GOST 27981.3-88

• gost-279813-88.pdf (434.66 KiB)
  ГОСТ 27981.3-88

GOST 27981.3−88 Copper of high purity. The method of emission-spectral analysis with photoelectric registration of spectrum

GOST 27981.3−88

Group B59

STATE STANDARD OF THE USSR

HIGH PURITY COPPER

The method of emission-spectral analysis with photoelectric registration of spectrum

Copper of high purity. Method of emission-spectral analysis
with photoelectric registration of spectrum

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:

B. M. Rogov, E. N. Gazalov, I., Swan, A. B. Korotin, G. V. Osipova, V. V., Podshivalov, V. I. Petrovichev

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 emission-spectral method of determination of impurities in high purity copper in the range of mass fraction ·10:

The method is based on measuring intensities of spectral lines of the identified elements in a diffractive spectrometer of the type MFS-6, MFS-8. The emission spectrum is excited by a DC arc between the dummy electrode and a graphite tablet of copper oxide obtained by dissolving the sample in nitric acid and thermal decomposition of salts.

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 is determined in two parallel batches.

2. APPARATUS, MATERIALS AND REAGENTS

Diffraction spectrometer type MFS-6, MFS-8.

Generator UGE-4, or any other DC source with device for high-frequency ignition of the arc, a rheostat and ammeter, providing a voltage of 200−400 V and currents up to 12 A. the electric resistance Furnace chamber laboratory of any type, allowing to regulate the heating temperature to 900 °C.

The drying Cabinet of the laboratory.

Machine for sharpening graphite and metal electrodes, for example, the model CP-35, or another type.

The mold of stainless steel (e.g., CVH) with a punch diameter of 4−6 mm, a height of 50−80 mm.

Laboratory scales of 4 class accuracy type VLA-1 kg or torsion W-1000 accuracy class 4.

Electrodes-graphite stand, copper electrode holders, water cooled, providing heat sink to prevent complete melt bead at a current of 10 A (Fig.1).

Damn.1. Elektrodvigateli

Electrode holders

1 — fitting for water inlet; 2 — pipe for cooling water outlet.

Damn.1

The spectral graphite electrodes from coal brands high purity or C-3 in the form of bars with stiptease sharpening with a platform with a diameter of 3 mm (Fig.2).

Damn.2. The spectral graphite electrodes from coal brands high purity or C-3 in the form of bars with stiptease sharpening with a platform with a diameter of 3 mm

1 — graphite electrode stand; 2 — pill sample or standard sample; 3 — graphite electrode; 4 — a drop of the melt

and — before exposure; b — during anodic polarity of the pill; in — during the cathodic polarity of the pill.

Damn.2

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, here and hereafter. — 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.

Agate mortar with pestle or bowl of porcelain glazed with a copper pestle.

Medical forceps.

Magnet.

The stopwatch according to GOST 5072 or clock signal.

Hardness tester TS-2 or the press, providing the efforts of 1−1. 5 cu.

Installation for the distillation of nitric acid of any type.

Installation for double distillation water aircraft type or a different type.

Cups for weighing according to GOST 25336.

Plastic cans with lids.

The bowls are made of quartz glass according to GOST 19908* or porcelain bowl according to GOST 9147.
______________
* On the territory of the Russian Federation GOST 19908−90, here and hereafter. — Note the manufacturer’s database.

Medical absorbent cotton wool GOST 5556.

Paper scale-coordinate according to GOST 334 stamps LN.

Distilled water according to GOST 6709, or bidistilled.

Deionized water obtained by passing distilled water through an ion exchange column with cation exchange resin, for example, marks KU-2−8, or bidistilled water.

Nitric acid of high purity according to GOST 11125, or nitric acid according to GOST 4461 (distilled in the installation) and diluted 1:1, 2:1.

The technical rectified ethyl alcohol according to GOST 18300.

The cation exchanger KU-2−8 according to GOST 20298.

Standard samples for composition of copper.

3. PREPARATION FOR ASSAY

3.1. Preparation of standard samples for calibration are given in Appendix 1.

3.2. Before you analyze some rubbing alcohol mortar, mold, bowls and tweezers. Consumption of alcohol per one definition 10, After combustion of each sample is wiped with alcohol and electrode holders.

