GOST 23862.11-79

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  ГОСТ 23862.11-79

GOST 23862.11−79 Rare-earth metals and their oxides. Chemical-spectral method of determination of impurities of vanadium, iron, cobalt, manganese, copper, Nickel (with Change No. 1)

GOST 23862.11−79

Group B59

INTERSTATE STANDARD

RARE EARTH METALS AND THEIR OXIDES

Chemical-spectral method of determination of impurities of vanadium, iron, cobalt, manganese, copper, Nickel

Rare-earth metals and their oxides. Chemical-spectral method of determination of impurities of vanadium, iron, cobalt, manganese, copper, nickel

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 Change No. 1, approved in April 1985 (IUS 7−85).


This standard specifies the chemical-spectral method of determination of impurities in rare earth metals and their oxides (except cerium dioxide and cerium).

The method is based on the group concentration of impurities by extraction of their chloroform diethyldithiocarbaminate and subsequent spectral analysis of the obtained concentrate.

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-13 with grating of 600 lines/mm operating in the first order reflection and 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.

Microphotometer registered G-II with recorder 9 1B1 or similar.

Spectromancer PS-18 or similar.

Libra torsion type VT-500 or similar.

Box of organic glass.

Mortar, pestle, funnel, and the rod of organic glass.

Muffle furnace with thermostatic control, providing temperature up to 400 °C.

Drying oven with thermostat providing temperatures up to 110 °C.

Tile electric.

The infrared lamp 3-C-1.

The machine tool for sharpening of electrodes.

Coals spectral high purity-7−3.

The shaped graphite electrode for spectral analysis of the brand high purity-7−4 6 mm in diameter with a crater with a diameter of 4 mm, depth 6 mm or electrodes of the same size, carved from a spectral coals brand high purity-7−3.

The shaped graphite electrode for spectral analysis of the brand high purity-7−4 6 mm in diameter, sharpened to a cone, or the electrodes of the same shape, carved from a coal-spectral high purity-7−3.

Cleaning firing in the arc of DC 15 And within 15 put each pair of electrodes before measurement (electrode, sharpened on a cone (top) — the cathode; the electrode to the crater (bottom) — anode).

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

Photographic plates spectrographic type II size 9x12 or 9х24 for normal blackening of analytical lines and the background in the spectrum.

The quartz Cup with a capacity of 30 cm.

Cup platinum.

Water deionized with a specific resistivity of from 20 to 24 Mω·cm.

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

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

Ammonia water according to GOST 3760−79, H. h., diluted 1:10.

Chloroform according to GOST 20015−88, double-distilled.

Sodium N, N'-diethyldithiocarbamate according to GOST 8864−71, a solution with a concentration of 20 g/DM; cook before eating.

Sodium chloride OS.h. 7−4.

The technical rectified ethyl alcohol GOST 18300−87, double-distilled in quartz apparatus.

Vanadium metal.

Radio engineering carbonyl iron according to GOST 13610−79, mark PS.

Cobalt grade K-1 according to GOST 123−98.

Manganese metal brands Мр0 according to GOST 6008−90.

Copper grade M-3 according to GOST 859−2001.

Nickel brand D2 GOST 849−97.

Solutions containing 1 mg/cmvanadium, iron, cobalt, manganese, copper and Nickel: 100 mg of one of the above metals is dissolved in the minimum quantity of nitric acid (1:1), the solution was transferred to volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix.

3. PREPARATION FOR ASSAY

3.1. Sample preparation comparison

3.1.1. The head sample comparison (GOS), containing 0.1% of each impurity determined based on the content of the corresponding metal in the mixture powder of graphite and metal impurities in the platinum Cup place of 9.94 g of powdered graphite and consistently poured 10 cmof each of solutions containing 0.1 mg/cmof the designated metals. The mixture is evaporated under infrared lamp until complete removal of nitrogen oxides, calcined in a muffle furnace at 350−400 °C for 5 min, triturated in a mortar made of organic glass for 1.5−2 hours, occasionally adding alcohol, dried in a drying Cabinet at 105−110 °C for 1 h and again grind to grinding of the formed lumps.

Grinding in a mortar, and drying under a heat lamp are in the box of organic glass.

