GB/T 5121.10-1996 Chemical analysis methods for copper and copper alloys - Determination of cobalt content

This standard specifies the determination method of tin content in copper and copper alloys. This standard is applicable to the determination of tin content in copper and copper alloys. Determination range: 0.001 0% to 0.50%. GB/T 5121.10-1996 Chemical analysis method for copper and copper alloys Determination of cobalt content GB/T5121.10-1996 Standard download decompression password: www.bzxz.net

1 Scope
National Standard of the People's Republic of China
Chemical analysis methods for copper and copper alloys-Determination of tin content Copper and copper alloys-Determination of tin content Part I Method 1
GB/5121.10---1996
Replaces B5121.10
GB 5122.183
GB 6520. 5
GB 8002. 2
GB 853:0. 13
Spectrophotometric determination of tin content using phenylfluorone-polyethylene glycol octylphenyl ether This standard specifies the method for measuring the tin content in copper and copper alloys. This standard is applicable to the determination of tin content in copper and copper alloys. Determination range: 0.0010%~0.50%. 2 Referenced 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 Standardization work guidelines for the preparation of chemical analysis methods GB1467-78 General principles and general provisions for chemical analysis methods of metallurgical products GB7729-87 General principles for spectrophotometric methods for chemical analysis of metallurgical products 3 Method summary
According to the type and content of the sample, the sample is dissolved in nitric acid, potassium sulfate-sulfuric acid or mixed acid, and the tin is co-precipitated and enriched with hydrated manganese dioxide or directly colored with phenylfluorone and polyethylene glycol octylphenyl ether in a dilute sulfuric acid medium, and its absorbance is measured at a wavelength of 510nm on a spectrophotometer.
4 Reagents
4.1 Potassium sulfate.
4. 2 Sulfuric acid (ol. 81 g/mL).
4.3 Nitric acid (pl.42 g/mL).
Ammonia water (0.90 g/mL).
Nitric acid (1+1).
4.6 Mixed acid: Add 300 ml nitric acid (4.3) and 200 ml sulfuric acid (4.2) to 500 ml water under constant stirring. 4.7
Manganese sulfate (MnSO4·H2O) solution (50 g/L). 4.8 Potassium permanganate solution (10 g/L).
4. 9 Sulfuric acid [c(H2SO4)=5 mol/L]. 4.10 Ascorbic acid solution (10 g/L).
4.11 Tartaric acid solution (100 g/L).
4.12 Oxalic acid (C,H,O4·2H2O) solution (1.3 g/L). 4.13 Polyethylene glycol phenyl ether solution (5+95). Approved by the State Administration of Technical Supervision on November 4, 1996, and implemented on April 1, 1997. GB/T 5121. 10-1996. 4.14 Phenylfluorone solution (0.3 g/L): Weigh 0.15 g of phenylfluorone. Dissolve it completely with 200 ml of anhydrous ethanol and 5 ml of sulfuric acid (113). Transfer it to a 500 ml volumetric flask, dilute to the mark with anhydrous ethanol, and mix well. 4.15 Tin standard: Stock solution: Weigh 0.1000 g of pure tin, place it in a 150 ml beaker, add 5 ml of sulfuric acid (4.2), heat to dissolve, cool and transfer it to a 1000 ml volumetric flask, wash the beaker with sulfuric acid (1+9) and dilute to the mark, and mix well. This solution contains 10) ug of tin per ml. 4.16 Tin standard solution: Pipette 20.00 mL of the tin standard storage solution (4.15) into a 500 mL volumetric flask, dilute to scale with 0.5 mol/L sulfuric acid Ec (H.S0), and mix well. This solution contains 4 g of tin in 1 mL. 4.17 p-Nitrophenol solution (1 g/L).
5 Instruments
Spectrophotometer.
