GOST 19863.7-91

• gost-198637-91.pdf (247.08 KiB)
  ГОСТ 19863.7-91

GOST 19863.7−91 Alloy of titanium. Methods for determination of manganese

GOST 19863.7−91

Group B59

STATE STANDARD OF THE USSR

ALLOYS OF TITANIUM

Methods for determination of manganese

Titanium alloys.
Methods for the determination of manganese

AXTU 1709

Date of introduction 1992−07−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of aviation industry of the USSR

DEVELOPERS

V. G. Davydov, doctor of engineering. Sciences; V. A. Moshkin, PhD. tech. Sciences; G. I. Friedman, PhD. tech. Sciences; L. A. Tenyakova; M. N. Gorlova, PhD. chem. Sciences; L. V. Antonenko, O. L. Sikorska, PhD. chem. Sciences

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 05.05.91 N 625

3. The frequency of inspection — 5 years

4. REPLACE GOST 19863.7−80

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies the photometric (with a mass fraction of from 0.02 to 2.5%) and atomic absorption (at a mass fraction of from 0.01 to 2.5%) methods for determination of manganese.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 25086 with the Supplement.

1.1.1. For the results analysis be the arithmetic mean of results of two parallel measurements.

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF MANGANESE

2.1. The essence of the method

The method is based on dissolving the sample in sulfuric acid, the oxidation of manganese to pneumococcal hodnoceni potassium and measurement of optical density at a wavelength of 525 nm.

2.2. Apparatus, reagents and solutions

Spectrophotometer or photoelectrocolorimeter.

Drying oven with thermostat.

Water, free from substances reducing agents: to 1000 cmof water is poured 10 cmof sulfuric acid solution 1:1, stirred, heated to boiling, add 0.2−0.3 g of potassium Odnokolenko, boiled for 10 min and cooled to room temperature.

Sulfuric acid according to GOST 4204 density 1.84 g/cmand a solution of 1:1, 1:3.

Nitric acid according to GOST 4461 density of 1,35−1,40 g/cmand a solution of 1:4.

Acids mixture in the conical flask with a capacity of 1 DMplaced 520 cmwater, carefully, in portions of 10 cmwith stirring with a glass rod pour 100 cmof sulphuric acid and 250 cm.of nitric acid, the solution was cooled to room temperature and stirred.

Acetone according to GOST 2603.

Potassium cognately, a solution of 50 g/DM: 25 g potassium jednolitego placed in a conical flask with a capacity of 500 cm, 400 cm pour thenitric acid solution, heated to dissolve potassium Odnokolenko, cooled to room temperature, transfer the solution into a volumetric flask with a capacity of 500 cm, is poured a solution of nitric acid to the mark and mix. The solution is prepared before use.

Sodium atomistically according to GOST 4197, a solution of 40 g/DM, cook before consumption.

Sodium sanitarily according to GOST 195.

Manganese metal according to GOST 6008* brand Мр00.
_______________
* On the territory of the Russian Federation GOST 6008−90, here and hereafter. — Note the manufacturer’s database.

If the surface of the metal manganese, is covered with the oxide film, it is purified. To do this, 2−3 g of manganese placed in a beaker with a capacity of 250 cm, 100 cm pouredwater, 60 cmof the mixture of acids and was stirred several times. After 3−5 min, when the metal surface is shiny, the solution is decanted, the chips were washed with water, washed twice with acetone, dried in a drying Cabinet at a temperature of 100−105 °C for 2−3 min and cooled in a desiccator to room temperature.

A standard solution of manganese

1 g of manganese placed in a tall glass with a capacity of 400 cm, poured 45−50 cmof water and 20 cmof sulfuric acid solution 1:1, cover with a watch glass and dissolved under heating. The solution is gently boiled for 2−3 min, cooled to room temperature. The glass is then rinsed with water above the glass, which dissolved the manganese. The solution is transferred into a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmstandard solution contains 0.001 g of manganese.

Potassium permanganate according to GOST 20490.

Allowed preparation of the solution a different way:

2,8776 g of potassium permanganate is placed in a tall glass with a capacity of 400 cm, pour 200cmof water, 20 cmof sulfuric acid solution 1:1 and dissolved by heating. To the solution add a few crystals of sodium semitecolo to the bleaching solution, the excess reducing agent removed by careful boiling for 5−6 min.

The solution was cooled to room temperature, transferred to a measuring flask with volume capacity of 1000 cm, made up to the mark with water and mix.

1 cmstandard solution contained

tains 0.001 g of manganese.

2.3. Analysis

2.3.1. A portion of the sample mass according to table.1 is placed in a conical flask with a capacity of 250 cm, 80 cm pour thesulfuric acid solution 1:3 and dissolved by heating.

Table 1

The solution was added dropwise nitric acid until the disappearance of violet colour and boil for 3 minutes the Walls of the flask is washed with 25−30 cmof water, poured 25 cmof a solution of potassium jednolitego and boiled for 10 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 250 cm, pre-flask was washed with water containing no reducing agents, the same water is poured to the mark and mix.

2.3.2. Optical density of the solution is measured at a wavelength of 525 nm in a cuvette with a layer thickness fotometricheskogo 20 mm.

2.3.3. Solution comparison is a compensatory solution, making it 25−30 cmof the solution prepared for measurement of optical density, add 2−3 drops of solution of sodium attestatio to the bleaching solution. For each series of samples using the corresponding compensating solution.

Mass fraction of manganese calculated according to the calibration schedule.

