This standard specifies the determination method of beryllium content in copper and copper alloys. This standard is applicable to the determination of beryllium content in copper and copper alloys. Determination range: 1.50% to 2.50%. GB/T 5121.17-1996 Chemical analysis method for copper and copper alloys Determination of beryllium content GB/T5121.17-1996 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 heryllium content,
Copper and copper alloys-Determination of heryllium content1 Scope
This standard specifies the method for determining the beryllium content in copper and copper alloys. This standard is applicable to the determination of the beryllium content in copper and copper alloys. Determination range: 1.50%~2.50%. 2 Referenced standards
GB/T5121.17--1996
Replaces GB5122.885
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, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Standardization work guidelines for chemical analysis method standards GB1467-78 General principles and general provisions for chemical analysis method standards for metallurgical products 3 Method summary
The sample is dissolved in nitric acid and copper is separated by electrolysis. Titanium, iron, nickel, magnesium, aluminum and other coexisting elements are complexed with hydrogen peroxide and ethylene-amine tetraacetic acid, and beryllium is precipitated with diammonium phosphate. After filtering, drying, ashing, and burning at 850°C to be pyrophosphate beryllium, the determination is carried out by weight method. 4 Reagents
4.1 Urea.
4.2 Nitric acid (1+1).
4.3 Sulfuric acid (1+1).
4.4 Hydrochloric acid (1+1).
4.5 Ammonia water (1+1).
4.6 Hydrogen peroxide (30%).
4.7 Ammonium hydrogen phosphate [(NH),HPO.] solution (100 g/L). 4.8 Ammonium acetate (CH;COONH,) solution (200 g/L). 4.9 Ammonium nitrate solution (500 g/L).
4.10 Ammonium nitrate solution (20 g/L).
4.11 Ethylenediaminetetraacetic acid solution (100 g/L): Weigh 25 g of ethylenediaminetetraacetic acid in a 300 mL beaker, add about 200 ml of hot water, and add ammonia water dropwise under stirring until completely dissolved. Boil for 3 to 5 minutes and cool to room temperature. Filter and dilute to 250 ml with water.e4.12 Silver nitrate solution (1 g/L).
4.13 Bromocresol green ethanol solution (0.4 g/L). Note: The reagents in 4.7 to 4.11 of this chapter must be filtered before use. Approved by the State Administration of Technical Supervision on November 4, 1996 280
Implemented on April 1, 1997bzxz.net
5 Instruments
5.1 Electrolytic analyzer.
5.2 Platinum mesh electrode and platinum spiral electrode.
6 Analysis steps
GB/T 5121.17—1996
Note: Beryllium and its compounds are toxic substances. Be especially careful when using and operating! The final precipitate should be properly handled. 6.1 Test material
Weigh 1.000g of sample to an accuracy of 0.0001g. Perform two independent coagulation tests and take the average value. 6.2 Test
6.2.1 Place the sample (6.1) in a 250-300 mL tall beaker, add 10 ml nitric acid and 5 ml sulfuric acid, cover with table III, and heat until the sample is completely dissolved. Boil for 3-5 minutes to remove nitrogen oxides, and wash table III and the wall of the cup with water. 6.2.2 Add 5 ml ammonium nitrate solution (4.9). Add water to about 100 ml and heat to 50-60 °C. Use the platinum mesh electrode as the cathode and the platinum spiral electrode as the anode, and perform electrolysis under stirring. First, electrolyze for 5 minutes with a current of 0.5 A, add 0.2 g urea (wash with a small amount of water), increase the current to 2 A, and electrolyze until the blue color of the solution disappears. After 1 hour, wash the table blood, the wall of the cup and the upper part of the electrode mesh with a small amount of water, and continue electrolysis for 15-20 minutes until no copper is precipitated on the newly immersed vanadium mesh electrode. Without cutting off the power supply, remove the electrode and wash with water. 6.2.3 Evaporate the solution to 90~100ml (if there is precipitation, filter it. If the sample contains titanium, add 3ml of hydrogen peroxide), add 10ml of ethylenediaminetetraacetic acid solution, heat and boil for 2~3min, cool. Add 15ml of diammonium hydrogen phosphate solution, neutralize with ammonia water until the solution is turbid, add hydrochloric acid until the solution is clear, and add 3 drops in excess. Add 15mL of ammonium acetate solution while stirring (at this time, add 3 drops of bromocresol green ethanol solution to the solution, the solution should be blue, and blue-green when containing titanium). Place the solution in a boiling water bath and stir continuously to transform the flocculent precipitation into a crystalline precipitation. Keep warm for 10~20 minutes and let stand for 4~5 hours. 6.2.4 Filter the precipitation with slow quantitative filter paper and add a small amount of pulp. Wash the beaker and the precipitate 4-5 times with warm ammonium nitrate solution (4.10), and wipe the glass rod and the wall of the beaker with filter paper to transfer the precipitate to the funnel. Continue to wash the filter paper and the precipitate 7-8 times (until there is no fluoride ion, and check with silver nitrate).
6.2.5 Transfer the filter paper containing the precipitate into a constant weight precipitate, dry and ashed, transfer it into a high temperature furnace and burn it at 850℃ for 1.52h. Take it out, cool it down slightly and put it into a desiccator. Place it on the balance table for 2h, weigh it. Repeat the burning until constant weight. 7 Expression of analytical results
Calculate the white content of beryllium according to formula (1):
(m2-mi)X 0.093 9
Be(%) - -
Where: m2—mass of crucible and precipitate g
mass of crucible, g;
mass of sample, nom;
0.0939—coefficient for converting beryllium pyrophosphate into beryllium. The result is expressed to two decimal places.
8 Allowable difference
The difference between the analysis results of the experimental rates should not be less than 0.05%. X 100.
(1)
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