EN 26352:1991

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Ferronickel - Bestimmung des Nickelgehaltes - Gravimetrisches Verfahren mit Dimethylglyoxim (ISO 6352:1985)Ferro-nickel - Dosage du nickel - Méthode gravimétrique à la diméthylglyoxime (ISO 6352:1985)Ferronickel - Determination of nickel content - Dimenthylglyoxime gravimetric method (ISO 6352:1985)77.100Železove zlitineFerroalloysICS:Ta slovenski standard je istoveten z:EN 26352:1991SIST EN 26352:2009en,fr,de01-november-2009SIST EN 26352:2009SLOVENSKI
STANDARD
International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.ME)I(~YHAPOflHAR OPI-AHM3ALWlfl l-l0 CTAH~APTM3ALWl.ORGANISATION INTERNATIONALE DE NORMALlSATlON Ferronickel - Determination od nicke1 content - Dimethylglyoxime gravimetric method Ferro-nickel - Dosage du nicke1 - M&hode gravimb trique a Ia dim&h ylglyoxime First edition - 1985-12-15 UDC 669.15-198 : 543.7 : 546.74 Ref. No. ISO 6352-1985 (E) Descriptors : ferroalloys, ferronickel, Chemical analysis, determination of content, nickel, gravimetric analysis, dimethylglyoxime. Price based on 6 pages SIST EN 26352:2009

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 6352 was prepared by Technical Committee ISO/TC 155, Nickel and nicke1 alle ys. 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 othenGse stated. 0 International Organkation for Standardkation, 1985 Printed in Switzerland SIST EN 26352:2009

INTERNATIONAL STANDARD ISO 6352-1985 (E) Ferronickel - Determination of nicke1 content - Dimethylglyoxime gravimetric method 1 Scope and field of application This International Standard specifies a gravimetric method for the determination of the nicke1 content of ferronickel in the range 15 to 60 % Hm). 2 References ISO 38511, Laboratory glassware - Burettes - Part 7: General requiremen ts. ISO 648, Laboratory glassware - One-mark pipettes. I S 0 1042, Labora tory glassware - One-mark volume tric flasks. ISO 5725, Precision of test methods - Determination of repea tability and reproducibility b y in ter-labora tory tests. 3 Principle Dissolution of a test Portion in nitric acid. Precipitation of silica by dehydration in perchloric acid. Removal of silica by filtration. Precipitation of nicke1 from a tartro-ammoniacal medium by an ethanolic Solution of dimethylglyoxime. A second precipitation of nicke1 and weighing after drying at 150 OC. Determination of residual nicke1 in the filtrates by atomic absorption spec- trometry. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Acetic acid, ~20 = 1,05 g/ml, diluted 1 + 1. 4.2 Ammonium hydroxide, 020 = 0,925 g/mI. 4.3 Dimethylglyoxime, 10 g/l Solution in ethanol. 4.4 Hydrochlorit acid, -20 = 1,19 g/ml. 4.5 Hydrochlorit acid, ~~~ = 1,19 g/ml, diluted 1 +9. 4.6 Nitrit acid, 1020 = 1,41 g/ml. 4.7 Nitrit acid, ~~~ = ‘l,41 g/ml, diluted 1 + 1. 4.8 Perchlorit acid, ~~~ = 1,61 g/ml [72 % (mlm)]. 4.9 Tartaric acid, 500 g/l Solution. 4.10 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. 5 Apparatus Ordinary laboratory apparatus, and 5.1 Filtration crucible, fritted glass, of approximately 10 to 20 Pm pore diameter. 5.2 Glass beakers, of capacity 600 ml, clean, unetched and flat bottomed. 5.3 Pipettes, of capacities 50 and 100 ml, in accordance with ISO 648, class A. 5.4 Volumetric flasks, of capacities 200 and 1 000 ml, in ac- cordante with ISO 1042, class A. 5.5 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 granules, millings or drillings and no further preparation of the Sample is necessary. 1 SIST EN 26352:2009

