GOST 24977.2-81

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  ГОСТ 24977.2-81

GOST 24977.2−81 Tellurium of high purity. Spectral method for the determination of impurities (with Amendments No. 1, 2)

GOST 24977.2−81*

Group B59

STATE STANDARD OF THE USSR

TELLURIUM OF HIGH PURITY

Spectral method of determination of impurities

Tellurium high purity. Spectral method for the determination of impurities

AXTU 1709

Date of introduction 1983−01−01

Resolution of the USSR State Committee on standards dated September 30, 1981 N 4486 time of the introduction set with 01.01.83

Resolution of the state standard from 07.09.92 N 1123 removed the limitation of the validity period

REPLACE GOST 21326.1−75

* REISSUE (March 1997) with Amendments No. 1, 2 approved in June 1987, September 1992 (IUS 11−87, 12−92)


This standard specifies the method of spectral determination of impurities in high purity tellurium of grades T-B4, T-OT and T-A1 in the range of a mass fraction in percent:

silver 5·10-2·10;

copper 5·10-3·10;

lead 7·10-2·10;

aluminum 1·10-1·10;

iron 2·10-2·10;

tin 7·10-4·10;

bismuth 8·10-2·10;

magnesium 2·10-1·10;

gold 5·10-2·10;

cobalt 2·10-1·10;

Nickel 7·10-1·10;

manganese 1·10-1·10;

Gallia 4·10-2·10;

India 1·10-3·10;

chrome 2·10-1·10.

Determination of impurities in high purity tellurium is carried out by the method of «three standards» with the use of the evaporation of impurities and the excitation spectrum of the arc AC.

(Changed edition, Rev. N 1).

1. GENERAL REQUIREMENTS

1.1. General requirements — according to GOST 24977.1−81.

(Changed edition, Rev. N 2).

2. APPARATUS, REAGENTS AND MATERIALS

The diffraction type spectrograph DFS-8 (grating 600 gr./mm, first order), DFS-452 (grating 1200 lines./mm, second order), or STE-1 with a three-stage attenuator and being an illumination system of the slit.

Spectrograph with quartz optics medium variance type of ISP-30 being the illumination system of the slit.

Note. Allowed the use of devices with photoelectric registration of spectrum and other spectral instruments, reagents and other materials, dry plates, providing the accuracy that rivals regulated in this standard.


Microphotometer designed to measure the density of blackening of spectral lines.

Spectromancer of PS-18.

The generator is activated the arc AC of any type.

Grinding machine carbon electrodes.

Laboratory scales General purpose of the 2nd accuracy class with a weighing error of no more than 0.001 g according to GOST 13718−68.

Boxes of organic glass.

Volumetric flasks according to GOST 1770−74.

Mortar made of organic glass.

The infrared lamp of any type with laboratory auto-transformer type CTL-250−2.

Quartz tableware (glasses, cups) according to GOST 19908−90.

Electrodes from coals of high purity on the other 48−20−78−76 with a diameter of 6 mm forms «glass» with the height of the head (2±1) mm, channel depth (10,0±0,2) mm, bore diameter (4,0±0,1) mm, neck length 5 mm, diameter 2 mm. in the analysis of tellurium brand T-A1 is permitted to use electrodes shaped «glass» with head height (10±1) mm, channel depth (8,0±0,2) mm, bore diameter (3,8±0,1) mm.

Contradictory from coals of high purity on the other 48−20−78−76, with a diameter of 6 mm, a length of 30−50 mm, one end sharpened to a hemisphere or a truncated cone with a diameter of pads 1.5−2 mm.

The graphite powder of high purity according to GOST 23463−79.

Photographic plates «spectrographic», type I or «slide» size 9x12, type II or SFC-02 on the other 6−43−1475−88 size 13x18 and 9x12 cm

Tellurium high purity brand of TV 4 on the other 6−04−65−82 or brand «extra» on the other 48−0515−028−89.

Nitric acid brand OS. H-19−14 23−4 or GOST 11125−84, if necessary, distilled twice in a quartz apparatus, and solutions of 1:1, 1:3 and 1:4.

Hydrochloric acid according to GOST 14261−77.

A mixture of hydrochloric and nitric acids 3:1.

Oxalic acid according to GOST 22180−76.

Tweezers medical stainless steel according to GOST 21241−89.

Sodium chloride of high purity.

The technical rectified ethyl alcohol GOST 18300−87.

Silver GOST 6836−80*.
______________
* On the territory of the Russian Federation GOST 6836−2002. — Note the manufacturer’s database.

Copper GOST 859−78*.
______________
* On the territory of the Russian Federation GOST 859−2001. — Note the manufacturer’s database.

Lead according to GOST 3778−77*.
______________
* On the territory of the Russian Federation GOST 3778−98. — Note the manufacturer’s database.

Bismuth GOST 10928−90.

Gold GOST 6835−80*.
______________
* On the territory of the Russian Federation GOST 6835−2002. — Note the manufacturer’s database.

