GOST 23862.10-79
GOST 23862.10−79 Rare-earth metals and their oxides. Chemical-spectral methods of determination of impurities of vanadium, tungsten, iron, cobalt, manganese, copper, molybdenum, Nickel, niobium, lead, tantalum, titanium and chromium (with Amendments No. 1, 2)
GOST 23862.10−79
Group B59
INTERSTATE STANDARD
RARE EARTH METALS AND THEIR OXIDES
Chemical-spectral methods of determination of impurities of vanadium, tungsten, iron, cobalt, manganese, copper, molybdenum, Nickel, niobium, lead, tantalum, titanium and chromium
Rare-earth metals and their oxides. Chemical-spectral methods of determination of impurities of vanadium, tungsten, iron, cobalt, manganese, copper, molybdeum, nickel, niobium, lead, tantalium, titanium and 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 specifies the chemical-spectral method of determination of vanadium, tungsten, iron, cobalt, manganese, copper, molybdenum, Nickel, niobium, lead, tantalum, titanium and chromium in yttria, lanthanum, ytterbium, the hotel Lutetia and their oxides (method I) and chemical-spectral method of determination of vanadium, manganese, iron, cobalt, Nickel, copper, rare earth metals and their oxides (except cerium dioxide and cerium) (method II).
(Changed edition, Rev. N 1, 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 23862.0−79.
Method I
Chemical-spectral method of determination of vanadium, tungsten, iron, cobalt, manganese, copper, molybdenum, Nickel, niobium, lead, tantalum, titanium and chromium in yttria, lanthanum, ytterbium, the hotel Lutetia and their oxides based on the group concentration of impurities by flocculation of colloidal solutions of diethyldithiocarbamate, dioksinov or hydroxides of impurity elements with the use of polyacrylamide in the presence of powdered graphite and subsequent spectral analysis of the obtained concentrate.
Intervals determined by a mass fraction of impurities:
| vanadium | from 5·10 |
| tungsten | from 5·10 |
| iron | from 5·10 |
| cobalt | 2·10 |
| manganese | from 5·10 |
| copper | from 5·10 |
| molybdenum | 2·10 |
| Nickel | 2·10 |
| of niobium | from 1·10 |
| lead | 2·10 |
| tantalum | from 1·10 |
| titanium | from 1·10 |
| chrome | from 5·10 |
Sec. 1. (Changed edition, Rev. N 1, 2).
2. APPARATUS, REAGENTS AND SOLUTIONS
The diffraction spectrograph DFS-8 with a 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.
Lamp infrared ikz-500 with voltage regulator type RNO-250−0,5 or similar.
Box of organic glass.
Rectifier 250−300, 30−50 A.
Spectromancer PS-18 or similar.
Microphotometer geregistreerde type MF-2 or similar.
Analytical scale type ADV-200.
Libra torsion bar type W-500.
Tile electric.
The machine tool for sharpening of electrodes.
Mortar made of fluoroplastic-4 or plexiglass.
Jars made of polyethylene.
Photographic plates of type ES.
Graphite powder of high purity according to GOST 23463−79.
Coals spectral high purity-7−3.
The electrodes are machined from high purity coals spectral-7−3, 6 mm in diameter, with a crater diameter of 4 mm and a depth of 6 mm.
Electrodes graphite fittings for spectral analysis 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.
Each pair of electrodes is subjected to a cleaning firing in the arc DC 15 A for 15 s immediately before analysis.
Crucibles of Gooch, diameter 15 mm.
Vanadium (V) oxide, h.d. a.
Tungsten (VI) oxide for spectral analysis, h. e. a.
Iron oxide, h.d. a.
Cobalt oxides according to GOST 4467−79, h.d. a.
Manganese (IV) oxide anhydrous OS.h. 9−2.
Copper oxide according to GOST 16539−79, powdery.
Molybdenum (VI) oxide, h.d. a.
Nickel oxide according to GOST 4331−78, CH.
Of niobium (V) oxide of the OS.h. 7−3.
Lead oxide, h.d. a.
Tantalum (V) oxide of the OS.h. 7−3.
Titanium (IV) oxide of the OS.h. 6−2.
Chromium oxide according to GOST 2912−79.
Water or double-distilled water deionized with a specific resistivity of from 20 to 24 Mω·cm.
