1、INTERNATIONAL STANDARD 2071 111: R 4igB INTERNATIONAL ORGANIZATION FOR STANDARDlZATlON .MLXLlYHAPOL,HAII OPrAHM3AUMR n0 CTAHLIAPTLi3AUAM.ORGANISATION ,NTERNAT,ONALE DE NORMAL,SAT,ON Aluminium oxide primarily used for the production of aluminium - Determination of zinc content - Flame atomic absorpti
2、on method Oxyde daluminium principalement utilise pour la production de Ialuminium - Dosage du zinc - Mkthode par absorption atomique dans la flamme First edition - 1976-09-15 1 .,( .s ! , Jj.$,*, .* $i : ; 8, : ,. ; k t; iii UDC 661.862.22 : 546.47 : 543.42 Ref. No. IS0 2071-1976 (E) Descriptors :
3、aluminium oxide, chemical analysis, determination of content, Ant, atomic absorption method. Price based on 4 pages Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-FOREWO
4、RD IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 Member Bodies). The work of developing International Standards is carried out through IS0 Technical Committees. Every Member Body interested in a subject for which a Technical
5、Committee has been set up has the right to be represented on that Committee. International organizations, governmental 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 appr
6、oval before their acceptance as International Standards by the IS0 Council. Prior to 1972, the results of the work of the technical Committees were published as IS0 Recommendations; these documents are now in the process of being transformed into International Standards. As part of this process, Tec
7、hnical Committee ISO/TC 47 has reviewed IS0 Recommendation R 2071 and found it technically suitable for transformation. International Standard IS0 2071 therefore replaces IS0 Recommendation R 2071 -1971 to which it is technically identical. IS0 Recommendation R 2071 was approved by the Member Bodies
8、 of the following countries : Austria Iran Belgium Israel Czechoslovakia Italy Egypt, Arab Rep. of Korea, Rep. of France Netherlands Germany New Zealand Greece Poland Hungary Portugal India South Africa, Rep. of Spain Sweden Switzerland Thailand United Kingdom U S.A. U.S.S.R. No Member Body expresse
9、d disapproval of the Recommendation. No Member Body disapproved the transformation of ISO/R 2071 into an International Standard. 0 International Organization for Standardization, 1976 l Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with
10、 ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-INTERNATIONAL STANDARD IS0 2071-1976 (E) Aluminium oxide primarily used for the production of aluminium - Determination of zinc content - Flame atomic absorption method 1 SCOPE AND FIELD OF APPLICATION This Intern
11、ational Standard specifies a flame atomic absorption method for the determination of the zinc content of aluminium oxide primarily used for the production of aluminium. The method is applicable to products having a zinc content, expressed as ZnO, equal to or greater than 0,002 % (m/m). 2 REFERENCES
12、IS0 802, Aluminium oxide primarily used for the production of aluminium - Preparation and storage of test samples. IS0 804, Aluminium oxide primarily used for the production of aluminium - Preparation of solution for analysis - Method by alkaline fusion. IS0 2073, Aluminium oxide primarily used for
13、the production of aluminium - Preparation of solution for analysis - Method by hydrochloric acid attack under pressure. IS0 2927, Aluminium oxide primarily used for the production of aluminium - Sampling. 3 PRINCIPLE Dissolution of a test portion by attack with hydrochloric acid under pressure. Aspi
14、ration of the solution in an acetylene/air flame and determination of the zinc content by spectrophotometric measurement of the absorption of the 213,8 nm line emitted by a zinc hollow-cathode lamp. The dissolution of the test portion can also be effected by alkaline fusion (see annex A). 4 REAGENTS
15、 During the analysis, use only reagents of recognized analytical grade and only water doubly distilled from a borosilicate glass apparatus with ground joints, or water of equivalent purity. Avoid the use of leaded glass. 4.1 Aluminium oxide, purity greater than 99,95 %, containing less than 0,001 %
16、(m/m) of ZnO. 4.2 Hydrochloric acid, p approximately 1.19 g/ml, about 38 % (m/m) solution. 4.3 Aluminium, acid solution (main solution). Pickle 11 g of extra-pure aluminium (99,999 % purity), in the form of shavings obtained by milling or drilling, in a little nitric acid solution, p approximately 1
17、,40g/ml, about 68 % (m/m) solution. Wash the pickled shavings with water and then dry them by washing with acetone. Weigh, to the nearest 0,001 g, 10,558 g of these dried shavings, place them in a beaker of suitable capacity (for example 500 ml) and add 144 ml of the hydrochloric acid solution (4.2)
