GOST 27981.2-88

• gost-279812-88.pdf (387.43 KiB)
  ГОСТ 27981.2-88

GOST 27981.2−88 Copper of high purity. Method of chemical-atomic-emission analysis

GOST 27981.2−88

Group B59

STATE STANDARD OF THE USSR

HIGH PURITY COPPER

Method of chemical-atomic-emission analysis

Copper of high purity. Method of chemical-atomic-emission analysis

AXTU 1709

Valid from 01.01.1990
until 01.01.2000*
_______________________________
* Expiration removed
Protocol N 7−95 Interstate Council
for standardization, Metrology and certification
(IUS N 11, 1995). — Note the manufacturer’s database.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

PERFORMERS:

Kopanev A. M., E. N. Gilbert, L. N. Shabanova, I. D. Denisov, G. L. Buchbinder, B. M. Rogov, E. N. Gazalov, I. I. Lebed

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 22.12.88 N 4443

3. The term of the first check — 1994

The frequency of inspection — 5 years

4. INTRODUCED FOR THE FIRST TIME

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies the chemical-atomic emission method for the determination of impurities in high purity copper in the range of mass fraction ·10%:

The method consists of dissolving the sample of copper in a mixture of hydrochloric acid and hydrogen peroxide, the separation of copper from impurities by extraction of di-2-ethylhexylphthalate acid, to obtain a concentrate of impurities on the graphite powder with the carrier — chloride and sodium analysis of the concentrate by atomic-emission in the arc of DC with photographic registration of spectrum.

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis and safety requirements when performing analyses according to GOST 27981.0.

1.2. Mass fraction of impurities in high purity copper is determined in parallel in three batches.

2. APPARATUS, REAGENTS AND SOLUTIONS

The quartz spectrograph medium dispersion type of ISP-30 being the lighting system or the type of spectrograph STE-1.

A constant current source to power the arc, providing a voltage of 200−400 V and currents up to 12 A.

Spectromancer.

Microphotometer.

Electromechanical shaker or apparatus for mixing liquids, for example, of the type AVB-4P.

Tile electric.

Muffle furnace with thermostat, providing a temperature of 900−950 °C.

Footwear of any type of the 2nd accuracy class with the error of weighing according to GOST 24104*.
_______________
* On the territory of the Russian Federation GOST 24104−2001. — Note the manufacturer’s database

Libra technical any type of weighing error in the attached passport.

Torsion scales of any type with a weighing error in the attached passport.

Grinding machine graphite electrodes.

Box with organic glass type 8БП-1-OS for sample preparation to spectral analysis (or another type).

Box with organic glass type 2БП2-OS for chemical preparation of samples cleaned using the cloth Petryanov air (or other type).

Devices made of organic glass for sample preparation to spectral analysis (stands for graphite electrodes, spatulas, Nobuaki, etc.).

Bowl platinum according to GOST 6563.

Glass coverslip.

Mortar and pestle made of organic glass or agate mortar, or mortar made of porcelain.

The PTFE cups with screw caps or pritertymi with a capacity of 20−25 cm.

Bowl varicellae quartz, or PTFE, or porcelain with a capacity of 25 and 100 cm.

Graphite electrodes, machined from high purity graphite rods-7−3 6 mm in diameter, sharpened to a cone with an apex angle of 15° and a platform with a diameter of 1.5 mm at the end.

Graphite electrodes with a diameter of 6 mm with a channel depth of 3 mm and 4 mm in diameter, machined from high purity graphite rods-7−3.

Graphite powder according to GOST 23463 brand high purity-7−3.

The graphite powder obtained by grinding the spectral pure graphite electrodes.

The infrared lamp.

Records of the photographic type 1 and type 2 for normal blackening of analytical lines and the surrounding background in the spectrum.

Glasses N-1−100 TCS according to GOST 25336.

Cups In a-1−1000 TCS according to GOST 25336.

Flasks conical KN-2−2000 TCS according to GOST 25336.

Funnel separating VD-1−100 TC GOST 25336.

Funnel separating VD-3−2000 TC GOST 25336.

Beakers with a capacity of 50 and 1000 cmaccording to GOST 1770.

Volumetric flasks 2−100−2, 2−200−2 according GOST 1770.

