 22-092h E06TS 0032230 3 FOREWORD IsO (the International Organization for Standardization) is a worldwide federation of nationaf 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 to the member bodies for approval before their acceptance as International Standards by the Iso Council. International Standard IsO 4280 was developed byTechnical Committee ISO/TC 47, Chemistry, and was circulated to the member bodies in March 1975. it has been approved by the member bodies of the following countries : Austria India Sweden Belgium Israel Switzerland Brazil Italy Thailand Bulgaria Mexico Turkey Egypt, Arab Rep. of Poland United Kingdom France Romania U.S.A. Germany South Africa, Rep. of U.S.S.R. Hungary Spain No member body expressed disapproval of the document. ? InternationalOrganizationforStandardization,1977 Organization for Standardization onal