18、. Add 1 drop of extra-pure mercury to aid the attack. Wait until the reaction subsides, then place the beaker on a sand bath and maintain a gentle heat until all the aluminium has dissolved. Allow to cool, transfer the solution quantitatively to a 500 ml one-mark volumetric flask, dilute to the mark
19、 and mix. 4.4 Zinc, standard solution, corresponding to 0,100 g of ZnO per litre. Weigh, to the nearest 0,000 1 g, 0,100 g of zinc oxide, previously calcined at 1 000 C for 1 h and cooled in a desiccator. Place this in a beaker of suitable capacity (for example 100 ml) and dissolve in 5,5 ml of the
20、hydrochloric acid solution (4.2). Dilute the solution and transfer it quantitatively to a 1 000 ml one-mark volumetric flask. Dilute to the mark and mix. 1 ml of this standard solution contains 0,100 mg of ZnO. 4.5 Zinc, standard solution, corresponding to 0,020 g of ZnO per litre. Take 100,O ml of
21、the standard zinc solution (4.4), place in a 500 ml one-mark volumetric flask, dilute to the mark and mix. 1 ml of this standard solution contains 0,020 mg of ZnO. 5 APPARATUS Ordinary laboratory apparatus and 5.1 Apparatus as specified in IS0 2073. 5.2 Burette, graduated in 0,05 ml, conforming to I
22、SO/R 385. 5.3 Spectrophotometer, atomic absorption type, fitted with a burner fed from cylinders of acetylene and com- pressed air. 1 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license f
23、rom IHS-,-,-IS0 2071-1976 (E) 5.4 Zinc hollow-cathode lamp. NOTE - All glassware, including reagent flasks, shall be of borosilicate glass or glass of another type not releasing zinc, or as an alternative, plastics material. Rubber stoppers shall not be used; use exclusively ground glass or plastics
24、 stoppers. 6 PROCEDURE 6.1 Test portion Weigh, to the nearest 0,001 g, 2 g of the test sample dried at 300 “C (see 3.3 of IS0 802). 6.2 Preparation of the calibration graph 6.2.1 Preparation of the standard matching solutions Into each of a series of six 100 ml one-mark volumetric flasks, place 50 m
25、l of the acid solution of aluminium (4.3) followed by the volumes of standard zinc solution (4.5) shown in the following table, measured with the aid of the burette (5.2) : Standard zinc solution (4.5) Corresponding mass of ZnO ml mg 0* 0 5,O 0.10 IO,0 0.20 15.0 0,30 20,o 0,40 25.0 0,50 * Blank test
26、 on the reagents used for the preparation of the calibration graph. Dilute to the mark and mix. 6.2.2 Photometric measurements 6.2.2.1 ADJUSTMENT OF THE INSTRUMENT, FITTED WITH ZINC HOLLOW-CATHODE LAMP (5.4) Switch on the current to the instrument (5.3) a sufficient time in advance to ensure stabili
27、zation. Adjust the wave- length to around 213,8 nm and also the sensitivity and the aperture of the slit according to the characteristics of the instrument. Adjust the pressure of the air and acetylene according to the characteristics of the burner, so as to obtain an oxidizing flame. 6.2.2.2 PHOTOM
28、ETRIC MEASUREMENTS Aspirate the series of standard matching solutions (6.2.1) in the flame, and for each measure the absorbance. Take care to keep the rate of aspiration constant throughout the preparation of the calibration graph. Spray water through the burner after each measurement. 6.2.3 Plottin
29、g the calibration graph Plot a graph having, for example, as abscissae the values, expressed in milligrams, of the quantities of ZnO contained in 100 ml of standard matching solution, and as ordinates the corresponding values of the absorbances, decreased by the measured value for the zero term of t
30、he standard matching solutions (blank test on the reagents used for the preparation of the calibration graph). 6.3 Determination 6.3.1 Preparation of the test solution Prepare the test solution according to the method specified in IS0 2073, placing the reaction solution in a 100 ml one-mark volumetr
31、ic flask. Dilute to the mark and mix. 6.3.2 Blank test Carry out a blank test at the same time as the determi- nation, following the same procedure and using the same quantities of all the reagents as for the determination, replacing the test portion with 2 g of the aluminium oxide (4.1) weighed to
32、the nearest 0,001 g. 6.3.3 Photometric measurements Carry out the measurements of the test solution (6.3.1), the blank test solution (6.3.2) and the standard matching solutions (6.2.1), in accordance with the procedure specified in 6.2.2.2. Take care to include with the measurement of the test solut
