ISO 12979 pdf download

ISO 12979 pdf download.Carbonaceous materials used in the production of aluminium — Pitch for electrodes — Determination of C/H ratio in the quinoline-insoluble fraction 1 Scope This International Standard describes a method for the determination of the atomic carbon/hydrogen ratio of quinoline-insoluble material isolated from coal-tar pitches. A procedure for the isolation of the quinoline-insoluble material in a form suitable for the analysis is described. NOTE The isolation procedure is not an alternative to ISO 6971 1 ) , which is to be used in all cases where the amount of quinoline-insoluble matter present in a pitch is to be determined. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes of openings . ISO 4788, Laboratory glassware — Graduated measuring cylinders. ISO 6257, Carbonaceous materials used in the production of aluminium — Pitch for electrodes — Sampling 3 Principle The quinoline-insoluble material is isolated from a finely divided sample of the coal-tar pitch by digestion with hot quinoline followed by pressure-filtration through a membrane filter. The isolated material is washed on the filter with hot quinoline then with hot toluene and dried. The carbon and hydrogen contents of the isolated quinoline-insoluble material are determined by combustion of a weighed aliquot portion of that material in a stream of oxygen and trapping and weighing the carbon dioxide and water which are formed. The atomic carbon/hydrogen ratio of the quinoline-insoluble material is calculated from its carbon and hydrogen contents and the relative atomic masses of carbon and hydrogen. 4 Isolation of quinoline-insoluble material for analysis 4.1 Reagents WARNING — Refer to the reagent supplier’s Health and Safety data sheets for the precautions which are to be taken for the safe use of quinoline and toluene. 4.1.1 Quinoline, of purity at least 97 %, freshly distilled, boiling between 235 °C and 237 °C at 0,1 01...