GB/T 8647.2-1988 Method for chemical analysis of nickel Chrome azurol S-polyethylene glycol phenyl ether-tetradecylpyridine bromide mixed micelle solubilization determination of aluminum content GB/T8647.2-1988 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method for nickel
Chromazurol S--- P-octylpolyethylene glycol phenyl ether-tetradecyl phridinium bromine mixed micellar solubilization
Determination of aluminium contentbzxz.net
Nickel --. Determination of aluminium content Chromazurol S--- P-octylpolyethylene glycol phenyl ether-tetradecyl phridinium bromine mixedmicellar solubilization spectrophotometric method This standard is applicable to the determination of aluminium content in nickel. Determination range: 0.0003% to 0.0020%. UDC: 669.24
GB8647.2.-88
This standard complies with GB146778 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". 1 Method Summary
The sample is dissolved in nitric acid. At pH 4.6~~5.2, benzoic acid ethyl acetate is used to extract aluminum benzoate and separate it from the main nickel. Aluminum in the organic phase is back-extracted with hydrochloric acid solution. Aluminum forms a complex with chrome azurol S-emulsifier OP-tetradecylpyridine bromide, and its absorbance is measured at a wavelength of 610nm on a spectrophotometer.
2 Reagents
The water used for preparing solutions and analysis is double distilled water. 2.1 Hydrochloric acid (1+19), high purity.
Ammonium hydroxide (1+20), high purity. Store in a plastic bottle. 2.2
2.3 Nitric acid (3+2), high purity.
2.4 Chrome Azure S solution (0.1%): weigh 0.20g Chrome Azure S and dissolve it in 100mL water, dilute to 200ml with anhydrous ethanol. Polyethylene glycol octylphenyl ether (emulsifier OP) solution (1+999). 2.5
Tetradecylpyridinium bromide (TPB) solution (0.4%). 2.7
Acetic acid-ammonium acetate buffer solution: dilute 485mL ammonium acetate solution (4mol/L) with acetic acid solution (4mol/L) to 500mL, mix.
Ammonium benzoate solution (12%): weigh 12g ammonium benzoate and dissolve it in water (add 2-3 drops of ammonium hydroxide to dissolve it completely), dilute to 100ml with water 2.8
.
2.9 Ammonium benzoate washing solution: Weigh 2g ammonium benzoate and dissolve it in 100mL water. Use dilute hydrochloric acid to carefully adjust the pH to between 4.6 and 4.8 on the acidometer.
2.10 Benzoic acid ethyl acetate solution (5%): Weigh 25g benzoic acid and dissolve it in ethyl acetate. Use ethyl acetate to dilute to 500mL. Hydroxylamine hydrochloride solution (10%), prepare it when used. 2.11
2.12 Ascorbic acid solution (1%), prepare it when used. 2.13
100mL.
Thymol blue solution (0.2%): Weigh 0.208 thymol blue and dissolve it in 50mL anhydrous ethanol, dilute with water to 1988-01-11 approved by China Nonferrous Metals Industry Corporation and implemented on January 1, 1989
GB 8647.2-88
2.14 Aluminum standard stock solution: Weigh 0.1000g of metallic aluminum (≥99.95%) in a 100mL beaker, add 10mL hydrochloric acid (1+1), dissolve completely at low temperature, transfer to a 1000mL volumetric flask, dilute with water to the mark, and mix. This solution contains 100ug aluminum in 1mL. 2.15 Aluminum standard solution: Transfer 5.00mL of aluminum standard stock solution (2.14), place it in a 500mL volumetric flask, add 5mL hydrochloric acid (!+1), dilute with water to the mark, and mix. This solution contains 1ug aluminum in 1mL. 3 Apparatus
3.1 Spectrophotometer.
3.2 Acidometer.
4 Analysis steps
4.1 Sample quantity
Weigh the sample according to Table 1.
Aluminum content, %
0. 000 3 --0. 000 8
>0. 000 8 ~ 0. 002
4.2 Blank test
Carry out a blank test together with the sample.