Aluminium GOST 11069−74*.
______________
* On the territory of the Russian Federation GOST 11069−2001. — Note the manufacturer’s database.

Magnesium.

Cobalt GOST 123−78*.
______________
* On the territory of the Russian Federation GOST 123−98. — Note the manufacturer’s database.

Manganese GOST 6008−90.

Gallium GOST 12797−77.

Indium GOST 10297−94.

Ammonium chronologicly according to GOST 3774−76.

Nickel GOST 849−70*.
______________
* On the territory of the Russian Federation GOST 849−97. — Note the manufacturer’s database.

Iron restored.

Tin GOST 860−75.

Mass fraction of metal not less than 99.99%.

Solutions of pure metals.

Silver solution: 0.1 g of metal was dissolved in 10 cmof nitric acid solution 1:3 with a weak heating, the solution was cooled and quantitatively transferred to a volumetric flask with a capacity of 100 cm, add 5 cmof nitric acid was adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of silver.

The copper solution: 0.1 g of metal was dissolved in 10 cmof nitric acid solution 1:1, the solution was cooled and quantitatively transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of copper.

Lead solution: 0.1 g of metal was dissolved in nitric acid solution 1:4, the solution was cooled, transferred quantitatively into a measuring flask with a capacity of 100 cm, adjusted to the mark with nitric acid solution 1:1 and stirred.

1 cmof the solution contains 0.001 g of lead.

The solution of bismuth: 0.1 g of metal was dissolved in 15 cmof nitric acid, the solution heated to boiling, cooled, transferred quantitatively into a measuring flask with a capacity of 100 cm, pour 5 cmof nitric acid was adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of bismuth.

Solution gold: 0.1 g of metal was dissolved in 10 cmof a mixture of hydrochloric and nitric acids 3:1, cooled, transferred quantitatively into a measuring flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of gold.

A solution of aluminium: 0.5 g of crushed metal are dissolved in 15 cmof nitric acid solution 1:1, the solution was cooled and quantitatively transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with nitric acid solution 1:1 and stirred.

1 cmof the solution contains 0.005 g of aluminum.

A solution of magnesium: 0.5 g of the metal is dissolved in 15 cmof nitric acid solution 1:1, the solution was cooled and quantitatively transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof the solution contains 0.005 g of magnesium.

A solution of cobalt: 0.5 g of crushed metal are dissolved in 20 cmof nitric acid solution 1:1, the solution was cooled, transferred quantitatively into a measuring flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof the solution contains 0.005 g of cobalt.

The solution of Nickel: 0.1 g of the crushed metal is dissolved in 10 cmof nitric acid solution 1:1, the solution was cooled, transferred quantitatively into a measuring flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of Nickel.

Solutions of iron:

Solution A. 1 g of the metal is dissolved in 20 cmof nitric acid solution 1:1 with a weak heating, the solution was cooled, transferred quantitatively into a measuring flask with a capacity of 100 cm, add 10 cmof nitric acid was adjusted to the mark with water and mix.

1 cmof the solution contains 0.01 g of iron.

Solution B. In a volumetric flask with a capacity of 100 cmwith a pipette measure out 10 cmof solution A, was adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of iron.

The solution of tin: 0.1 g of finely ground metal is placed in a beaker with a capacity of 50 cmand add 2cmof nitric acid. After the transition of the whole sample in metalogeny acid in a beaker pour 15 cmof water and add 2 g of oxalic acid. After the solids are dissolved, the solution transferred to a volumetric flask with a capacity of 100 cm. To dissolve the remaining crystals of oxalic acid, the glass is washed with 2−3 cmof water and the washings decanted into a volumetric flask, adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of tin.

Solution India: 0.5 g of metal was dissolved in 10 cmof nitric acid solution 1:1, and the solution heated to boiling, cooled, quantitatively transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

1 cmof the solution contains 0.005 g India.

A solution of gallium: gallium 0.1 g dissolved in 10 cmof nitric acid solution 1:1, and the solution heated to boiling to remove the oxides of nitrogen, cooled, quantitatively transferred to a volumetric flask with a capacity of 100 cm, add 5 cmof nitric acid was adjusted to the mark with water and mix.

1 cmof the solution contains 0.001 g of gallium.

Solutions of manganese and chromium prepared as described in GOST 24977.1−81.

For the preparation of solutions it is possible to use the oxides, carbonate, or nitrate salts of the above metals qualification h. d. a. or H. h

(Changed edition, Rev. N 1, 2).

3. PREPARATION FOR ASSAY

3.1. Samples comparison. The basis for the preparation of samples of comparison is graphite powder with the addition of 2.5% sodium chloride.

Head comparison sample, containing 0,02% of silver, copper, gold and gallium, at 0.004% of tin, lead, iron, Nickel and bismuth, 0.008% manganese, 0.12 percent chromium, aluminum, magnesium and cobalt, 0.08% to India prepared as follows:

A mixture of 1. In a quartz Cup with a capacity of 50 cmwas placed 4.0 g of a basis and introduce specified in table.1A, the number of solutions of elements.

