1、BRITISH STANDARD BS 6783-2: 1986 EN 26352:1991 ISO 6352:1985 Sampling and analysis of nickel, ferronickel and nickel alloys Part 2: Method for determination of nickel in ferronickel (dimethylglyoxime gravimetric method) ISO title: Ferronickel Determination of nickel content Dimethylglyoxime gravimet
2、ric method The European Standard EN 26352:1991 has the status of a British Standard UDC 669.1524-198:620.1:543.7:546.74BS6783-2:1986 This British Standard, having been prepared under the directionof the Non-ferrous Metals Standards Committee, waspublished under the authorityofthe Board of BSI andcom
3、es intoeffect on 31December 1986 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference NFM/10 Draft for comment 84/39885 DC ISBN 0 580 15521 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the No
4、n-ferrous Metals Standards Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: British Non-ferrous Metals Federation British Steel Industry Engineering Equipment and Materials Users Association Ministry of Defence Process Plant Association Stainless Ste
5、el Fabricators Association of Great Britain Coopted members Amendments issued since publication Amd. No. Date of issue CommentsBS6783-2:1986 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 3 2 References 3 3 Principle 3 4 Re
6、agents 3 5 Apparatus 3 6 Sampling and samples 3 7 Procedure 3 8 Expression of results 5 9 Test report 5 Annex A Determination of nickel in combined filtrates by atomic absorptionspectrometry 6 Annex B Statistical report of interlaboratory tests 7 Table 1 Results of statistical analysis 5 Table 2 Ana
7、lyst and laboratory factors 9 Table 3 Results of statistical analysis by groups of four samples 10BS6783-2:1986 ii BSI 01-2000 National foreword This Part of BS 6783 has been prepared under the direction of the Non-ferrous Metals Standards Committee. It is identical with ISO 6352:1985 “Ferronickel D
8、etermination of nickel content Dimethylglyoxime gravimetric method” published by the International Organization for Standardization (ISO). In 1991 the European Committee for Standardization (CEN) accepted ISO6352:1985 as European Standard EN 26352:1991 without any modifications. At present this Brit
9、ish Standard consists of nine Parts all concerned with analysis of nickel, ferronickel and nickel alloy. Further International Standards are in preparation on sampling and analysis of nickel, ferronickel and nickel alloys and, when available, these will be published as further Parts of this British
10、Standard. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the f
11、ollowing. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Part of BS 6783”. In British Standards
12、 it is current practice to use the symbol “L” for litre (and in its submultiples) rather than “l”. The Technical Committee has reviewed the provisions of ISO 385-1 and ISO 648, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard.
13、 ISO 385-1 is related to BS 846:1985 “Specification for burettes” and ISO 648 is related to BS 1583:1986 “Specification for one-mark pipettes”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct appl
14、ication. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standards Corresponding British Standards ISO 1042:1983 BS 1792:1982 Specification for one-mark volumetric flasks (Identical) ISO 3534:1977 BS 5532 Statistical termin
15、ology Part 1:1978 Glossary of terms relating to probability and general terms relating to statistics (Identical) ISO 5725:1981 BS 5497 Precision of test methods Part 1:1979 Guide for the determination of repeatability and reproducibility for a standard test method (Technically equivalent) Summary of
16、 pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to10 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUR
17、OPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 26352 November 1991 UDC 669.1524-198:620.1:543.7:546.74 Descriptors: Ferroalloys, ferronickel, chemical analysis, determination of content, nickel, gravimetric analysis, dimethylglyoxime English version Ferronickel Determination of nickel content Dim
18、ethylglyoxime gravimetric method (ISO 6352:1985) Ferro-nickel Dosage du nickel Mthodegravimtrique la dimthylglyoxime (ISO6352:1985) Ferronickel Bestimmung des Nickelgehaltes Gravimetrisches Verfahren mit Dimethylglyoxim (ISO 6352:1985) This European Standard was approved by CEN on 1991-11-06. CEN me
19、mbers are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on applica
20、tion to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the
21、 same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardi
22、zation Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN 1991 Copyright reserved to all CEN members Ref. No. EN26352:1991 E2 blankEN26352:1991 BSI 01-2000 3 1 Scope and field of application This International Standard specifies
23、 a gravimetric method for the determination of the nickel content of ferronickel in the range 15 to 60 % (m/m). 2 References ISO 385-1, Laboratory glassware Burettes Part1: General requirements. ISO 648, Laboratory glassware One-mark pipettes. ISO 1042, Laboratory glassware One-mark volumetric flask
24、s. ISO 5725, Precision of test methods Determination of repeatability and reproducibility by inter-laboratory 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 nickel from a ta
