EN 27520:1991

Ferronickel - Determination of cobalt content - Flame atomic absorption spectrometric method (ISO 7520:1985)

Applies to cobalt contents in the range 0,025 to 2,5 % (m/m). Specifies principle, reagents, apparatus, sampling and samples, procedure, expression on results, special cases and test report.

Ferronickel - Bestimmung des Cobaltgehaltes - Atomabsorptions-Spektralfotometrisches Verfahren (ISO 7520:1985)

Ferro-nickel - Dosage du cobalt - Méthode par spectrométrie d'absorption atomique dans la flamme (ISO 7520:1985)

La présente Norme internationale spécifie une méthode de dosage du cobalt par spectrométrie d'absorption atomique dans la flamme dans les ferro-nickels dont la teneur en cobalt est comprise entre 0,025 et 2,5 % (m/m).

Feronikelj - Določevanje kobalta - Plamenska atomska absorpcijska spektrometrična metoda (ISO 7520:1985)

General Information

• Status: Published
• Publication Date: 05-Nov-1991
• Withdrawal Date: 05-May-1992
• ICS: 77.100 - Ferroalloys
• Technical Committee: CEN/SS M14 - Nickel
• Drafting Committee: CEN/SS M14 - Nickel
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 13-Oct-1999
• Completion Date: 13-Oct-1999
• Ref Project: SIST EN 27520:2009 - Ferronickel - Determination of cobalt content - Flame atomic absorption spectrometric method (ISO 7520:1985)

Overview

EN 27520:1991 specifies a standardized method for the determination of cobalt content in ferronickel using flame atomic absorption spectrometry (AAS), based on ISO 7520:1985. This method applies to cobalt concentrations ranging from 0.025% to 2.5% by mass. It provides a detailed procedure including reagents, apparatus, sampling, sample preparation, and calculation of results. EN 27520:1991 facilitates precise and reproducible chemical analysis critical for quality control in nickel alloy production.

Key Topics

• Scope and Range
  The standard covers ferronickel samples with cobalt content between 0.025% and 2.5% (m/m).

• Analytical Principle
  Cobalt is measured using flame atomic absorption spectrometry at a wavelength of 240.7 nm with an air-acetylene flame. Samples are dissolved using a nitric acid-hydrochloric acid mixture, with silica removed by perchloric acid treatment and filtration. Lanthanum solution is added to eliminate interference effects for accurate measurement.

• Reagents and Solutions
  Utilizes high-purity chemicals such as nitric acid, hydrochloric acid, perchloric acid, hydrofluoric acid, and lanthanum chloride. Standard cobalt solutions and nickel plus iron matrix solutions are prepared to calibrate the spectrometer.

• Sample Preparation and Sampling
  Samples are typically millings, drillings, or granules requiring no further preparation, though cleaning is prescribed if contamination by oil or grease is suspected. The test portion size is typically around 4 grams.

• Apparatus Requirements
  Includes an atomic absorption spectrometer equipped with a cobalt hollow cathode lamp, standard laboratory glassware per ISO specifications, and PTFE beakers for high silicon samples.

• Calibration and Measurement
  Calibration curves are established from standard solutions prepared with nickel-iron matrix. Measurement involves aspirating test solutions, blanks, and calibration standards into the flame to record absorbance. Calibration graphs ensure results fall within linear response ranges.

• Calculation and Expression of Results
  Cobalt content is calculated from absorbance readings using a formula accounting for dilution factors, blank corrections, and sample mass. Results are expressed as a mass percentage, providing essential data for metallurgical quality assurance.

• Precision and Repeatability
  Interlaboratory testing confirmed the method’s reliability, showing consistent repeatability and reproducibility across cobalt concentration ranges typical of ferronickel.

• Safety Notes
  Handling of hazardous reagents like hydrofluoric acid and perchloric acid requires caution and use of proper fume hoods due to their corrosive and oxidizing properties.