Hydrochloric acid of high purity according to GOST 14261−77 diluted 1:1 and 1:10.
Ammonia water according to GOST 24147−80, OS.CH., diluted 1:10.
Sodium N, N'-diethyldithiocarbamate according to GOST 8864−71, solutions with concentrations of 20 and 1 g/DM.
Sodium mercaptoquinolinate (toxinet), a freshly prepared solution with a concentration of 5 g/DM.
The technical rectified ethyl alcohol GOST 18300−87, double-distilled in quartz apparatus.
Lanthanum oxide, pure for specific impurities.
Ytterbium oxide, pure for specific impurities.
Lutetium oxide, pure for specific impurities.
Yttrium oxide, pure for specific impurities.
Polyacrylamide, an aqueous solution with a concentration of 2 g/DM.
Paper universal indicator.
Sodium chloride OS.h. 6−2.
Sec. 2. (Changed edition, Rev. N 1, 2).
3. PREPARATION FOR ASSAY
3.1. Sample preparation comparison
3.1.1. The parent sample on the basis of graphite powder (GAGP) containing 1% each of the determined impurities, is prepared as follows.
Hitch weight 0,0178 g of vanadium oxide (V), 0,0126 g of an oxide of tungsten (VI), 0,0143 g of iron oxide, 0,0137 g of nitrous oxide of cobalt, 0,0158 g of manganese oxide (IV) anhydrous, 0.0125 g of copper oxide powder, 0,0150 g of an oxide of molybdenum (VI) 0,0141 g of the black oxide of Nickel, 0,0143 g of an oxide of niobium (V) 0,0108 g of lead oxide, 0,0122 g of an oxide of tantalum (V), 0,0167 g of titanium oxide (IV), 0,0146 g of chromium oxide was placed in a mortar made of organic glass or fluoroplastic-4 and add 0,8156 g of powdered graphite. The mixture is thoroughly triturated with ethyl alcohol for 50 min and dried under an infrared lamp. In order to avoid introducing dirt grinding in a mortar, and drying under infrared lamp is carried out in a box of organic glass.
3.1.2. References OS 1-OS 3 prepare a serial dilution GULP, and then each subsequent sample is powdered graphite.
The content of each of the designated impurities in samples OS 1-OS 3 and added to the mixture of graphite powder sample of the previous sample are given in table.1.
Table 1
| Marking sample | The mass fraction of each of the identified elements, % | The mass of charge, g | |
| powder graphite |
the previous sample (in parentheses symbol) | ||
| OS 1 |
1·10 |
1,800 |
0,200 (GULP) |
| OS 2 |
3·10 |
1,400 |
0,600 (OS 1) |
| OS 3 |
1·10 |
1,333 |
0,667 (OS 2) |
| OS 4 |
3·10 |
1,400 |
0,600 (OS 3) |
| OS 5 |
1·10 |
1,333 |
0,667 (OS 4) |
| OS 6 |
3·10 |
1,400 |
0,600 (OS 5) |
| OS 7 |
1·10 |
1,333 |
0,667 (OS 6) |
| OS 8 |
3·10 |
1,400 |
0,600 (OS 7) |
Listed in the table.1 sample powder of graphite and the previous sample is placed in a mortar, ground thoroughly with ethyl alcohol for 30 min and dried under an infrared lamp. Grinding in a mortar, and drying under infrared lamp is carried out in a box of organic glass.
4. ANALYSIS
4.1. The concentration of impurities
Concentration is carried out in a box organic glass, heating elements of electric ranges should be closed graphite or quartz cuvette.