33、ion and blank test solution respectively, two standard matching solutions containing quantities of ZnO as close as possible to those to be determined. 7 EXPRESSION OF RESULTS By means of the calibration graph (see 6.2.3), determine the quantities of ZnO corresponding to the values of the photometric
34、 measurements of the test solution and of the blank test solution. The zinc content, expressed as a percentage by mass of zinc oxide (ZnO), is given by the formula (m0 -m,) x50 1 000 where m, is the mass, in milligrams, of zinc oxide found in the test solution; ml is the mass, in milligrams, of zinc
35、 oxide found in the blank test solution. Express the result to three places of decimals. 8 TEST REPORT The test report shall include the following particulars : a) the reference of the method used; b) the results and the method of expression used; c) any unusual features noted during the determinati
36、on; d) any operation not included in this International Standard or in the International Standards to which reference is made, or regarded as optional. 2 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitt
37、ed without license from IHS-,-,-IS0 2071-1976 (E) ANNEX A DISSOLUTION OF THE TEST PORTION BY ALKALINE FUSION The following particulars and modifications, peculiar to the dissolution of the test portion by alkaline fusion, shall be applied to the method already specified. A.1 REAGENTS Delete the reag
38、ent 4.2 and add the following : A.4.6 Sodium carbonate, anhydrous. A.4.7 Boric acid (HaBOa). A.4.8 Hydrochloric acid, approximately 8 N solution. Dilute 670 ml of a hydrochloric acid solution, p approxi- mately I,19 g/ml, about 38 % (m/m) solution, with water to 1 000 ml and mix. A.2 APPARATUS Repla
39、ce the apparatus specified in 5.1 by the following : A.5.1 Apparatus as specified in IS0 804. A.3 PROCEDURE Delete 6.1, 6.3.1 and 6.3.2 and replace them respectively by the following : A.6.1 Test portion Weigh, to the nearest 0,001 g, 5 g of the test sample dried at 300 “C (see 3.3 of IS0 802). A.6.
40、3 Determination A.6.3.1 Preparation of the test solution Prepare the test solution in accordance with the method specified in IS0 804, taking care to effect the recovery of the fused mass (see 6.2 and 6.3 of IS0 804) by 90 ml of the hydrochloric acid solution (A.4.8), adjusting the final volume of t
41、he principal solution P to 250 ml. A.6.3.2 Blank test Carry out a blank test at the same time as the determi- nation, and following the same procedure, in the presence of extra-pure aluminium oxide, in accordance with the method specified in 6.4.1 of IS0 804. 3 Copyright International Organization f
42、or Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 2071-1976 (E) ANNEX B IS0 PUBLICATIONS RELATING TO ALUMINIUM OXIDE PRIMARILY USED FOR THE PRODUCTION OF ALUMINIUM IS0 802 - Preparation and storage of test
43、samples. IS0 803 - Determination of loss of mass at 300 “C (conventional moisture). IS0 804 - Preparation of solution for analysis - Method by alkaline fusion. IS0 805 - Determination of iron content - l,lO-Phenanthroline photometric method. IS0 806 - Determination of loss of mass at 1 000 and 1 200
44、 C. IS0 900 - Determination of titanium content - Diantipyrylmethane photometric method. IS0 901 - Determination of absolute density - Pyknometer method. IS0 902 - Measurement of the angle of repose. IS0 903 - Determination of untamped density. IS0 1232 - Determination of silica content - Reduced mo
45、lybdosilicate spectrophotometric method. IS0 1617 - Determination of sodium content - Flame emission spectrophotometric method. IS0 1618 - Determination of vanadium content - N-Benzoyl-N-phenylhydroxylamine photometric method. IS0 2069 - Determination of calcium content - Flame atomic absorption met
46、hod. ISO/R 2070 - Determination of calcium content - Spectrophotometric method using naphthalhydroxamic acid. IS0 2071 - Determination of zinc content - Flame atomic absorption method. ISO/R 2072 - Determination of zinc content - PAN photometric method. IS0 2073 - Preparation of solution for analysi
47、s - Method by hydrochloric acid attack under pressure. IS0 2828 - Determination of fluorine content - Alizarin complexone and lanthanum chloride spectrophotometric method. IS0 2829 - Determination of phosphorus content - Reduced phosphomolybdate spectrophotometric method. IS0 2865 - Determination of
48、 boron content - Curcumin spectrophotometric method. IS0 2926 - Particle size analysis - Sieving method. IS0 2927 - Sampling. IS0 2961 - Determination of an adsorption index. IS0 3390 - Determination of manganese content - Flame atomic absorption method. Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
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