2.3.4. Construction of calibration curve

In six of the seven conical flasks with a capacity of 250 cmmeasure from microburette 0,2; 0,5; 1,0; 1,5; 2,0; 2,5 cmstandard solution of manganese, which corresponds to 0,0002; 0,0005; 0,001; 0,0015; 0,002; 0,0025 g manganese, poured on 80 cmof sulfuric acid solution 1:3 and continue at PP.2.3.1 and 2.3.2.

Solution comparison is the solution in which manganese is not entered.

According to the obtained values of optical density of the solutions and their corresponding masses of manganese build the calibration graph.

2.4. Processing of the results

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

, (1)

where is the mass of manganese in the sample solution found by the calibration schedule g;

 — weight of sample in aliquote part of the solution, g

.

2.4.2. Discrepancies in the results must not exceed the values given in table.2.

Table 2

3. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF MANGANESE

3.1. The essence of the method

The method is based on dissolving the sample in hydrochloric and bridgestation acids and measuring the nuclear absorption of manganese at a wavelength of 279.5 nm in the flame acetylene-air.

3.2. Apparatus, reagents and solutions

Spectrophotometer of atomic absorption with a radiation source for manganese.

Acetylene according to GOST 5457.

Hydrochloric acid according to GOST 3118 density of 1.19 g/cm, mortar is 2:1 and 1:1.

Nitric acid according to GOST 4461 density of 1,35−1,40 g/cmand a solution of 1:1.

Boric acid according to GOST 9656.

Hydrofluoric acid according to GOST 10484.

Acid bridgestation: 280 cmhydrofluoric acid at a temperature of (10±2) °C add portions 130 g of boric acid and stirred. The reagent is prepared and stored in a plastic container.

Titanium sponge according to GOST 17746* stamps TG-100.
_______________
* On the territory of the Russian Federation GOST 17746−96. — Note the manufacturer’s database.

A solution of titanium 10 g/DM, 1 g of titanium was placed in a conical flask with a capacity of 250 cm, add 80 cmof a hydrochloric acid solution of 2:1, 4 cmbridgestation acid and dissolved with moderate heating. After dissolution, the sample is added twenty drops of nitric acid and boil the solution for 1 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

Manganese metal according to GOST 6008 brand Мр00.

Standard solutions of manganese

Solution a: 0.5 g of manganese metal is placed in a conical flask with a capacity of 100 cm, add 30 cmof a solution of nitric acid at a moderate heat. After dissolution, the sample solution twice evaporated with water to volume of 10 cmfor removal of nitrogen oxides. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of manganese.

Solution B: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

1 cmof a solution contains 0.0001 g of manganese.

Solution: 10 cmof a solution transferred to a volumetric flask with a capacity of 10 cm, made up to the mark with water and mix.

1 cmof the solution contains 0,0000

1 g of manganese.

3.3. Analysis

3.3.1. A portion of the sample mass according to table.3 is placed in a conical flask with a capacity of 100 cm, flow 20 cmof a hydrochloric acid solution of 2:1, 1 cmbridgestation acid and dissolved with moderate heating.

Table 3

After dissolution of the sample add 5−10 drops of nitric acid and boil the solution for 1 min. the Solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 250 cm, add 5 cmof hydrochloric acid of 1:1, made up to the mark with water and mix.

3.3.2. The solution in the reference experiment is prepared according to claim 3.3.1.

3.3.3. Construction of calibration curve

3.3.3.1. When the mass fraction of manganese from 0.01 to 0.1% in seven volumetric flasks with a capacity of 100 cmpour 20 cmof a solution of titanium, six of them measure 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 cmstandard solution, which corresponds to 0,00001; 0,00002; 0,00004; 0,00006; 0,00008; 0,0001 g of manganese.

3.3.3.2. When the mass fraction of manganese from 0.1 to 0.75% in five volumetric flasks with a capacity of 100 cmpour 10 cmof a solution of titanium, four of them measure 1,0; 2,5; 5,0; 7,5 cmstandard solution B, which corresponds to 0,0001; 0,00025; 0,0005; 0.00075 g of manganese.

3.3.3.3. When the mass fraction of manganese over 0.75 to 2.5% in seven volumetric flasks with a capacity of 100 cmpour 4 cmof solution of titanium, six of them measure 3,0; 5,0; 7,0; 9,0; 11,0; 12,0 cmstandard solution B, which corresponds to 0,0003; 0,0005; 0,0007; 0,0009; 0,0011; 0,0012 g of manganese.

3.3.4. The solutions in flasks (see PP.3.3.3.1, 3.3.3.2, 3.3.3.3) add 2 cmof hydrochloric acid 1:1, made up to the mark with water and mix.

3.3.5. The sample solution, solution control experience and solutions to build the calibration curve is sprayed in the flame acetylene-air (oxidative) and measure the atomic absorption of manganese at a wavelength of 279.5 nm.

3.3.6. According to the obtained values of atomic absorption and corresponding mass concentrations of manganese build a calibration curve in the coordinates «Value of atomic absorption — Mass concentration of manganese in g/cm».

The mass concentration of manganese in the sample solution and the solution of control and experience determined by the calibration schedule.

3.4. Processing of the results

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

, (2)

where is the mass concentration of manganese in the sample solution found by the calibration schedule, g/cm;

 — mass concentration of manganese in solution in the reference experiment, was found in the calibration schedule, g/cm;

 — the volume of the sample solution, cm;

 — weight of sample, g

.

3.4.2. Discrepancies in the results must not exceed the values given in table.4.

Table 4