Table 1A

With the introduction of the solutions ensure that the solution impregnating the base, falling on the bottom wall of the Cup. To do this, as the fluids of impurities of the graphite powder is dried under a lamp to remove the smell of nitric acid. The resulting mixture was thoroughly mixed for 60 min.

A mixture of 2. In a quartz Cup with a capacity of 50 cmis placed 1.0 g basis, introduced to her 1 cmof solution of gold, carefully dried at a temperature not above 70 °C. the Dried powder is moistened with concentrated nitric acid, dried and repeated wetting, and then thoroughly dried to remove odor of nitric acid.

Both mixtures are combined, thoroughly mixed in a mortar for 60 min.

A series of working samples comparison get, diluting the primary and each of the subsequent samples, the comparison of 2.5−2 times basis.

Each of the prepared samples comparison mixed with four times by weight the amount of tellurium. The content of impurities in the obtained samples is calculated by comparison against the tellurium (assuming that the content of impurities in the tellurium is equal to the content of impurities in the reference sample divided by four).

The content of impurities in the basis determined by the method of additions and introduced the amendment in the estimated impurity content in the samples comparison.

References (mixed with tellurium) by calculation contain a number of impurities listed in the table.1.

Table 1

For the analysis of tellurium brand T-A1 you can use the first five samples of comparison or to prepare a series of samples of comparison from which to fully eliminate impurities that are not specified in the specified brand of tellurium.

Allowed to prepare samples comparison introduction the basis of impurities in the form of nitrate salts and oxides with a mass fraction of main substance not less than 99.99%.

The maximum allowable error value setting the values of CRM certified characteristics of the samples of the comparison does not exceed 2.6% of the certified value of the content component.

Prepared samples of the comparison is stored in a plastic container with a tight-fitting lid.

(Changed edition, Rev. N 1, 2).

4. ANALYSIS

4.1. From each sample metallic tellurium take two sample and mix them with the primary (if the samples of comparison for the analysis of tellurium brand T-A1 prepared on the basis of graphite powder without addition of sodium chloride, samples are mixed with graphite powder) in a ratio of 4:1 and placed in the channels of carbon electrodes (full channel), burnt in the arc of an alternating current power 15−18 And within 15 s. From each sample the sample is prepared in six sample comparisons for three electrodes.

The spectra photographed using a three-step attenuator using a diffraction spectrograph (in the analysis of tellurium brand T-A1, you can use the type spectrograph ISP-30).

The width of the diffraction slit of the spectrograph 0.018 mm (prismatic — 0.015 mm). Photographic plates of the type II size 13x18 (in the analysis of tellurium brand T-A1 in the cassette charging two plates in the region of 330 nm — half slide or type I, in the area of 310−220 nm — type II size 9x12).

Evaporation of the sample and the excitation spectra is carried out in the arc of an alternating current power 18 A for 60 s. the analysis of tellurium brand T-A1 and electrodes with a channel size of 3,8x8 mm excitation spectra carried out in the arc of an alternating current power of 8 And over 40 C.

The arc gap of 2.5 mm.

On one photographic plate for photographing the spectra of six samples and three samples of the spectrum comparison.

(Changed edition, Rev. N 1, 2).

5. PROCESSING OF THE RESULTS

5.1. With microphotometer measure the blackening of analytical lines of the determined elements () and background () near line (wavelengths in nm):

On microphotometer measure the blackening of the lines of the designated element in the spectra of samples comparison in all three steps of the attenuator to construct the characteristic curve (see Annex 1 GOST 24977.1−81).

Build the characteristic curve of photographic plates and find the corresponding measured pochernenija the values of the logarithms of the intensity , .

Calculate the value of a , find the arithmetic mean of the results obtained on the three spectrograms of each reference sample and build the calibration graphs in the coordinate , where is the mass fraction of impurities in the samples comparison, %. All the necessary calculations, using the design tool or the table in Annex 2 GOST 24977.1−81. According to the obtained calibration chart find the content of impurities corresponding to the calculated sample values .

In determining impurities, the density of the blackening of analytical lines which lies in the region of normal pochernenija, and in the analysis of tellurium brand T-A1 calibration graphs constructed in the coordinates .

The analysis result should be the arithmetic mean of two parallel definitions for the three spectrograms, each received on the same photographic plate.

(Changed edition, Rev. N 1,

2).

5.2. Discrepancies in the results of two parallel measurements () and the results of two tests () at a confidence probability of 0.95 should not exceed the values given in table.2.

Table 2

Permitted discrepancies for the intermediate mass fraction of impurities calculated by linear interpolation or according to the formulas:

for silver, copper, lead, Nickel, bismuth, tin, cobalt and gold:

; ;

for indium, gallium, chromium, manganese, magnesium, iron and aluminum:

; ;

where is the arithmetic mean of the results of parallel measurements;

 — the average of the two results of the analysis.

(Changed edition, Rev. N 2).