Samples are taken from two sample weighing 5−10 g of Sample was placed in varicellae bowl, pour nitric acid, diluted 1:1, at a rate of 8−10 cmof acid per 1 g of sample and dissolve when heated.

The resulting solutions evaporated to dryness, the bowl with the dry salts are placed in an oven and calcined at a temperature of (600±50) °C for 30 min after the termination of allocation of oxides of nitrogen. The resulting copper oxide is ground in a mortar. Oxide powders selected from three sample weighing 0,500 g of each source of the sample and pressed into tablets.

Allowed the weight loss pills from 0.300 to 1,000 g to achieve the required lower limits of the contents of the determined elements.

Samples in the form of oxide powders is also pressed into tablets. Weight pills samples for calibration and the sample analyzed should be the same.

Prepared for analysis the tablets were stored in buksh, plastic or plastic jars with screw lids.

4. ANALYSIS

4.1. Tablet samples are placed on graphite electrodes-stand. The end portion of the electrodes for removal of surface contaminants calcined in an arc of DC current within 20 s at a current of 6−10 A, using the electrode-stand as the anode of the arc (see the devil.2). For upper electrode use graphite rods of high purity stamps or pre-annealed rods stamps-3.

4.2. The analysis is carried out in two stages: when the anode and cathode polarity of the pill.

4.2.1. At the first stage determine the mass fraction of volatile impurities: cadmium, selenium, arsenic, tellurium, lead, bismuth, phosphorus, antimony, zinc, tin. Conducted pre-burning pills using graphite stand is placed on the tablet as the anode. For this first arc light constant current between the upper electrode and the support. Only after fusing of the tablets of the anode spot of the arc moves to the resulting melt (Wren) oxides. This transition can be accelerated by the fact that after the ignition is turned off and turns on the power up until the arc does not go to the melt. The duration of the firing upon the transfer of the arc to the melt 5.

At the end of the firing begin analytical exposition duration 40 in absolute mode.

Originally established in the interelectrode gap periodically adjust throughout the exposure on a zoomed image of the arc on the screen special short throw projection system by moving the electrode holders.

Registration of spectra is carried out at the entrance slit width of 0.035 mm, the illumination of the entrance slit of a raster condenser, the discharge gap is 30 mm, the strength of the arc current is 10 A, exposure time 40 s.

4.2.2. In the second stage determine the mass fraction of semi-impurities: iron, manganese, Nickel, silver, cobalt, silicon, and chromium.

Formed in the first stage of analysis, the bead is placed on a graphite sweetalicious stand and hold his firing for 5 s, using a graphite stand as the cathode.

Registration of spectra is carried out at a discharge gap of 3 mm, the strength of the arc current is 5 A, the exposure time 20−30 s in absolute or relative modes, using a signal comparison, the signal measured in channel spectral undecomposed light.

Allowed to carry out the second stage without removing the bead from the base at the end of the first stage by changing the polarity of the electrode with the sample, and the amperage of the arc.

4.3. For each pill to register the readings of the output of the measuring device (), proportional to the intensity of the spectral lines of the element at the wavelength given in table.1.

Table 1

Notes:

1. Allowed to use other conditions analysis and other analytical lines, providing the metrological characteristics, in accordance with the requirements of this standard.

2. Allowed determination of magnesium in the sample.

4.4. Construction of calibration graphs

To construct the calibration graphs and the establishment of a calibration dependency use standard samples for calibration, prepared in accordance with Annex 1, or standard samples for composition of copper. The number of samples is at least four, the mass fraction of detectable elements in standard reference materials should cover the range of measurements.

On PP.4.1 and 4.2 receive spectra from three tablets of each sample and copper oxide (accounting background) prepared according to Appendix 1, calculate the average intensity of a spectral line of the element.

When working on the installation of MFS-6 calibration graphs are built in coordinates ,

where is the intensity of the spectral lines, the readings of the millivoltmeter;

 — mass fraction of the element in the SB %.

Using cell install MFS-6 can be calibrated according to the instruction manual for receiving digital millivoltmeter measurement results in percent content.

When working on the installation MFS-8 value of the mass fraction of the element in the standard samples of composition and their corresponding average intensity of spectral lines introduced in the computer.

