GOST 21877.6-76

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  ГОСТ 21877.6-76

GOST 21877.6−76 Babbit tin and lead. Methods for determination of bismuth (with Amendments No. 1, 2)

GOST 21877.6−76

Group B59

STATE STANDARD OF THE USSR

BABBIT TIN AND LEAD

Methods for determination of bismuth

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

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 (I & C 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

REPLACE GOST 1380.5−70

LISTED by: Change No. 1 approved and enacted by Order of the Federal Agency for technical regulation and Metrology of 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 2463

Change N 1, 2 made by the manufacturer of the database in the text N 6 ICS 1983 ICS N 10 1987


This standard applies to tin and lead babbits and sets photocolorimetric methods for determination of bismuth (with bismuth content of from 0.002 to 0.10%) and atomic absorption method for determination of bismuth (with bismuth content of from 0.005 to 0.1%).

(Changed edition, Rev. N 1).

1. GENERAL REQUIREMENTS

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

2. METHOD OF DETERMINATION OF BISMUTH WITH SELENOLOGY ORANGE

2.1. The essence of the method

The sample is dissolved in a mixture of bromatological acid and bromine, adding perchloric acid. Tin and antimony is distilled off in the form of bromides, lead is removed in the form of chloride. Bismuth is separated from copper and Nickel by coprecipitation with ferric hydroxide and determine fotometricheskie complex kylinalove orange at a wavelength of 531 nm.

(Changed edition, Rev. N 1, 2).

2.2. Apparatus, reagents and solutions

Photoelectrocolorimeter or spectrophotometer with all accessories.

Hydrochloric acid by the GOST 3118−77, diluted 1:1, 1:8.

Nitric acid GOST 4461−77 and diluted 1:1, solutions of concentration 1 mol/land 0.1 mol/DM.

Bromatologia acid according to GOST 2062−77.

The acid chloride.

Bromine churchyard 4109−79.

Mix to dissolve: 90 cmbromatological acid is mixed with 10 cmof bromine.

Iron chloride according to GOST 4147−74, a solution of 10 g/DM; prepared as follows: 1 g of ferric chloride dissolved in 10 cmof hydrochloric acid diluted 1:1 and diluted with water to 100 cm.

Ammonia water according to GOST 3760−79 and diluted 1:20.

Ascorbic acid, freshly prepared solution of 100 g/DM.

Sodium fluoride according to GOST 4463−76, a solution of 1 g/DM.

Selenology orange solution of 1 g/DMin 1 n nitric acid solution.

Bismuth metal according to GOST 10928−75*.
______________
* Valid GOST 10928−90, here and hereafter. — Note the manufacturer’s database.

Standard solutions of bismuth.

Solution A, prepared as follows: 0.1 g of metal bismuth was dissolved in a beaker with a capacity of 250 cmto 20 cmof concentrated nitric acid, boil to remove oxides of nitrogen, cooled, transferred to a volumetric flask with a capacity of 1 liter, adjusted to the mark with water and mix.

1 cmof solution A contains 0.1 mg of bismuth.

Solution B is prepared as follows: 100 cmsolution And transferred to a volumetric flask with a capacity of 500 cm, add 20 cmof concentrated nitric acid, adjusted to the mark with water and mix.

1 cmof the solution contains 0.02 mg of bismuth.

(Changed edition, Rev. N 1, 2).

2.3. Analysis

2.3.1. A portion of the babbit weighing 0.5 g were placed in a glass with a capacity of 100 cmand dissolved in 10 cmof the mixture to dissolve, then add 5 cmof perchloric acid and evaporated until the appearance of white fumes of perchloric acid. If the solution is cloudy, add another 5 cmmixture and again evaporated until the appearance of fumes of perchloric acid. This operation is repeated until the enlightenment of the solution, indicating the completeness of distillation of antimony and tin.

Then the solution was cooled, added 20 cmwater 7 cmof hydrochloric acid diluted 1:1 and cooled in running water. The separated precipitate of lead chloride is filtered off on a medium density filter and washed with a small amount of the cooled hydrochloric acid, diluted 1:8.

