GB/T 15072.6-1994 Chemical analysis methods for precious metals and their alloys - Determination of iridium content in platinum and palladium alloys
Some standard content:
National Standard of the People's Republic of China
Chemical analysis methods for precious metals and their alloys
Determination of iridium content in platinum and palladium alloys
Platinum ,palladium alloys--Determination of iridium content1 Subject content and scope of application
This standard specifies the method for determining the iridium content in platinum and palladium alloys. GB/T 15072.6.- 94
Replaces GB148979
This standard applies to the determination of iridium content in PtIr10, PtIr17.5, PtIr25, PdIr10 and PdIr18 alloys. The determination range is 5%~30%.
2 Reference standards
GB1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB1467 General principles and general provisions for chemical analysis method standards for metallurgical products 3 Summary of methods
The sample is sealed with hydrochloric acid and hydrogen peroxide and chlorinated and dissolved. The palladium-iridium alloy test solution is replaced with active copper powder to separate palladium, and the iridium is oxidized to tetravalent with sodium chlorate solution in a hydrochloric acid medium.
In a hydrochloric acid and sulfuric acid medium, iridium (IV) is titrated with a standard titration solution of ferrous sulfate. The end point is indicated by the current method, and the coagulation potential is -+ 0.5 V.
4 Reagents
4.1 Hydrogen peroxide (30%).
4.2 Hydrochloric acid (pl.19g/ml.)
4.3 Hydrochloric acid (1+1).
4.4 Hydrochloric acid (1→11).
4.5 Sulfuric acid (2+1).
4.6 Sulfuric acid (1+1).
Saturated sodium chloride solution.
4.8 Sodium fluoride solution (100g/1).
4.9 Active copper powder: weigh 1.0 zinc powder in a 100mL beaker, add 1~2mL water to moisten. 10) ml copper sulfate (197g/L), shake for 2~3min, add 30ml hydrochloric acid (4.4). When the violent reaction stops, pour out the upper solution, add 40ml hydrochloric acid (4.3) and soak overnight. Pour off the upper solution, rinse with water four times, and use. 4.10 Standard solution: weigh 0.250±0.002g sponge-like metallic silver powder, accurate to 0.00005g, put into a special glass tube and dissolve according to Appendix A. Transfer the solution to a 1000ml volumetric flask, add 500ml hydrochloric acid (4.2), cool to room temperature, dilute with water until the solution changes, mix well, 4.11 Ferrous sulfate standard titration solution [c (FeS0, 7H.0) = 0.0011mol/L] 4.11.1 Preparation: Weigh 0.318g ferrous sulfate, dissolve in 1000ml sulfuric acid (4+96), mix well: State Technical Supervision Bureau approved 1994-05-11 199412-01 implementation
GB/T 15072.6-94
4.11.2 Calibration: Calibration is carried out in parallel with the determination of the sample. Take three portions of 20.00ml Iridium standard solution and place them in 100ml measuring cylinders respectively. , add 0.5ml sodium chlorate solution, 4mL hydrochloric acid (4.2), mix well, and let stand for about 10min. For example, 0.2mL of saturated sodium chloride solution, 5mL of sulfuric acid (4.6), add water to a total volume of about 35mL. Insert the air tube and blow air on the air blowing device for 10min [air flow rate per cup is about 1L/min]. Rinse the air tube and the measuring cylinder with about 10mL of water, and blow air for another 10min. Remove and transfer the solution to a 100mL beaker. Rinse the air tube and the measuring cylinder with about 5mL of water. Repeat times. In the above solution, insert a platinum indicator electrode and a saturated calomel electrode, and select a potential of +0.5V. Start the magnetic stirrer and first use a pipette such as 20.00mL of ferrous sulfate standard titration solution. Then use a microburette to titrate the remaining iridium (IV). Current indication, plot the end point. The range of the volume of ferrous sulfate standard titration solution consumed in parallel calibration should not exceed 0.07mL, and the average value is taken. Calculate the actual concentration of ferrous sulfate standard titration solution according to formula (1): mi
V. × 0.192 2
The actual concentration of the standard ferrous sulfate titration solution, mol/L.; Where; c—
The mass of the iridium standard solution transferred, g;
The volume of the standard ferrous sulfate titration solution consumed in the calibration, ml (1)
0.1922--The mass of iridium in grams equivalent to 1.00mL of the standard ferrous sulfate titration solution c(FeSO0,)-1.000mol/LJ.