A sample of REE oxides with a mass of 2 g or the corresponding amount of REE is placed in a quartz glass with a capacity of 100 cmand dissolved in 7−12 cm
of hydrochloric acid diluted 1:1, when heated, the glass under the close watch glass. The solution is evaporated to wet salts, the residue is dissolved in approximately 50 cm
of water. Solutions of ammonia (1:10) or hydrochloric acid diluted 1:10, set rn-2 (universal indicator paper). The resulting solution was heated to ~90 °C, pour 2.5 cm
of solution diethyldithiocarbamate sodium (20 g/DM
), 5 cm
of a solution of polyacrylamide, wherein the pH of the resulting solution should be 5,5. The contents of the beaker are thoroughly mixed quartz wand for 3−5 min until the formation of insoluble brown gel-like particles of fiber, add 50 mg of powdered graphite, 2 cm
of a solution of sodium thiocynate and again thoroughly stirred for 3−5 min, Cooled to room temperature, the solution and the precipitate was filtered through filter «blue ribbon» placed in the crucible of the Gooch, using a Bunsen flask with suction. The residue (concentrate of impurities) is washed 2−3 times with a solution of sodium diethyldithiocarbamate (1 g/DM
) in portions of 5 cm
, washing wand, wall of glass and the crucible. Then the crucible of the Gooch (with the sediment) was placed in a quartz Cup with a capacity of 30 cm
and dried the precipitate to dryness (without ashing filter) for 10−15 min the Precipitate with the filter is transferred to a quartz Cup with a capacity of 10 cm
(filter down) and incinerated filter for 3−5 min on a hotplate, a closed quartz plate. After ashing the filter Cup is available watch glass and allowed to stand still on the hot plate for 10−15 min.
After cooling, all the dry residue is transferred from the Cup onto the tracing paper, add 2 mg of sodium chloride, stirred and the resulting mixture is filled electrodes for spectral analysis.
Analysis of each sample is conducted three parallel batches. Simultaneously with each batch of tests carried out through all stages of the analysis three control experience on all the reagents, obtaining three dry residue-the concentration
rata.
4.2. Spectral analysis of concentrates
To each concentrate obtained from control experiments, and 50 mg each of the samples of comparison 1 OS-OS 8 added 2 mg of sodium chloride and clean-defined spectral impurity oxides of the analyzed REE and stirred. Each mixture was placed in a crater electrode (anode) with a diameter of 4 mm and a depth of 6 mm. of the Upper electrode, sharpened to a cone, serves as a cathode; between the electrodes ignite the arc DC. Current of 15 A. the Distance between the electrodes is 3 mm. the Spectra are photographed on a spectrograph DFS-8, using photographic plates, ES. The width of the slit of a spectrograph — 15 µm, exposure time of 45 s. Intermediate diaphragm in the condenser being selected so that blackening of the background near analytical lines were in normal pochernenija.
In the same conditions photographed three times the spectra of concentrates of samples analysed, three times the spectra of the concentrates obtained from control experiments, and two-fold spectra of each reference sample.
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 designated element (see table.2) and the surrounding background
and calculate the difference of pochernenija
and
find the average value
. Calibration curve constructed in the coordinates (
,
) using the values
for the samples comparison.
Table 2
| The designated element |
Wavelength of analytical lines, nm |
| Vanadium |
318,54 |
| Tungsten |
294,44* |
| Iron | 248,33 |
| Cobalt |
242,49 304,4 |
| Manganese |
280,11 |
| Copper |
324,75 |
| Molybdenum |
317,03 |
| Nickel |
300,25** |
| Niobium |
295,09 |
| Lead | 283,31 |
| Tantalum |
271,47*** |
| Titan |
307,86 302,16 |
| Chrome |
Of 284.33 |
________________
* In the analysis of ytterbium and its oxide — 294,70 nm.
** In the analysis of ytterbium and its oxide — 301,20 nm; yttrium and lanthanum — 305,0 nm.
*** Analysis of lanthanum and its oxides in the admixture of tantalum is not carried out.
Using the values for the concentrates of the sample and concentrates control experiments, calibration schedule, find the average value of the content-defined impurities.
5.2. Mass fraction of the element () in percent is calculated by the formula
where is the mass of the sample graphite powder collector, mg;
— the weight of the portion of the sample, mg;
the average value of the mass fraction of the element in the concentrates of the sample, %;
the average value of the mass fraction of the element in concentrates in the reference experiment, %.
5.3. Discrepancies in the results of three parallel measurements (the ratio of largest to smallest), and the discrepancy between the results of the two analyses (most of them less) should not exceed values of allowable differences specified in table.3.
