GOST 15027.1-77
GOST 15027.1−77 Bronze without tin. Method for the determination of copper (with Amendments No. 1, 2)
GOST 15027.1−77
Group B59
INTERSTATE STANDARD
BRONZE WITHOUT TIN
Method for determination of copper
Non-tin bronze.
Method for the determination of copper
AXTU 1709
Date of introduction 1979−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. REPLACE GOST 15027.1−69
4. The standard fully complies ST SEV 1527−79
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
Section number, paragraph |
| GOST 493−79 |
Chapeau |
| GOST 614−97 |
Chapeau |
| GOST 859−2001 |
Sec. 2 |
| GOST 2062−77 |
Sec. 2 |
| GOST 3760−79 |
Sec. 2 |
| GOST 3769−78 |
Sec. 2 |
| GOST 4109−79 |
Sec. 2 |
| GOST 4204−77 |
Sec. 2 |
| GOST 4461−77 |
Sec. 2 |
| GOST 4478−78 |
Sec. 2 |
| GOST 5841−74 |
Sec. 2 |
| GOST 6563−75 |
Sec. 2 |
| GOST 6691−77 |
Sec. 2 |
| GOST 10484−78 |
Sec. 2 |
| GOST 18175−78 |
Chapeau |
| GOST 18300−87 |
Sec. 2 |
| GOST 18704−78 |
Sec. 2 |
| GOST 25086−87 |
1.1, 4.5 |
6. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
7. EDITION with Amendments No. 1, 2 approved in February 1983, March 1988 (IUS 6−83, 6−88)
This standard specifies a gravimetric method for the electrolytic determination of copper in the tin bronze according to GOST 18175, GOST and GOST 614 493.
The method is based on the allocation of copper by electrolysis when a current of 1.5−2 And weighing evolved at the cathode precipitate of copper and determination remaining in the electrolyte of copper methods: atomic absorption in flame acetylene — air at a wavelength of 324,7 nm and photometric with cuprizone.
(Changed edition, Rev. N 1, 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 25086 add: the result of the analysis taking the arithmetic mean of three (two) of parallel definitions.
(Changed edition, Rev. N 1, 2).
2. APPARATUS, REAGENTS AND SOLUTIONS
Electrolysis setup with a platinum mesh electrode according to GOST 6563.
Atomic absorption spectrometer with a source of radiation for copper.
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461 and diluted 1:1 and 1:2.
Hydrofluoric acid according to GOST 10484.
Sulfuric acid according to GOST 4204 and diluted 1:1, 1:4, 1:50 and 1:99.
Hydrazine sulfate according to GOST 5841, a solution of 10 g/DM.
Rectified ethyl alcohol according to GOST 18300.
Ammonium sulfate according to GOST 3769.
Bromatologia acid according to GOST 2062.
Boric acid according to GOST 18704.
Mix to dissolve I; prepared as follows: to 600 cmof a solution of nitric acid, diluted 1:1, add 40 cm
hydrofluoric acid, 15 g of boric acid, mix and add water to 1000 cm
. Solution store in a plastic container.
Citric acid according to GOST 10484.
Sulfamic acid according to GOST 4478, solution 100 g/DM.
Bromine according to GOST 4109.
The mixture for dissolving II, is prepared by mixing nine volumes bromatological acid with one volume of bromine.
Ammonia water according to GOST 3760 and diluted 1:4.
Urea according to GOST 6691, a solution of 10 g/DM.
Ammonium citrate, solution; is prepared as follows: 150 g of citric acid dissolved in 400 cmof water, add with stirring 100 cm
of concentrated ammonia solution, cool, add another 100 cm
of ammonia, cool and add water to volume of 1000 cm
.
Bis-cyclohexanone-oxalyl-dihydrazone (cuprizone), the solution is prepared as follows: 2.5 g cuprizone dissolved with stirring in 900 cmof water at a temperature of 60−70 °C.
After cooling, the solution was filtered into a dark glass jar, add water to volume of 1000 cm. The solution to fit 10 days.
Copper according to GOST 859, with a mass fraction of copper not less than 99.9%.
