GOST 21877.10-76

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  ГОСТ 21877.10-76

GOST 21877.10−76 Babbit tin and lead. Methods for determination of aluminium (with Amendments No. 1, 2)

GOST 21877.10−76

Group B59

STATE STANDARD OF THE USSR

BABBIT TIN AND LEAD

Methods for determination of aluminium

Tin and lead babbits. Methods for the determination of aluminium*

AXTU 1709**
________________

* The name of the standard. Changed the wording, Rev. N 2.

** Added, Rev. N 2.

Valid from 01.01.78
to 01.01.83*
_______________________________
* Expiration removed
according to the Protocol of the Intergovernmental Council
for standardization, Metrology and certification
(IUS N 2, 1993). — Note the manufacturer’s database.

DEVELOPED by the Central research Institute for tin industry (Tsniiolovo)

Director V. A. Arsenico

Supervisor S. V. Meshkov

Executor G. V. Ivanova

INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

Zam. Minister N.N. Chepelenko

The draft all-Union scientific research Institute of standardization (VNIIS)

Director A. V. Gichev

APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from may 24, 1976 N 1264

MADE: the Change in N 1, approved and put into effect by the Decree of the USSR State Committee for standards from 14.02.83 N 805 with 01.07.83, Change No. 2, approved and put into effect by the Decree of the USSR State Committee for standards from 25.06.87 N 2464 with 01.03.88

Change N 1, 2 made by the manufacturer of the database in the text ICS No. 6, 1983, ICS # 10, 1987

This standard applies to tin and lead babbits and sets photocolorimetric and spectrochemical methods for the determination of aluminum content (when the content of aluminum, from 0.002 to 0.05%).

(Changed edition, Rev. N 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 21877.0−76.

2. PHOTOCOLORIMETRIC METHOD FOR DETERMINATION OF ALUMINIUM CONTENT

2.1. The essence of the method

The method is based on dissolving the sample in a mixture of hydrochloric and bromatological acids with bromine. Antimony and tin is removed by Stripping in the form of bromides. Other deformity of the elements separated with thioacetamide. Measure the optical density of the coloured compounds of aluminum with eryhromycin R at a wavelength of 530 nm.

2.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer with all accessories.

a pH meter.

Hydrochloric acid by the GOST 3118−77 and the solution of concentration 1 mol/DM.

Bromatologia acid according to GOST 2062−77.

Nitric acid GOST 4461−77 and diluted 1:1.

Sulfuric acid GOST 4204−77 and diluted 1:24.

Bromine according to GOST 4109−79.

Mix to dissolve: mix 45 cmof hydrochloric acid density of 1.19 g/cmand 45 cmbromatological acid with a density of 1.49 g/cmto the mixture and carefully add 10 cmof bromine.

The thioacetamide a solution of 10 g/DM.

Hydrogen peroxide according to GOST 10929−76, a solution of 300 g/DM.

Acetic acid GOST 61−75.

Urea according to GOST 6691−77.

A solution of ferric chloride; prepared as follows: 0.05 g of iron, reduced hydrogen, dissolved in 5 cmof hydrochloric acid density of 1.19 g/cmby adding few drops of hydrogen peroxide. After decomposition of the excess amount of peroxide, the solution was cooled, transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

Sodium hydroxide (caustic soda) according to GOST 4328−77, solution concentration of 2 mol/DM; prepared as follows: 80 g of sodium hydroxide dissolved in water, cooled, transferred into a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water.

Thioglycolic acid, a solution of approximately 10 g/l; prepared as follows: mix 10 cmthioglycolic acid (96% strength) and 12 cmof acetic acid, diluted with water and adjusted to the mark with water in a volumetric flask with a capacity of 1000 cm.

Ammonium acetate according to GOST 3117−78.

Anhydrous sodium acetate according to GOST 199−78.

Buffer solution; prepared as follows: 46.4 g of ammonium acetate and 18.2 g sodium acetate dissolved in water with stirring. The solution is transferred into a measuring flask with volume capacity of 1000 cmand bring the water almost to the mark. solution pH should be 6. To obtain pH 6 if necessary, add solution of concentration 2 mol/DMsodium hydroxide or acetic acid and then adjusted to the mark with water. To measure pH use a pH meter.