Table 3
| The designated element |
Mass fraction, % |
The permissible divergence |
| Vanadium |
5·10 |
3,1 |
3·10 |
2,9 | |
1·10 |
2,7 | |
| Tungsten |
5·10 |
2,8 |
3·10 |
2,5 | |
1·10 |
2,4 | |
| Iron | 3·10 |
3,5 |
6·10 |
3,1 | |
2·10 |
3,0 | |
| Cobalt |
2·10 |
2,7 |
3·10 |
2,3 | |
1·10 |
2,2 | |
| Manganese |
5·10 |
2,5 |
1·10 |
2,4 | |
5·10 |
2,0 | |
| Copper |
5·10 |
3,5 |
1·10 |
3,2 | |
5·10 |
3,2 | |
| Molybdenum |
2·10 |
2,0 |
8·10 |
2,7 | |
5·10 |
2,5 | |
| Nickel |
2·10 |
3,3 |
1·10 |
2,8 | |
1·10 |
2,6 | |
| Niobium |
1·10 |
2,6 |
1·10 |
2,3 | |
3·10 |
2,0 | |
| Lead |
2·10 |
2,7 |
1·10 |
2,3 | |
1·10 |
2,2 | |
| Tantalum |
1·10 |
2,5 |
1·10 |
2,3 | |
3·10 |
2,3 | |
| Titan | 1·10 |
2,7 |
8·10 |
2,5 | |
5·10 |
2,4 | |
| Chrome | 5·10 |
2,5 |
2·10 |
2,3 | |
2·10 |
2,3 |
Method II
Chemical-spectral method of determination of vanadium, manganese, iron, cobalt, Nickel, copper, rare earth metals and their oxides (except cerium dioxide and cerium) is based on the simultaneous spectral determination of impurity elements in the concentrate of impurities based on powder of graphite.
The concentrate of impurities is obtained by adsorption of their diethyldithiocarbamate and ticciati complexes on the PTFE column followed by desorption of impurity elements with acetone and evaporation of the organic solution of graphite powder.
Intervals determined by a mass fraction of impurities:
| vanadium | from 3·10 |
| manganese | from 1·10 |
| iron | from 3·10 |
| cobalt | from 3·10 |
| Nickel | from 1·10 |
| copper | 2·10 |
(Changed edition, Rev. N 2).
6. APPARATUS, REAGENTS AND SOLUTIONS
The diffraction spectrograph DFS-8 with the grating 600 gr/mm with a three-lens Achromat 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.
Spectromancer PS-18 or similar.
Microphotometer geregistreerde type MF-2 or similar.
Box of organic glass.
Analytical scale type ADV-200.
Libra torsion bar type W-500.
Lamp infrared ikz-500 with voltage regulator type RNO-250−0,5, or similar.
Tile electric.
The machine tool for sharpening of electrodes.
Mortar made of fluoroplastic-4 or plexiglass.
Photographic plates of type ES.
Graphite powder of high purity according to GOST 23463−79.
Coals spectral high purity-7−3.
The electrodes are machined from high purity coals spectral-7−3, 6 mm in diameter, with a crater diameter of 4 mm and a depth of 6 mm.
Electrodes graphite fittings for spectral analysis high purity-7−4 6 mm in diameter, sharpened to a cone.
Flask Bunsen.
The quartz glasses with a capacity of 100 cm.
Column of PTFE powder, 3.5 g of PTFE powder (fraction less than 0.1 mm) is placed in a filter funnel with a filter of sintered glass powder class THEN 160 or PORES 40 filter diameter of 20 mm and compacted to the height of the fluoropolymer layer is 15 mm.
The cylinders with a lateral branch with a capacity of 30 cm.
Water, or deionized double-distilled water with specific electrical resistance of 20 to 24 Mω·cm.
Hydrochloric acid of high purity according to GOST 14261−77 diluted 1:1 and 1:10.
Ammonia water according to GOST 24147−80, OS.CH., diluted 1:10.
Sodium N, N'-diethyldithiocarbamate according to GOST 8864−71, solutions with concentrations of 20 and 1 g/DM.
Sodium mercaptoquinolinate (dioxines) a freshly prepared solution with a concentration of 5 g/DM.
Acetone high purity.
The quartz Cup with a capacity of 20−30 cm.
Sodium chloride OS.h. 6−2.
The technical rectified ethyl alcohol GOST 18300−87, double-distilled in quartz apparatus.
Vanadium (V) oxide, h. d. a.
Iron oxide, h.d. a.
Cobalt oxides according to GOST 4467−79, h.d. a.
Manganese (IV) oxide anhydrous OS.h. 9−2.