5 Apparatus
5.1 Current titration apparatus.
5.1.1 Ordinary polarograph (galvanometer sensitivity 1×10-8A/mm/M). 5.1.2 Platinum wire indicator electrode, ×L, mm, 1.0×2.0. 5.1.3 Magnetic stirrer.
5.1.4 Saturated potassium chloride agar salt bridge.
5.1.5 Iron core stirring rod.
5.1.6 Saturated potassium fluoride calomel electrode.
5.2 Blowing device: as shown in the figure below.
5.3 Constant temperature magnetic stirrer.
GB/T15072.6—94
Schematic diagram of blowing device
1-Oil-free gas compressor; 2 Two-way glass piston; 3-Safety bottle; 4-Gas washing bottle (500mL): 5-Potassium dichromate-sulfuric acid washing liquid: 6-Air flow meter (10~15L/min); 7 Volumetric cylinder (100mL); 8-Blowing tube, with 6 small holes at the end; 9-Glass tube ($20mm) 6 Sample
The sample is processed into debris, and finally degreased with ketone, washed, dried, and mixed. 7 Analysis steps
7.1 Test material
Weigh the sample according to Table 1. Accurate to 0.00005g. The dilution volume of the test solution is 100mL, and the aliquot volume is 20.00ml. Table 1
Iridium content, %
5.00~6.50
>6. 50 ~7. 50
>7. 50~8. 50
>8.50~9. 50
> 9. 50-~10. 50
≥10. 50~11. 50
>11. 50~~12. 50
≥12. 50~13. 50
13. 50~~ 14. 50
Sample quantity g
Content, %
>17.50~18.50
18. 50~19. 50
>19. 50~~ 20. 50
>20. 50~ 21. 50
>21.50~~22. 50
>22.50~23. 50 | 50
>16.50~17.50
GB/T 15072.6--94
Continued Table 1
Sample amount,
Carry out two independent determinations and take the average value. 7.2 Determination
7.2.1 Dissolution
Iridium content, %
26. 50 ~ 27. 50
27. 50~28.50
>28.50～30.00
Sample amount
Sample is dissolved according to Appendix A. Transfer the test solution into a 100mL volumetric flask, add 30mL hydrochloric acid (4.2), cool to room temperature, dilute to the mark with water, and mix.
7.2.2 Test solution treatment
7.2.2.1 Transfer 20.00ml of palladium alloy test solution to a 100ml beaker, evaporate to 2ml at low temperature (do not evaporate!), and remove. Add 40ml of hydrochloric acid (4.4) and active copper powder, place the beaker in a water bath on a constant temperature magnetic stirrer, heat and stir in a water bath at 5060 (for 30min, and remove. Filter the test solution into a 200ml beaker with absorbent cotton, wash the beaker and precipitate four times with hydrochloric acid (4.4). Evaporate the filtrate to 5ml at low temperature, add 10ml of hydrochloric acid (4.2), 2ml of sodium chlorate solution, cover the surface blood, and boil to 5ml, and remove. Transfer the test solution to a 100ml measuring cylinder, wash the cup wall and surface m with 6ml of hydrochloric acid (4.2) three times, and then rinse with water four times, about 2.5ml add 1ml sodium chlorate solution, mix well, let stand for about 10min, add 20ml sulfuric acid (4.5). 7.2.2.2 Pipette 20.00ml of platinum alloy test solution into a 100ml measuring cylinder, add 8ml hydrochloric acid (4.2), 5ml sulfuric acid (4.6) and 0.2ml saturated sodium chloride solution, add water to the volume of about 35ml. 7.2.3 Blow
Insert the blow tube into the test solution (7.2.2.1) or (7.2.2.2), and blow on the blow device (the air flow rate of palladium alloy test solution is 1.5L/min per cup, and the air flow rate of platinum alloy test solution is 11./min per cup). Blow for 10min first, rinse the measuring cylinder wall and blow tube with about 10ml water, blow for another 10min, and remove it. Transfer the test solution into a 100ml beaker, rinse the blow tube and measuring cylinder with about 5ml water, and repeat = times. 7.2.4 Titration
Place the test solution (7.2.3) on an amperometric titration apparatus and insert a platinum indicator electrode and a saturated calomel electrode. Set the potential to +0.5 V. Turn on the magnetic stirrer and first use a pipette to add 20.00 mL of ferrous sulfate standard titration solution to titrate most of the iridium (N), and then use a microburette to titrate the remaining (NV). Plot the volume of the ferrous sulfate standard titration solution against the corresponding current value, and extrapolate the two straight lines. The volume corresponding to the intersection is the end point of the titration.
