GOST 1652.1-77
GOST 1652.1−77 Alloys copper-zinc. Methods for determination of copper (with Amendments No. 1, 2, 3, 4)
GOST 1652.1−77
Group B59
STATE STANDARD OF THE USSR
ALLOYS COPPER-ZINC
Methods for determination of copper
Copper-zinc alloys. Methods for the determination of copper
AXTU 1709
Date of introduction 1978−07−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
Y. F. Chuvakin, M. B. Taubkin, A. A. Nemodruk, N. In. Egiazarov (head), A. I. Vorobyov
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. REPLACE GOST 1652.1−71
4. The standard fully complies with ISO 1554−76*
________________
* Access to international and foreign documents referred to here and hereinafter, can be obtained by clicking on the link to the site shop.cntd.ru. — Note the manufacturer’s database.
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph |
| GOST 8.315−91 |
2.4.5, 3.5.4 |
| GOST 859−78 |
2.2, 3.2 |
| GOST 1020−77 |
Chapeau |
| GOST 3652−69 |
2.2 |
| GOST 3760−79 |
2.2 |
| GOST 4204−77 |
2.2 |
| GOST 4232−74 |
3.2 |
| GOST 4461−77 |
2.2, 3.2 |
| GOST 5457−75 |
2.2 |
| GOST 5841−74 |
2.2 |
| GOST 6344−73 |
2.2 |
| GOST 6563−75 |
2.2 |
| GOST 6691−77 |
2.2, 3.2 |
| GOST 9656−75 |
2.2 |
| GOST 10163−76 |
3.2 |
| GOST 10484−78 |
2.2 |
| GOST 15527−70 |
Chapeau |
| GOST 17711−93 |
Chapeau |
| GOST 18300−87 |
2.2 |
| GOST 22867−77 |
2.2 |
| GOST 25086−87 |
1.1, 2.4.5, 3.5.4 |
| GOST 27067−86 |
3.2 |
| GOST 27068−86 |
3.2 |
6. Resolution of the state standard from
7. REVISED (June 1997) with Amendments No. 1, 2, 3, 4, approved in October 1981 and November 1987, October 1989, December 1992 (IUS 12−81, 2−88, 2−90, 3−93)
This standard specifies the electrolytic gravimetric and titrimetric methods for the determination of copper when the mass fraction of copper from 45% in copper-zinc alloys according to GOST 15527, GOST and GOST 17711 1020.
The standard fully complies with ISO 1554−76.
(Changed edition, Rev. N 3).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 25086 add: the result of the analysis be the arithmetic mean of results of three (two) of parallel definitions.
(Changed edition, Rev. N 2).
2. GRAVIMETRIC, ELECTROLYTIC METHOD OF DETERMINING COPPER
2.1. The essence of the method
The method is based on the electrolytic release of copper at a current density of 1.5 to 2.0 A/DMand a voltage of from 2.0 to 2.5 In and weighing evolved at the cathode precipitate of copper. The copper remaining in the electrolyte is determined photometrically with cuprizone or pikramenos-Epsilon or atomic absorption method in the flame acetylene-air.
2.2. Apparatus, reagents and solutions
Installation of electrolysis with a platinum mesh electrode according to GOST 6563.
Photoelectrocolorimeter or spectrophotometer with all accessories.
Atomic absorption spectrometer with all accessories and lamp with hollow cathode for copper.
Nitric acid according to GOST 4461 and diluted 1:1.
Sulfuric acid according to GOST 4204, diluted 1:1 and 1:4 solution 1 mol/DM.
Hydrazine sulfate according to GOST 5841.
Hydrofluoric acid according to GOST 10484.
The technical rectified ethyl alcohol according to GOST 18300.
Ammonium nitrate according to GOST 22867.
Irrigation solution; prepared as follows: 10 cmof concentrated nitric acid and 20 g of ammonium nitrate dissolved in 1 DM
of water.
Acetylene according to GOST 5457.
Citric acid according to GOST 3652.
Ammonia water according to GOST 3760 and diluted 1:4.