Pipette 4−2-1, 4−2-2, 5−2-2, 6−2-5, 6−2-10 according to GOST 20292*.
________________
* On the territory of the Russian Federation there are 29169−91 GOST, GOST 29227−91−29229−91 GOST, GOST 29251−91-GOST 29253−91. — Note the manufacturer’s database.

Developer:

Allowed the use of fixing solutions of a different composition.

Acetone according to GOST 2603.

Nitric acid of high purity according to GOST 11125, diluted 1:1.

Hydrochloric acid of high purity according to GOST 14261, diluted 1:1, 1:2,5; 1:10.

Hydrogen peroxide high purity (stable product).

Sodium chloride according to GOST 4233, a solution of 40 g/DM.

Potassium carbonate — sodium carbonate according to GOST 4332.

Potassium hydroxide according to GOST 24363.

Hexane.

Acid di-2-ethylhexyladipate (di-2-EHDHFK), purified.

The technical rectified ethyl alcohol according to GOST 18300.

The iron carbonyl is obtained by the method, high purity-6−2.

Bismuth GOST 10928* brand Vi00.
______________
* On the territory of the Russian Federation GOST 10928−90. — Note the manufacturer’s database.

Cadmium GOST 1467* brand Кд0.
______________
* On the territory of the Russian Federation GOST 1467−93. — Note the manufacturer’s database.

Cobalt GOST 123* stamps K0.
______________
* On the territory of the Russian Federation GOST 123−98 (01.07.2009 valid GOST 123−2008). — Note the manufacturer’s database.

Silicon dioxide according to GOST 9428.

Manganese GOST 6008* brand Mr or Mr 0 00.
______________
* On the territory of the Russian Federation GOST 6008−90. — Note the manufacturer’s database.

Copper according to GOST 859* brand M0k.
______________
* On the territory of the Russian Federation GOST 859−2001. — Note the manufacturer’s database.

Chrome according to GOST 5905* brand X00.
______________
* On the territory of the Russian Federation GOST 5905−2004. — Note the manufacturer’s database.

Nickel GOST 849* stamps D0.
______________
* On the territory of the Russian Federation GOST 849−97 (01.07.2009 standards 849−2008). — Note the manufacturer’s database.

Zinc GOST 3640* brand C0.
______________
* On the territory of the Russian Federation GOST 3640−94. — Note the manufacturer’s database.

Standard samples for composition of copper.

3. PREPARATION FOR ASSAY

3.1. Preparation of standard solutions of elements according to claim 2.2.1 GOST 27981.1.

3.2. Preparation of multi-element standard solutions

3.2.1. Preparation of solution 1

In a volumetric flask with a capacity of 100 cmis introduced to 15 cmof hydrochloric acid of 2 cmAnd standard solutions of cadmium, cobalt and chromium, adjusted to the mark with water.

1 cmof solution 1 contains 20 ág of cadmium, of cobalt, and chromium.

3.2.2. Preparation of solution 2

In a volumetric flask with a capacity of 100 cmis introduced to 15 cmof hydrochloric acid and 5 cmof solution 1 and bring to the mark with water.

1 cm2 of solution contains 1 ág of cadmium, of cobalt, and chromium.

3.2.3. Preparation and certification of synthetic compound according to claim 2.2.3 GOST*
______________
* Consistent with the original. — Note the manufacturer’s database.

3.3. Preparation of comparison samples based on graphite powder with a mass fraction of sodium chloride 4%

3.3.1. Preparation of a graphite powder containing 4% of sodium chloride

9,600 g of the graphite powder is placed in Teflon (or other material) container with a capacity of 100 cm, flow 10 cmsodium chloride solution and dry the mixture first on the tile, and then under a heat lamp. The resulting mixture was stirred in a mortar for 1.5 h. Keep the mixture in a tightly closed Teflon (or other material) glass.

3.3.2. Preparation of a primary reference sample (OOS)

Prepare the basic pattern comparison with a mass fraction of each impurity determined by 0.1%: in Teflon (or other material) container with a capacity of 100 cmis placed 9,880 g of graphite powder and poured sequentially with 10 cmstandard solutions And of iron, cadmium, cobalt, bismuth, Nickel, tin, manganese, chromium, zinc and 20 cmstandard solution silicon. Evaporation of solutions of impurities on the graphite powder is performed under an IR lamp. Each subsequent admixture is introduced into a well-dried graphite powder. After evaporation of the graphite powder containing the impurities, is introduced in solution form, dried to a constant weight and mixed in the bowl, and then in a mortar for 1 h.

