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  • ISO 4277:1977

    Withdrawn A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.

    Cryolite, natural and artificial Conventional test for evaluation of free fluorides content

    Available format(s):  Hardcopy, PDF, PDF 3 Users, PDF 5 Users, PDF 9 Users

    Withdrawn date:  16-02-2019

    Language(s):  English, French

    Published date:  01-11-1977

    Publisher:  International Organization for Standardization

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    Abstract - (Show below) - (Hide below)

    Applicable to products having contents of AlF3 of more than 0.15 % (m/m) or of NaF of more than 0.4 % (m/m). Covers sintering of a test portion with a known quantity of sodium fluoride in a muffle furnace at a temperature of (790 10) C. Under these conditions, aluminium fluoride in excess of that required by the stoichiometric formula AlF3 .3NaF reacts to form cryolite; extraction of the ground sintered mass with boiling water. Acidification with hydrochloric acid solution to a pH less than 3.7 and titration of the excess sodium fluoride with thorium nitrate solution in the presence of alizarin-S as indicator. Has also been approved by the IUPAC.

    General Product Information - (Show below) - (Hide below)

    Document Type Standard
    Publisher International Organization for Standardization
    Status Withdrawn

    Standards Referenced By This Book - (Show below) - (Hide below)

    BS 4993-5:1980 Methods of test for aluminium fluoride for industrial use Determination of moisture content (Karl Fischer method)
    BS 4993-9:1980 Methods of test for aluminium fluoride for industrial use Determination of sulphur content (X-ray fluorescence spectrometric method)
    BS 5050-11(1980) : 1980 METHODS OF TEST FOR CRYOLITE - DETERMINATION OF SULPHATE CONTENT
    BS 5050-9(1980) : 1980 METHODS OF TEST FOR CRYOLITE - DETERMINATION OF MOISTURE CONTENT (KARL FISHER METHOD)
    ISO/TR 4277:2009 Cryolite, natural and artificial Conventional test for evaluation of free fluorides content
    BS 4993-8:1980 Methods of test for aluminium fluoride for industrial use Determination of sulphate content
    BS 5050-13(1983) : 1983 METHODS OF TEST FOR CRYOLITE - DETERMINATION OF PHOSPHORUS CONTENT
    BS 5050-10(1980) : 1980 METHODS OF TEST FOR CRYOLITE - DETERMINATION OF MOISTURE CONTENT (GRAVIMETRIC METHOD)
    BS 5050-12(1980) : 1980 METHODS OF TEST FOR CRYOLITE - DETERMINATION OF SULFUR CONTENT (X-RAY FLUORESCENCE SPECTROMETRIC METHOD)
    BS 4993-10:1983 Methods of test for aluminium fluoride for industrial use Determination of phosphorus content
    PD ISO/TR 4277:2009 Cryolite, natural and artificial. Conventional test for evaluation of free fluorides content
    BS 4993-6:1980 Methods of test for aluminium fluoride for industrial use Determination of moisture content (gravimetric method)
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