GOST 23862.23-79

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  ГОСТ 23862.23-79

GOST 23862.23−79 Rare-earth metals and their oxides. Methods for determination of manganese (Change No. 1)

GOST 23862.23−79

Group B59

INTERSTATE STANDARD

RARE EARTH METALS AND THEIR OXIDES

Methods for determination of manganese

Rare-earth metals and their oxides. Methods of determination of manganese

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 3989 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 a visual colorimetric and kinetic methods for determination of manganese (5·10% 1·10%) in rare earth metals and their oxides (except cerium and its dioxide) with a preliminary separation of manganese and a visual colorimetric method (5·10% to 2·10%) in Lantana, Samaria, europium, gadolinium, dysprosium, tuliya, ytterbium, of Lutetia, yttria and their oxides.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 23862.0−79.

2. A VISUAL COLORIMETRIC METHOD FOR THE DETERMINATION OF MANGANESE

The method is based on oxidation of manganese by periodate in nitrate medium in the presence of phosphate and cobalt. The manganese content find by comparing the color intensity of the sample solution with a color intensity of the solutions comparison.

2.1. Apparatus, reagents and solutions

Set of cylinders for colorimetrically of colorless glass with ground stoppers with a height of 200 mm and a diameter of 8 mm.

The chemical glasses with a capacity of 50 cm.

Glass hour.

Volumetric flasks with a capacity of 100 cm.

Tile electric.

Nitric acid of high purity according to GOST 11125−84; 6 and 3 mol/DMsolutions.

Phosphoric acid according to GOST 6552−80, H. h

Sulfuric acid GOST 4204−77; 0,001 mol/DMsolution.

Distilled water GOST 6709−72.

Potassium periodate, a solution with a concentration of 20 g/DM3 mol/DMnitric acid, aqueous solution with a concentration of 2 g/DM(boiled).

Cobalt nitrate according to GOST 4528−78, h. e. a., a solution with a concentration of 10 g/DM.

Manganese sulfate according to GOST 435−77.

A standard solution of manganese (spare) containing 0.1 mg/cmmanganese: 0,0439 g of manganese sulfate is dissolved in 0.001 mol/DMsulfuric acid and bring the volume of solution in a volumetric flask with a capacity of 100 cmmark of 0.001 mol/DMsulfuric acid.

The solution of manganese containing 1 µg/cmof manganese, prepared on the day of use by dilution of a backup solution with water, to which is added 2−3 drops of 6 mol/DMnitric acid 100 times.

(Redrafted From

M. N 1).

2.2. Analysis

2.2.1. A portion of the sample weighing 1 g is placed in a beaker with a capacity of 50 cm, moistened with 2−3 cmof water, pour 4 cm6 mol/DMnitric acid, cover the beaker watch glass and dissolve with a moderate heat. At the completion of the dissolution, remove the watch glass and the solution is evaporated to wet salts. The residue is dissolved in 1.5 cm6 mol/DMnitric acid, poured two drops of phosphoric acid, one drop of a solution of cobalt and 5 cmperiodate solution of potassium with a concentration of 20 g/DM3 mol/DMnitric acid. Beaker cover watch glass, contents of glass bring to the boil and continue to boil for another 5 min. the volume of the solution should not be less than 5 cm, which gradually pour the solution of potassium periodate. After cooling, the solution was transferred to a cylinder for colorimetrically washed with an aqueous solution of potassium periodate with a concentration of 2 g/DM. The intensity of color is compared on white background with color intensity scale comparison, watching from the top down.

(Changed edition, Rev.

N 1).

2.2.2. Preparation of the scale comparison

In glasses with a capacity of 50 cmis administered at 0; 0,20; 0,50; 1,00; 1,50 and 2.00 cmof solution of manganese (containing 1 µg/cmmanganese), add 20 mg of the respective oxide of REE, containing not more than 5·10% manganese, poured 4 cm6 mol/DMnitric acid and evaporated to ~0.1 cm. Then poured 1.5 cm6 mol/DMnitric acid, two drops of phosphoric acid, one drop of a solution of cobalt and 5 cmof a solution of potassium periodate. Beaker cover watch glass, contents of glass are heated to the boil and continue to boil for another 5 minutes while maintaining the amount of not less than 5 cmby the addition of a solution of periodate. After cooling the solutions are transferred into the cylinders to colorimetrical

Anija.