3.3.3. Preparation of working samples comparison (OS)

References (OC1-ОС9) prepare serial dilution of OOS, and then each subsequent OS graphite powder with a mass fraction of sodium chloride 4%. The mass fraction of each of the designated impurities in the OS (in percentages) and sample for each OS are given in table.1. The above sample is placed in a mortar, thoroughly grind in the presence of ethyl alcohol for 30 min and dried under an infrared lamp.

Table 1

The samples of the comparison is stored in a tightly-closed cups made of PTFE or plastic, or other material.

All operations on preparation of samples of the comparison performed in box organic glass, carefully wiping the walls with ethanol. One definition consumed 10 g of alcohol and 5 cmcalico.

3.4. Cleaning technical di-2-EHDHFK according to claim 2.2.5 GOST 27981.1.

3.5. The establishment of the volume of the solution of di-2-APTTC* required for stoichiometric extraction
________________
* Consistent with the original. — Note the manufacturer’s database.

In a separating funnel with a capacity of 100 cmis introduced 20 cmof a standard solution of copper and 26 cmof a solution of purified di-2-EHDHFK, perform the extraction of copper for 15 min, separated from raffinate and determine in it the concentration of copper by any method, for example atomic absorption in the flame acetylene-air or propane-butane-air. 1 cmof the raffinate should contain 0.01 to 0.08 mg of copper. If the copper content is more re-perform the extraction by changing accordingly (increasing or decreasing) the amount of the used extractant.

The establishment of the volume of the solution of di-2-EHDHFK required for stoichiometric extraction is performed once for each batch of the extractant.

3.6. Dissolution samples

A portion of the sample of copper with a mass of 1,000 g was placed in a beaker with a capacity of 100 cm. To remove surface contamination, the sample is washed once with hydrochloric acid, diluted 1:10, and twice with water. Measuring cylinder with a capacity of 25 cmin a glass pour 12 cmof hydrochloric acid, cover the beaker with glass and injected under glass, with a pipette 3−5 cmof 30% hydrogen peroxide solution. 2−3 min after completion of the reaction add another 3−5 cmof peroxide. After complete dissolution of the sample Cup put on a tile, the contents slowly to the boil. After 3−5 min, the glass tiles were removed and cooled.

3.7. Separation of copper

Glass glass is removed and the solution is quantitatively transferred to a separating funnel with a capacity of 100 cm, using a 5−7 cmwater. The funnel is injected hexane solution of di -2-EHDHFK in the amount determined in paragraph 3.5. Copper extracted within 15−20 min raffinate is separated and transferred back to the glass. The organic layer is discarded, the funnel washed with acetone, and then with double-distilled water. The raffinate is returned to the funnel, add to it 20 cmof hexane and shake for 3−5 min to remove residual organic substances.

The raffinate is separated and transferred into a Cup for evaporation capacity of 50 cm. Then add 100 mg of graphite powder with a mass fraction of sodium chloride 4% and carefully evaporate the solution under an infrared lamp at a temperature of 80−100 °C.

The obtained dry residue is a concentrate of impurities involved in the analysis.

3.8. The control experience

In a glass with a capacity of 100 cmis administered with a graduated cylinder of 12 cmof hydrochloric acid and 12 cmof 30% hydrogen peroxide solution. The solution is heated on a heating plate until the decomposition of the peroxide, and transferred with 3−5 cmof water in a Cup for evaporation capacity of 50 cm. Hereinafter, according to claim 3.7.

Allowed to have a reference experiment using a standard sample of copper, for example, CCA А1921Х (only for items, which are FROM certified). For this to analyze the technique.

3.9. The firing electrodes

To remove surface contaminants calcined electrodes in the arc of direct current at 12 A for 20 s. the Purification annealing is subjected to each pair of electrodes directly before analysis, including arc electrode with the channel as the anode, and the electrode is sharpened to a cone, as the cathode of the arc.