8 Expression of analysis results
The percentage content calculated according to formula (2):
I(%)- c×Vxx0.1922 × 100
ma XV
actual concentration of ferrous sulfate standard titration solution, mol/L; where c-----
total volume of test solution, ml;
V.----volume of test solution taken, ml.;
V---volume of ferrous sulfate standard titration solution consumed in titrating the test solution, ml.; mo—mass of sample, g;
(2)
0.1922—mass of iridium in grams equivalent to 1.00ml ferrous sulfate standard titration solution (Lc(FeSO.)=1.00mol/1) in grams.
The result should be expressed to two decimal places.
9 Allowable difference
GB/T15072.6-94
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Iridium content
5. 00~~9. 00
>9.00～11.00
>11. 00~17. 00
≥17. 00~19. 00
>19. 00~24. 00
>24.00~~26.00
>26. 00～30. 00bZxz.net
Allowable difference
A1 Method Summary
GB/T 15072.6--94
Appendix A
Sealed tube fluoride dissolution method for refractory precious metals and their alloys (reference)
The sample is placed in a special hard glass tube, and a mixed solvent of hydrochloric acid and hydrogen peroxide is added. The mouth of the glass tube is sealed in the flame of a gasoline blowtorch, and the glass tube is placed at a temperature of 140-300°C to dissolve the sample. This method is applicable to the dissolution of refractory precious metals and their alloys that are refractory or insoluble under normal conditions. A2 Reagents and equipment
A2.1 Hydrochloric acid (p1.19g/mL).
A2.2 Hydrogen peroxide (30%).
A3 Apparatus
A3.1 Glass sealing tube: Use a 95-type hard glass tube with a wall thickness of 2.5-4mm and an inner diameter of about 14mm, blown into the shape of Figure Al. 100~150
Figure A1 Schematic diagram of glass sealing tube shape
A3.2 Protective steel sleeve: Use medium carbon steel to turn into the shape of Figure A2. Figure A2 Schematic diagram of protective steel sleeve shape
1-Steel sleeve cap; 2-Copper sheet; 3-Steel sleeve body; 4-Steel sleeve cavity A3.3 Special washing bottle: Use a glass tube to pull into a curved tube with a capillary, connect it to a soft plastic bottle, and make it into the shape of Figure A3. 84
A4 Operation steps
GB/T 15072.6-
Figure A3 Schematic diagram of the shape of a special washing bottle
1--Plastic bottle; 2--Rubber stopper; 3 Glass tube A4.1 Dissolution of insoluble precious metals and their alloys except iridium and iridium coinage: Weigh the metal or alloy sample and place it in the glass tube of Figure A1. First add 5~10mL of hydrochloric acid, and then carefully add 1~~2mL of hydrogen peroxide along the tube wall at a volume ratio of hydrochloric acid to hydrogen peroxide of 5:1 before sealing the tube. Hold the glass tube with your left hand and immediately immerse the tube body in ice water to prevent the mixed solvent from reacting violently. Use the flame of an oxygen-gasoline blowtorch to gradually heat the melted neck glass, rotate the glass tube, seal the tube mouth with tweezers and remove the excess molten glass. Continue to heat the tube head at high temperature and appropriately adjust the depth of the tube body immersed in ice water so that the glass at the head of the tube melts and shrinks into a circular arc seal. Remove the sealed tube from the ice water, lower the flame temperature (turn off oxygen) and anneal the tube seal for 1~2 minutes. After cooling, place the tube in an iron sleeve (to prevent the sealed tube from bursting and damaging other sealed tubes), and place it in an oven and heat it to 140℃ to dissolve the sample. A4.2 Dissolution of iridium and iridium monoxide: Place the sample in a glass tube as above, add solvent, and seal the tube. Place the sealed tube in the protective steel sleeve as shown in Figure A2, fill the steel sleeve cavity with gasoline, pad a piece of copper sheet at the mouth of the steel sleeve, and then tighten the screw cap at the mouth of the steel sleeve to prevent air leakage. Place the steel sleeve in a crucible furnace and heat it to 250~300℃ to dissolve the sample. A4.3 Operation of opening the tube to release the test solution: Take out the glass sealed tube with dissolved sample from the oven or protective steel sleeve and cool it to room temperature (when taking out the sealed tube from the protective steel sleeve, the steel sleeve should be cooled to room temperature before loosening the screw cap and taking out the sealed tube). Use a file to file a notch along the circle 10~15mm away from the seal, and clean the outer wall of the sealed tube. Put the sealed tube into the refrigerator and freeze it for more than 2 hours, take it out, and immediately use pliers to clamp it at the notch and break the seal. Pour the test solution into the beaker, insert the capillary of the bottle washing bottle as shown in Figure A3 into the inverted sealed tube mouth, and connect the beaker to the bottom of the capillary. When squeezing the plastic washing bottle with your hands, the water jetted from the capillary will wash the test solution in the tube into the beaker along the inner wall of the glass tube. 85
Additional remarks:
GB/T 15072.6—
This standard was proposed by the Nonferrous Metals Industry Corporation. This standard was drafted by the Kunming Precious Metals Research Institute. This standard was drafted by the Kunming Precious Metals Research Institute. The main drafter of this standard is Guo Qiuquan
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB946 (Pt-6)-78 "X-ray Fluorescence Spectrometric Analysis Method of Iridium in Platinum-Iridium Alloy" will be invalid.
The results should be expressed to two decimal places.
9Tolerance
GB/T15072.6-94
The difference between the analysis results of laboratories should not be greater than the tolerance listed in Table 2. Table 2
Iridium content
5. 00~~9. 00
>9.00～11.00
>11. 00~17. 00
≥17. 00~19. 00
>19. 00~24. 00
>24.00~~26.00
>26. 00～30. 00
Tolerance
A1 Method Summary
GB/T 15072.6--94
Appendix A
Sealed tube fluoride dissolution method for refractory precious metals and their alloys (reference)
The sample is placed in a special hard glass tube, and a mixed solvent of hydrochloric acid and hydrogen peroxide is added. The mouth of the glass tube is sealed in the flame of a gasoline blowtorch, and the glass tube is placed at a temperature of 140-300°C to dissolve the sample. This method is applicable to the dissolution of refractory precious metals and their alloys that are refractory or insoluble under normal conditions. A2 Reagents and equipment
A2.1 Hydrochloric acid (p1.19g/mL).
A2.2 Hydrogen peroxide (30%).