A computer generates the equation of the calibration dependence

, (1)

where  — mass fraction of element, %;

, is the regression coefficients determined by the method of least squares for each element;

 — the intensity of the spectral lines.

After the establishment of the calibration dependencies define the mass fraction of the element in each of the three tablets and evaluate the possibility of averaging according to claim 5.2. If the condition p. 5.2 measure repeat.

Correction of charts is carried out monthly on Appendix 2.

5. PROCESSING OF THE RESULTS

5.1. The calculation of the mass fraction of detectable elements (in percentage) are carried out using the calibration curve in manual handling or equation of this graph when processing on a computer.

5.2. The results of the measurements of three of the tablets obtained from the analysis of one sample of copper, averaged, if the extreme measurements (and ) differ by an amount not greater than

, (2)

where is the mean value of results of measurement, %;

, are the coefficients in accordance with table.2.

Allowed to exclude the most different from the mean value of the measurement result and use the average result of measurements of the two tablets provided

. (3)

Allowed using the set graphs in the logarithmic scale coordinates .

The arithmetic mean of the results of the three (two) dimensions taken for the result of parallel detection.

5.3. The analysis result should be the arithmetic mean of two parallel definitions, if the difference between the two when =0.95 does not exceed allowable absolute differences calculated by the formula

, (4)

where is the mean value of results of two parallel definitions %;

, are the coefficients in accordance with table.2.

If exceeded , repeat analysis of new batches of the same sample. In the case of repeated discrepancies in the results of parallel measurements analyze a new sample.

5.4. The reproducibility of the results of primary and repeated tests are considered satisfactory if the discrepancy between the results of the two tests does not exceed at =0,95 allowable absolute differences calculated by the formula

, (5)

where is the arithmetic mean of the results of the two tests, %;

, are the coefficients in accordance with table.2.

Table 2

5.5. Control the accuracy of the results of the analysis carried out on copper FROM any category at least once in a month by playing the mass fraction of the element in the FROM of two parallel measurements.

The arithmetic mean value of results of parallel measurements to take FROM the reproduced value of the mass fraction of the element if the difference does not exceed calculated according to the formula (4).

The results of the analysis of copper believe satisfy the required accuracy, if the reproduced value of the mass fraction of the element differs from a certified not more than 0.71, calculated according to the formula (5).

If this condition is not satisfied, the analysis stops to ascertain and eliminate the causes of the observed deviation.

Allowed checking the accuracy of other methods, with the error not exceeding the error-controlled method.

The results of the analysis of copper believe satisfy the required accuracy, if the condition

,

where the results of analysis controlled and control methods;

and  — the permissible differences of the two analyses, regulated, controlled, and control methods.

ANNEX 1 (recommended). PREPARATION OF STANDARD SAMPLES FOR CALIBRATION

ANNEX 1
Recommended

Standard designs are the powders of copper oxide obtained by dissolving the pure base in nitric acid, the introduction of the dosed additives of solutions of impurities and a subsequent evaporation and thermal decomposition of mixtures of nitrates.

1. EQUIPMENT, REAGENTS, SOLUTIONS

Analytical scale any type of the 2nd accuracy class with the error of weighing according to GOST 24104.

Electric chamber any type of heating temperature to 800 °C.

Beakers, conical flasks according to GOST 25336.

Volumetric flasks 2−250−2, 2−100−2 according GOST 1770.

Bowl, porcelain mortar according to GOST 9147, or mortar agate, or Jasper.

Banks, polyethylene, PTFE, with screw-caps or boxy according to GOST 25336.

Bowl quartz GOST 19908.

Burette 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, here and hereafter. — Note the manufacturer’s database.

Pipettes 1−2-1,2, 6 (7)-2−5, 10, 25 according to GOST 20292.

Carbonyl iron is particularly clean.

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

Met brand M00k GOST 859*.
______________
* On the territory of the Russian Federation GOST 859−2001. — Note the manufacturer’s database.

Tin GOST 860.

Cadmium brand Кд0 according to GOST 1467*.
______________
* On the territory of the Russian Federation GOST 1467−93, here and hereafter. — Note the manufacturer’s database.

Nickel brand N 1U GOST 849*.
______________
* On the territory of the Russian Federation GOST 849−97 (01.07.2009 standards 849−2008). — Note the manufacturer’s database.

