GOST 6674.2-96
GOST 6674.2−96 copper phosphorous Alloys. Method for determination of copper
GOST 6674.2−96
Group B59
INTERSTATE STANDARD
COPPER PHOSPHOROUS ALLOYS
Method for determination of copper
Copper-phosphorous alloys.
Method for determination of copper
ISS 77.120.30
AXTU 1709
Date of introduction 2000−07−01
Preface
1 DEVELOPED by the Interstate technical Committee for standardization MTK 107, Donetsk state Institute of non-ferrous metals (Danism)
SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 10 dated 3 October 1996)
The adoption voted:
| The name of the state | The name of the national authority for standardization |
| The Republic Of Azerbaijan | Azgosstandart |
| The Republic Of Belarus | Gosstandart Of The Republic Of Belarus |
| The Republic Of Kazakhstan | Gosstandart Of The Republic Of Kazakhstan |
| The Republic Of Moldova | Moldovastandart |
| Russian Federation | Gosstandart Of Russia |
| The Republic Of Tajikistan | Tajikistandart |
| Turkmenistan | Glavgosekspertiza «Turkmenstandartlary" |
| The Republic Of Uzbekistan | Standards |
| Ukraine | Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated December 19, 2000 N 384-St inter-state standard GOST 6674.2−96 introduced directly as state standard of the Russian Federation from July 1, 2001
4 REPLACE GOST 6674.2−74
1 Scope
This standard specifies electrogravimetry method for the determination of copper in its content of over 80% in copper-phosphorous alloys.
2 Normative references
The present standard features references to the following standards:
GOST 4204−77 sulfuric Acid. Specifications
GOST 4461−77 nitric Acid. Specifications
GOST 6563−75 technical articles made of noble metals and alloys. Specifications
GOST 6674.0−96 copper phosphorous Alloys. General requirements for methods of analysis
GOST 17299−78 ethyl Alcohol technical. Specifications
3 General requirements
General requirements for methods of analysis GOST 6674.0.
4 the essence of the method
The method is based on the electrolytic release of copper from solutions of salts of nitric and sulphuric acids on a platinum cathode and a subsequent measurement of its mass.
5 Apparatus, reagents and solutions
Electrolysis installation.
The cylindrical platinum mesh electrodes according to GOST 6563.
Nitric acid according to GOST 4461, diluted 1:1.
Sulfuric acid according to GOST 4204, diluted 1:4.
Ethyl alcohol, technical (hydrolysis) (ethanol) according to GOST 17299.
6 analysis
A sample of alloy weighing 1 g is placed in a beaker with a capacity of 250 cm, flow 10 cm
of nitric acid, diluted 1:1, and cover with a watch glass. After complete dissolution of the sample clock and the glass wall of the beaker is washed with water and boiling removes oxides of nitrogen, then diluted with water to 150 cm
.
Into the solution is dipped a platinum mesh electrodes. The cathode should be pre-dried and weighed. The solution is electrolyzed with a current of 1.5−2.0 A and a voltage of 2−2. 4 V.
20 min after the start of electrolysis was added 5 cmof sulphuric acid, diluted 1:4, and continue the electrolysis at a current of 1 A until the complete discoloration of the solution. The side of the Cup and protruding parts of the electrodes rinsed with water, add about 20−30 cm
of water and the solution is subjected to electrolysis for another 10 minutes If after 10 minutes svezhemorozhenoj of the grid of the cathode is not a red bar will appear highlighted in copper, the electrolysis is complete. If the process of separation of copper has not ended, the electrolysis is continued for 5−10 min and again check the completeness of the selection.
At the end of the electrolysis without turning off the current, the electrodes are washed, gradually lowering the glass electrolyte.
After that, turn off the juice and wash the cathode with copper, immersing it successively in three beakers with water, and then into the beaker with ethanol.
The cathode is dried at a temperature of 100−105 °C for 5 min, cooled in a desiccator and weighed.
7 Processing of results
7.1 Mass fraction of copper , %, is calculated by the formula
where is the mass of copper allocated for the cathode, g;
— the weight of the portion of alloy,
7.2 the discrepancy between the results of the parallel determinations should not exceed admissible (at p = 0.95) value equal to 0.10%.
7.3 the discrepancy between the results of the analysis shall not exceed allowable (at p = 0.95) value, equal to 0.20%.
