GOST 11739.22-90

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  ГОСТ 11739.22-90

GOST 11739.22−90 Alloys aluminium cast and wrought. Methods for the determination of rare earth elements and yttrium

GOST 11739.22−90

Group B59

STATE STANDARD OF THE USSR

ALLOYS ALUMINIUM CAST AND WROUGHT

Methods for the determination of rare earth elements and yttrium

Aluminium casting and wrought alloys.
Methods for determination of rare-earth elements and yttrium

AXTU 1709

Valid from 01.07.91
before 01.07.96*
_______________________________
* Expiration removed
Protocol 5−94 N Interstate Council
for standardization, Metrology and certification
(IUS N 11/12, 1994). — Note the manufacturer’s database.

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; O. L. Sikorska, PhD. chem. Sciences; L. V. Antonenko

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 28.06.90 N 1962

3. The frequency of inspection — 5 years

4. REPLACE GOST 11739.22−78

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard specifies a gravimetric method for the determination of rare earth elements in mass fraction of from 0.2 to 2.0% and the atomic absorption method for the determination of the mass fraction of yttrium in yttrium, from 0.1 to 2.0%.

1. GENERAL REQUIREMENTS

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

1.1.1. The result of the analysis taking the arithmetic mean of the results of the two definitions.

2. GRAVIMETRIC METHOD FOR THE DETERMINATION OF RARE EARTH ELEMENTS

2.1. The essence of the method

The method is based on dissolving the sample in a solution of sodium hydroxide, the separation of aluminum, zinc, copper, Nickel, cadmium, deposition of rare-earth elements, oxalic acid, calcining the precipitate at a temperature of 900−1000 °C to oxide and weighing.

2.2. Apparatus, reagents and solutions

Oven muffle.

Sodium hydroxide according to GOST 4328, solutions of 200 g/land 20 g/DM.

Ammonia water according to GOST 3760.

Hydrochloric acid according to GOST 3118, density of 1.19 g/cm, mortar 1:1, 2:98 and 1:99.

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

A mixture of acids: 90 cmof a hydrochloric acid solution of 1:1 were placed in a glass with a capacity of 500 cm, is poured 10 cmof nitric acid solution and stirred.

Sodium tetraborate 10-water according to GOST 4199, solution 20 g/DM.

Oxalic acid according to GOST 22180, solution, saturated at room temperature, and a solution of 30 g/DM.

Ammonium chloride according to GOST 3773, a solution of 250 g/DM.

Methyl orange, solution 1 g/DM.

Adsorbent (materiana paper): 100 g of crushed filters (red ribbon) is placed in a beaker with a capacity of 500 cm, 300 cm pouredhot water and stirred with a stirrer to obtain a homogeneous

mass.

2.3. Analysis

2.3.1. A portion of the sample weighing 1 g is placed in a beaker with a capacity of 300 cm, flow 40 cmof sodium hydroxide solution 200 g/DM, and first dissolved at room temperature, and after the cessation of violent reaction when heated.

To a solution of 200 cm pouredboiling water, stirred, allowed to settle for 30−40 min and filtered off the precipitate using two medium density filter (white ribbon) with the adsorbent. The beaker and precipitate was washed 5−6 times with a solution of sodium hydroxide 20 g/lportions of 20 cm.

2.3.2. The filter cake is dissolved over the glass, which was performed dissolving the sample in 40 cmhot mix of acids, priliva first 20 cmof the mixture and twice with 10 cm, the filter was washed five times with hot hydrochloric acid solution: 2:98 in portions of 20 cm.

The cooled solution was poured 50 cmof a solution of ammonium chloride, add 2 drops of methyl orange, the ammonia until the color in yellow and 100 cmof borax solution while stirring with a glass rod. The solution and the precipitate was allowed to settle for 50 min.

The precipitate was filtered off through a filter medium density («white ribbon») with adsorbent is washed 5−6 times with a solution of borax and dissolve on the filter in 30 cmhot solution of hydrochloric acid 1:1 on glass, which conducted the deposition, the filter was washed five times with hot hydrochloric acid solution (2:98) in portions of 20 cm

.

2.3.3. The solution was evaporated to wet salts, pour 50 cmof hot hydrochloric acid (1:99) and dissolved salts when heated. Then the solution was poured 30 cmof hot water and several doses of 50 cmhot saturated solution of oxalic acid, thoroughly stirring the solution with a glass rod so that it touches the bottom of the glass. The solution and the precipitate was allowed to settle for 12 h and then filtered through two medium density filter (white ribbon) with the adsorbent.

Precipitate was washed 5−6 times with a solution of oxalic acid 30 g/DMportions 20 cm.

2.3.4. The filter with precipitate was placed in a brought to constant weight and weighed porcelain crucible, dried, carefully incinerated, preventing ignition, calcined in a muffle furnace at a temperature of 900−1000 °C for 2 h, cooled in a desiccator and weighed.

2.4. Processing of the results

2.4.1. The mass fraction of the sum of rare earth elements (a) percentage calculated by the formula

, (1)

where is the mass of the crucible with the sediment, g;

 — weight of crucible, g;

 — the ratio of the oxide of rare earth element to an element:

yttrium oxide to yttrium 0,7874;

of lanthanum oxide on lanthanum 0,8527;

oxide of neodymium at a neodymium 0,8573;

oxide of praseodymium in praseodymium 0,8544;

cerium oxide in the cerium 0,8141;

 — the weight of the portion of the sample,

2.4.2. Discrepancies in the results must not exceed the values given in table.1.

Table 1

3. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF YTTRIUM

3.1. The essence of the method

The method is based on dissolving the samples in hydrochloric acid in the presence of hydrogen peroxide and subsequent measurement of the atomic absorption of yttrium at a wavelength of 410,2 nm in a flame acetylene-nitrous oxide.

