GOST 13047.3-2002
GOST 13047.3−2002 Nickel. Cobalt. Methods for determination of cobalt in cobalt
GOST 13047.3−2002
Group B59
INTERSTATE STANDARD
NICKEL. COBALT
Methods for determination of cobalt in cobalt
Nickel. Cobalt.
Methods for determination of cobalt in cobalt
ISS 77.120.40*
AXTU 1732
_____________________
* In the Index «National standards» 2005 GLD —
OKS 77.120.40 and
Date of introduction 2003−07−01
Preface
1 DEVELOPED by Interstate technical committees for standardization MTK 501 Nickel and MTC 502 «Cobalt», JSC «Gipronikel ' Institute"
INTRODUCED by Gosstandart of Russia
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 21 dated may 30, 2002)
The adoption voted:
| The name of the state |
The name of the national authority standardization |
| The Republic Of Azerbaijan |
Azgosstandart |
| The Republic Of Armenia |
Armastajad |
| The Republic Of Belarus |
Gosstandart Of The Republic Of Belarus |
| Georgia |
Gosstandart |
| The Kyrgyz Republic |
Kyrgyzstandard |
| The Republic Of Moldova |
Moldovastandart |
| Russian Federation |
Gosstandart Of Russia |
| The Republic Of Tajikistan |
Tajikstandart |
| Turkmenistan |
The MDCSU «Turkmenstandartlary" |
| The Republic Of Uzbekistan |
Standards |
| Ukraine |
Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation on standardization and Metrology from September 17 2002 N 334-St inter-state standard GOST 13047.3−2002 introduced directly as state standard of the Russian Federation from July 1, 2003
4 REPLACE GOST 741.1−80 except section 1
AMENDED, published in the IUS N 7, 2004
The amendment introduced by the legal Bureau «Code"
1 Scope
This standard specifies electrogravimetry (in mass fraction to 98.8%) and calculated (at a mass fraction of more than 98.8 percent) methods for the determination of cobalt in cobalt GOST 123.
2 Normative references
The present standard features references to the following standards:
GOST 123−98 Cobalt. Specifications
GOST 199−78 Sodium acetate 3-water. Specifications
GOST 3118−77 hydrochloric Acid. Specifications
GOST 3760−79 Ammonia water. Specifications
GOST 3769−78 Ammonium sulfate. Specifications
GOST 4204−77 sulfuric Acid. Specifications
GOST 4461−77 nitric Acid. Specifications
GOST 5457−75 Acetylene, dissolved and gaseous. Specifications
GOST 5841−74 Hydrazine sulfate
GOST 6563−75 technical articles made of noble metals and alloys. Specifications
GOST 8776−99 Cobalt. Methods of chemical-atomic-emission spectral analysis
GOST 11125−84 nitric Acid of high purity. Specifications
GOST 13047.1−2002 Nickel. Cobalt. General requirements for methods of analysis
GOST 13047.5−2002 Nickel. Cobalt. Methods for determination of Nickel in cobalt
GOST 13047.6−2002 Nickel. Cobalt. Methods for determination of carbon
GOST 13047.7−2002 Nickel. Cobalt. Methods of determining sulphur
GOST 13047.8−2002 Nickel. Cobalt. Method for determination of silicon
GOST 13047.9−2002 Nickel. Cobalt. Method of determination of phosphorus
GOST 13047.10−2002 Nickel. Cobalt. Methods for determination of copper
GOST 13047.11−2002 Nickel. Cobalt. Method of determining zinc
GOST 13047.12−2002 Nickel. Cobalt. Methods for determination of antimony
GOST 13047.13−2002 Nickel. Cobalt. Methods for determination of lead
GOST 13047.14−2002 Nickel. Cobalt. Methods for determination of bismuth
GOST 13047.15−2002 Nickel. Cobalt. Method for determination of tin
GOST 13047.16−2002 Nickel. Cobalt. Methods for determination of cadmium
GOST 13047.17−2002 Nickel. Cobalt. Methods of iron determination
GOST 13047.18−2002 Nickel. Cobalt. Methods for determination of arsenic
GOST 13047.19−2002 Nickel. Cobalt. Method for the determination of aluminium
GOST 13047.20−2002 Nickel. Cobalt. Method for determination of magnesium
GOST 13047.21−2002 Nickel. Cobalt. Methods for determination of manganese
GOST 18300−87 ethyl rectified technical. Specifications
GOST 24147−80 aqueous Ammonia of high purity. Specifications
3 General requirements and safety requirements
General requirements for methods of analysis and safety requirements when performing work — according to GOST 13047.1.