3.1.2. References (OS) to prepare a serial dilution of STATE, and then each subsequent powder graphite.

The mass fraction of the designated impurities and added to the mixture of graphite powder sample and the previous sample are given in table.1.

Table 1

These powder sample of graphite and the previous OS was placed in a mortar made of organic glass and carefully grind in for 1 hour, adding alcohol until mushy state mass is dried in a drying Cabinet at 105−110 °C to constant weight and triturated.

The comparison samples stored in the desiccator in packages of tracing paper.

4. ANALYSIS

4.1. The concentration of the impurities is carried out in a box of organic glass.

A sample of REE oxide content of 1 g or the corresponding amount of metal is placed in a quartz Cup, pour 4−6 cmof hydrochloric acid diluted 1:1, heated on a heating plate until fully dissolved, evaporated on a water bath to dryness, add 30−40 cmof water, ammonia to pH 4 and transferred to a separatory funnel, is introduced 1 cmof a solution of sodium diethyldithiocarbamate, 5 cmof chloroform and vigorously shaken for 1 min.

After separation the organic phase was transferred to another separatory funnel and repeat extraction under the same conditions two more times. The combined extract (organic layer) was washed twice with water in portions of 10 cm, transferred to a dry quartz Cup, add 50 mg of graphite powder (header) and evaporated at room temperature. The walls of the Cup is washed with 1 cmof concentrated nitric acid, the sample is evaporated in a water bath and calcined in a muffle furnace at 350−400 °C for 1−2 min Obtained dry residue is subjected to spectral analysis.

Analysis of each sample is carried out in two parallel batches. Simultaneously with each batch of tests put two test experience for all reagents, guiding them through all stages of analysis and getting two dry residue concentrate.

4.2. Spectral analysis of concentrates

To each concentrate obtained from the sample and control experiments, and to 47 mg each of the samples of comparison 1 OS — OS 8 is added 3 mg of sodium chloride and stirred in a mortar made of organic glass for 1 min. Each mixture using the funnel and rod of organic glass to fill in the crater bottom electrode with a diameter of 4 mm and a depth of 6 mm of the anode. The upper electrode is a cathode electrode, sharpened to a cone. Between them using high-frequency spark lit arc DC A. 15 Spectra in the region: 270.0 cm-photograph of 345.0 nm on a spectrograph DFS-13. The exposure time is 80 s, the distance between the electrodes is 3 mm, the width of the slit of a spectrograph — 25 µm.

The range of concentrates of each sample and control experience, as well as the spectra of each of the samples of comparison 1 OS — OS 8 photographed twice.

Exposed photographic plates show washed with water, fixed, washed in running water (15 min) and dried.

5. PROCESSING OF THE RESULTS

5.1. In each spectrogram photometric blackening of analytical lines of the determined elements (see table.2).

Table 2

Fotometrirovanie lines, blackening which are in the region of the straight portion of the characteristic curve of the emulsion, carried out in microphotometer MF-2. In each spectrogram photometric blackening of analytical lines of the designated element and the surrounding background and calculate the difference of pochernenija . Two parallel values of and obtained with two spectrogram, calculate the arithmetic mean value . Using the values obtained for the samples comparison (OS), build a calibration curve in the coordinates (, ), where  — the contents of the designated impurities in the OS. On this chart, find the content of impurities in the concentrates, using the values for concentrate samples and in the reference experiment.

Fotometrirovanie weak lines, which is close to the blackening the blackening the background is performed on the registered microphotometer (see GOST 23862.3

-79).

5.2. Mass fraction of impurities () in percent is calculated by the formula

,

where is the mass of the concentrate, g;

 — the weight of the portion of the sample, g;

 — average mass fraction of impurities in the concentrate samples, %;

 — the average value of mass fractions of impurities concentrate in the reference experiment, %;

 — coefficient taking into account the systematic error of the method; find the results of detection of additives impurity elements introduced in the sample.

5.3. Under the control of the reproducibility of parallel measurements find the content of impurities in the concentrates of samples corresponding to the values of and , and according to the formula calculate the content of impurities in the oxides of the REE. Differences between the thus obtained results of two parallel measurements (the ratio of larger to smaller), as well as discrepancies in 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