Nickel, ferronickel and nickel alloys - Determination of sulphur content - Iodometric titration method after induction furnace combustion (ISO 7527:1985)

This International Standard specifies a titrimetric method after combustion for the determination of the Sulfur content of nicke1 and ferronickel in the range 0,001 to 0,3 % (mlm), and of nicke1 alloys in the range 0,002 to 0,l % (mlm). Examples of compositions are given in the annex.

Nickel, Ferronickel und Nickellegierung - Bestimmung des Schwefelgehaltes - Iodometrisches Titrationsverfahren nach Verbrennung im Induktionsofen (ISO 7527:1985)

Nickel, ferro-nickel et alliages de nickel - Dosage du soufre - Méthode par titration iodométrique après combustion dans un four à induction (ISO 7527:1985)

La présente Norme internationale spécifie une méthode titrimétrique après combustion, pour le dosage du soufre à des teneurs comprises entre 0,001 et 0,3 % (m/m) dans le nickel et le ferro-nickel et à des teneurs comprises entre 0,002 et 0,1 % (m/m) dans les alliages de nickel. Des exemples de composition sont donnés dans l'annexe.

Nikelj, feronikelj in nikljeve zlitine - Določevanje žvepla - Jodometrijska titracijska metoda po zgorevanju v indukcijski peči (ISO 7527:1985)

General Information

Status
Published
Publication Date
23-Sep-2009
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
14-Sep-2009
Due Date
19-Nov-2009
Completion Date
24-Sep-2009

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Nickel, Ferronickel und Nickellegierung - Bestimmung des Schwefelgehaltes - Iodometrisches Titrationsverfahren nach Verbrennung im Induktionsofen (ISO 7527:1985)Nickel, ferro-nickel et alliages de nickel - Dosage du soufre - Méthode par titration iodométrique après combustion dans un four à induction (ISO 7527:1985)Nickel, ferronickel and nickel alloys - Determination of sulphur content - Iodometric titration method after induction furnace combustion (ISO 7527:1985)77.120.40Nikelj, krom in njune zlitineNickel, chromium and their alloysICS:Ta slovenski standard je istoveten z:EN 27527:1991SIST EN 27527:2009en,de01-november-2009SIST EN 27527:2009SLOVENSKI

STANDARD
SIST EN 27527:2009
SIST EN 27527:2009
SIST EN 27527:2009

International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.MEIKflYHAPO,QHAR OPI-AHM3AL&lR fl0 CTAH~APTM3AL&WWORGANISATION INTERNATIONALE DE NORMALISATION Nickel, ferronickel and nicke1 alloys - Determination of Sulfur content - lodimetric titration method after induction furnace combustion Nickel, ferro-nicke1 et alliages de nicke/ - Dosage du soufre - AMhode par titrage iodomhtrique apr&s combustion dans un four 6 induc tion First edition - 1985-12-15 UDC 669.24 : 543.242.3 : 543.645 Ref. No. ISO 7527-1985 (E) Descriptors : nickel, nicke1 alloys, ferronickel, Chemical analysis, determination of content, sulphur, volumetric analysis. Price based on 7 pages SIST EN 27527:2009

Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standards bodies (ISO member bedies). The work of preparing International Standards is normally carried out through ISO technical committees. Esch member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental 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. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 7527 was prepared by Technical Committee ISO/TC 155, Nickel and nicke/ alloys. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its Jatest edition, unless otherwise stated. 0 International Organization for Standardization, 1985 Printed in Switzerland SIST EN 27527:2009

INTERNATIONAL STANDARD ISO 75274985 (E) Nickel, ferronickel and nicke1 alloys - Determination of Sulfur content - lodimetric titration method after induction furnace combustion 1 Scope and field of application This International Standard specifies a titrimetric method after combustion for the determination of the Sulfur content of nicke1 and ferronickel in the range 0,001 to 0,3 % (mlm), and of nicke1 alloys in the range 0,002 to 0,l % (mlm). Examples of compositions are given in the annex. 2 References ISO 38511, Laboratory glassware - Burettes - Part 7: General requiremen ts. ISO 648, Laboratory glassware - One-mark pipettes. I S 0 1042, Labora tot-y glassware - One-mark volume tric flasks. ISO 5725, Precision of test methods - Determination of repea tability and reproducibility b y in ter-labora tot-y tes ts. ISO 7525, Nickel - Determination of Sulfur content - Methylene blue molecular absorption spectrometric method a fter genera tion o f h ydrogen sulfide. 3 Principle Combustion of a test Portion in a flow of Oxygen at a high temperature in a high frequency induction furnace in the presence of fluxes and accelerators. Absorption of the Sulfur dioxide formed in an acidified starch- iodide Solution and continuous titration with potassium iodate Standard volumetric Solution. 4 Reagents and materials During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Oxygen (02), 99,5 % (mlm) minimum. 4.2 Ascarite or soda lime, 0,7 to 1,2 mm (14 to 22 mesh). 4.3 Magnesium perchlorate [Mg(ClO&l, 0,7 to 1,2 mm (14 to 22 mesh). 4.4 Glass-wool. 4.5 Crucibles and lids. 4.51 Ceramic crucibles shall be of precise dimensions so that the Sample is positioned correctly in the induction coil of the furnace (sec 9.1). 4.5.2 Pre-ignite the crucibles in air or Oxygen in a furnace for not less than 1 h at 1 100 OC and store in a desiccator or closed Container. A resistance furnace with a combustion tube through which a flow of Oxygen Passes may be used. Crucible lids, used to help retain the solid Oxidation products in the hot Zone, are pre-ignited in a similar manner. 4.6 Fluxes: Low Sulfur tin, topper plus tin, topper or vanadium pentoxide (sec 9.2). 4.7 Accelerators: Low Sulfur topper, iron, tungsten or nicke1 (see 9.2). 4.8 Nickel, low Sulfur of known val 4.9 Standard reference steel, con 0,2 % (mlm) Sulfur. ue [