Copper oxide according to GOST 16539−79, powdery.
Nickel oxide according to GOST 4331−78, CH.
Sec. 6. (Changed edition, Rev. N 2).
7. PREPARATION FOR ASSAY
7.1. Sample preparation comparison
The parent sample on the basis of graphite powder (GAGP) containing 1% each of the determined impurities, is prepared as follows: sample mass 0,0178 g of an oxide of vanadium (V), 0,0143 g of iron oxide, 0,0137 g of nitrous oxide of cobalt, 0,0158 g of manganese (IV) oxide, anhydrous, 0.0125 g of powdered copper oxide 0,0141 g of an oxide of Nickel placed in a mortar from ftoroplast-4 or plexiglass and add 0,9118 g of powdered graphite. The mixture is thoroughly mulled with addition of ethanol for 50 min and dried under an infrared lamp. In order to avoid introducing dirt grinding in a mortar, and drying under infrared lamp is carried out in a box of organic glass.
References OS 1-OS 8 prepare a serial dilution GULP, and then each subsequent sample is powdered graphite.
The mass fraction of each of the designated impurities in samples OS 1 OS 8 and added to the mixture of graphite powder sample and the previous sample are given in table.4.
Table 4
| Marking sample | The mass fraction of each of the determined impurities, % | The mass of charge, g | |
| powder graphite |
the previous sample | ||
| OS 1 |
1·10 |
One thousand eight hundred |
0,200 (GULP) |
| OS 2 |
3·10 |
1,400 |
0,600 (OS 1) |
| OS 3 |
1·10 |
1,333 |
0,667 (OS 2) |
| OS 4 |
3·10 |
1,400 |
0,600 (OS 3) |
| OS 5 |
1·10 |
1,333 |
0,667 (OS 4) |
| OS 6 |
3·10 |
1,400 |
0,600 (OS 5) |
| OS 7 |
1·10 |
1,330 |
0,667 (OS 6) |
| OS 8 |
3·10 |
1,403 |
0,600 (OS 7) |
Listed in the table.4 sample graphite powder of the prior sample is placed in a mortar and carefully fray adding ethyl alcohol for 30 min and dried under an infrared lamp.
Grinding in a mortar, and drying under infrared lamp is carried out in a box of organic glass.
(Changed edition, Rev. N 2).
8. ANALYSIS
8.1. The concentration of impurities
A portion of the analyzed oxides of REE with weight of 0.5−5 g or the corresponding amount of metal is placed in a quartz glass with a capacity of 100 cmand dissolved in 2−20 cm
of hydrochloric acid diluted 1:1, when heated, the glass under the close watch glass. Remove the watch glass, the solution is evaporated to wet salts, the residue is dissolved in approximately 50 cm
of water. Ammonia solution, diluted 1:10, or hydrochloric acid diluted 1:10, set pH ~2 (universal indicator paper).
To the obtained solution pour 2.5 cmof a solution of N, N'-diethyldithiocarbamate sodium concentration of 20 g/DM
and 2 cm
of a solution of sodium thiocynate. This should be pH=5,5−6 (control by universal indicator paper). The solution was filtered through a PTFE column, installed in the flask Bunsen, in the vacuum created a water vacuum pump.
Then the column was washed 30−60 cmof a solution of N, N'-diethyldithiocarbamate sodium with a concentration of 1 g/DM
portions of 5 cm
and installing it in the cylinder with side outlet. Passed through a column of 15 cm
of acetone in the vacuum created a water vacuum pump. The eluate containing the concentrated impurities, is transferred into a quartz Cup, evaporated in a water bath to a volume of ~2−3 cm
, add 50 mg of powdered graphite and evaporated to dryness.
Analysis of each sample is conducted three parallel batches. Simultaneously with each batch of tests carried out through all stages of the analysis three control experience in chemicals, getting three dry residue concentrate.
(Changed edition, Rev.
N 2).