Eryhromycin R, the solution is prepared as follows: 0.35 g of reagent was dissolved in 2 cmof nitric acid of density 1.4 g/cm, add 60 cmof water and 0.3 g of urea, the contents mix and leave in a dark place. After 24 hours the solution is filtered through a dense filter into a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water. Store the solution in a dark bottle.

Standard solutions of aluminium.

Solution A, prepared as follows: 0.1 g of aluminum (with a purity not less than 99.99%) dissolved in 20 cmof hydrochloric acid diluted 1:1, the solution is transferred into a measuring flask with volume capacity of 1000 cmand was adjusted to the mark with water.

1 cmof solution A contains 0.1 mg of aluminium.

Solution B is prepared as follows: take 25 cmof solution A in a volumetric flask with a capacity of 500 cm, add 4 cmof hydrochloric acid diluted 1:1, and adjusted to the mark with water. Solution B is prepared immediately before use.

1 cmof a solution contains 0.005 mg of aluminium.

(Changed edition, Rev. N 1, 2)

.

2.3. Analysis

2.3.1. A portion of the babbit weighing 1 g is placed in a tall glass with a capacity of 250 cmand dissolved by heating in 15 cmof the mixture of acids to dissolve. The solution is carefully evaporated to dryness, without bringing it to boil. Then add 5 cmof hydrochloric acid, 0.5−1 cmof bromine and evaporated again to dryness. This operation is repeated again. To the residue poured 5 cmof nitric acid, diluted 1:1 and boiled until the bromine volatilization, then carefully pour about 1.0 cmof concentrated sulfuric acid and evaporated until the appearance of fumes of sulphuric anhydride. The cooled solution was added 25 cmof water, cover with a glass watch glass and heated to boiling, then pour 10 cmof a solution of thioacetamide, the solution was boiled for 10 min, filter the precipitate on a medium density filter and washed 5−6 times with sulfuric acid, diluted 1:24. The precipitate is discarded. To filtrate add 1−2 cmof perhydrol and evaporated to dryness. The dry residue leached 1 cm1 n hydrochloric acid solution, 5 cmof water and transferred to volumetric flask with a capacity of 100 cm.

When the content of aluminum up to 0.005% solution in a volumetric flask was adjusted with water to 20 cm, add 1 cmof solution of ferric chloride, 10 cmof a solution of thioglycolic acid and dropwise a 2 n solution of sodium hydroxide before the formation of the violet color of the solution. Then added dropwise 1 n hydrochloric acid solution until the disappearance of color and in excess of 2 cm. Then add 20 cmof a solution of erioglaucine and after 5 min, 30 cmbuffer solution. Dilute to the mark with water and after 20 minutes, measure the optical density of the solution at a wavelength of 530 nm in a cuvette with a layer thickness of 3 cm as a solution of comparison, using a solution not containing aluminum.

When the aluminum content of more than 0,005% solution translated into a measuring flask with a capacity of 100 cm, 10 cm was added1 n hydrochloric acid solution and adjusted to the mark with water. Aliquot part of the solution was pipetted and transferred to another volumetric flask with a capacity of 100 cm, is diluted with water to 20 cmand further analysis are as described above.

(Changed red

Ktsia, Rev. N 1).

2.3.2. Construction of calibration curve

In ten volumetric flasks with a capacity of 100 cmmake of pipettes or microburette: 0; 0,5; 1,0; 2,0; 4,0; 6,0; 8,0; 10,0; 12,0 and 15.0 cmstandard aluminum solution B and dilute with water to 20 cm. Further analysis are as indicated in claim 2.3.1. Based on the obtained values of optical density calibration curve building.

(Changed edition, Rev. N 1).

2.4. Processing of the results

2.4.1. The aluminum content () in percent is calculated by the formula

,

where the amount of aluminum found in the calibration schedule g;

 — volume of initial solution, cm;

 — volume aliquote part of the original solution, cm;

 — the weight of the portion of the sample,

(Changed edition, Rev. N 1).

2.4.2. Allowable absolute differences the results of the analysis shall not exceed the values specified in table.1.

Table 1

(Changed edition, Rev. N 2).

