GOST 12556.2-82

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  ГОСТ 12556.2-82

GOST 12556.2−82 Alloys platinum-rhodium. Methods of spectral analysis (with Change No. 1)

GOST 12556.2−82

Group B59

STATE STANDARD OF THE USSR

ALLOYS OF PLATINUM-RHODIUM

Methods of spectral analysis

Alloys platinum-rhodium. Methods of spectral analysis

AXTU 1709*
______________
* Introduced advanced Edit. N 1.

Valid from 01.01.84
to 01.01.89*
_______________________________
* Expiration removed
Protocol N 3−93 Interstate Council
for standardization, Metrology and certification
(IUS No. 5/6, 1993). — Note the manufacturer’s database.

DEVELOPED by the Ministry of nonferrous metallurgy of the USSR

PERFORMERS

A. A. Kuranov, G. S. HAK, N. With. Stepanova, N. D. Sergienko, T. I. Belyaev, E. E. Safonova

INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

Zam. Minister Vladimir Boroday

APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards, dated 30 September 1982, N 3865

REPLACE GOST 12556−67 in part of sec. 3

The Change N 1, approved and put into effect by the Decree of the USSR State Committee for standards from 13.06.88 N 1730 with 01.01.89

Change No. 1 made by the manufacturer of the database in the text IUS N 9, 1988


This standard specifies the methods of spectral determination of impurities: palladium, iridium, ruthenium, gold, silver, iron, Nickel, copper, silicon, aluminum, lead, antimony, zinc, tin and magnesium in a platinum-rhodium alloys.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 22864−83.

(Changed edition, Rev. N 1).

1.2. The numerical value of the result of the analysis must end with a digit of the same rank as that of the normalized indicator grade composition.

(Added, Rev. N 1).

2. SPECTRAL METHOD OF DETERMINATION OF IMPURITIES IN SAMPLES
OF ARBITRARY SHAPE AND A SMALL MASS (WHEN THE MASS FRACTION OF GOLD,
SILICON, ALUMINUM, LEAD, ANTIMONY, ZINC, TIN,
Of NICKEL from 0.005 to 0.05%, of RUTHENIUM, IRON from 0.01 to 0.08%,
Of PALLADIUM from 0.005 to 0.10%, IRIDIUM from 0.02 to 0.08%,
MAGNESIUM from 0.003 to 0.03% SILVER, COPPER from 0.001 to 0.02%)

2.1. The essence of the method

The method is based on placing the sample of the alloy in the globule (liquid drop of melt), photographing its spectrum in the arc discharge and the measurement of line intensities of impurities. The relationship of spectral line intensity with impurity concentration set at the calibration charts.

2.2. Apparatus, reagents and solutions

The spectrograph diffraction large dispersion.

The quartz spectrograph medium dispersion.

The three-stage attenuator.

Generator DC arc.

Arc generator of alternating current.

Microphotometer.

Clips (electrode holders).

Standard samples of the enterprise.

Electrodes, carbon, made of spectral pure coal brands high purity-7 or C-2.

Analytical scale.

Stopwatch.

Photographic plates of the spectral type II or ES, a sensitivity of 10−15 conventional units.

Grinding machine carbon electrodes.

Hydrochloric acid by the GOST 3118−77, diluted 1:1.

The developer and fixer.

(Changed edition, Rev. N 1).

2.3. Preparation for assay

2.3.1. Samples for analysis must be in the form of tape, wire or shavings with a mass of 2.0 g For the removal of surface contamination, the samples are boiled in hydrochloric acid (1:1) for 3 min, washed with water and dried.

2.4. Analysis

2.4.1. The spectra are photographed on the big dispersion spectrograph with slit width 0.02 mm and coverage via its three-lens Achromat condenser with diaphragm on the middle lens of the condenser with a height of 5 mm. in the Interelectrode gap to adjust continuously throughout the exposure for the image of the arc on the screen of the intermediate diaphragm.

The electrodes were applied to the spectral coals with a diameter of 6 mm. Bottom electrode figure with padding and millimeter recess in the end face of the electrode. In the recess is placed a sample to be analyzed or of standard sample mass of 0.1 g For the upper electrodes used charcoal, sharpened to a hemisphere or a truncated cone with ground diameter of 1.5 mm.

Spectra photographed with an exposure of 45 to 60 with through a three-stage attenuator on a photographic plate of the type II or ES.

The excitation source is an arc DC current of 8 A. the Sample includes anode. Together with the analyzed samples on the same plate photographed spectra of standard samples analyzed grade alloy. For each standard sample receive two parallel spectrogram, for each test sample three.

A photographic plate showing within 3 to 6 min at developer temperature of 20 °C. the Shown plate is rinsed in water, fixed, washed in running water, dried and photometric.

(Changed edition, Rev. N 1).

2.5. Processing of the results

2.5.1. Wavelength of analytical spectral lines are given in table.1.

Table 1

2.5.2. Determination of the mass fraction of the elements are by the method of «three standards» with the objective photoretrieval. The calibration graphs are built for each analyzed element. Y-axis delay value difference pucherani lines of impurities and the main substances, and the horizontal axis — the values of the logarithms of the concentrations of standard samples.

With the help of calibration curve by the known values of the difference of pochernenija find the contents of the analyzed element in the sample.

2.5.3. The convergence of the method is characterized by the relative standard deviation given in table.2.

Table 2

For the results analysis be the arithmetic mean of three parallel measurements under the condition of:

,

where is the greatest result of the parallel measurements;

least the result of the parallel measurements;

 — relative standard deviation describing repeatability of measurements;

 — the arithmetic mean calculated from parallel measurements (3).

3. SPECTRAL METHOD of DETERMINATION of IMPURITIES IN SAMPLES PRODUCED IN the FORM of MONOLITHIC PIECES (WITH a MASS FRACTION of GOLD, PALLADIUM, IRIDIUM AND IRON from 0.01 to 0.20%)

3.1. The essence of the method

The method is based on the excitation spectrum of the discharge arc AC to the measurement of line intensities of impurities. The relationship of intensity with concentration is set by calibration with standard samples. As one of the electrodes used a monolithic piece.

3.2. Apparatus, reagents and solutions — p. 2.2.

3.3. Preparation for assay

3.3.1. Samples for analysis must be in the form of a piece of arbitrary shape a mass of not less than 50 g with the area of 300−400 mm. To remove surface contamination, the samples are boiled in hydrochloric acid (1:1) for 3 min, washed with water and dried.

3.4. Analysis

3.4.1. The spectra are photographed on the spectrograph medium dispersion at slit width of 0.01 mm, electrode gap 1.5 mm, exposure time 30 s. the light Source of arc discharge of alternating current power of 5 A.

The pieces analyzed and standard samples serve as the lower electrodes. As the upper electrode use standard charcoal, sharpened to a hemisphere or a truncated cone with ground diameter of 1−2 mm.

The spectra photographed using a three-step attenuator on the photographic plate of the type II. When fotomaterialy choose the step with the optimal pochernenija analytical lines.

For each standard sample receive two parallel spectrogram, for each test sample three.

A photographic plate showing within 3 to 6 min at developer temperature of 20 °C. the Shown plate is rinsed in water, fixed, washed in running water, dried and photometric.

(Changed edition, Rev. N 1).

3.5. Handling results according to claim 2.5.