4. ANALYSIS

Each concentrate obtained from a test sample or after conducting a test of experience, are placed in the channel of the graphite electrode with a diameter of 4 mm and depth 3 mm. From each sample, samples Packed in the two electrodes. In the channel of the same graphite electrodes placed each of the samples of comparison OC1-ОС9.

Way get: six electrodes concentrates the sample, three-electrode concentrates the reference experiment and two electrodes with each of the comparison samples (OC1, OC2,… ОС9). The electrode with the concentration of impurities or reference sample is an anode (lower electrode). The arc cathode is a graphite electrode, sharpened to a cone. Between the electrodes ignite the arc of direct current strength of 10 A. the Spectra are photographed on the spectrograph. Intermediate diaphragm 5 mm. the Width of the slit of a spectrograph 10 microns. Exposure time (to complete combustion of sodium) 30 s. During the exposure distance between the electrodes is maintained at 3 mm. Used spectral photographic plates: type 1 for registration in the region of wavelengths less than 300 nm; type 2 for a region of wavelengths 300−220 nm.

Exposed photographic exhibit, washed with water, fixed, washed in running water for 15 min and dried.

5. PROCESSING OF THE RESULTS

5.1. In each spectrogram photometric blackening of analytical lines of the designated element (table.2) and nearby background (minimum blackening near the analytical line of the element on either side, but with the same in all spectra taken on one disc) and calculate the difference pucherani . For each of the three portions count (=1, 2, 3) as the arithmetic average of the values obtained on the two spectrograms ; . Three values of (=1, 2, 3), calculated for each sample, find the arithmetic mean . From the obtained average values are transferred to corresponding values of the logarithms of relative intensity , in accordance with the Annex to GOST 9717.3. Values and comparison of samples for build calibration curve in the coordinates ().

Table 2

The values for the concentrates of the sample find the schedule for the calibration values of the averaged mass fraction of the designated impurities in the concentrates of the samples. Similarly, values for concentrates in the reference experiment find the average value of the mass fraction of the designated impurities in the concentrates of the reference experiment.

Mass fraction of nd impurity in the sample in percent () is calculated by the formula

, (1)

where  — weight of a graphite powder with a mass fraction of sodium chloride 4% (header), g;

 — the weight of the portion of the copper sample, g;

 — average mass fraction of impurities in the concentrates of the analyzed samples, %;

 — average mass fraction of impurities in the concentrate a control of the experience, %.

The amount must not exceed the established method for the lower limit is determined by the values of the mass fraction of impurities. Failure to comply with this condition must be carefully phased in to clean the room, jobs, used equipment, change the reagents, materials, and then to repeat the analysis.

If the control experiment was carried out using a standard sample of copper the mass percent of impurities in the sample in percent () is calculated by the formula

, (2)

where is the certified value of the mass fraction of the element in the standard sample, %.

The final result of the analysis should be the arithmetic mean of the three definitions, each of which is obtained in two dimensions.

5.2. While monitoring convergence results of parallel measurements of the three values , , obtained two spectrograms, each taken for three batches of the sample, select the largest and smallest values, pass them to the values and using the app GOST 9717.3 and find the corresponding values of the mass fraction of impurities in the sample and .

The ratio of the highest of the three results of parallel measurements to smallest with the confidence coefficient =0.95 does not exceed the values of permissible differences of the three results of parallel measurements.

For several values of the mass fraction of the element of the admitted discrepancies in the results of three parallel measurements are given in table.3.

Table 3

5.3. When comparing two results of the analysis, each of which is obtained by three parallel definitions, the ratio of largest to smallest results at a confidence level =0.95 does not exceed the values of permissible differences given in table.3.

Allowable differences for intermediate values of the mass fraction of the element are calculated by using linear interpolation.

5.4. The correctness of analysis results control using standard samples of composition of copper, or certified mixture in which the certified value of the mass fraction of each of the identified elements is different from the mass fraction of this element in the analyzed sample not more than 2 times. The result of the analysis is considered correct if a discrepancy is found the mass fraction of the element and the corresponding certified values of the standard sample does not exceed the permissible differences of the results of the analysis are given in table.3.

Allowed to use the addition method in accordance with GOST 25086.