4 Electrogravimetry method
4.1 Method of analysis
The method is based on weighing the mass of cobalt, Nickel, copper and zinc emitted by electrolysis on a platinum cathode from the ammonium environment, and determining the residual weight of cobalt in the solution after electrolysis spectrophotometric or atomic absorption method. The mass fraction of Nickel, copper and zinc is determined according to GOST 13047.5, 13047.10 GOST, GOST 13047.11 or GOST 8776 and taken into account when processing the results.
A spectrophotometric method based on measurement of light absorption at a wavelength of 500 nm complex compounds of cobalt with nitroso-R-salt.
Atomic absorption method based on measurement of absorption at a wavelength of 240,7 nm resonant radiation of the cobalt atoms formed as a result of atomization upon introduction of the sample solution into the flame acetylene-air.
4.2 measuring instruments, auxiliary devices, materials, reagents, solutions
Installation for electrolysis with ammeter, voltmeter, rheostat, providing carrying out the electrolysis while stirring at a current of 3−4 A and a voltage of 2−3 V.
Atomic absorption spectrophotometer measurements in the flame acetylene-air.
Lamp complete cathode for the excitation of spectral lines of cobalt.
Spectrophotometer or photoelectrocolorimeter, which provides measurements in the wavelength range of 490−540 nm.
The electrodes are platinum mesh according to GOST 6563.
Acetylene gas according to GOST 5457.
Nitric acid according to GOST 4461, if necessary, purified by distillation, or according to GOST 11125, diluted 1:1.
Sulfuric acid according to GOST 4204, diluted 1:1 and 1:9
Ammonia water according to GOST 3760 or GOST 24147, diluted 1:9.
Ammonium sulfate according to GOST 3769.
Hydrochloric acid according to GOST 3118, diluted 1:1.
Hydrazine sulfate according to GOST 5841.
Sodium acetate 3-water according to GOST 199, solution mass concentration of 0.5 g/cm.
Nitroso-R-salt [1], the solution of the mass concentration of 0.001 g/cm.
The technical rectified ethyl alcohol according to GOST 18300.
Universal indicator paper in [2].
Filters obestochennye in [3] or other medium density.
Cobalt GOST 123.
Cobalt solutions of known concentration.
The solution And the mass of cobalt concentration 0.001 g/cm: in a glass or flask with a capacity of 250 cm
is placed a portion of the cobalt ground 1,0000 g, pour 25−30 cm
of nitric acid, diluted 1:1, dissolved by heating, the solution boiled for 3−5 min, poured 20 cm
of sulphuric acid diluted 1:1, evaporated to the appearance of sulphuric acid fumes, cooled, to the residue poured 80−100 cm
of water, dissolve the salt by heating, the solution was cooled, transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water.
Solution B mass concentration of cobalt 0.0001 g/cm: in a volumetric flask with a capacity of 100 cm
is taken as 10 cm
of solution A, pour 10 cm
of sulphuric acid diluted 1:1, made up to the mark with water.
Solution of mass concentration of cobalt 0,00001 g/cm: in a volumetric flask with a capacity of 100 cm
is taken as 10 cm
of a solution, pour 5 cm
of sulphuric acid, diluted 1:9, made up to the mark with water.
4.3 Preparation for analysis
4.3.1 To construct the calibration curve in the determination of the mass of cobalt by spectrophotometric in volumetric flasks with a capacity of 100 cmis taken 1, 2, 4, 6, 8, 10 cm
solution, top up with water to 15 cm
, add 1−2 drops of sulfuric acid diluted 1:1, pour 5 cm
sodium acetate, and then do as specified
The mass of cobalt in solutions for calibration curve is 0,00001; 0,00002; 0,00004; 0,00006; 0,00008; 0,00010 G.
The values of absorption and their corresponding masses of cobalt build a calibration curve based on the value of absorption solution, prepared without the introduction of a solution of cobalt.
4.3.2 For calibration curve in the mass determination of cobalt by atomic absorption method in a volumetric flask with a capacity of 250 cmare selected 1, 2, 4, 6, 8, 10 cm
of a solution, made up to the mark with water and measure the absorbance as specified
The mass of cobalt in solutions for the calibration is 0,0001; 0,0002; 0,0004; 0,0006; 0,0008; 0,0010 G.
4.4 analysis
4.4.1 In a glass or flask with a capacity of 250 cmis placed a portion of the sample with a mass of 1,000 g, pour 15−20 cm
of nitric acid, diluted 1:1, dissolved by heating, boil the solution for 2−3 min, cooled, poured 15 cm
sulphuric acid diluted 1:1, evaporated the solution until vapors of sulphuric acid, cool.