Applications

• Quality Control in Ferroalloy Production
  Ensures consistent cobalt levels in ferronickel alloys, critical for performance in stainless steel and specialty alloys.

• Chemical Analysis Laboratories
  Provides a validated procedure for routine cobalt testing in ferronickel samples, enabling traceability and comparability of results worldwide.

• Regulatory Compliance
  Supports compliance with material specifications requiring precise cobalt quantification, aiding in certification and quality assurance processes.

• Research and Development
  Used in metallurgical research to characterize alloy compositions and optimize manufacturing processes involving ferronickel.

Related Standards

• ISO 7520:1985
  The international standard upon which EN 27520:1991 is based, specifying the cobalt determination method in ferronickel.

• ISO 385/1, ISO 648, ISO 1042
  Standards covering laboratory glassware essential for accurate volumetric measurements in the analytical process.

• ISO 5725
  Defines the precision and repeatability requirements for chemical test methods, relevant for method validation and quality control.

• ISO 6352
  Details determination of nickel content in ferronickel by gravimetric method, often performed in conjunction with cobalt analysis.

---

By following EN 27520:1991, laboratories can ensure accurate, repeatable, and internationally comparable cobalt content measurements in ferronickel. This standard supports quality assurance and material verification throughout the ferroalloy industry, enabling reliable control of alloy composition critical to downstream metal production.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Ferronickel - Bestimmung des Cobaltgehaltes - Atomabsorptions-Spektralfotometrisches Verfahren (ISO 7520:1985)Ferro-nickel - Dosage du cobalt - Méthode par spectrométrie d'absorption atomique dans la flamme (ISO 7520:1985)Ferronickel - Determination of cobalt content - Flame atomic absorption spectrometric method (ISO 7520:1985)77.100Železove zlitineFerroalloysICS:Ta slovenski standard je istoveten z:EN 27520:1991SIST EN 27520:2009en,fr,de01-november-2009SIST EN 27520:2009SLOVENSKI
STANDARD
International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.MEX~YHAPOAHAR OPI-AHM3AUMR fl0 CTAH,QAPTM3ALWl~ORGANISATION INTERNATIONALE DE NORMALISATION Ferronickel - Determination of Cobalt content - Flame atomic absorption spectrometric method Ferro-nicke1 - Dosage du Cobalt - Mhthode par spectromhrie d’absorption atomique dans Ia flamme First edition - 1985-11-15 UDC 669.243.881: 543.422 : 546.73 Ref. No. ISO 75204985 (E) Descriptors : nickei, ferronickel, Chemical analysis, determination of content, Cobalt, atomic absorption method. Price based on 3 pages SIST EN 27520:2009

Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standards bodies (ISO member bodies). 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 7520 was prepared by Technical Committee ISO/TC 155, Nickel and nicke/ alfoys. 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 latest edition, unless othennlise stated. 0 International Organkation for Standardkation, 1985 Printed in Switzerland SIST EN 27520:2009