3.2. Apparatus, reagents and solutions

Spectrophotometer of atomic absorption with a radiation source for yttrium.

Acetylene according to GOST 5457.

Nitrous oxide medical.

Hydrochloric acid according to GOST 3118, density of 1.19 g/cm, mortar 1:1 and 1:99.

Nitric acid according to GOST 4461, density 1,35−1,40 g/cm.

Sulfuric acid according to GOST 4204, density 1.84 g/cm.

Hydrofluoric acid according to GOST 10484.

Potassium chloride according to GOST 4234, solution 20 g/DM.

Hydrogen peroxide according to GOST 10929.

Nickel chloride according to GOST 4038, a solution of 1 g/DM.

Aluminium GOST 11069* brand А999.
_______________
* On the territory of the Russian Federation GOST 11069−2001. — Note the manufacturer’s database.

A solution of aluminum 20 g/DM: 10 g of aluminum is placed in a beaker with capacity of 500 cm, add 50 cmof water and then small portions of 300 cmof a hydrochloric acid solution (1:1) and dissolve with a moderate heat, adding 1 cmof solution of chloride Nickel. 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.

Yttrium metal high purity.

Standard solutions of yttrium.

Solution a: 1 g of metal yttrium was placed in a conical flask with a capacity of 250 cm, adding 25 cmof a solution of hydrochloric acid (1:1) and dissolve in low heat. After the dissolution of the yttrium solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 200 cm, made up to the mark with water and mix.

1 cmof the solution contains 0.005 g of yttrium.

Solution B: 20 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, add 5 cmof hydrochloric acid (1:1), made up to the mark with water and mix.

1 cmof the solution contains 0.001 g of yttrium.

Solution: 10 cmsolution And transferred to a volumetric flask with a capacity of 100 cm, add 5 cmof hydrochloric acid (1:1), made up to the mark with water and mix.

1 cmof the solution contains

0.0005 g of yttrium.

3.3. Analysis

3.3.1. A portion of sample weighing 0.5 g is placed in a conical flask with a capacity of 250 cm, pour approximately 10 cmof water and then small portions of 25 cmof a hydrochloric acid solution 1:1. The beaker cover watch glass and gently warmed until complete dissolution of the sample. Add 3−5 drops of hydrogen peroxide and boil the solution for 3 min.

Watch glass and walls of the flask rinsed with water. The solution was cooled to room temperature, transferred to a volumetric flask with a capacity of 100 cm, add 5 cmof hydrochloric acid (1:1), 20 cmof potassium chloride solution, made up to the mark with water and mix.

3.3.2. When the mass fraction of silicon is less than 1% solution, if it is not transparent, was filtered through a dry filter medium density (white ribbon) in a beaker, discarding the first portions of the filtrate.

3.3.3. When the mass fraction of silicon in excess of 1% after completion of dissolution according to claim 3.3.1 solution is filtered through a filter medium density (white ribbon) in a volumetric flask with a capacity of 100 cm.

The filter cake was washed 2−3 times with hot hydrochloric acid (1:99) in portions of 10 cm(primary filtrate).

The filter with precipitate was placed in a platinum crucible, dried, incinerated, preventing ignition, and calcined at 500−600 °C for 3 min. After cooling, the contents of the crucible add 4 drops of sulfuric acid, 5 cmhydrofluoric acid and nitric acid drop by drop until a clear solution. The solution was then evaporated to dryness, after cooling, the residue moistened with 2−3 cmof water and dissolve in 2−3 cmof hydrochloric acid (1:1) under heating.

The solution is attached to the main filtrate in a volumetric flask with a capacity of 100 cm, made up to the mark with water and mix.

3.3.4. The solution in the reference experiment is prepared according to PP.3.3.1, 3.3.2 and 3.3.3, using is sample the sample the sample of aluminium.

3.3.5. Construction of calibration graphs

3.3.5.1. When the mass fraction of yttrium from 0.1 to 1.0% in seven volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminum in six of them measure 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 cmstandard solution, which corresponds to 0,0005; 0,001; 0,002; 0,003; 0,004; 0,005 g of yttrium.

3.3.5.2. When the mass fraction of yttrium in excess of 1.0 to 2.0% in seven volumetric flasks with a capacity of 100 cmpoured in 25 cmof a solution of aluminum in six of them measure 5,0; 6,0; 7,0; 8,0; 9,0; 10,0 cmstandard solution B, which corresponds to 0,005; 0,006; 0,007; 0,008; 0,009; 0,01 g of yttrium.

3.3.5.3. The solutions in flasks in PP.3.3.5.1 and 3.3.5.2 add 5 cmof hydrochloric acid (1:1) for 20 cmof potassium chloride solution, made up to the mark with water and mix.

3.3.6. The sample solution, solution control experience and solutions to build the calibration curve is sprayed into the flame of acetylene-nitrous oxide and measure the atomic absorption of yttrium at a wavelength of 410,2 nm.

According to the obtained values of atomic absorption and corresponding mass concentrations of yttrium to build a calibration curve.

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

3.4. Processing of the results

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

, (2)

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

 — mass concentration of yttrium 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.2.

Table 2