2.3. Processing of the results

2.3.1. Mass fraction of manganese () in percent is calculated by the formula

,

where is the mass of manganese in the sample, µg;

 — the weight of the portion of the sample,

The result of the analysis take the average of results of two parallel measurements.

2.3.2. 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.1.

Table 1

3. A VISUAL COLORIMETRIC METHOD FOR THE DETERMINATION OF MANGANESE WITH PRELIMINARY SEPARATION OF MANGANESE

The method is based on pre-concentration impurities of manganese flocculation kolloidnyh solutions of diethyldithiocarbamate and thiocynate of manganese using polyacrylamide and subsequent determination of manganese in permanganate ion.

3.1. Apparatus, reagents and solutions

Cylinders for colorimetrically of colorless glass with ground stoppers with a height of 200 mm and a diameter of 8 mm, previously rinsed with a solution of potassium periodate in water with a concentration of 2 g/DM.

The chemical glasses with a capacity of 100 cm.

Glass hour.

Volumetric flasks with a capacity of 100 cm.

Muffle furnace with thermostat providing temperatures up to 800 °C.

Tile electric.

Crucibles of Gooch, diameter 15 mm.

The flask with the Bunsen water jet pump.

The quartz Cup with a capacity of 30 cm.

The thermometer at 50−150 °C.

Paper universal indicator.

Filter «yellow ribbon».

Nitric acid according to GOST 11125−84, OS.CH., diluted 1:1 and 3 mol/DMsolution.

Phosphoric acid according to GOST 6552−80, H. h

Sulfuric acid GOST 4204−77; 0,001 mol/DMsolution.

The water is deionized.

Potassium periodate, a solution with a concentration of 20 g/DM3 mol/DMnitric acid, aqueous solution with a concentration of 2 g/DM(boiled).

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

Sodium diethyldithiocarbamate according to GOST 8864−71, solutions with concentrations of 20 and 1 g/DM.

Sodium 8-mercaptoquinolinate (toxinet), a solution with a concentration of 5 g/DM.

Cobalt nitrate according to GOST 4528−78, h. e. a., a solution with a concentration of 10 g/DM.

Polyacrylamide, an aqueous solution with a concentration of 0.2 g/DM.

Manganese sulfate according to GOST 435−77.

A standard solution of manganese (spare) containing 0.1 mg/cmmanganese: 0,0439 g of manganese sulfate is dissolved in 0.001 mol/DMsulfuric acid and bring the volume of solution in a volumetric flask with a capacity of 100 cmmark of 0.001 mol/DMsulfuric acid.

The solution of manganese containing 1 µg/cmof manganese, prepared on the day of use by dilution of a standard (fallback) solution 100 times with water by adding 2−3 drops of nitric acid, diluted 1:1.

(Amended

, Edit. N 1).

3.2. Analysis

3.2.1. A portion of the REE oxide or metal with a mass of 1−5 g (depending on the expected manganese content) is placed in a beaker with a capacity of 100 cm, moistened with 2−3 cmof water and is dissolved in from 4 to 15 cmof nitric acid (1:1) under heating. The solution is evaporated to wet salts, the residue is dissolved in ~80 cmof water, with the pH ~2−3.

The resulting solution was heated to ~90 °C, pour 2.5 cmof a solution of diethyldithiocarbamate sodium concentration of 20 g/l(pH of the resulting solution to 5.5), 5 cmof a solution of polyacrylamide. The solution was mixed thoroughly for 2−3 min., while maintained at a temperature of ~80−90 °C. After stirring the formed insoluble brown gel-like particles. Next, the beaker content was cooled to ~70 °C, injected 2 cmsolution of 8-mercaptoquinolinate (thiocynate) of sodium and is again thoroughly mixed for 5 minutes, Cooled to room temperature, the solution and the precipitate was filtered through a filter of «yellow ribbon» placed in the crucible of the Gooch.

Precipitate was washed twice with a solution of diethyldithiocarbamate sodium with a concentration of 1 g/DMportions of 2 cm, washing the side of the Cup and the crucible. Then the crucible of the Gooch with the sediment was placed in a quartz Cup with a capacity of 30 cm, dry residue is dried for 3−5 min on a hotplate and then the precipitate is calcined for 5−7 min in a muffle furnace at 800 °C.