A3 Apparatus
A3.1 Glass sealing tube: Use a 95-type hard glass tube with a wall thickness of 2.5-4mm and an inner diameter of about 14mm, blown into the shape of Figure Al. 100~150
Figure A1 Schematic diagram of glass sealing tube shape
A3.2 Protective steel sleeve: Use medium carbon steel to turn into the shape of Figure A2. Figure A2 Schematic diagram of protective steel sleeve shape
1-Steel sleeve cap; 2-Copper sheet; 3-Steel sleeve body; 4-Steel sleeve cavity A3.3 Special washing bottle: Use a glass tube to pull into a curved tube with a capillary, connect it to a soft plastic bottle, and make it into the shape of Figure A3. 84
A4 Operation steps
GB/T 15072.6-
Figure A3 Schematic diagram of the shape of a special washing bottle
1--Plastic bottle; 2--Rubber stopper; 3 Glass tube A4.1 Dissolution of insoluble precious metals and their alloys except iridium and iridium coinage: Weigh the metal or alloy sample and place it in the glass tube of Figure A1. First add 5~10mL of hydrochloric acid, and then carefully add 1~~2mL of hydrogen peroxide along the tube wall at a volume ratio of hydrochloric acid to hydrogen peroxide of 5:1 before sealing the tube. Hold the glass tube with your left hand and immediately immerse the tube body in ice water to prevent the mixed solvent from reacting violently. Use the flame of an oxygen-gasoline blowtorch to gradually heat the melted neck glass, rotate the glass tube, seal the tube mouth with tweezers and remove the excess molten glass. Continue to heat the tube head at high temperature and appropriately adjust the depth of the tube body immersed in ice water so that the glass at the head of the tube melts and shrinks into a circular arc seal. Remove the sealed tube from the ice water, lower the flame temperature (turn off oxygen) and anneal the tube seal for 1~2 minutes. After cooling, place the tube in an iron sleeve (to prevent the sealed tube from bursting and damaging other sealed tubes), and place it in an oven and heat it to 140℃ to dissolve the sample. A4.2 Dissolution of iridium and iridium monoxide: Place the sample in a glass tube as above, add solvent, and seal the tube. Place the sealed tube in the protective steel sleeve as shown in Figure A2, fill the steel sleeve cavity with gasoline, pad a piece of copper sheet at the mouth of the steel sleeve, and then tighten the screw cap at the mouth of the steel sleeve to prevent air leakage. Place the steel sleeve in a crucible furnace and heat it to 250~300℃ to dissolve the sample. A4.3 Operation of opening the tube to release the test solution: Take out the glass sealed tube with dissolved sample from the oven or protective steel sleeve and cool it to room temperature (when taking out the sealed tube from the protective steel sleeve, the steel sleeve should be cooled to room temperature before loosening the screw cap and taking out the sealed tube). Use a file to file a notch along the circle 10~15mm away from the seal, and clean the outer wall of the sealed tube. Put the sealed tube into the refrigerator and freeze it for more than 2 hours, take it out, and immediately use pliers to clamp it at the notch and break the seal. Pour the test solution into the beaker, insert the capillary of the bottle washing bottle as shown in Figure A3 into the inverted sealed tube mouth, and connect the beaker to the bottom of the capillary. When squeezing the plastic washing bottle with your hands, the water jetted from the capillary will wash the test solution in the tube into the beaker along the inner wall of the glass tube. 85
Additional remarks:
GB/T 15072.6—
This standard was proposed by the Nonferrous Metals Industry Corporation. This standard was drafted by the Kunming Precious Metals Research Institute. This standard was drafted by the Kunming Precious Metals Research Institute. The main drafter of this standard is Guo Qiuquan
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB946 (Pt-6)-78 "X-ray Fluorescence Spectrometric Analysis Method of Iridium in Platinum-Iridium Alloy" will be invalid.
The results should be expressed to two decimal places.
9Tolerance
GB/T15072.6-94
The difference between the analysis results of laboratories should not be greater than the tolerance listed in Table 2. Table 2
Iridium content
5. 00~~9. 00
>9.00～11.00
>11. 00~17. 00
≥17. 00~19. 00
>19. 00~24. 00
>24.00~~26.00
>26. 00～30. 00
Tolerance
A1 Method Summary
GB/T 15072.6--94
Appendix A
Sealed tube fluoride dissolution method for refractory precious metals and their alloys (reference)
The sample is placed in a special hard glass tube, and a mixed solvent of hydrochloric acid and hydrogen peroxide is added. The mouth of the glass tube is sealed in the flame of a gasoline blowtorch, and the glass tube is placed at a temperature of 140-300°C to dissolve the sample. This method is applicable to the dissolution of refractory precious metals and their alloys that are refractory or insoluble under normal conditions. A2 Reagents and equipment
A2.1 Hydrochloric acid (p1.19g/mL).
A2.2 Hydrogen peroxide (30%).