Ammonium citrate solution: 150 g of citric acid dissolved in 40 cmof water, stirring, add 100 cm
of ammonia and cooled. Then add 100 cm
of ammonia, again cool and add water to 1 DM
.
Phenolphthalein 0,1% alcohol solution.
Bicyclohexyl-oxacillinase (cuprizone), a 0.5% solution in a mixture of water and alcohol (4:1).
Metal copper brand M0 according to the GOST 859.
Standard solutions of copper
Solution a: 0,1000 g of copper is dissolved in 10 cmof nitric acid, in low boiling removes oxides of nitrogen. After cooling, the solution is transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix.
1 cmof solution A contains 0.1 mg of copper.
Solution B: 25 cmsolution And placed in a volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix.
1 cmof a solution contains 0.01 mg of copper.
Solution: 0.1 g of copper is dissolved in 10 cmof nitric acid (1:1). After dissolution and cooling, add 5 cm
of sulphuric acid (1:1) and the solution is evaporated prior to the allocation of white smoke of sulfuric acid. The residue is cooled, rinse the walls of the glass with water and re-evaporated prior to the allocation of white smoke of sulfuric acid. After cooling, the residue is dissolved in 20−30 cm
of sulphuric acid (1 mol/DM
) when heated, the solution is transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with sulphuric acid (1 mol/DM
) and mixed.
1 cmof the solution contains 1 mg of copper.
Solution G: 10 cmsolution is placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with sulphuric acid (1 mol/DM
) and mixed.
1 cmsolution G contains 0.1 mg of copper.
Solution D: 10 cmsolution G was placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with sulphuric acid (1 mol/DM
) and mixed.
1 cmof solution D contains 0.01 mg of copper.
Boric acid according to GOST 9656.
Sulfamic acid, solution 100 g/DM.
Urea according to GOST 6691.
Mix to dissolve: 600 cmof nitric acid, diluted 1:1, add 40 cm
hydrofluoric acid and 15 g of boric acid, stirred to dissolve and made up to 1 DM
. Solution store in a plastic container.
Ascorbic acid, a solution of 10 g/DM.
Thiourea according to GOST 6344, solution 100 g/DM.
Pyramid-Epsilon, a solution of 1 g/DM.
2.1, 2.2. (Changed edition, Rev. N 4).
2.3. Analysis
2.3.1. For alloys not containing tin, lead and silicon
A sample of alloy weighing 1 g is placed in a beaker with a capacity of 250−300 cm, add 15 cm
of nitric acid, diluted 1:1, cover with a watch glass and dissolve first without heating and then with heating.
After dissolution of the sample and removal of nitrogen oxides by boiling washed the glass and walls of beaker with water, diluted the solution with water to 100−150 cm, add 0.5−1 g of urea, 7 cm poured
sulphuric acid, diluted 1:4, highlight copper by electrolysis.
The electrolysis is conducted at a current of 1.5−2 A and a voltage of 2.5 V with stirring.
For alloys with a mass fraction more than 1% of iron or manganese is added during the electrolysis 0.5 g of hydrazine sulphate.
After the bleaching solution the side of the Cup and protruding parts of the electrodes is washed with water, added to a glass about 20 cmof water and continue the electrolysis for another 10−15 min. If the newly immersed part of the cathode, copper is not separated, the electrolysis is complete. Otherwise, the electrolysis lead for another 30 minutes and re-control of the completeness of separation of copper.
At the end of the electrolysis without turning off the current, the electrodes are rinsed from probyvali water. Then turn off the current and washed cathode with copper, immersing it successively in three beakers of distilled water, then immersed in a beaker containing 150−200 cmof ethanol (the alcohol in the glass used for washing no more than 15−20 cathodes). The cathode is dried at a temperature of about 105 °C to constant weight, cooled and weighed.