8.2. Spectral analysis of concentrates
To each concentrate obtained from the samples, control experiments, and 50 mg each of the samples of comparison 1 OS-OS 8 added 2 mg of sodium chloride and stirred. Each mixture was placed in a crater electrode (anode) with a diameter of 4 mm and a depth of 6 mm. of the Upper electrode, sharpened to a cone, serves as a cathode, between the electrodes ignite the arc DC power of 15 A. the Distance between the electrodes is 3 mm. the Spectra are photographed on a spectrograph DFS-8 with the grating 600 gr/mm (first order), using photographic plates, ES. The width of the slit of a spectrograph — 15 µm, exposure time of 45 s. Intermediate diaphragm in the condenser being selected so that blackening of the background near analytical lines were in normal pochernenija.
In the same conditions photographed three times the spectra of concentrates of samples analysed, three times the spectra of the concentrates obtained from control experiments, and two-fold spectra of each reference sample.
Exposed plates show washed with water, fixed, washed in running water for 15 min and dried.
8.3. Regeneration of the column
After separation of the concentrate of impurities column of Teflon-4 are installed in the flask Bunsen and washed six times with hydrochloric acid (1:1) in portions of 5 cm, and then through her missing 50 cm
of distilled water. After that, the column is ready for use.
9. PROCESSING OF THE RESULTS
9.1. In each spectrogram photometric blackening of analytical lines of the designated element (see table.5) and the surrounding background
and calculate the difference of pochernenija
and
find the average value
. Calibration curve constructed in the coordinates (
for sample comparison. Using the values
for the concentrates of the sample and concentrates control experiments, calibration schedule, find the average values of the mass fraction of the designated impurities.
Table 5
| Basis |
The designated element |
Wavelength of analytical lines, nm |
| Oxide of lanthanum, yttrium, samarium, europium, terbium, holmium, thulium, ytterbium and lutetium | Vanadium |
318,4 |
| Iron |
Of 248.3 | |
| Cobalt |
252.1 bln 282,1 | |
| Manganese |
257,6 | |
| Copper |
327,4 | |
| Nickel |
300,3 305,1 | |
| Oxides of praseodymium and neodymium | Vanadium |
318,4 |
| Iron |
259,8 | |
| Cobalt |
252.1 bln 304,4 | |
| Manganese |
257,6 Of 280.1 | |
| Copper |
327,4 | |
| Nickel |
300,3 305,1 | |
| The oxide of gadolinium | Vanadium |
318,4 |
| Iron |
Of 248.3 | |
| Cobalt |
252.1 bln 304,4 | |
| Manganese |
257,6 Of 280.1 | |
| Copper |
327,4 RB 282.4 | |
| Nickel |
305,1 303,7 | |
| Oxide of dysprosium | Vanadium |
318,4 |
| Iron |
272,1 | |
| Cobalt |
252.1 bln 304,4 | |
| Manganese |
257,6 Of 279.5 | |
| Copper |
327,4 | |
| Nickel |
305,1 303,7 Of 301.2 | |
| The oxide of erbium |
Vanadium |
318,4 |
| Iron |
Of 248.3 | |
| Cobalt |
252.1 bln 304,4 | |
| Manganese |
Of 280.1 | |
| Copper |
324,7 | |
| Nickel |
Of 301.2 |
(Changed edition, Rev. N 2).
9.2. Mass fraction of impurity is defined () in percent is calculated by the formula
where is the mass of the sample graphite powder collector, mg;
— the weight of the portion of the sample, mg;
the average value of the mass fraction of the designated impurities in the concentrates of the sample, %;
the average value of the mass fraction of the designated impurities in the concentrates in the reference experiment, %.
9.3. Discrepancies in the results of three parallel measurements (the ratio of largest to smallest), and the discrepancy between the results of the two analyses (most of them less) should not exceed the values of permissible differences given in table.6.
Table 6
| The designated element |
Mass fraction, % |
The permissible divergence |
| Vanadium |
3·10 |
3,3 |
5·10 |
3,1 | |
5·10 |
2,9 | |
| Iron |
3·10 |
3,5 |
6·10 |
3,1 | |
2·10 |
3,0 | |
| Cobalt |
3·10 |
3,0 |
2·10 |
2,7 | |
1·10 |
2,2 | |
| Manganese |
1·10 |
2,9 |
1·10 |
2,4 | |
1·10 |
2,0 | |
| Copper |
2·10 |
3,5 |
1·10 |
3,2 | |
1·10 |
3,0 | |
| Nickel |
1·10 |
3,3 |
1·10 |
2,8 | |
1·10 |
2,6 |
(Changed edition, Rev. N 2).