ISO 7527-1985 (EI 7 Procedure 4.12 Potassium iodate, Standard volumetric solution. Dissolve exactly 0,222 5 g of potassium iodate in 900 ml of water containing 1 g of sodium hydroxide. Transfer to a 1 000 ml one-mark volumetric flask. Make up to the mark with water and mix. WARNING - The risks related to combustion analysis are mainly burns in pre-igniting the ceramic crucibles and in the fusions. Use crucible tongs at all times and suitable ~ Containers for the used crucibles. Normal precautions for handling Oxygen cylinders shall be taken. 1 ml of this Standard volumetric Solution is equivalent to 0,l mg S. 7.1 Determination 4.13 Potassium iodate, Standard volumetric Solution. 7.1.1 Weigh, to the nearest 0,001 g, 0,9 to 1 ,l g of the test Sample, and transfer to a pre-ignited crucible (4.5) containing a suitable amount of the preferred flux (4.6). Add the appropriate quantity of accelerator (4.7), if required. The flux and ac- celerator used will depend on the individual characteristics of the equipment and the type of material being analysed. Typical additions to a 1,O g test Portion are 2 g of topper, 1 g of topper plus 1 g of iron, 2 to 3 g of tungsten, or 1 g of vanadium pent- Oxide plus 1 g of iron powder. Place the crucible lid in Position. Transfer 200 ml of potassium iodate Solution (4.12) to a 1 000 ml one-mark volumetric flask. Make up to the mark with water and mix. 1 ml of this Standard volumetric Solution is equivalent to 0,02 mg S. NOTE - The Sulfur equivalents of 4.12 and 4.13 are based on the com- plete conversion . and recovery of Sulfur as Sulfur dioxide. Well- established Standards of known Sulfur content are used for Solution standardization. 7.1.2 Place the crucible and contents on the pedestal post of the furnace and, with Oxygen flowing, raise to the combustion Position. 7.1.3 Add 50 to 70 ml of hydrochloric acid (4.10) and 2 ml of starch-iodide Solution (4.11) to the absorption vessel. Add suf- ficient potassium iodate Solution (4.13) from a burette to obtain the intensity of the blue colour which will be taken as the end- Point of the final titration. Refill the burette to the zero mark. 5 Apparatus 5.1 The apparatus required for combustion in a high fre- quency induction furnace and titration of the evolved Sulfur dioxide may be obtained commercially from a number of manufacturers. Follow the manufacturer’s instructions for the Operation of the equipment (see 9.3). NOTE - For Sulfur contents stronger iodate Solution (4.12). higher than 0,02 % (mlm) use the 5.2 Burettes, of capacity 50 ml, graduated in divisions of 0,l ml ; and of capacity 10 ml, graduated in divisions of 0,02 ml, in accordance with ISO 385/1, class A. 7.1.4 Switch on the furnace and combust the Sample while passing Oxygen through the System. Titrate continuously with the potassium iodate Solution (4.13) to maintain the blue starch-iodine colour Chosen as the end-point. DO not allow the Solution to become colourless at any time during the titration because of possible loss of Sulfur dioxide. After the contents of the crucible have combusted completely, as shown by no further decrease of the blue colour, usually after about 5 min, turn off the power supply to the induction coil. 5.3 Pipettes, in accordance with ISO 648, class A. 5.4 Volumetric flasks, in accordance with ISO 1042, class A. 7.1.5 Note the volume of titrant added. 6 Sampling and samples 7.1.6 Repeat 7.1.1 to 7.1.5. 6.1 Sampling and preparation of the laboratory Sample shall be carried out by normal agreed procedures or, in case of dispute, by the relevant International Standard. 7.2 Blank test 7.2.1 Charge a pre-ignited crucible (4.5) with the quantity of flux and accelerator to be used in the determination (7.1) and add 1,00 g of pure nicke1 of known low Sulfur content (4.8). 6.2 The laboratory Sample normally is in the form of a powder, granules, millings or drillings and no further prep- aration of the Sample is necessary. 7.2.2 Proceed as directed in 7.1.2 to 7.1.5. 6.3 If it is suspected that the laboratory Sample taminated with oil or grease from the milling or drilling it shall be cleaned by washing with high purity acetone ing in air. is con- NOTES process, and dry- 1 The volume ‘of titrant corresponds to the blank flux, accelerator and Sulfur in the pure nickel. due to the crucible, 2 The blank should not exceed 0,001 % (mlm) Sulfur. 6.4 If the laboratory Sample contains particles or pieces of widely varying sizes, the test Portion should be obtained by riffling. 3 If the blank reading is abno the Source of contamination. lrmally high, investigate and eliminate 2 SIST EN 27527:2009

ISO 75274985 (E) 7.3 Calibration 7.3.1 Select a certified Standard ref
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