2.3.2. For alloys containing silicon in excess of 0.05%
A sample of alloy weighing 1 g is placed in a platinum Cup, pour 10 cmof nitric acid, diluted 1:1, and 2−3 cm
hydrofluoric acid, cover with a lid of PTFE or platinum and dissolve first without heating and then with heating. Evaporate the solution until wet salts, then pour 5 cm
of sulphuric acid diluted 1:1, and evaporated the solution to release white smoke of sulfuric acid. A Cup of cool, dissolve salt in 30−40 cm
of hot water, transfer the solution into a glass with a capacity of 250−300 cm
, top up with water to 100−150 cm
, 8 cm pour
nitric acid, diluted 1:1, and produce copper by electrolysis as described in claim 2.3.1
.
2.3.3. For alloys containing tin over 0.05%
2.3.3.1. By placing the tin in a soluble fluoride complex
A sample of alloy weighing 1 g is placed in a Teflon beaker with a capacity of 250 cm, add 6−8 drops (0.4−0.5 cm
) hydrofluoric acid, 10 cm
of nitric acid, diluted 1:1, PTFE glass close lid and dissolve first without heating and then with heating. The lid and the side of the Cup washed with water and the solution heated to boiling, then diluted with water to 150 cm
and the electrolysis is carried out as specified in clause
2.3.3.2. With the separation of tin in the form of metalbands acid
A sample of alloy weighing 1 g is placed in a beaker with a capacity of 250 cm, add 15 cm
of nitric acid, diluted 1:1, cover with a watch glass and dissolved under heating. After complete dissolution of the sample and remove the oxides of nitrogen by boiling. Glass and walls of beaker rinse with water, add 3 g of ammonium nitrate and the solution evaporated to 5−10 cm
. The residue is diluted with hot water up to 60−70 cm
, a glass cover watch glass and the solution boiled for 5 min. Glass and the side of the Cup washed with water, the precipitate metalbands acids defend in a water bath at 60−70 °C for about 30 min and filtered on a filter with a dense filtrowanie ground. The filter residue thoroughly washed with hot flushing with a solution of 7−8 times. To the filtrate add water up to 150 cm
, add 7 cm
of sulphuric acid, diluted 1:4, and further analysis are as indicated in claim
2.3.3.3. (Deleted, Rev. N 3).
2.3.4. For alloys with a mass fraction of lead from 0.3 to 3%
A sample of alloy weighing 1 g was dissolved in 15 cm.of nitric acid diluted 1:1 in glass with a capacity of 250−300 cm
, covered with watch glass during heating. After dissolution of the sample and removal of nitrogen oxides by boiling washed the glass and walls of beaker with water, diluted the solution with water to 100−150 cm
and carry out the electrolysis. 25−30 min add 7 cm
of sulphuric acid, diluted 1:4, and continue the electrolysis as described in claim
(Changed edition, Rev. N 3).
2.3.5. Universal method of dissolution for all brands of copper-zinc alloys
A sample of alloy weighing 1 g is placed in a beaker with a capacity of 600 cmand dissolved in 25 cm
of the mixture to dissolve without heating. After the reaction, the side of the Cup then rinsed with water, heat the solution to a temperature of about 90 °C and leave the solution for 1 h at the same temperature until complete removal of nitrogen oxides. Cooled to room temperature and add 50 cm
of water. Ammonia is added to the appearance of the precipitate, and then nitric acid diluted 1:1, to dissolve the precipitate, add another 20 cm
of nitric acid, diluted 1:1, 10 cm
of a solution of sulfamic acid and diluted with water to 300 cm
. Then do as mentioned in paragraph
2.3.6. Photometric determination of the residual copper cuprizone
(Changed edition, Rev. N 4).
2.3.6.1. The electrolyte and washings after separation of copper by electrolytic method, if necessary, is evaporated to a volume of 200 cm, cooled and transferred to a volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix.
2.3.6.2. In a volumetric flask with a capacity of 100 cmis placed 25 cm
of the electrolyte, dilute with water to about 50 cm
, add 10 cm
of ammonium citrate solution, one drop of solution of phenolphthalein and ammonia, diluted 1:4, laboratoi the color of the solution. Then add 1 cm
of ammonia, diluted 1:4 in excess of 10 cm
solution cuprizone immediately topped up to the mark with water and mix.