3. SPECTROCHEMICAL METHOD FOR DETERMINATION OF ALUMINIUM CONTENT

3.1. The essence of the method

The method is based on the translation of the sample metal oxide. The oxidized sample is mixed with carbon powder and placed in the crater, the lower carbon electrode. For the excitation spectrum is used, the alternating current arc. Spectrum arc is photographed with a spectrograph. Measure the blackening of analytical lines and «internal standard». Concentrations of the determined elements are found in the calibration schedule.

3.2. Apparatus, materials and reagents

Spectrograph for the registration of the ultraviolet region of the spectrum with being a lighting system or any type of spectrograph operating in the ultraviolet region, with photographic or photoelectric registration.

Arc generator of alternating current.

A muffle furnace with thermostatic control.

Drying Cabinet.

Quartz vypaivali Cup.

The glasses are made of quartz.

Libra torsion or analytical.

Microphotometer.

Mortar made of organic glass.

Photographic plates spectrographic type 1 or ES.

Spectral-clean coals.

Bath or electric hot plate.

Developer and fixer according to GOST 10691.0−73* — GOST 10691.4−73**. Allowed the use of developer and fixer of any composition.
_______________
* Valid GOST 10691.0−84;
** A 10691.4 GOST-84. — Note the manufacturer’s database.

Copper oxide, h. d. a. under GOST 16539−79.

Ethyl alcohol according to GOST 5962−67*.
______________
* On the territory of the Russian Federation GOST R 51652−2000. — Note the manufacturer’s database.

Lead oxide according to GOST 9199−77, h.d. a.

Nitric acid GOST 4461−77, H. h, distilled.

Of antimony trioxide, h.d. a.

Aluminium oxide, C. D. and.

Tin oxide according to GOST 22516−77, h.d. a.

(Changed edition, Rev. N 1, 2).

3.3. The preparation of calibration samples

Samples are prepared identical to the content of the main components of the analyzed samples. The basis for the preparation of specimens is a mixture of appropriate amounts of oxides: tin, antimony and copper (for grades of babbit B88, B83 and BS6), tin, antimony and lead (for grades of babbit B16, bn, and BS6).

In the parent sample containing 1% of aluminum based on the metal, the latter is administered in the form of oxides. The sample is mixed with alcohol. Then dried, calcined and again thoroughly mixed.

Working samples prepared serial dilution of each of the preceding sample basis. Prepare a series of samples with the aluminum content in them from 0.003 to 0.1%.

3.4. Medium samples are taken a sample weight of 3−5 g, which is placed in a quartz glass or Cup, pour 50−70 cmof nitric acid, diluted 1:1. The sample is dissolved with moderate heating. The solution was evaporated to dryness, and then calcined, the resulting nitrate salt in a muffle furnace at a temperature of 500−550 °C for 20 min.

Obtained by dissolving and calcining the precipitate of metal oxides and references stuffed into the crater of carbon electrodes, having a size of 3x3 mm with side hole 1 mm. in Front of spectroheliogram carbon electrodes, it is necessary to anneal in the arc of an alternating current power And 10−12 for 15 s.

When spectrographically electrodes are placed so that the bottom electrode was the electrode with the sample, the upper carbon electrode, sharpened to a truncated cone with the diameter of the via pad of 1.5−2.0 mm. Spectra excited in the arc of an alternating current power 10−12 A.

The exposure time, an intermediate aperture, slit width choose optimal for obtaining intensity spectra at normal pochernenija. Spectra excited in the arc of an alternating current power of 10 A. the time of the plate 3 min at a temperature of 18−20 °C. the spectra produced on the plate of type 1 or ES.

Determination of aluminum eroded from the sample along three parallel definitions.

(Changed edition, Rev. N 2).

3.5. Processing of the results

3.5.1. The resulting spectrograms photometric blackening lines of the designated element and the line «internal standard».

In table.2 shows the analytical lines and «internal standard».

Table 2

The results of electrophoretic spectra of the standards to build calibration graphs in the coordinate .

The results of electrophoretic spectra of samples find the graphs of the aluminum content. The result is then multiplied by a conversion factor of 1.2.

3.5.2. Allowable absolute differences the results of the analysis shall not exceed the values specified in table.3.

Table 3