Silver GOST 6836*.
______________
* On the territory of the Russian Federation GOST 6836−2002. — Note the manufacturer’s database.

Cobalt grade 0 according to GOST 123*.
______________
* On the territory of the Russian Federation GOST 123−98 (01.07.2009 valid GOST 123−2008). — Note the manufacturer’s database.

Sodium meta-silicate 9-water or tetraethoxysilane.

Chrome brand Х99Б according to GOST 5905*.
______________
* On the territory of the Russian Federation GOST 5905−2004. — Note the manufacturer’s database.

Manganese metal according to GOST 6008*.
______________
* On the territory of the Russian Federation GOST 6008−90. — Note the manufacturer’s database.

Lead nitrate (N) according to GOST 4236, recrystallized, or lead according to GOST 3778*.
______________
* On the territory of the Russian Federation GOST 3778−98. — Note the manufacturer’s database.

Phosphorus GOST 8655.

Tellurium according to normative-technical documentation.

Selenium according to normative-technical documentation.

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

Nitric acid according to GOST 4461 (distilled in quartz apparatus) or nitric acid high purity according to GOST 11125, and diluted 1:1, 2:1.

The technical rectified ethyl alcohol according to GOST 18300.

Silver nitrate according to GOST 1277, a solution of 20 g/DM.

Tartaric acid according to GOST 5817.

Oxalic acid according to GOST 22180.

Sodium hydroxide according to GOST 4328, solution 100 g/DM.

Arsenic metal.

Deionized water obtained by passing distilled water through an ion exchange column with cation exchange resin, or bidistilled water obtained by distillation in a quartz apparatus.

Antimony brand Su00 according to GOST 1089.

2. PREPARATION OF SOLUTIONS OF IMPURITIES

2.1. Each hanging mass 0,6250 g of Nickel, cobalt, iron, zinc, lead, bismuth, cadmium, arsenic, phosphorus, silver, selenium, tellurium dissolved in 25 cmof nitric acid in separate beakers with a capacity of 250 cm, the solutions were transferred to volumetric flasks with a capacity of 250 cmand was adjusted to the mark with nitric acid, diluted 1:1.

1 cmof each solution contains 2.5 mg of each of the above impurities.

2.2. A sample of chromium weighing 0,6250 g dissolved in 20−30 cmof hydrochloric acid in a boiling water bath. Then the solution is evaporated to dry salts. To the dry salts and add 5−10 cmof nitric acid and the solutions were evaporated to wet salts. The processing operation of the salts of nitric acid repeat three more times, each time evaporating to wet salts. Then pour 100 cmof nitric acid, diluted 1:1, put the resulting solution in a volumetric flask with a capacity of 250 cmand was adjusted to the mark with nitric acid, diluted 1:1.

From the resulting solution sampled 10−20 cmand placed in a beaker with a capacity of 50 cmto test for the presence of chlorine with a solution of silver nitrate. When the solution revealed the presence of chlorine, the operation is repeated.

1 cmof solution contains 2.5 mg of chromium.

2.3. The weight of tin weight of 0,6250 g were placed in a glass with a capacity of 250 cm, add 5 g of oxalic acid, and then 20 cmof nitric acid, diluted 2:1, and allowed to stand without heating to dissolve the sample. Transfer the solution into a volumetric flask with a capacity of 250 cmand was adjusted to the mark with nitric acid, diluted 2:1.

1 cmof solution contains 2.5 mg of tin.

2.4. A portion of the antimony by weight 0,6250 g placed in a beaker with a capacity of 250 cm, add 4 g of tartaric acid, and then dissolved in excess of hot nitric acid when boiled. The solution was transferred to volumetric flask with a capacity of 250 cmand was adjusted to the mark with nitric acid, diluted 1:1.

1 cmof solution contains 2.5 mg of antimony.

2.5. A portion of silicate of sodium with a mass 1,0117 g is placed in a volumetric flask with a capacity of 100 cm, dissolved in 5−7 cmof water, made up to the mark with nitric acid, diluted 1:2, or a portion of tetraethoxysilane weight 0,7418 g is placed in a volumetric flask with a capacity of 100 cm, was dissolved in ethanol, made up to the mark with ethanol, mix.

1 cmof the solution contains 1 mg of silicon.