A3 Apparatus
A3.1 Glass sealing tube: Use a 95-type hard glass tube with a wall thickness of 2.5-4mm and an inner diameter of about 14mm, blown into the shape of Figure Al. 100~150
Figure A1 Schematic diagram of glass sealing tube shape
A3.2 Protective steel sleeve: Use medium carbon steel to turn into the shape of Figure A2. Figure A2 Schematic diagram of protective steel sleeve shape
1-Steel sleeve cap; 2-Copper sheet; 3-Steel sleeve body; 4-Steel sleeve cavity A3.3 Special washing bottle: Use a glass tube to pull into a curved tube with a capillary, connect it to a soft plastic bottle, and make it into the shape of Figure A3. 84
A4 Operation steps
GB/T 15072.6-
Figure A3 Schematic diagram of the shape of a special washing bottle
1--Plastic bottle; 2--Rubber stopper; 3 Glass tube A4.1 Dissolution of insoluble precious metals and their alloys except iridium and iridium coinage: Weigh the metal or alloy sample and place it in the glass tube of Figure A1. First add 5~10mL of hydrochloric acid, and then carefully add 1~~2mL of hydrogen peroxide along the tube wall at a volume ratio of hydrochloric acid to hydrogen peroxide of 5:1 before sealing the tube. Hold the glass tube with your left hand and immediately immerse the tube body in ice water to prevent the mixed solvent from reacting violently. Use the flame of an oxygen-gasoline blowtorch to gradually heat the melted neck glass, rotate the glass tube, seal the tube mouth with tweezers and remove the excess molten glass. Continue to heat the tube head at high temperature and appropriately adjust the depth of the tube body immersed in ice water so that the glass at the head of the tube melts and shrinks into a circular arc seal. Remove the sealed tube from the ice water, lower the flame temperature (turn off oxygen) and anneal the tube seal for 1~2 minutes. After cooling, place the tube in an iron sleeve (to prevent the sealed tube from bursting and damaging other sealed tubes), and place it in an oven and heat it to 140℃ to dissolve the sample. A4.2 Dissolution of iridium and iridium monoxide: Place the sample in a glass tube as above, add solvent, and seal the tube. Place the sealed tube in the protective steel sleeve as shown in Figure A2, fill the steel sleeve cavity with gasoline, pad a piece of copper sheet at the mouth of the steel sleeve, and then tighten the screw cap at the mouth of the steel sleeve to prevent air leakage. Place the steel sleeve in a crucible furnace and heat it to 250~300℃ to dissolve the sample. A4.3 Operation of opening the tube to release the test solution: Take out the glass sealed tube with dissolved sample from the oven or protective steel sleeve and cool it to room temperature (when taking out the sealed tube from the protective steel sleeve, the steel sleeve should be cooled to room temperature before loosening the screw cap and taking out the sealed tube). Use a file to file a notch along the circle 10~15mm away from the seal, and clean the outer wall of the sealed tube. Put the sealed tube into the refrigerator and freeze it for more than 2 hours, take it out, and immediately use pliers to clamp it at the notch and break the seal. Pour the test solution into the beaker, insert the capillary of the bottle washing bottle as shown in Figure A3 into the inverted sealed tube mouth, and connect the beaker to the bottom of the capillary. When squeezing the plastic washing bottle with your hands, the water jetted from the capillary will wash the test solution in the tube into the beaker along the inner wall of the glass tube. 85
Additional remarks:
GB/T 15072.6—
This standard was proposed by the Nonferrous Metals Industry Corporation. This standard was drafted by the Kunming Precious Metals Research Institute. This standard was drafted by the Kunming Precious Metals Research Institute. The main drafter of this standard is Guo Qiuquan
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB946 (Pt-6)-78 "X-ray Fluorescence Spectrometric Analysis Method of Iridium in Platinum-Iridium Alloy" will be invalid.6—
This standard was proposed by the Nonferrous Metals Industry Corporation. This standard was drafted by the Kunming Precious Metals Research Institute. This standard was drafted by the Kunming Precious Metals Research Institute. The main drafter of this standard is Guo Qiuquan
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB946 (Pt-6)-78 "X-ray Fluorescence Spectroscopy Analysis Method of Iridium in Platinum-Iridium Alloy" will be invalid.6—
This standard was proposed by the Nonferrous Metals Industry Corporation. This standard was drafted by the Kunming Precious Metals Research Institute. This standard was drafted by the Kunming Precious Metals Research Institute. The main drafter of this standard is Guo Qiuquan
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB946 (Pt-6)-78 "X-ray Fluorescence Spectroscopy Analysis Method of Iridium in Platinum-Iridium Alloy" will be invalid.
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