GOST 23862.13-79

• gost-2386213-79.pdf (271.93 KiB)
  ГОСТ 23862.13-79

GOST 23862.13−79 Lanthanum, neodymium, gadolinium, dysprosium, yttrium and their oxides. Method of determination of impurities of oxides of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium (with Amendments No. 1, 2)

GOST 23862.13−79

Group B59

INTERSTATE STANDARD

LANTHANUM, NEODYMIUM, GADOLINIUM, DYSPROSIUM, YTTRIUM AND THEIR OXIDES

Method of determination of impurities of oxides of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium,

Lanthanum, neodymium, gadolinium, dysprosium, yttrium, and their oxides. Method of determination of impurities as oxides of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium

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 fluorescent method for the determination of impurities of oxides of praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, in lanthanum, neodymium, gadolinium, dysprosium, yttria and their oxides.

The method is based on excitation of spark, or x-ray emission spectra of luminescence of ions of rare earth elements impurities (activators) in the crystal of the analyzed materials and the registration of the received radiation. Impurities find a method of additives.

Determined mass fraction of impurities of oxides when excited by x-rays:

Determined mass fraction of oxides in the excitation of the spark:

(Changed edition, Rev. N 1, 2).

1. GENERAL REQUIREMENTS

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

2. APPARATUS, MATERIALS AND REAGENTS

Set for detection of luminescence spectra in the regime of afterglow (damn.1).

1 — spark generator IG-3; 2 — shielding case; a 3 — disk shutter with four movable tungsten electrodes; 4 — odnogruppnitsa brush; 5 — blade shutter; 6 — stationary tungsten electrode; 7 — cuvette with crystallophosphorus; 8 — motor SL-521; 9 — diffraction monochromator MDR-2; 10 — photomultiplier FEU-18; 11 — electric motor RD-09; 12 — rectifier high-voltage stable VSV-2; 13 — electronic chart recorder

Damn.1

Set for detection of luminescence spectra excited by x-rays (Fig.2).

1 — power supply x-ray tube; 2 — x-ray tube; 3 — cuvette-proportinately with tablet-crystallophosphorus; 4 — condenser; 5 — monochromator; 6 — photomultiplier; 7 — high-voltage stabilizer; 8 — photomultiplier; 9 — potentiometer

Damn.2

A muffle furnace with a thermostat that provides temperature to 1200 °C.

Tile electric.

Drying oven with thermostat providing temperatures up to 120 °C.

Mortars and pestles, agate or from glass or niobium.

Box of organic glass.

Analytical scale type VAR-200 or similar.

Libra torsion type VT-500 or similar.

Platinum crucibles N 7.

Crucibles lundbye N 122 with a capacity of 15−20 cm.

Absorbent cotton wool GOST 5556−81.

Tracing paper according to GOST 892−89.

The quartz Cup with a capacity of 30−50 cm.

Boat porcelain with GOST 9147−80.

Nitric acid of high purity according to GOST 11125−84 diluted 1:1.

Hydrochloric acid of high purity according to GOST 14261−77 diluted 1:1.

Sodium chloride according to GOST 4233−77, H. h, solution with concentration 10 g/DM.

Deionized water (twice).

The technical rectified ethyl alcohol GOST 18300−87.

Oxide of lanthanum, praseodymium, samarium, europium, gadolinium, dysprosium, terbium, yttrium, clean-defined impurities.

Solutions I spare praseodymium, samarium, dysprosium, terbium containing 1 mg/cmof one of REE (calculated as oxide): 100 mg of the REE oxides were placed in a glass with a capacity of 50 cm, moistened with water, poured 0,5−1 cmof hydrochloric acid, heated on a hot plate until dissolved, cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, mix.

I working solutions containing 1 µg/cmREE (calculated as oxide), is prepared by dilution of the replacement solutions I water 1000 times.

Solutions II spare samarium, europium, gadolinium, dysprosium, terbium containing 1 mg/cmof one of REE (calculated as oxide): 100 mg of the REE oxides were placed in a glass with a capacity of 50 cm, moistened with water, poured 0,5−1 cmof nitric acid, heated on a hot plate until dissolved, cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

II working solutions containing 1 µg/cmREE (calculated as oxide), is prepared by dilution replacement fluids II water 1000 times.

Solution III backup containing 3 mg/cmoxides of praseodymium, neodymium and samarium, is prepared as follows: 300 mg of each oxide were placed in a glass with a capacity of 100 cm, moistened with water, poured 6−10 cmof hydrochloric acid, heated on a hot plate until dissolved, evaporated under a glass bulb to wet salts, transferred to a volumetric flask with a capacity of 100 cm, adjusted to the mark with water, mix.

III working solution containing 3 mg/cmof each oxide, is prepared by dilution of the reserve water solution III to 1,000 times. Solution IIIworking freshly prepared, containing 1.5 µg/cmof each oxide, is prepared by dilution of the working solution III with water twice.

(Changed edition, Rev. N 1, 2).

3. ANALYSIS

3.1. Preparation of crystal

3.1.1. A crystal of lanthanum in quartz Cup is placed on 300 mg of the sample of an oxide of lanthanum (or the corresponding amount of metal), pour in 2 cmof sodium chloride solution, and 0.5−1 cmof hydrochloric acid. In two cups of injected working solutions I of praseodymium, samarium, dysprosium (1 µg/cm) so that the content of these REE were larger than the expected content of the sample is 1.5−3 times. Then all four cups are placed on the electric stove, a test portion is dissolved, evaporated to dryness, calcined in a muffle furnace at 700−750 °C for 20−25 min and cooled to room temperature.