The filtrate collected in a beaker with a capacity of 250 cm, add 10 cmof ferric chloride solution, neutralize with ammonia, add 10 cmto the excess and leave in a warm place until coagulation of the precipitate. The precipitate was filtered through a medium density filter, washed with hot ammonia solution, diluted 1:20. The filter cake is dissolved in 5 cmof hot nitric acid diluted 1:1, collecting the filtrate in a beaker, in which was conducted the deposition. The filter is washed several times with hot water.

When the content of bismuth to 0.015% use entire solution. Higher contents of bismuth solution was cooled, transferred to a volumetric flask with a capacity of 100 cm, add 10 cmof nitric acid, diluted 1:1, adjusted to the mark with water and mix.

Select aliquot part of the solution in a beaker with a capacity of 250 cmin accordance with table.1.

Table 1

Solution or its aliquot part was evaporated to dryness. To the cooled residue add 2 cmto 1 N. the solution of nitric acid. The side of the Cup is washed with 3−4 cmof water and heat the solution to boiling. The cooled solution was added 4 cmof ascorbic acid solution, 3 cmof a solution of sodium fluoride and 1 cmkylinalove orange. The solution was transferred to volumetric flask with a capacity of 25 cm, top up to the mark with water and mix. After 10 minutes measure the optical density of the coloured compounds at a wavelength of 531 nm, using a cuvette with a layer thickness of 3 see Solution comparison is the zero solution.

2.3.2. Building a graded graphics

Six glasses with a capacity of 250 cmselect 0; 1,0; 2,0; 3,0; 4,0 and 5,0 cmstandard solution B of bismuth, and carefully evaporated to dryness. To the cooled residue add 3 cm1 n nitric acid solution and further analysis are as indicated in claim 2.3.1.

On the found values of optical densities and corresponding concentrations of bismuth build the calibration graph.

2.3.1, 2.3.2. (Changed edition, Rev. N 1).

2.4. Processing of the results

2.4.1. The contents of bismuth () in percent is calculated by the formula

,

where the amount of bismuth 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 given in table.2.

Table 2

(Changed edition, Rev. N 2).

3. METHOD OF DETERMINATION OF BISMUTH WITH THIOUREA (WITHOUT SEPARATION OF COPPER)

3.1. The essence of the method

The sample is dissolved in a mixture of bromatological acid and bromine, adding perchloric acid. Tin and antimony is distilled off in the form of bromides, lead is removed in the form of chloride. Bismuth is determined by photocolorimetry complex with thiourea at a wavelength of 440 nm.

3.2. Apparatus, reagents and solutions

Photocolorimeter or spectrophotometer with all accessories.

Bromatologia acid according to GOST 2062−77.

Bromine according to GOST 4109−79.

Mix to dissolve; prepared as follows: 90 cmbromatological acid is mixed with 10 cmof bromine.

The acid chloride.

Hydrochloric acid by the GOST 3118−77, diluted 1:1, 1:8.

Nitric acid GOST 4461−77.

Thiourea according to GOST 6344−73.

Bismuth metal according to GOST 10928−75, standard solution; is prepared as follows: 0.1 g of metallic bismuth dissolved in 20 cmof concentrated nitric acid, boil to remove oxides of nitrogen, cooled, transferred to a volumetric flask with a capacity of 1 liter, adjusted to the mark with water and mix.

1 cmof the solution contains 0.1 mg of bismuth.

(Changed edition, Rev. N 1).

3.3. Analysis

3.3.1. A portion of the babbit weighing 0.5 g were placed in a glass with a capacity of 100 cmand dissolved in 10 cmof the mixture to dissolve, then add 5 cmof perchloric acid and evaporated until the appearance of white fumes of perchloric acid. If the solution is cloudy, add another 5 cmmixture and again evaporated until the appearance of fumes of perchloric acid. This operation is repeated until the enlightenment of the solution, indicating the completeness of distillation of antimony and tin.