6 Analysis steps
6.1 Test materials
Weigh the sample according to Table 1, accurate to 0.0001 g. Table 1
Tin content, somebzxz.net
0. 001 0~0. 003 0
0. 003 0~0. 006 0
0. 006 0~ 0. 012
20.012~0.040
>0.040~0. 080
0.080～0. 15
0.15~0.28
0. 28 ~0. 50
Sample g
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
6.3.1 Dissolution and enrichment
6.3.1.1 Sample volume with tin content not more than 0.012%.ml
Volume.ml
Put the sample (6.1) in a 400ml beaker, add 20ml nitric acid (4.5), cover with a watch glass, heat to dissolve and boil to remove nitrogen oxides, wash Table III and the wall of the cup with water, add water to 150ml, add 5mL manganese sulfate solution, boil, add 5mL potassium permanganate solution dropwise with constant stirring, boil for 5min, let stand for 3min, filter with medium-speed quantitative filter paper, wash the beaker and precipitate with hot water 4 to 5 times. Wipe the glass rod and the precipitate in the beaker with a small piece of filter paper and put it in the funnel, and then wash the beaker and precipitate with hot water 2 to 3 times. Transfer the precipitate and filter paper into a 200mL beaker, add 10mL nitric acid, 8mL sulfuric acid (4.2), cover with a glass, heat until sulfur trioxide emits white smoke, if the solution is black, add 1-2mL nitric acid (4.3) to evaporate, repeat the process until the solution is clear. The following operations are performed according to the sample type: a) Electrolytic copper: wash the glass with water and remove it, heat at low temperature until sulfur trioxide emits white smoke, move the beaker to a high temperature to evaporate for 10min, cool, add 20mL water, cover with glass III, boil for 1min, cool, wash glass III with water, transfer to a 100mlL volumetric flask, wash the beaker with water and dilute to the scale, mix well. According to Table 1, transfer the test solution to a 50ml volumetric flask. Add 1 drop of p-nitrophenol solution, neutralize with ammonia water until the solution just turns yellow, immediately drop sulfuric acid (4.9) until the yellow color fades and add 5ml in excess. Cool. b) Processing of copper and copper alloys: Add 8g potassium sulfate to a beaker, cover with Table III, heat until the potassium sulfate dissolves, then transfer the beaker to a wet electric stove, heat until the solution boils and keep for 50min. Cool, add 50ml water, boil for 1min, cool, wash the table with water, transfer the solution to a 100ml volumetric flask, wash the beaker with water and dilute to the mark, mix. According to Table 1, transfer the test solution to a 50ml volumetric flask, add 1 drop of p-nitrophenol solution, neutralize with ammonia water until the solution just turns yellow, immediately drop sulfuric acid (4.9) until the yellow color fades and add 5ml in excess and cool. 6.3.1.2 Samples with tin content greater than 0.012%
Operate according to the sample type:
a) Add copper: Put the sample (6.1) into a 200ml beaker, add 8g potassium sulfate and 8ml sulfuric acid (4.2). Cover with a lid, heat until the potassium sulfate is dissolved, then move the beaker to a high-temperature electric furnace. After the sample and copper sulfate precipitate are completely dissolved, keep the solution at a boiling state for 50min, cool, add 50ml water, boil for 1min, cool, wash the lid with water, and transfer the solution to the corresponding volumetric flask according to Table 1. Wash the beaker with water and dilute to the scale, mix well. Transfer the test solution into a 50ml volumetric flask according to Table 1, neutralize with ammonia water until copper oxyfluoride is precipitated, immediately add sulfuric acid (4.9) dropwise until the precipitate is dissolved and 5ml excess, and cool. b) Copper alloy: Place the sample (6.1) in a 200mL beaker, add 5mL of mixed acid, and cover with Table III. Heat at low temperature until the sample is completely dissolved, add 10mL of water, boil to remove nitrogen oxides, cool, wash the table with water, transfer the solution to the corresponding volumetric bottle according to Table 1, wash the beaker with water and dilute to the scale, and mix well. If there is lead sulfate precipitation or black silicide at this time, filter 250mL of the test solution in the beaker according to Table 1 and transfer it to a 50mL volumetric flask, and add 5mL of sulfuric acid (4.9). 6.3.2 Color development
Add 5 drops of potassium permanganate solution to the volumetric flask, let it stand for 1min, add 3mL of ascorbic acid solution, mix, let it stand for 1min, add 2mL of tartaric acid solution, 2mL of oxalic acid solution, 2.5mL of polyethylene glycol octylphenyl ether solution, and 3.0mL of phenylfluorone solution. Dilute to the scale with water. Mix well. Let it stand for 10min.