Standard solutions of copper.
Solution A, prepared as follows: 0.5 g of copper is dissolved in 10 cmof nitric acid, diluted 1:1, and remove the oxides of nitrogen by boiling, transferred to a volumetric flask with a capacity of 500 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0.001 g of copper.
Solution B is prepared as follows: 10 cmof solution A is placed in a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
1 cmof a solution contains 0.0001 g of copper.
(Changed edition, Rev. N 1).
3. ANALYSIS
3.1. For alloys not containing tin, lead and silicon
The weight of bronze weighing 0.5−1 g were placed in a glass with a capacity of 250−300 cm, add 15 cm
of nitric acid, diluted 1:1, cover with a watch glass and dissolve without heating, and then by 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
, 7 cm poured
sulphuric acid, diluted 1:4, and produce 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 of iron or manganese in excess of 1% is added during electrolysis in small portions 1.0−1.5 cm.of the hydrazine sulfate solution.
After the bleaching solution the side of the Cup and protruding parts of the electrodes is washed with water, add about 20 cmof water and continue the electrolysis for another 10−15 min. If the 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 with ethyl alcohol. The cathode is dried at (100±5) °C to constant weight, cooled and weighed.
(Changed edition, Rev. N 2).
3.2. For alloys containing silicon
The sample of bronze with a weight of 1 g was placed in a platinum Cup, pour 10 cmof nitric acid, diluted 1:1, 2−3 cm
hydrofluoric acid and cover with a lid of PTFE or platinum. Once dissolved, evaporated to a small volume (until wet salts).
Then pour 5 cmof 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 cold water, the solution is heated, transferred to a beaker 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 3.1
.
3.3. For alloys containing tin
The sample of bronze with a weight of 1 g was placed in Teflon beaker with a capacity of 250 cm, add 6−8 drops (0.4−0.5 cm
) hydrofluoric acid, 15 cm.
of nitric acid diluted 1:1, cover (plate) made of PTFE or platinum and is dissolved without heating, and then by heating. The lid and the side of the Cup washed with water and heated to boiling, then diluted with water to 150 cm
and the electrolysis is carried out as specified in clause 3.1.
3.4. For alloys with a mass fraction of lead from 0.8% to 2%
The sample of bronze with a weight of 1 g is 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 electrolysis by applying a mesh of the cylindrical electrodes, 15−20 min add 7 cm
of sulphuric acid, diluted 1:4, and continue the electrolysis as described in claim 3.1.
3.5. For alloys with a mass fraction of lead of more than 20%
The sample of bronze with a weight of 1 g is dissolved in 15 cmof nitric acid, diluted 1:2 in a beaker with a capacity of 250−300 cm
, covered with watch glass during heating. After dissolution, the sample is washed with glass and glass walls of 50 cm
of water, poured a thin stream of 5−6 cm
of sulphuric acid, diluted 1:4 (under constant stirring with a glass rod), add 2 g of ammonium sulfate and defend the solution for 3−4 h. the Precipitate of lead sulphate filtered off on a tight filter and washed 5−6 times with sulfuric acid, diluted 1:50.
From the filtrate allocate copper by electrolysis as described in claim 3.1.
3.6. For alloys with a mass fraction of antimony to 0.05%
The sample of bronze with a weight of 1 g was placed in a beaker with a capacity of 300 cm, adding 25 cm
of the mixture to dissolve I and dissolved by careful heating. The solution is incubated 1 h at 90 °C, cooled to room temperature, add 50 cm
of water, ammonia until the appearance of the precipitate, the nitric acid diluted 1:1, to dissolve the solids and in excess of 20 cm
of nitric acid, diluted 1:1, add 10 cm
of a solution of sulfamic acid, dilute with water to 150 cm
and the electrolysis is carried out as specified in clause 3.1.