After cooling, the residue is dissolved in a quartz Cup in a 1.5 cmof nitric acid (1:1) with moderate heating. The solution was added 2 drops of phosphoric acid, one drop of a solution of cobalt and 5 cmof a solution of potassium periodate. In a Cup put the glass bead, cover the watch glass, the solution is heated to boiling and continue to boil for another 5 min. Solution was cooled and transferred to a cylinder for colorimetrically. The intensity of color is compared on white background with color intensity scale comparison, observing the color over

have down.

3.2.2. Preparation of the scale comparison

In glasses with a capacity of 50 cmimpose on 0; 0,20; 0,50; 1,00; 1,50; 2,00 cmof a solution of manganese (containing 1 µg/cmmanganese), poured 1.5 cmof nitric acid (1:1), two drops of phosphoric acid, one drop of a solution of cobalt and 5 cmof a solution of potassium periodate in 3 mol/DMnitric acid. In a glass put a glass bead, cover the watch glass, the solution is heated to boiling and continue to boil for another 5 min.

After cooling, the solution is transferred into the cylinders to colorimetrically.

Simultaneously with the analysis of samples carried out control experience through all stages of the analysis and introduce the amendment.

Amount of manganese in a control experiment should not exceed 0.2 µg. Otherwise, the reagents are replaced.

3.3. Processing of the results

3.3.1. Mass fraction of manganese () in percent is calculated by the formula

,

where is the mass of manganese in the sample, µg;

 — the mass of manganese in a control experiment, µg;

 — the weight of the portion of the sample,

The result of the analysis take the average of results of two parallel measurements.

3.3.2. 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

4. KINETIC METHOD FOR THE DETERMINATION OF MANGANESE

The method is based on catalytic action of manganese ions (II) to the oxidation of Ash-acid by hydrogen peroxide. The content of manganese is found by the calibration schedule.

4.1. Apparatus, reagents and solutions

The quartz cylinders with ground stoppers with a capacity of 20 and 10 cm, calibrated at 10 and 5 cm.

The quartz glasses with a capacity of 50 cm.

Quartz separating funnel with a capacity of 50 cm.

Before working utensils thoroughly washed distilled with sulfuric acid (1:1), water was placed in a beaker with a capacity of 1000 cmand boiled for 30−40 min.

Photoelectrocolorimeter FEK-56 or similar device.

Tile electric.

The water is deionized.

Sulfuric acid GOST 4204−77, H. h, double-distilled in quartz apparatus (selected middle fraction), diluted 1:1.

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

Acetic acid according to GOST 18270−72, OS.h.

Hydrogen peroxide according to GOST 10929−76, H. h, 3% solution, prepared on the day of use.

Sodium acetate according to GOST 199−78, H. h

Solution buffer pH 5: a suspension of sodium acetate with a mass of 19 g was placed in a beaker with a capacity of 300 cm, dissolved in water, poured 3,43 cmof acetic acid. The beaker content was transferred into a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water and mix.

Citric acid, OS.CH., a solution with a concentration of 500 g/DM.

1-amino-8-naphthol, 3,6-disulfonate monogalia salt (H-acid), h, optionally recrystallized from aqueous solutions 1·10mol/DMsolution: a sample recrystallized Ash-acid weight 0,037 g is placed in a quartz cylinder, was adjusted to the mark with water of 10 cm, immersed in water, heated to 70−80 °C for 1−2 min, cooled to room temperature and stirred. Cylinder wrapped in dark paper. Prepared on the day of use.

For recrystallization of Al-acid cook it hot saturated solution is filtered through a filter previously washed several times with hot water. The solution was cooled to 10−12 °C, filter the crystals and dry between sheets of filter paper. Recrystallized Ash-acid store in a dark jar with a glass lid.

Carbon tetrachloride according to GOST 20288−74, h. e. a., further distilled in a quartz apparatus.

Sodium N, N'-diethyldithiocarbamate according to GOST 8864−71, h. e. a., a solution with a concentration of 20 g/DM.

Potassium permanganate according to GOST 20490−75, H. h

Ethylenediamine base, h, a 30% solution.

A standard solution of manganese (alternate): a suspension of potassium permanganate 2,878 grams are placed in a beaker with a capacity of 100 cm, is dissolved in water. The beaker content was transferred into a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water, mix; 1 cmof solution contains 1 mg of manganese.

