GOST 23862.4-79

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  ГОСТ 23862.4-79

GOST 23862.4−79 Rare-earth metals and their oxides. Spectral method of determination of vanadium, iron, cobalt, silicon, manganese, copper, Nickel, lead, titanium, chrome (with Amendments No. 1, 2)

GOST 23862.4−79

Group B59

INTERSTATE STANDARD

RARE EARTH METALS AND THEIR OXIDES

Spectral method of determination of vanadium, iron, cobalt, silicon, manganese, copper, Nickel, lead, titanium, chromium

Rare-earth metals and their oxides. Spectral method of determination of vanadium, iron, cobalt, silicon, manganese, copper, nickel, lead, titanium, chromium

ISS 77.120.99
AXTU 1709

Date of introduction 1981−01−01

The decision of the State Committee USSR on standards on October 19, 1979 N 3988 date of introduction is established 01.01.81

Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)

EDITION with Amendments No. 1, 2 approved in April 1985, may 1990 (IUS 7−85, 8−90).


This standard establishes a spectral method for the determination of impurities in rare-earth metals (previously translated into oxide) and their oxides.

The method is based on excitation and photographic registration of arc emission spectra of the analyte samples and comparison with subsequent determination of content of impurities in the calibration schedule.

Intervals determined by a mass fraction of impurities:

(Changed edition, Rev. N 1).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 23862.0−79.

2. APPARATUS, MATERIALS AND REAGENTS

The diffraction spectrograph DFS-8 with a grating of 600 lines/mm operating in the first order reflection, from being a lighting system or similar.

The diffraction spectrograph DFS-13 with a grating 1200 lines/mm operating in the first order reflection, from being a lighting system or similar.

The arc generator DG-2 with optional rheostat or similar, adapted to ignite the DC arc high frequency discharge.

Rectifier 250−300, 30−50 A.

Microphotometer geregistreerde type MF-2 or similar.

Spectromancer of PS-18 or similar.

Libra torsion type VT-500 or similar.

Box of organic glass.

Mortars and pestles made of organic glass.

Muffle furnace with thermostatic control, providing temperature up to 1000 °C.

Lamp infrared ikz-500 with voltage regulator type RNO-250−0,5 or similar.

The machine tool for sharpening of electrodes.

Spectrographic plates of the type ES or equivalent, providing normal blackening of analytical lines and the background in the spectrum.

Coals spectral OS.h. 7−3, with a diameter of 6 mm.

The electrodes are machined from a spectral coals OS.h. 7−3, 6 mm in diameter, with a crater diameter of 4 mm and a depth of 4 mm.

The shaped graphite electrode for spectral analysis of OS.h. 7−4, 6 mm in diameter, sharpened to a cone, or the electrodes of the same shape, carved from a spectral coals high purity-7−3, with a diameter of 6 mm (1);

the electrodes are machined from a spectral coals OS.h. 7−3 6 mm in diameter, with a crater with a diameter of 2 mm, depth 3 mm, wall thickness 0,5−0,7 mm, a height of the sharpened part is 8 mm (2).

Each pair of electrodes is subjected to a cleaning firing in the arc DC 15 A for 15 s immediately before analysis.

Graphite powder of high purity according to GOST 23463−79.

Vanadium (V) oxide, h.d. a.

Iron oxide, h.d. a.

Cobalt oxide according to GOST 18671−73.

Silicon dioxide according to GOST 9428−73, h.d. a.

Manganese dioxide anhydrous OS.h. 9−2.

Copper oxide according to GOST 16539−79, powdery.

Nickel oxide black GOST 4331−78, CH.

Lead oxide, h.d. a.

Titanium dioxide of the OS.h. 7−3.

Chromium oxide brand OXM-0 GOST 2912−79, metallurgical.

Oxide of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, neodymium, gadolinium, ytterbium, lutetium and yttrium, clean-defined impurities.

Sodium chloride OS.h. 6−4.

The technical rectified ethyl alcohol GOST 18300−87.

Buffer a mixture of graphite powder with a mass fraction of sodium chloride at 50%: 1 g of sodium chloride is mixed with 1 g of powder graphite in a mortar made of organic glass for 30 min.

Sec. 2. (Changed edition, Rev. N 1, 2).

3. PREPARATION FOR ASSAY

3.1. Sample preparation comparison

Each reference sample (OS) is prepared by mixing the corresponding oxides, REE, clean-defined impurities (base) with a sample comparison, graphite powder (OSGP) in a ratio of 10:1.

In terms of the method in accordance with the ratio of the masses of miscible substances, the mass fraction of each impurity in the OS in the calculation of the mass fraction in the sample equal to one-tenth the mass fraction of this impurity in OSGP.

(Changed edition, Rev. N 1).

3.2. Sample preparation comparison, graphite powder

The head sample comparison, graphite powder (GOHP) containing 0.1% of manganese and copper and 1.0% of vanadium, iron, cobalt, silicon, Nickel, lead, titanium and chromium, prepared by the mechanical mixing of graphite powder with oxides of the respective metals.