The pH value of the solution should be about 8.5−9 on the indicator paper.
After 20−30 min, measure the optical density on a photoelectrocolorimeter with an orange filter in the cell with thickness of the absorbing layer of 2−3 cm or on the spectrophotometer at 600 nm in a cuvette with a thickness of absorbing layer 1 cm. Solution comparison the solution serves as the reference experiment.
2.3.6.3. Construction of calibration curve.
In five out of six volumetric flasks with a capacity of 100 cmis placed 5,0; 10,0; 15,0; 20,0 and 30,0 cm
standard solution B, which corresponds to 0,05; 0,10; 0,15; 0,2 and 0,3 mg of copper. All flasks is poured water to a volume of approximately 50 cm
, add 10 cm
of a solution of citrate of ammonium and then do as mentioned in paragraph
Solution comparison is the solution not containing copper.
On the found values of optical densities and their corresponding grades of copper to build the calibration graph.
2.3.6. Photometric determination of the residual copper pikramenos-Epsilon
2.3.6.1. The electrolyte and washings after separation of copper by electrolysis was evaporated to a volume of 40−50 cm. After cooling, add 2 cm
of sulphuric acid (1:1) and the solution is evaporated prior to the allocation of white smoke of sulfuric acid. The residue is cooled, rinse the walls of the glass with water and re-evaporated prior to the allocation of white smoke of sulfuric acid.
After cooling, to the residue add 20−30 cmof water and heated to dissolve the salts. After cooling, the solution was transferred to volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix.
2.3.6.2. In a volumetric flask with a capacity of 50 cmis placed aliquot part (1 cm
) of the resulting solution, add 4 cm
of sulphuric acid (1 mol/DM
), 2 cm
of ascorbic acid solution, 2 cm
of mortar Piramida-Epsilon, made up to the mark with water and mix.
Measure the optical density of the solution on the spectrophotometer at 550 nm or photoelectrocolorimeter with a yellow filter in a cuvette with a thickness of the absorbing layer 2 see Solution comparison solution is the same sample just before adding Piramida-Epsilon is administered 2 cmof a solution of thiourea .
2.3.6.3. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 50 cmis placed 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cm
standard solution D copper. To all flasks add sulfuric acid (1 mol/DM
) to a volume of 5 cm
, 2 cm
of ascorbic acid solution, 2 cm
kramina-Epsilon and further analysis is carried out as specified in clause
Solution comparison is the solution not containing copper.
2.3.6 and
2.3.7. Method of atomic-absorption determination of copper
2.3.7.1. Preparation for analysis is also carried out according to claim
2.3.7.2. Preparation of the calibration solutions
Eight volumetric flasks with a capacity of 250 cmis placed at 15 cm
of nitric acid, add water to 100 cm
, add 7 cm
of sulphuric acid (1:4) and 0.5−1 g of urea. Then, in seven volumetric flasks placed 2,0; 4,0; 6,0; 8,0; 12,0; 16,0 20.0 cm
standard solution A, which corresponds to 0,2; 0,4; 0,6; 0,8; 1,2; 1,6 and 2.0 mg of copper. The solutions were topped up to the mark with water and mix.
(Changed edition, Rev. N 3).
2.3.7.3. Analysis
The electrolyte solution is sprayed into the flame of acetylene-air and measure the atomic absorption of copper, using light with a wavelength of 324,7 nm, in parallel with solutions for constructing the calibration curve and the reference experiment.
According to the obtained values of the nuclear absorption corresponding copper content in the electrolyte is determined by the constructed schedule.
2.4. Processing of the results
2.4.1. Mass fraction of copper () in percentage in the case of determining the remaining in the electrolyte of copper by atomic absorption spectrometry described by the formula
where is the mass of the cathode with segregated copper, g;
— the mass of cathode, g;
— the concentration of copper was found in the calibration schedule, g/cm
;
— the volume of the electrolyte, cm
;
— weight of charge, g
.