To the residue poured 50−60 cmof water, add 3−4 g of ammonium sulfate and dissolved salts when heated. The solution is poured, with stirring, ammonia until the odor and give 80 cm
excess.
Solution and the precipitate is kept in a warm place for 25−30 min. the Precipitate was filtered off on a filter (red or white ribbon), collecting the filtrate in a beaker with a capacity of 250 cm, the filter was washed 2−3 times with ammonia diluted 1:9, the filtrate is used as specified
The filter cake is dissolved in 10−15 cmof hot hydrochloric acid, diluted 1:1, the filter is washed 3−4 times with hot water collecting the filtrate and washings in a beaker, in which was conducted the deposition. The solution is poured 10 cm
of sulphuric acid diluted 1:1, evaporated to the appearance of sulphuric acid fumes, cooled, poured 20−30 cm
of water and dissolved salts when heated. The solution was transferred to volumetric flask with a capacity of 250 cm
and used as specified in 4.
4.3.
4.4.2 To the filtrate add 2.0 g of hydrazine, top up with water to a volume of 200 cmand the electrolysis is carried out for 1−1. 5 h while stirring the solution using a pre-weighed platinum electrodes at a current of 3−4 A and a voltage of 2−3 V. After the bleaching solution the side of the Cup and protruding parts of the electrodes is washed with water, pour 15−20 cm
of water and continue electrolysis 10−15 minutes the Electrodes are removed from solution, washed with water, turn off the current. The electrodes are washed with ethanol, dried at a temperature of 95−105 °C for 15−20 minutes, cool and weigh.
4.4.3 Solution after the electrolysis was evaporated to a volume of 40−50 cmand poured sulphuric acid, diluted 1:1, to pH 1−2 by universal indicator paper. Attach the solution to the solution in a volumetric flask with a capacity of 250 cm
, made up to the mark with water and determine in the solution the mass of cobalt by spectrophotometry, as described in 4.4.4, or atomic absorption method as specified
4.4.4 When using the spectrophotometric method in a volumetric flask with a capacity of 100 cmis taken aliquot part of the solution, prepared according to 4.4.3, ammonia is added to the appearance of the precipitate of iron hydroxide and dissolved in 2−3 drops of sulfuric acid diluted 1:1.
The solution is poured 5 cmsodium acetate, boil for 2−3 min, poured 10 cm
of the solution, nitroso-R-salt, boil for 2−3 min, poured 10 cm
of nitric acid, diluted 1:1, boiled for 1 min. the Solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water.
After 5−7 min. measure the light absorption of the solution on the spectrophotometer at a wavelength of 500 nm or photoelectrocolorimeter in a region of wavelengths of 490−540 nm. As a solution comparison, using solution calibration curve prepared without the introduction of a solution of cobalt.
The mass of cobalt in the sample solution found by the calibration graphics, built in 4.3.1, taking into account the dilution factor of the solution.
4.4.5 When using the atomic absorption method for the determination measure the absorbance of sample solution at 4.4.3 and solutions for calibration curve at 4.3.2 at a wavelength of 240,7 nm, slit width is not more than 1.0 nm at least two times, sequentially inserting them into a flame, wash the system with water, check the zero point and the stability of the calibration curve.
The values of absorption solutions for the calibration and corresponding masses of cobalt build the calibration graph.
The value of absorbance of sample solution find the mass of cobalt in the calibration schedule.
4.5 Processing the analysis results
Mass fraction of cobalt , %, is calculated by the formula
where is the mass of the cathode after electrolysis, g;
— the mass of the cathode before electrolysis, g;
— mass of anode before electrolysis, g;
— weight of anode after electrolysis, g;
— the mass of cobalt in the sample solution, g;
— weight of sample, g;
— mass fraction of Nickel in the sample, %;
— mass fraction of copper in the sample, %;
— mass fraction of zinc in sample, %.
4.6 accuracy Control analysis
Control of metrological characteristics of the results of the analysis carried out according to GOST 13047.1.
The error analysis method is 0.3%. Standards control: permitted discrepancies in the results of two or three parallel definitions
or
respectively 0.2% and 0.3%; the permissible discrepancy of the two results of the analysis
is 0.4%.
5 Calculation method
When the mass fraction of cobalt in excess of 98.8 per cent mass fraction of cobalt is determined by the calculation method. To do this, find the sum of the mass fraction of impurities, normalized to GOST 123 and silicon and aluminum, determined according to GOST 13047.5 — 13047.21 GOST or GOST 8776 taken, without rounding, and subtract it from 100%.
The rounding of the difference in spend to the number of significant digits specified in the tables of chemical composition to GOST 123.