3.7. For alloys with a mass fraction of antimony over 0.05%
The sample of bronze with a weight of 1 g was placed in a beaker with a capacity of 250−300 cmand dissolved in 15 cm
of the mixture for dissolution II on careful heating. After dissolving, the solution was evaporated to dryness. Then another two times add 15 cm
of the mixture for the dissolution of II and the solution evaporated to dryness each time. To the dry residue add 10 cm
of nitric acid and the solution evaporated to a syrupy condition. Then add 10 cm
sulphuric acid diluted 1:1, and the solution was evaporated until a white smoke of sulfuric acid.
The residue is cooled, rinse walls of beaker with water and again evaporated until a white smoke of sulfuric acid. To the cooled residue add 50 cmof water, heated to dissolve the salts, is cooled and in case of sedimentation on the filter tight filter and washed 3−4 times with sulfuric acid diluted 1:99. The precipitate is discarded, the filtrate is added 10 cm
boiled nitric acid, diluted 1:1, 10 cm
of a solution of sulfamic acid, water to a volume of 100−150 cm
and the electrolysis is carried out as specified in clause 3
.1.
3.8. Determination of residual copper in the electrolyte
The electrolyte, after separation of copper, is evaporated to a volume of 40 cm, transferred to a volumetric flask with a capacity of 50 cm
, made up to the mark with water and mix.
3.8.1. Determination of copper by atomic absorption spectrometry
3.8.1.1. Measure the atomic absorption of copper in the flame acetylene-air at a wavelength of 324,7 nm in parallel with the solutions to construct the calibration curve.
3.8.2. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 100 cmis placed 0,5; 1,0; 2,0; 3,0; 4,0 and 5,0 cm
standard solution B copper. To all flasks add 5 cm
of nitric, diluted 1:1, and sulfuric diluted 1:1, acid, made up to the mark with water and measure the atomic absorption of copper, as specified in clause
3.8.3. Definition of copper by the photometric method with cuprizone
3.8.3.1. Aliquot part of the electrolyte is 50 cmis placed in a volumetric flask with a capacity of 100 cm
, is poured 10 cm
of a solution of ammonium citrate and ammonia solution, diluted 1:4 to slightly alkaline reaction, then add 2 cm
of ammonia solution diluted 1:4, 10 cm
solution cuprizone immediately topped up to the mark with water and mix. the pH of the obtained solution should be of 8.5−9.0. After 5 min, but not later than 30 min, measure the optical density of the solution on a photoelectrocolorimeter with an orange filter in the cell length of 3 cm or on the spectrophotometer at a wavelength of 600 nm in a cuvette length of 1 cm with a Solution of comparison is the solution of the reference experiment.
3.8.4. Construction of calibration curve
In six of the seven volumetric flasks with a capacity of 100 cmis placed 0,5; 0,75; 1,0; 1,5; 2,0 and 2,5 cm
standard solution B copper.
To all flasks add 5 cmof nitric acid, diluted 1:1, 10 cm
of a solution of citrate of ammonium and further analyze as described in section
According to the obtained results build a calibration curve. Solution comparison is the solution not containing copper.
3.6−3.8.4. (Added, Rev. N 1).
4. PROCESSING OF THE RESULTS
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 — volume of the solution of the electrolyte, cm
;
— the mass of cathode, g;
— the mass of the cathode with segregated copper, g;
— the concentration of copper was found in the calibration schedule, g/cm
;
— weight of charge, g
.
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 — volume of the solution of the electrolyte, cm
;
— volume aliquote part of the solution, cm
;
— the mass of cathode, g;
— the mass of the cathode with segregated copper, g;
— the mass of copper was found in the calibration schedule g;
— the weight of the portion,
G.
4.3. The absolute discrepancies in the results of parallel measurements (the rate of convergence) must not exceed the permissible values given in the table.
| Mass fraction of copper, % |
|
|
| From 50 to 80 |
0,15 | 0,4 |
| SV. 80 |
0,20 | 0,5 |
(Changed edition, Rev. N 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 (a measure of reproducibility) shall not exceed the values given in the table.
4.5. Control of accuracy of analysis results
Control of accuracy of analysis results is carried out according to State standard samples without tin bronzes, certified in the prescribed manner, in accordance with GOST 25086.
4.4, 4.5. (Added, Rev. N 2).
