GB/T 5121.12-1996 Chemical analysis methods for copper and copper alloys - Determination of antimony content

This standard specifies the method for measuring the antimony content in copper and copper alloys. This standard is applicable to the determination of antimony content in copper and copper alloys. Determination range: 0.001 0% to 0.070%. GB/T 5121.12-1996 Chemical analysis method for copper and copper alloys Determination of antimony content GB/T5121.12-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method for copper and copper alloys
Determination of antimony content
Copper and copper alloys-Determination of antimony content1ScopebZxz.net
This standard specifies the method for measuring the antimony content in copper and copper alloys. GB/T 5121.12.--1996
Replaces G35121.12
(GB 5122.17
GB 6520.4.86
Gr 8002.887
GB 8550. 14
This standard is applicable to the determination of antimony content in copper and copper alloys. Determination range: 0.0010%~0.070%. 2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest versions of the following standards: GB1.4-88 Guidelines for standardization work, regulations for the preparation of chemical analysis methods, GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products, GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products 3 Method summary
The sample is dissolved in mixed acid, sulfuric acid smokes and evaporates to near dryness. In the hydrochloric acid medium, the complex formed by the complex anion of pentavalent antimony and crystal violet is extracted with toluene, and the absorbance is measured at a wavelength of 610nm on a spectrophotometer. 4 Reagents
4.1 Anhydrous sodium carbonate.
4.2 Toluene.
4.3 Hydrofluoric acid (pl.13g/mL).
4.4 Mixed acid: 1 unit volume of hydrochloric acid (p1.19g/ml.) and 1 unit volume of nitric acid (pl.42g/ml.) are mixed. 4.5 Hydrochloric acid (1+1).
4.6 Sulfuric acid (1+1).
|4.7 Phosphoric acid (1+1).
4.8 Tin chloride solution (100g/L): Weigh 10g of stannous chloride (SnClz: 2H,0), place in a 250ml beaker, add 100ml of hydrochloric acid (4.5), and dissolve under slight heat. Prepare immediately before use. 4.9 Sodium nitrite solution (100g/L). Prepare immediately before use. 4.10 Solution (500g/L).
4.11 Crystal violet solution (2g/L).
4.12 Standard storage solution: Weigh 0.1000g of pure antimony in a 150ml beaker, add 20ml of sulfuric acid (pl.84g/ml), heat until completely dissolved, cool, and transfer. Pour into a 1000mL volumetric flask. Add 160ml sulfuric acid (4.6), cool, dilute to scale with water. Mix well. This solution contains 0.1mg antimony in 1mL.
4.13 Standard solution: Pipette 5.00mL antimony standard stock solution into a 100mL volumetric flask, dilute to scale with hydrochloric acid (4.5). Mix well. This solution contains 5μg antimony in 1ml.
5 Instruments
Spectrophotometer.
6 Analysis steps
6.1 Test materials
GB/T 5121.12--1996
Weigh the test materials according to Table 1, accurate to 0.0001g. Table 1
Antimony content, %
0. 001 0~0. 005 0
>0. 005 0~0. 010
0. 010-- 0. 025
>0. 025 ~0. 050
≥>0. 050~(0. 25
Carry out two independent determinations and take the average value. 6.2 Blank test
Carry out a blank test with the sample.
6.3 Determination
Sample base g
Dilution volume, ml
6.3.1 Place the sample (6.1) in a 100mL beaker, add 5mL of mixed acid, dissolve with slight heat (add ~5 drops of hydrofluoric acid when analyzing silicon bronze and silicon brass), add 5mL of sulfuric acid, and mix. Heat at low temperature until white smoke appears, and evaporate until almost dry (keep moist). Cool slightly, add 10mL of hydrochloric acid to dissolve the salts.
For samples with an antimony content greater than 0.010%, transfer the solution to a volumetric flask according to Table 1, wash the beaker with hydrochloric acid, and add the washing liquid to the volumetric flask. Dilute to the mark with hydrochloric acid, mix well, and transfer 10.00mL to the original beaker. 6.3.2 Warm the solution, add 0.8ml of stannous chloride solution while shaking, mix well, let stand for 2 minutes, and cool. Transfer the solution to a 125ml separatory funnel, wash the beaker with 10ml of hydrochloric acid in several times, and add the washing liquid to the separatory funnel. 6.3.3 Add 4ml of phosphoric acid to the separatory funnel, mix well, and add 2ml of sodium nitrite solution. Liquid, shake for 2 minutes, add 0.5ml solution, shake for 30 seconds, immediately dissolve 50mL water along the inner wall of the separatory funnel, and quickly add 0.5mL crystal violet solution and 25.0ml Ⅱl benzene. Cover the stopper tightly, shake vigorously for 1 minute, discard the aqueous phase, transfer the organic phase into a 25ml dry volumetric flask pre-added with 0.3-1g anhydrous sodium carbonate, cover the stopper, and shake several times.
6.3.4 Transfer part of the solution into 1cm absorption blood, use toluene as a reference, and measure its absorbance at a wavelength of 610nm on a spectrophotometer. 6.3.5 Subtract the The absorbance of the blank solution. Find the corresponding antimony amount from the working curve. 6.4 Drawing of the working curve
6.4.1 Transfer 0, 1.00, 2.00, 3.00, 4.00, 5.00mL of antimony standard solution and place it in a group of 100mL beakers. Dilute to the scale with hydrochloric acid, and proceed as in 6.3.2 to 6.3.4. 6.4.2 Subtract the absorbance of the reagent blank, and draw the working curve with the antimony amount as the horizontal axis and the absorbance as the vertical axis. 7 Expression of analysis results
Calculate the percentage of antimony according to formula (1):
GB/T 5121.12-1996
Sb(%)
Wherein: mi-
-the amount of antimony found from the working curve, g; V total volume of test solution, mL.
V,-the volume of the test solution taken, mL;
m.the mass of the sample. g.
m, .VoX 10-6
The result is expressed to 3 decimal places. If the antimony content is less than 0.010%, it is expressed to 4 decimal places. 8 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 2. Table 2
0.001 0~~0.003 0
>0. 003 0~0. 010
>0. 010~~0. 020
>0.020~0.040
>0. 040~0. 070
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