When excited by x-rays: six of the platinum crucible was placed in 300 mg of the sample of an oxide of lanthanum (or the corresponding amount of metal), pour 1 cmwater and 2 cmof hydrochloric acid. Two of the crucible injected at 1 cmworking solution III (3 µg/cm); in the other two crucible injected at 1 cmworking solution III(1.5 µg/cm) in the remaining two of the crucible administered by 1 cmof water. All six crucibles were placed on the cold electric stove, the sample is dissolved by gradual heating, evaporated to dryness, calcined in a muffle furnace at a temperature of 700−750 °C for 25 min and cooled to room temperature. The obtained crystal niobium lightly ground in a mortar and stored in a desiccator in packages of tracing paper.

(Changed edition, Rev. N 1

, 2).

3.1.2. A crystal of neodymium in a glass with a capacity of 50 cmare placed 150 mg of the sample of oxide of neodymium (or the corresponding amount of metal), moisten with water, pour 1−1,5 cmof hydrochloric acid, heated on a hot plate until dissolved, cooled to room temperature, transferred to a volumetric flask with a capacity of 25 cmand was adjusted to the mark with water (solution A).

Then four quartz Cup was placed in 300 mg of an oxide of lanthanum, praseodymium clean and Samaria, pour in 1 cmof solutions A, sodium chloride and hydrochloric acid. Then do as stated in claim 3.1.1, using working solutions I, praseodymium and samarium. Calcined in a muffle furnace at 700−800 °C for 15−20 min.

3.1.3. A crystal of dysprosium: a glass with a capacity of 50 cmare placed 150 mg of the sample of dysprosium oxide (or the corresponding amount of metal), moisten with water, pour 1−1,5 cmof hydrochloric acid, heated on a hot plate until dissolved, cooled to room temperature, transferred to a volumetric flask with a capacity of 25 cmand was adjusted to the mark with water (solution B).

Then four quartz Cup was placed in 300 mg of an oxide of yttrium, terbium clean, pour 1 cmof solutions B, sodium chloride and hydrochloric acid. Then do as stated in claim 3.1.1, using the working solution I of terbium. Calcined in a muffle furnace at 800−850 °C for 25−30 min.

3.1.4. A crystal of yttrium or gadolinium in lodowych crucible was placed in 300 mg of the sample of yttrium or gadolinium, previously translated into oxide or oxides, pour 1 cmwater and 2 cmof hydrochloric acid. Two of the crucible introduce working solutions II to the value of the mass fraction of the designated impurities REE exceeded their estimated value in the sample is 1.5−3 times. In two other Cup pour 1 cmof water.

When analyzing samples with a mass fraction of each of the designated impurities more than 1·10%, each impurity is determined from the individual crystallophosphorus. To determine each impurity in four lodowych crucible was placed in 300 mg of the sample of an oxide of yttrium or gadolinium oxide. Two of the crucible enter the corresponding working solution II so that the value of the mass fraction of the designated impurities was larger than the expected value in the sample is 1.5−3 times. In two other Cup pour 1 cmof water.

The content of each crucible is stirred with a glass rod, evaporated to dryness in an oven at 100−110 °C, transferred to a mortar and grind for 1−2 minutes, moved back into the same crucible, calcined in a muffle furnace at 1000−1100 °C for 1 h and cooled to room temperature.

(Changed edition, Rev. N 1, 2).

3.2. Excitation and registration of luminescence spectra

Every crystalliser ground in a mortar and placed in a cuvette with a quartz window. In the analysis of each oxide excite and record the luminescence spectra of crystal phosphors four sequentially starting with most supplements. A cuvette crystallophosphorus placed behind the disc surface (see hell.1). The luminescence spectra excited by a spark discharge between the fixed tungsten electrode and one of the four mobile tungsten electrode, mounted on the metal disk surface, rotated by the engine of SL-521 with a speed of 50. Wherein the input slit of the monochromator shutter closed shutter. The width of the entrance slit of the monochromator 15−20 ám, the output — 20−40 microns. 2·10s after termination of the spark discharge entrance slit of the monochromator is opened and recorded in the afterglow of crystallophosphorus for 2·10s.

(Changed edition, Rev. N 2).

3.2.1. The luminescence spectra of each crystallophosphorus excite and register in sequence starting with most supplements. Crystalliser placed in the cuvette-probatively, then, lifting the flap, introduce it into the chamber through a locking hole. The luminescence spectra excited by x-rays, when the voltage on the x-ray tube is 25 kV for the determination of neodymium and 15 kV for the determination of praseodymium and samarium. The width of the entrance slit of the monochromator and PMT voltage set in the analysis sample with more additive so that the height of the peak on registerme was 40−50% of full-scale potentiometer. The background noise should not exceed 10% of the scale, which is achieved by gain control potentiometer. The width of the exit slit should be 1.5 times the width of the entrance slit.

(Changed edition, Rev. N 1, 2).

4. PROCESSING OF THE RESULTS

4.1. In each registrarme measure the height () of the peak of the analytical lines of impurity element (see table.1).

Table 1

Two parallel values of and obtained with two registrovanym for crystal phosphors prepared with the samples without additives, find arithmetic mean value . Mass fraction of each of the designated oxides () in percent is calculated by the formula

,

where  — mass fraction determined by the oxide additive, %;

the peak height of the analytical lines in registrarme obtained for crystallophosphorus prepared from the samples with additive.

If the value of supplements do not meet the requirements laid down in paragraph 3.1, the analysis is repeated with the introduction of new additives.

4.2. Under the control of reproducibility of results of parallel measurements on two parallel values of and obtained with two registrovanym for crystal phosphors prepared with the samples without additives, calculated values and the results of each of the parallel definitions. Discrepancies in the results of two parallel determinations or the results of the two tests should not exceed values of allowable differences specified in table.2.

Table 2