INTERNATIONAL STANDARD ISO 75204985 (E) Ferronickel - Determination of Cobalt content - Flame atomic absorption spectrometric method 1 Scope and field of application This International Standard specifies a flame atomic absorption spectrometric method for the determination of the Cobalt con- tent of ferronickel in the range 0,025 to 2,5 % (mlm). 2 References ISO 385/1, Laborstory glassware - Burettes - Part 1: General requiremen ts. ISO 648, Laboratory glassware - One-mark pipettes. ISO 1042, Laborstory glassware - One-mark volumetric flasks. ISO 5725, Precision of test methods - Determination of repea tabiWy and reproducibility by in ter-labora tory tests. ISO 6352, Ferronickel - Determination of nicke/ tonten t - Dimethylglyoxime gravimetric method. 3 Principle Dissolution of a test Portion in a nitric acid-hydrochloric acid mixture. Precipitation of silica by dehydration in perchloric acid. Removal of silica by filtration. Addition of lanthanum for elimination of potential interferences. Determination of Cobalt by atomic absorption spectrometry in an air-acetylene flame at a wavelength of 240,7 nm. NOTE - This analysis tan be carried out on solutions which have been used for the determination of nicke1 by ISO 6352. 4 Reagents During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Hydrochlorit acid, 020 = 1,19 g/ml. 4.2 Hydrochlorit acid, ~20 = 1,19 g/ml, diluted 1+9. 4.3 Nitrit acid, 020 = 1,41 g/ml, diluted 1 + 1. 4.4 Perchlorit acid, ~20 = 1,61 g/ml [72 % (mlm)]. 4.5 Hydrofluoric acid, ~2~ = 1,14 g/ml, diluted 1 + 1. WARNING - Hydrofluoric acid is extremely irritating and corrosive to skin and mucous membranes, producing severe skin burns which are slow to heal. In case of skin contact wash weil with water and seek medical advice. 4.6 Lanthanum, Solution, containing 200 g of La per litre. Weigh 250 g of lanthanum chloride hexahydrate ( LaC13m 6H2O) and transfer to a 600 ml beaker. Add 25 ml of hydrochloric acid (4.1) and 300 ml of water. Stir to complete dissolution. Filter, if necessary, into a 500 ml one-mark volumetric flask, make up to the mark with water and mix. 4.7 Nickel plus iron, matrix Solution, containing 12 g of Ni and 28 g of Fe per Iitre. 4.7.1 Weigh 12,0 g of high purity nicke1 powder [containing less than 0,001 % (mlm) Cobalt] into an 800 ml beaker. Add 50 ml of water and 50 ml of nitric acid (pzo = 1,41 g/ml). When the initial reaction subsides, stir and heat to complete dissolu- tion. Dilute to about 250 ml with water. 4.7.2 Weigh 28,0 g of high purity iron powder [containing less than 0,001 % (mhd Cobalt1 into an 800 ml beaker. Add 100 ml of hydrochloric acid diluted 1 + 1. Carefully add 50 ml of nitric acid (920 = 1,41 g/ml) and heat to complete dissolution and Oxidation of iron. Dilute to about 250 ml. 4.7.3 Carefully combine the nicke1 Solution (4.7.1) with the iron Solution (4.7.2). Filter into a 1 000 ml one-mark volumetric flask, make up to the mark with water and mix. 4.8 Cobalt, Standard Solution, corresponding to 0,500 g of Co per litre. Weigh, to the nearest 0,001 g, 0,500 g of high purity [99,9 % (mlm) Co, minimuml Cobalt powder, transfer to a 600 ml beaker and add 40 ml of nitric acid (4.3). Heat to complete dissolution, boil gently to expel oxides of nitrogen, cool and transfer to a 1 000 ml one-mark volumetric flask containing 160 ml of nitric acid (4.3). Make up to the mark with water and mix. 1 ml of this Standard Solution contains 0,500 mg of Co. SIST EN 27520:2009

ISO 75204985 (EI 5 Apparatus Ordinary laboratory glassware, and 5.1 Atomic absorption spectrometer, equipped with a laminar flow burner for an air-acetylene flame and a Cobalt hollow cathode lamp. 5.2 Burette, of capacity 50 ml, graduated in divisions of 0,l ml, in accordance with ISO 385/1, class A. 5.3 Glass beakers, of capacity 600 ml, clean, unetched and flat bottomed. 5.4 Pipettes, of capacities 25 and 50 ml, in accordance with ISO 648, class A. 5.5 Volumetric flasks, of capacities 250; 500; and 1 000 ml, in accordance with ISO 1042, class A. 5.6 Polytetrafluoroethylene (PTFE) beaker, of capacity 600 ml, for samples with a high Silicon content. 6 Sampling and samples 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. 6.2 The laboratory Sample normally is in the form of millings, drillings or granules and no further preparation of the Sample is necessary. 6.3 If it is suspected that the laboratory Sample is con- taminated with oil or grease from the milling or drilling process, it shall be cleaned by washing with high purity acetone and dry- ing in air. 6.4 If the laboratory Sample contain
...