6.3.3 Measurement
Put part of the solution into a 1cm absorption tube and use the blank solution accompanying the sample as a reference. Measure its absorbance at a wavelength of 510nm on a spectrophotometer and find the corresponding tin amount from the working curve. 6.4 Drawing of the working curve
6.4.1 Pipette 0,0.80, 1.60, 2.40, 3.20, 4.00 ml of tin standard solution are placed in a group of 50 mL hooded bottles 1, and 5 ml of sulfuric acid (4.9) is added. The following is carried out according to 6.3.2. 6.4.2 Transfer part of the solution into a 1 cm absorbent tube, use the reagent blank as a reference, and measure the absorbance at a spectrophotometric wavelength of 510 nm. Use the tin amount as the horizontal axis and the absorbance as the vertical axis to draw a working curve. 7 Expression of analysis results
Calculate the percentage of tin according to formula (1):
Sn(%) - X10 × 100
Where: m, the amount of tin found from the working curve, g; V.—total volume of test solution, ml.;
V. The volume of the test solution taken, ml.;
ma-·The mass of the sample, g.
The result is expressed to two decimal places. If the tin content is less than 0.10%, it shall be expressed to 3 decimal places; if it is less than (°010%, it shall be expressed to 1 decimal place.
8 Allowable difference
The difference between the analysis results of laboratories shall not be greater than the allowable difference listed in Table 2.243
9 Range
0. 001 0~ 0. 003 0
0.003 0--0. 006 0
≥ 0. 006 0~ 0. 012
>0.012~0.035
>0. 035~- 0. 12
>0. 12～0. 30
20. 30~~0. 50
GB/T 5121. 10 -- 1996
Part 2
Method 2
Determination of tin content by potassium iodate titration
This standard specifies the method for determining the tin content in copper and copper alloys. This standard is applicable to the determination of the tin content in copper and copper alloys. Determination range: >0.50%~10.00%. 10 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of this standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4---88 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB1467-78 General principles and general provisions for chemical analysis method standards for metallurgical products 11 Summary of the method
The sample is dissolved in hydrochloric acid and hydrogen peroxide, and tin is separated by coprecipitation with ferric hydroxide. In the hydrochloric acid solution, mercuric chloride is used as a catalyst, and sodium hypophosphite is used to reduce tetravalent tin to divalent tin. Valence tin. Use starch as indicator and titrate with potassium iodate standard titration solution. 12 Reagents
Calcium carbonate.
12.2 Hydrogen peroxide (30%).
Hydrochloric acid (1+1).
Ammonia water (1+1).
Ferric chloride (FeCl, ·6H,O) solution (10g/L) Washing solution: Dissolve 0.5g ammonium chloride in water, add 50mL ammonia water (1+1), and dilute to 1000ml with water. Mercury solution: Dissolve 0.5g mercuric chloride in 100ml water. 12.8
Sodium hypophosphite (NaH2P02·H,O) solution (614g/L). 12.9 Ammonium thiocyanate solution: Dissolve 50g ammonium thiocyanate in 100ml water. 12.10
Potassium iodide solution: Dissolve 10g potassium iodide in 100ml water. Saturated sodium bicarbonate solution.
Potassium iodate standard titration solution.
GB/T 5121. 10— 1996
12.12.1 Standard titration solution of iodic acid [c(1/6KI0,)=0.08mol/L]. 12.12.1.1 Preparation
Dissolve 0.85g sodium hydroxide in 500mL water, add 3.00g potassium iodate and 12g potassium iodide, transfer to a 1000ml volumetric flask after dissolution, dilute to scale with water, and mix well. 12.12.1.2 Calibration
Weigh 0.90g pure copper and 0.1000g pure tin (99.95%), place in a 400ml beaker, add 20ml hydrochloric acid (12.3), cover with table III, add 5~10mL hydrogen peroxide (12.2), wash table III with water after copper and tin are dissolved, add 100ml water, and heat for 2min. The following is carried out according to 14.3.2 to 14.3.4. Weigh another 0.90g of pure copper and make a blank test together with the calibration. Perform three parallel measurements. The range of the volume of potassium iodate standard titration solution consumed in the calibration should not exceed 0.10mL. Take the average value. Otherwise, re-calibrate. Calculate the actual concentration of potassium iodate standard titration solution according to formula (2): m
c = (V,- V.) × 0. 059 34
武: c-
actual concentration of potassium iodate standard titration solution, mol/L; volume of potassium iodate standard titration solution consumed by tin-containing solution during calibration, mL; V-volume of potassium iodate standard titration solution consumed by blank solution during calibration, ml.n,
0.059 34-
mass of tin, g;
mass of tin equivalent to 1.00ml. potassium iodate standard titration solution [c(1/6KIO,)=1.000mol/L], g/mol12.12.2potassium iodate standard titration solution [c(1/6KI0))=0.03mol/L]. 12.12.2.1 Preparation
Pipette 200.0mL of potassium iodate standard titration solution (12.12.1) into a 500mL volumetric flask, dilute to the mark with water, and mix. 12.12.2.2 Calibration
Weigh 2.000g of pure copper and 0.0200g of pure tin (99.95%), place in a 400mL beaker, add 30mL of hydrochloric acid (12.3), cover with a beaker, drop 5-10mL of hydrogen peroxide (12.2), wash the beaker with water after the copper and tin are dissolved, add 100mL of water, heat for 2min, and proceed as in 14.3.2-14.3.4. Take another 2.00g of pure copper and perform a blank test together with the calibration. The range of the volume of potassium iodate standard titration solution consumed for the three parallel determinations should not exceed 0.20 ml, and the average value is taken. The actual concentration of potassium iodate standard titration solution is calculated according to formula (2). 12.13 Starch solution: Weigh 0.5 g of soluble starch, place it in a 200 mL beaker, add a little water, stir well, pour it into 100 ml of boiling water, boil, and cool.