25、rtro-ammoniacal medium by an ethanolic solution of dimethylglyoxime. A second precipitation of nickel arid weighing after drying at150 C. Determination of residual nickel in the filtrates by atomic absorption spectrometry. 4 Reagents During the analysis, unless otherwise stated, use only reagents of
26、 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, 20= 0,925 g/ml. 4.3 Dimethylglyoxime, 10 g/l solution in ethanol. 4.4 Hydrochloric acid, 20= 1,19 g/ml. 4.5 Hydrochloric acid, 20= 1,19 g/ml, di
27、luted 1 + 9. 4.6 Nitric acid, 20= 1,41 g/ml. 4.7 Nitric acid, 20= 1,41 g/ml, diluted 1 + 1. 4.8 Perchloric acid, 20= 1,61 g/ml 72 % (m/m). 4.9 Tartaric acid, 500 g/l solution. 4.10 Hydrofluoric acid, 20= 1,14 g/ml, diluted 1 + 1. WARNING Hydrofluoric acid is extremely irritating and corrosive to ski
28、n and mucous membranes, producing severe skin burns which are slow to heal. In case of skin contact, wash well with water and seek medical advice. 5 Apparatus Ordinary laboratory apparatus, and 5.1 Filtration crucible, fritted glass, of approximately 10 to 20 4m pore diameter. 5.2 Glass beakers, of
29、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 and1000ml, in accordance with ISO 1042, class A. 5.5 Polytetrafluoroethylene (PTFE) beaker, of capacity 600 ml, for samples wit
30、h 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
31、 and no further preparation of the sample is necessary. 6.3 If it is suspected that the laboratory sample is contaminated with oil or grease from the milling or drilling process, it shall be cleaned by washing with high purity acetone and drying in air. 6.4 If the laboratory sample contains particle
32、s or pieces of widely varying sizes, the test portion should be obtained by riffling. 7 Procedure WARNING Fuming perchloric acid is a powerful oxidant and can cause an explosive mixture when in contact with organic materials. All evaporations should be done in fume cupboards suitable for use with pe
33、rchloric acid. 7.1 Test portion Weigh, to the nearest 0,001 g, 3,9 to 4,1 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, following the same procedure and using the same quantities of all the reagents.
34、7.3 Preparation of crucible 7.3.1 Filter through the crucible (5.1) a hot mixture of 20 ml of hydrochloric acid (4.4), 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.EN26352:1991 4 BSI 01-2000 7.3.2 Dry the crucible in an oven at
35、150 C for 2 h. Cool in a desiccator for 60 min and weigh quickly. NOTE 1This procedure is used to condition a new crucible or to clean a used crucible after the analysis is completed. NOTE 2For highest accuracy, the crucible and precipitate(7.5.9) should be weighed, as closely as possible, under the
36、 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 adding25mlof water followed by 50 ml of nitricacid diluted 1 + 1. Cover the beaker with a watch-glass and heat gently, if necessary, to complete dissolution. NOT
37、EFor ferronickel samples containing more than 1 % (m/m) silicon, use a polytetrafluoroethylene beaker (5.5). Attack the test portion 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
38、 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 C until abundant white fumes of perchloric acid are obtained. Reflux at
39、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 C until abundant white fumes are obtained. Reflux at this temperature for 20 min. Remove the beaker from the hotplate and allow to
40、 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 fou
41、r times with warm water. Discard the silica precipitate, make up the filtrate to the mark with water and mix thoroughly. 7.5 Determination 7.5.1 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 fo
42、r samples containing less than 30 % (m/m) nickel and 50 ml for samples containing more than30 % (m/m) 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 (
43、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 C. 7.5.3 Pour in, while stirring, 4 ml of dimethylglyoxime solution (4.3) for each 10 mg of nickel estimated to b
44、e 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 fi
45、ve times with warm water (about 40 to 50 C). 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 (4.4), 10 ml of nitric acid (4.6) and 30 ml of water. Wash
46、the filter carefully with three 20 ml portions of the acid mixture, following the addition of each portion by washing with warm water. Ensure that all the red precipitate is dissolved and finally wash the filter thoroughly with warm water. 7.5.7 Reprecipitate the nickel by repeating the steps in 7.5
47、.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. R
48、etain the filtrate for processing in 7.5.10. 7.5.9 Dry the crucible and precipitate in an oven at150 C for 2 h, cool in a desiccator for 60 min and weigh quickly, under the same conditions as used in7.3.2. 7.5.10 Combine the filtrates from 7.5.5 and 7.5.8. Evaporate to a viscous consistency. Add 50
49、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. 7.5.11 Determine the nickel content of the combined filtrates by atomic absorption. See Annex A. NOTE 1The nickel content of the combined filtrates should not exceed 0,2 % (m/m) nickel in the original sample. NOTE 2High levels of nickel in the filtrates may indicate a faulty crucible