2.4.2. Mass fraction of copper () in percentage in the case of determining the remaining in the electrolyte of copper by the photometric method is calculated by the formula
where is the mass of the cathode with segregated copper, g;
— the mass of cathode, g;
— the mass of copper was found in the calibration schedule g;
— the volume of the electrolyte, cm
;
— volume aliquote part of the solution, cm
;
— the weight of the portion,
2.4.1,
2.4.3. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed 0,15%.
2.4.4. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed 0,21%.
2.4.3,
2.4.5. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315 in accordance with GOST 25086.
(Changed edition, Rev. N 4).
3. TITRIMETRIC IODOMETRIC METHOD FOR THE DETERMINATION OF COPPER IN ALLOYS WITH A MASS FRACTION OF NOT MORE THAN 0.1% OF IRON, NOT MORE THAN 0.2% SILICON
3.1. The essence of the method
The method is based on the recovery of cu (II) to cu (I) with potassium iodide and titration of liberated iodine with a solution of sodium servational.
3.2. Reagents and solutions
Nitric acid according to GOST 4461 and diluted 1:1.
Sulfamic acid, saturated solution.
Urea according to GOST 6691, saturated solution; prepared as follows: 100 g of urea dissolved in 100 cmof hot water.
Sodium Chernovetskiy according to GOST 27068; 0.05 M solution; prepared from fixanal or 25 g of salt is dissolved in water and diluted with water in a volumetric flask with a capacity of 1 DMto the mark. To stabilize the solution add 0.3−0.5 cm
of chloroform per 1 DM
of the solution.
Potassium iodide according to GOST 4232 and a solution of 200 g/DM, freshly prepared.
Ammonium radamisty according to GOST 27067.
A mixture of Bruns: is prepared as follows: 20 g potassium iodide and 64 g Rodenstock ammonium dissolved in water and diluted to 1 DM.
The water-soluble starch according to GOST 10163, a solution of 5 g/DM, freshly prepared.
Copper brand M0k or M00k GOST 859.
3.3. Analysis
A sample of alloy weighing 0.3 g when the content of copper not more than 70%, and 0.2 grams for the other alloys placed in a conical flask with a capacity of 250 cm, flow 10 cm
of nitric acid, diluted 1:1 and dissolved by heating. After dissolution add 2 cm
of a solution of sulfamic acid or 1 cm
of a solution of urea to remove oxides of nitrogen. The walls of the flask is washed with water, diluted to 100 cm
, flow 20 cm
of a solution of potassium iodide or 10 cm
of a mixture of Bruns and titrated with a solution of sodium servational.
When the brown colouring of the solution will be barely noticeable, add 2−5 cmof starch solution and continue titration to the disappearance of the blue color of the solution.
3.4. Determination of the mass concentration of the solution servational sodium
0.2 g of copper was placed in a conical flask with a capacity of 250 cm, flow 10 cm
of nitric acid, diluted 1:1 and dissolved by heating. Add 2cm
of a solution of sulfamic acid or 1 cm
of the urea solution, pour 100 cm
of water, 20 cm
of a solution of potassium iodide or 10 cm
of a mixture of Bruns and titrated with a solution of sodium servational as specified in claim 3.3.
The mass concentration of the solution servational sodium (), expressed in grams of copper per 1 cm
of a solution, calculated by the formula
where is the mass of the copper sample, g;
the volume of the solution servational sodium, spent on titration, sm
.
3.5. Processing of the results
3.5.1. Mass fraction of copper () in percent is calculated by the formula
where is the mass concentration of the solution servational sodium, expressed in grams of copper 1 cm
;
the volume of the solution servational sodium, expended for titration of sample, cm
;
— the weight of the portion of alloy,
3.5.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed 0.30 percent.
(Changed edition, Rev. N 2, 3, 4).
3.5.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (the reproducibility) shall not exceed 0.42 percent.
(Changed edition, Rev. N 3, 4).
3.5.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved GOST 8.315 in accordance with GOST 25086.
(Changed edition, Rev. N 4).