ISO 6352-1985 (E) 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 contains particles or pieces of widely varying sizes, the test Portion should be obtained by riff ling. 7 Procedure WARNING - Fuming perchloric acid is a powerful oxi- dant and tan Cause an explosive mixture when in contact with organic materials. All evaporations should be done in fume cupboards suitable for use with perchloric acid. 7.1 Test Portion Weigh, to the nearest 0,001 g, 3,9 to 4,l g of the laboratory Sample and transfer to a 600 ml glass beaker (5.2). 7.2 Blank test Carry out a blank test in parallel with the determination, follow- ing the same procedure and using the same quantities of all the reagents. 7.3 Preparation of crucible 7.3.1 Filter through the crucible (5.1) a hot mixture of 20 ml of hydrochloric acid (4.41, 10 ml of nitric acid (4.6) and 30 ml of water. Wash the crucible with warm water until all the acid has been removed. 7.3.2 Dry the crucible in an oven at 150 OC for 2 h. Cool in a desiccator for 60 min and weigh quickly. NOTES 1 This procedure is used to condition a new used crucible after the ana lysis is completed. crucible or to clean a 2 For highest accuracy, the crucible and precipitate (7.5.9) should be weighed, as closely as possible, under the same temperature and humidity conditions as the empty crucible. 7.4 Preparation of test solution 7.4.1 Dissolve the test Portion (7.1) by adding 25 ml of water followed by 50 ml of nitric acid diluted 1 + 1. Cover the beaker with a watch-glass and heat gently, if necessary, to complete dissolution. NOTE - For ferronickel samples containing more than 1 % (mlm) Silicon, use a polytetrafluoroethylene beaker (5.5). Attack the test por- tion by adding successively 25 ml of water, 40 ml of nitric acid (4.7) and 10 ml of hydrochloric acid (4.4). To obtain complete dissolution of the Sample, add, at the end of effervescence, 10 ml of hydrofluoric acid (4.10) and 40 ml of perchloric acid (4.8). Heat until evolution of fumes of perchloric acid. Allow to cool and transfer the Solution quantitatively to a glass beaker (5.2). Heat to 260 OC until abundant white fumes of perchloric acid are obtained. Reflux at this temperature for 20 min and proceed as directed in 7.4.2, “Remove the beaker. . .“. 7.4.2 When the metal is dissolved, add 40 ml of perchloric acid (4.8) and heat at 260 OC until abundant white fumes are obtained. Reflux at this temperature for 20 min. Remove the beaker from the hotplate and allow to cool. Add 20 ml of hydrochloric acid (4.4) and 200 ml of warm water. Filter off the silica using a medium porosity filter Paper, collecting the filtrate in a 1 000 ml one-mark volumetric flask. Rinse the beaker and wash the silica precipitate three times with hydrochloric acid diluted 1 + 9 and four times with warm water. Discard the silica precipitate, make up the filtrate to the mark with water and mix thoroughly. 7.5 Determination 7.51 Pipette from the test Solution into a 600 ml beaker, an aliquot containing 60 to 120 mg of nickel, and dilute to 300 ml with water. Use a 100 ml aliquot for samples containing less than 30 % (mlm) nicke1 and 50 ml for samples containing more than 30 % (mlm) nickel. 7.5.2 Add 10 ml of tartaric acid Solution (4.9) to the aliquot (7.5.1). Pour in, while stirring, ammonium hydroxide (4.2) until the colour of the Solution changes from yellow to blue-green (PH is slightly alkaline). The Solution must remain clear. Restore the yellow colour by slowly adding sufficient acetic acid (4.1). The pH must be between 4 and 5. Heat the Solution to 60 OC. 7.5.3 Pour in, while stirring, 4 ml of dimethylglyoxime Solution (4.3) for each 10 mg of nicke1 estimated to be present. Add 20 ml in excess. 7.5.4 Make the Solution slightly ammoniacal (pH of about 10) by addition of sufficient ammonium hydroxide. Stir vigorously for about 30 s and allow the precipitate to settle for 30 min. 7.5.5 Filter the Solution through a medium porosity Paper. Wash the precipitate five times with warm water (about 40 to 50 OC). Retain the filtrate for processing in 7.5.10. 7.5.6 Dissolve the precipitate through the filter into the beaker used for the first precipitation, using a hot mixture of 20 ml of hydrochloric acid (4.41, 10 ml of nitric acid (4.6) and 30 ml of water. Wash the filter carefully with three 20 ml por- tions of the acid mixture, following the addition of each Portion by washing with warm watet=. Ensure that all the red precipitate is dissolved and finally wash the filter thoroughly with warm water. 7.5.7 Reprecipitate the nicke1 by repeating the Steps in 7.5.2 to 7.5.4 inclusive but use only 2 ml of tartaric acid Solution (4.9) and only 5 ml excess of dimethylglyoxime Solution (4.3). 7.5.8 Filter the precipitate on the dried and preweighed fritted glass crucible (7.3.2). Clean the beaker thoroughly and wash the precipitate five times with warm water. Retain the filtrate for processing in 7.5.10. 7.5.9 Dry the crucible and precipitate in an oven at 150 OC for 2 h, cool in a desiccator for 60 min and weigh quickly, under the same conditions as used in 7.3.2. SIST EN 26352:2009