A standard solution of manganese (working) prepared on the day of use by successive dilution with water reserve solution 10,000 times; 1 cmof the resulting solution contains 0.1 MK

g of manganese.

4.2. Analysis

4.2.1. A portion of the REE oxide or metal weighing 1 g is placed in a quartz beaker, dissolved in 4 cmof hydrochloric acid diluted 1:1, evaporated to dryness, cooled to room temperature and dissolved in 20 cmbuffer solution. The resulting solution was transferred to a separating funnel, poured 1.5 cmof a solution of sodium diethyldithiocarbamate, 5 cmof carbon tetrachloride and shaken for 1 min. the Organic phase was transferred in a quartz glass. To the aqueous phase add 1.5 cmof a solution of sodium diethyldithiocarbamate, manganese re-extracted for 1 min 5 cmof carbon tetrachloride. The combined organic phase was evaporated to dryness at a moderate heat, cooled to room temperature. To the dry residue poured 1 cmof hydrochloric acid diluted 1:1, wash the side of the Cup with water and heated. The beaker content was transferred to a quartz cylinder with a glass stopper with a capacity of 20 cm, adjusted with water to a volume of 10 cmand mixed. From the obtained solution is taken 1−2 cm(depending on manganese content) in a quartz cylinder with a capacity of 10 cm, 0.2 cm pourthe citric acid solution, 1 cmof a solution of Ethylenediamine, 0.5 cmsolution, PH acid, 0.5 cmof hydrogen peroxide solution, adjusted with water to 5 cmand mixed. The solution was incubated at room temperature for 5 min and the optical density is measured on a photoelectrocolorimeter (490 nm) in a cuvette with a thickness of the light absorbing layer 10 mm. as a solution comparison, use water.

Simultaneously with the analysis of the sample through all stages of the analysis carried out control experience in chemicals. The value of the optical density of the solution in the reference experiment is subtracted from the value of optical density of test solution and according to the obtained value of the optical density find the mass of manganese graduirovannam

mu schedule.

4.2.2. Construction of calibration curve

Quartz separating funnel pour 2 cmof buffer solution and administered 0; 0,2; 0,4; 0,6; 0,8; 1,0 cmworking standard solution (containing 0.1 µg/cmmanganese), 1.5 cmof a solution of sodium diethyldithiocarbamate, 5 cmof carbon tetrachloride and shaken for 1 min. the Organic phase was transferred to a quartz beaker, and the aqueous phase re-extracted manganese for 1 min, with the addition of 1.5 cmof a solution of sodium diethyldithiocarbamate and 5 cmof carbon tetrachloride.

The combined organic phase was evaporated to dryness at a moderate heat, cooled to room temperature. To the dry residue poured 1 cmof hydrochloric acid (1:1), washed the walls of the beaker with water and heated for 5−10 min at 70−80 °C, cooled to room temperature. The beaker content was transferred to a quartz cylinder with a glass stopper with a capacity of 20 cm, adjusted with water to 10 cmand mixed. From the solution taken 20 cmin a quartz cylinder with a capacity of 10 cm, 0.2 cm pourthe citric acid solution, 1 cmof Ethylenediamine, 0.5 cmsolution, PH acid, 0.5 cmof hydrogen peroxide solution, adjusted with water to 5 cmand mixed. The solution was incubated at room temperature for 5 minutes and measure the optical density on photocolorimetry (490 nm) in a cuvette with a thickness of the light absorbing layer 10 mm. as a solution comparison, use water. The value of optical density of the zero solution (a solution containing no manganese) is subtracted from values of optical density of standard solutions. The procedure for plotting repeated at least three times.

The found average values of optical densities and corresponding masses of manganese build a calibration curve in the coordinates of the mass of the manganese — optical density of the solutions. A separate points graphics test when analyzing samples.

(Amended

, Edit. N 1).

4.3. Processing of the results

4.3.1. Mass fraction of manganese () in percent is calculated by the formula

,

where is the mass of manganese in the sample, µg;

 — the weight of the portion of the sample based on the oxide, g;

 — volume aliquote parts of a solution of the sample, cm.

The result of the analysis take the average of results of two parallel measurements.

4.3.2. 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.3.

Table 3