The solution was then cooled, poured 20 cmof water, 7 cmof hydrochloric acid diluted 1:1 and cooled in running water. The separated precipitate of lead chloride is filtered off on a medium density filter and washed with a small amount of the cooled hydrochloric acid, diluted 1:8. The filtrate and the washings collected in the beaker with a capacity of 250 cmand evaporated until the appearance of fumes of perchloric acid.

When the lead content to 0.5% operation office of lead is lowered.

Rate of the solution transferred to a volumetric flask with a capacity of 100 cm, is poured into precisely measured 20.0 cmof a solution of thiourea, adjusted to the mark with water and mix.

Measure optical density of solution on a photoelectrocolorimeter at a wavelength of 440 nm using cuvettes with a layer thickness of 5 cm with a Solution of comparison is the solution of the control ops

TA.

3.3.2. Construction of calibration curve

In glasses with a capacity of 100 cmselect 0; 0,5; 2,0; 3,0; 4,0 and 5,0 cmstandard solution of bismuth, add 5 cm
perchloric acid and heated to release vapors of perchloric acid. The solutions were cooled, transferred to volumetric flasks with a capacity of 100 cm, poured from a pipette or burette at 20 cmof a 10% solution of thiourea, adjusted to the mark with water and photometrist. As a solution comparison, using a zero solution.

On the found values of optical densities and corresponding concentrations of bismuth build the calibration graph.

3.3.1, 3.3.2. (Changed edition, Rev. N 1).

3.4. Processing of the results

3.4.1. The contents of bismuth () in percent is calculated by the formula

,

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

 — the weight of the portion of the sample,

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

Table 3

(Changed edition, Rev. N 2).

4. ATOMIC ABSORPTION METHOD FOR DETERMINATION OF BISMUTH

4.1. The essence of the method

The method is based on selective absorption of light from a standard source of atoms of bismuth. The solution is sprayed in an acetylene-air flame atomic absorption spectrometer and measure the absorbance at the wavelength of 233,1 nm.

4.2. Apparatus, reagents and solutions

Spectrometer of atomic absorption.

The glasses are made of PTFE with a capacity of 50 cm.

Nitric acid GOST 4461−77.

Hydrofluoric acid according to GOST 10484−78.

The mixture of acids to dissolve: hydrofluoric and nitric acid is mixed with water in the ratio 2:3:5 respectively; stored in a plastic container.

A standard solution of bismuth And prepared as described in step 2.2.

4.3. Analysis

4.3.1. A portion of the Babbitt weight specified in the table.4, is placed in a beaker made of PTFE with a capacity of 50 cmand poured in small portions to 10 cmof the mixture for dissolution. Further analysis was carried out as specified in GOST 21877.3−76.

Table 4

The solution is poured into a measuring flask with a capacity of 50 cm, flow 10 cmof the mixture to dissolve, made up to the mark with water and mix. The obtained solution is sprayed in air-acetylene flame atomic absorption spectrometer and photometric at a wavelength of 223,1 nm under the conditions specified in GOST 21877.3−76.

The concentration of bismuth on the calibration set schedule, fotometriya simultaneously with the analyzed solutions a series of solutions with known content of bismuth.

4.3.2. To build a calibration curve in a volumetric flask with a capacity of 50 cm, measure off microburette 0; 1,0; 2,0; 3,0; 4,0; 5,0 and 6.0 cmto the standard solution And bismuth, poured 10 cmof the mixture for dissolution, adjusted to the mark with water and mix.

Photometric solutions as well as solutions of the analyzed samples.

According to the obtained average values of absorbance and known concentrations of bismuth build the calibration graph.

4.4. Processing of the results

4.4.1. The contents of bismuth () in percent is calculated by the formula

,

where is the concentration of bismuth was found in the calibration schedule, µg/cm;

 — volume fotometricheskogo solution, cm;

 — the weight of the portion of the babbit, g;

 — conversion factor from micrograms to grams.

4.4.2. Allowable absolute differences the results of the analysis at a confidence level of 0.95, should not exceed the values given in table.5.

Table 5

________________
* Correspond to the original. — Note the manufacturer’s database.


(Changed edition, Rev. N 2).


Section 4. (Added, Rev. N 1).