ISO 63524985 IE) 7.5.10 Combine the filtrates from 7.5.5 and 7.5.8. Evaporate to a viscous consistency. Add 50 ml of hydrochloric acid (4.4) in 10 to 15 ml portions and heat. Add 50 ml of hot water and bring to the boil. Allow to cool and transfer to a 200 ml one- mark volumetric flask. Make up to the mark with water and mix. 8.2.1.2 The test was carried out on test solutions of 50 ml for nicke1 contents lower than 30 % (mlm) and 25 ml for contents higher than 30 % (mlm). These solutions became 100 ml and 50 ml, respectively, in the final procedure adopted after com- pletion of the Programme (sec 7.5.1). lt is expected that the repeatability and the reproducibility will be better when the method is used as specified. 7.5.11 Determine the nicke1 content of the combined filtrates by atomic absorption. See annex A. 8.2.2 Statistical results NOTES 1 The nicke1 content of the combined filtrates should not exceed 0,2 % (mlm) nicke1 in the original Sample. 2 High levels of nicke1 in the filtrates may indicate a faulty crucible. 3 If the nicke1 in the filtrate is high, or if the sensitivity of the atomic absorption instrument is very high, it may be necessary to dilute the Solution from 7.5.10 for atomic absorption analysis. Repeatability and two reproducibilities were calculated accord- ing to the principles of ISO 5725. The values resulting from this analysis are given in table 1. A report on the interlaboratory tests and statistical analysis is given in annex B. Table 1 - Results of statistical analysis Nickel content [% bnhdl 15 to 30 31 to 45 Standard deviation 8 Expression of results 8.1 Calculation - within analyst, .s,,,,, - between analyst/within Ia boratory, sW2 - between laboratories, ,sb The nicke1 content, expressed as a percentage by mass, is given by the formula Repeatability, r = 2,83 e, 0,047 0,066 0,047 0,095 0,054 0,047 0,13 0,19 20,32 (m2 - ml) ’ ’ 000 + wf (%) mo x v Reproduci bility, laboratory, RW 0,19 where Rvv = 2,83 ,/s;, + & Reproducibility, between Ia boratories, R 0,24 0,33 0,35 m. is the mass, in grams, of the test Portion; ml is the mass, in grams, of the empty crucible; ~22 is the mass, in grams, of the crucible and the nicke1 dimethylglyoxime precipitate; V is the volume, in millilitres, of the aliquot part of the test Solution taken in 7.5.1; Wf (%) is the correction for percentage of nicke1 which is determined in the combined filtrates (7.5.11); 20,32 is the conversion factor, multiplied by 100, of nicke1 dimethylglyoxime to nickel. R = 2,83 J.s;, + SW* + s; NOTES TO TABLE 1 1 These values of the repeatability and reproducibility tan be retained as normally representative of the Performance of the analytical method specified in this International Standard and applied to similar samples. 2 The repeatability and reproducibility for establishing splitting limits. data may be used as guidelines 9 Test report 8.2 Precision The test report shall include the following information: 8.2.1 Laboratory tests the reference to the method used; b) the results of the analysis; 8.2.1.1 This International Standard was subjected to an inter- laboraton/ test Programme involving seven countries, 20 lab- oratories and 39 analysts. Eight samples of commercial ferro- nicke1 covering the range of 21 to 41 % (mlm) nicke1 were analysed. Esch laboratory was requested to supply two deter- minations by each of two analysts for each Sample. Cl the number of independent replications; d) any unusual features noted during the analysis; in this International Stan- e) any operatio In not included dard or regarded as optional. SIST EN 26352:2009

ISO 6352-1985 (E) A.1 General Annex A Determination of nicke1 in combined filtrates by atomic absorption spectrometry (This annex forms an integral part of the Standard.) A.2 Reagents A.2.1 Hydrochlorit acid, 1?20 = A.2.2 Nickel, Standard Solution, Ni per litre. Weigh, to the nearest 0,005 g, 1,19 g/ml. corresponding to 0,l g of 1 ,OO g of nicke1 metal, [99,9 % (mlm) minimumi, transfer to a 600 ml beaker and dissolve in 40 ml nitric acid ~~~~ = 1,41 g/ml) diluted 1 + 1. Evaporate to a viscous syrup, cool, redissolve the salts in water and transfer to a 1 000 ml one-mark volumetric flask. Make up to the mark with water and mix. Pipette 25,0 ml of this Solution into a 250 ml one-ma volumetric flask. Ma ke up to the mark with water and mix. rk 1 ml of this Standard Solution contains 0,l mg of Ni. A.3 Apparatus Ordinary laboratory apparatus, and A.3.1 Burette, of capacity 50 ml, graduated in divisions of 0,05
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