2.6. A portion of the arsenic, pre-cleaned from oxide films by mass 0,6250 g were placed in a glass with a capacity of 250 cm, 125−150 cm pourboiling nitric acid, and dissolve by heating. The solution was cooled, transferred to a volumetric flask with a capacity of 250 cm, made up to the mark with nitric acid, diluted 1:1, and stirred.

1 cmof solution contains 2.5 mg of arsenic.

2.7. A portion of nitrate of lead weight 0,9988 g is placed in a volumetric flask with a capacity of 250 cm, dissolved in 10−15 cmof water, made up to the mark with nitric acid, diluted 1:1, mix.

1 cmof solution contains 2.5 mg of lead.

3. PREPARATION OF STANDARD SAMPLES

3.1. Preparation of solutions 1−4

Solution 1: in a volumetric flask with a capacity of 250 cmare placed by pipette at 10 cmnitric acid solutions of tin, cobalt, manganese, bismuth, cadmium, arsenic, tellurium, chromium, made up to the mark with nitric acid, diluted 1:1, mix.

1 cmof the solution 1 contains 0.1 mg of tin, cobalt, manganese, bismuth, cadmium, arsenic, tellurium, chromium.

Solution 2: in a volumetric flask with a capacity of 250 cmare placed by pipette at 10 cmof nitric acid solutions of lead, Nickel, antimony, zinc, selenium, made up to the mark with nitric acid, diluted 1:1, mix.

1 cm2 of solution contains 0.1 mg of lead, Nickel, antimony, zinc, selenium.

Solution 3: in a volumetric flask with a capacity of 100 cmis placed with a pipette at 20 cmsolutions, nitrate phosphorus, iron and silver, made up to the mark with nitric acid, diluted 1:1, mix.

1 cm3 of solution contains 0.5 mg of phosphorus, iron and silver.

A solution of 4to 10 cmof a solution of silicate of sodium is placed in a volumetric flask with a capacity of 100 cm, made up to the mark with nitric acid, diluted 1:2, mix or 10 cmalcohol solution of tetraethoxysilane was placed in a volumetric flask with a capacity of 100 cm, made up to the mark with alcohol, mix.

1 cmof the solution 4 contains 0.1 mg of silicon.

3.2. Preparation of solutions of copper

In five glasses with a capacity of 2000 cmis placed on 200 g of copper, pour nitric acid, diluted 1:1, the rate of 7−8 cmof acid per 1 g of copper is dissolved by heating.

3.3. The calculated volumes of solutions of 1−4 in accordance with the table.3 bring in four glasses with solutions of copper.

Table 3

The resulting solutions was evaporated in a quartz bowls to dry salt, the salt is calcined in chamber furnaces at a temperature of 600−650 °C until the complete decomposition of nitrates and the removal of nitrogen oxides.

The oxide mixture ground in a mortar or crushed in any way, prevent pollution of material FROM the designated elements.

The mass fraction of elements in SB — in accordance with the table.4.

Table 4

Co and copper oxide without impurities stored in glass or plastic jars with screw lids. The method of storage needs to eliminate the possibility of contamination and moisture. The validity period WITH at observance of storage conditions 5 years.

Change the mass of the batches of copper and impurities, depending on the requirements in the standard samples and the mass fraction of impurities depending on the composition of the analyzed samples with the appropriate conversion.

3.4. Certified values of elements in the copper is determined by the procedure of preparation.

Error by establishing certified characteristics does not exceed 5% at confidence probability =0,95.

APPENDIX 2 (recommended). CORRECTION OF THE CALIBRATION GRAPHS

ANNEX 2
Recommended

1. Correction schedule the installation MFS-8

For the correction of the graph is measured intensity of a spectral line of the analyzed element in for grading or in two control samples with the maximum and minimum mass fractions of the element.

Introduced in the computer of the measured intensity.

A computer calculates the correction coefficients by the formula

; (7)

, (8)

where ,  — intensity of spectral lines of the element in two, measured in the calibration;

,  — intensity of spectral lines of an element, measured in the correction;

, the coefficients in formula (1).

If the inequalities for the coefficients and are not met, then tune the installation.

The equation of the calibration dependence with account of the correction coefficients has the form

. (9)

2. Correction schedule the installation of MFS-6

The correction graph is produced according to the instructions.