Before weighing, the silica is calcined in a muffle furnace at 700−800 °C for 30 min and cooled in a desiccator.

12.5 mg copper oxide and 15.8 mg of anhydrous manganese dioxide is placed in a mortar made of organic glass and add 71,7 mg of powdered graphite. The mixture was thoroughly triturated with ethanol for 30 min and dried under an infrared lamp. Then 10 mg of the mixture, and 17.9 mg of vanadium pentoxide and 14.3 mg of iron oxide, of 14.1 mg of cobalt oxide, 21.4 mg of silicon dioxide, 14,1 mg of an oxide of Nickel, 10.8 mg of lead oxide, 16.7 mg of titanium dioxide, at 14.6 mg of chromium oxide was placed in a mortar made of organic glass and add 866,1 mg of powdered graphite. The mixture was thoroughly triturated for 1 h, adding alcohol to maintain a pasty condition of the masses, and dried under an infrared lamp.

The rest OSGP prepare serial dilution GOGP, and then each subsequent sample is powdered graphite. The content of each of the designated impurities in OGP (based on the metal content of a mixture of oxides and powdered graphite) and added to the mixture of graphite powder sample and the previous sample are shown in table.1.

Table 1

Listed in the table.1 sample powder of graphite and the previous sample is placed in a mortar made of organic glass, carefully grind the mixture for 30 min, adding alcohol to maintain a pasty condition of the masses, and dried under an infrared lamp. The grinding and drying are in the box of organic glass. OSGP stored in tightly closed cans of organic glass.

4. ANALYSIS

4.1. Analysis are oxides of REE. Metals transferred to the oxide according to GOST 23862.0−79.

4.2. A portion of the sample (and sample basis) mass of 40 mg is mixed with 4 mg of graphite powder and 2 mg of sodium chloride or 6 mg pre-mixed powder of graphite and sodium chloride in the ratio 2:1. The resulting mixture (20 mg) was placed in the craters of the two electrodes.

A portion of each asset (see paragraph 3.1) weighing 44 mg mixed with 2 mg of sodium chloride, the resulting mixture (20 mg) was placed in the craters of the two electrodes.

The lower electrode with the mixture serves as the anode, the cathode is the upper electrode (I). Allowed to be used as the cathode electrode (II), which is pre-placed (repeated immersion) buffer mixture. Between electrodes to ignite an arc DC current of 15 A. the exposure Time 45 s. the Distance between the electrodes is 3 mm.

The spectra photographed in the region 240−340 nm with a spectrograph DFS-8 (for analysis of oxides of lanthanum, cerium, neodymium, europium, gadolinium, ytterbium, lutetium, yttrium) or in a region of 280−330 nm with a spectrograph DFS-13. The width of the slit of a spectrograph — 15 microns. In the cassette placed records of type of ES.

In the determination of silicon in the region of 240−260 nm allowed the use of a spectrograph ISP-30.

The spectrum of each sample, each asset, and the basics of photographing twice. Exposed photographic exhibit, washed with water, fixed, washed in running water for 15 min and dried.

(Changed edition, Rev. N 1).

5. PROCESSING OF THE RESULTS

5.1. In each spectrogram photometric the blackening of analytical lines of the designated element (table.2) and background near it and calculate the difference of pochernenija . Two parallel values and obtained two spectrograms taken for each sample, find the average value . According to the obtained average values (tables app GOST 13637.1−93) find the value of .

Table 2

5.2. If the analytical line of the designated element in the spectra of the basics of the OS is missing, then, using the obtained values and for samples comparison, build a calibration curve in the coordinates . The result of the analysis taking the value of the mass fraction of impurities in the sample was found in this schedule by value .

Discrepancies between the results of the two analyses (the ratio of largest to smallest) should not exceed values of allowable differences specified in table.3.

Table 3

5.3. Under the control of the reproducibility of parallel measurements on two parallel values and obtained from two spectra taken for each sample, find parallel values and calibration schedule and find the value and the results of each of the parallel definitions of the impurities in the sample. The ratio of the greater to the smaller of them should not exceed the values allowable differences specified in table.3.

5.2, 5.3. (Changed edition, Rev. N 1).

5.4. If in the spectra of the basis of comparison samples (OS), there is a weak line of the element, then the construction of calibration curve, corrected for the value of the mass fraction of the element in the base OS. An amendment is permissible only under the condition that this value does not exceed the specified for the method lower limit of determination.

After receiving the adjusted calibration curve, then do as indicated in the claims.5.2 and 5.3.

5.5. When you control the accuracy of using GSO 2820−73 the linkage basis (p.3.1) weighing of 40 mg is mixed with a suspension of GSO with a mass of 4 mg and a charge of sodium chloride with a mass of 2 mg. mixture of 20 mg was placed in craters of the two electrodes and conduct an analysis as specified in PP.4.2, 5.1, 5.2, 5.4. The result of the analysis is considered correct if the ratio values and (calculate the ratio of largest to smallest) satisfies the condition p. 18 GOST 23862.0−79.

(Added, Rev. N 2).