Sample volume, g
Volume of diluted test solution, ml
Volume of test solution, mL
Note: The glass volumetric flask, separating funnel, beaker and other instruments used in the analysis process must be thoroughly washed with hot hydrochloric acid (1+1) before use. 4.3 Determination
4.3.1 Place the sample (4.1) in a 300mL beaker, add 40mL nitric acid (2.3) in portions, cover with table III, heat at low temperature to completely dissolve the sample, evaporate to a thick slurry, and evaporate on a water bath until almost dry. Remove and cool, rinse the table and the wall of the cup with a small amount of water, heat to dissolve the salts, transfer to a 100mL volumetric flask after cooling, dilute to the scale with water, and mix. 4.3.2 Pipette the test solution into a 125mL separatory funnel according to Table 1, add water to 20mL, add 1mL hydroxylamine hydrochloride solution (2.11), 5mL ammonium benzoate solution (2.8), and mix well. (If white precipitate appears, carefully add ammonium hydroxide (2.2) until the white precipitate is just dissolved). Adjust the pH to 4.6-5.2 (check with a precision pH test paper of 3.8-5.4), add 25mL ethyl acetate benzoate solution (2.10), oscillate for 1.5 tmin, let stand to separate, and remove the aqueous phase. 4.3.3 Rinse the stopper and inner wall of the separatory funnel with a small amount of water, and discard the aqueous phase. Add 10mL ammonium benzoate washing solution (2.9), oscillate 30 times, and discard the aqueous phase. Rinse the inner wall of the separatory funnel with a small amount of water again (do not shake), and discard the aqueous phase. 4.3.4 Use hydrochloric acid solution (2.1) to extract twice (10 mL each time, shake for 1 minute). Collect the two extracts in a 100 mL beaker, evaporate to about 0.2~~0.3 mL at low temperature, remove and cool slightly, rinse Table III and the wall of the beaker with water, the volume is about 5 mL, heat to slightly boil to dissolve the salts, cool, and transfer to a 50 mL volumetric flask, control the volume to about 20 mL. 4.3.5 Add 1 mL of ascorbic acid solution (2.12) and 3 drops of thymol blue solution (2.13) to the volumetric flask, and adjust the pH with hydrochloric acid (2.1) or ammonium hydroxide (2.2) until the solution turns orange. Add 0.5 mL of hydrochloric acid (2.1), 2.5 mL of chrome blue solution (2.4), and add 2.5 mL of OP solution (2.5), 2.5 mL of TPB solution (2.6), and 5 mL of ammonium acetate buffer solution (2.7) along the wall of the flask (shake the spoon gently after adding each reagent). After standing for 5 minutes, dilute with water to the scale, mix thoroughly, and leave for 10 minutes. Transfer part of the solution into a 1 cm colorimetric 4.3.6. Take the blank solution accompanying the sample as a reference, measure its absorbance at a wavelength of 610nm on the spectrophotometer, and find the corresponding aluminum content from the working curve.
4.4 Drawing of working curve
GB8647.2-88
Pipette 0, 1.00, 2.00, 3.00, 4.00, 5.00mL of aluminum standard solution (2.15), respectively, and place them in a group of 50mL volumetric flasks, add water in turn to control the volume to about 20mL, and proceed as in 4.3.5. Take the reagent blank solution as a reference, measure its absorbance at a wavelength of 610nm on the spectrophotometer, and draw a working curve with the aluminum content as the horizontal axis and the absorbance as the vertical axis. 5 Calculation of analysis results
Calculate the percentage of aluminum by the following formula:
Al(%) = m: V,X 10-
Wherein: m, —-amount of aluminum found from the working curve, g; V. —-total volume of test solution, mL;
V, —volume of test solution taken, mL;
sample volume,.
6 Allowable difference
-× 100
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
0. 000 3 ~ 0. 000 8
>0. 000 8~ 0. 002 0
Additional remarks:
This standard is under the technical jurisdiction of Beijing Mining Research Institute. This standard was drafted by Beijing Mining Research Institute and Jinchuan Nonferrous Metals Company. This standard was drafted by Chongqing Smelter.
The main drafter of this standard is Liu Zhidong.
Allowable Difference
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB128-76 "Nickel Chemical Analysis Method" will be invalid. %
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