13 Instruments
Tin reduction device, see schematic diagram 1.
14 Analysis steps
14.1 Test material
Inner diameter 2
GB/T 5121.10—1996
1 Tin solution; 2 Conical flask; Rubber tube; 4 Glass tube; 5 Saturated sodium bicarbonate solution Figure 1 Schematic diagram of tin reduction device
Weigh the sample according to Table 3, accurate to 0.0001 g. Table 3
Tin content, %
>0. 50～3. 00
>3.00~10.00
Material·g
Carry out two independent determinations and take the average value. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
Amount of hydrochloric acid, mL
Concentration of standard titration solution
0.03 mol/1.
0. 08 mol/L
14.3.1 Place the sample in a 400mL beaker, add hydrochloric acid according to the amount in Table 3, cover with a watch glass, add 5～10mL of hydrogen peroxide, and after the sample is completely dissolved, cover with Table III, add 100mL of water, and heat for 2min. 14.3.2 Add 25mL of ferric chloride solution, neutralize with ammonia water until the copper ions are converted into copper ammonia complex ions and the excess is 5mL, cover with Table III, boil for 2min, filter with medium-speed qualitative filter paper when the solution is warm, wash with warm washing liquid 3~~~4 times, and discard the filtrate. 14.3.3 Use 90mL of warm hydrochloric acid to dissolve the precipitate on the wall of the cup and the filter paper, and wash the filter paper, then wash the beaker and filter paper with warm water 4~5 times, collect the filtrate and washing liquid in a 500mL conical flask, add 10mL of mercuric chloride solution and 10mL of sodium hypophosphite solution. Cover with the Geiger funnel stopper filled with saturated sodium bicarbonate solution according to the schematic diagram, or insert the other end of the conical flask stopper into the cup filled with saturated sodium bicarbonate solution according to the schematic diagram, boil for 5min, cool slightly, and then cool to below 15℃. If brown arsenic precipitates appear before black metallic mercury precipitates when the solution begins to boil, boil for only 1 minute, remove the stopper, and filter the solution through a G3 filter into another 500 mL flask while the solution is warm.In a conical flask, wash the ground snail with a small amount of hydrochloric acid, add 5mL of mercuric chloride solution to the solution, and then cover it with a Geiger funnel stopper filled with saturated sodium bicarbonate solution as shown in the diagram, or insert the other end of the conical flask stopper into a saturated sodium bicarbonate solution as shown in the diagram, boil for 5 minutes, cool slightly, and then cool to below 15°C. 14.3.4 Remove the stopper of the reduction device, quickly add 10mL of ammonium sulfide solution, 5mL of potassium iodide solution, 10ml of starch solution, and 1-2g of calcium carbonate, and titrate with potassium iodate standard titration solution (12.12.1 or 12.12.2) according to Table 3 until the test solution turns star blue and is stable for at least 20 seconds as the end point.
15 Expression of analysis results
GB/T 5121. 10
Calculate the percentage of tin according to formula (3):
Snc%) - c:(Va- V)× 0. 059 34 × 100m
Wu Zhong: (—actual concentration of potassium iodate standard titration solution.mol/L; V,—volume of potassium iodate standard titration solution consumed by the test solution during the determination, ml. Volume of potassium iodate standard titration solution consumed by the blank solution during the determination, ml; V
—mass of the sample.
The result should be expressed to two decimal places
16 Tolerance
The difference in analysis results between laboratories should not be greater than the tolerability listed in Table 4, Table 4
>0. 50~1. 00
1. 00~～2. 00
>2. 00~~ 6. 00
6. 00~10. 00
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