GOST 21877.4-76

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  ГОСТ 21877.4-76

GOST 21877.4−76 Babbit tin and lead. Methods for determination of lead (with Amendments No. 1, 2)

GOST 21877.4−76

Group B59

STATE STANDARD OF THE USSR

BABBIT TIN AND LEAD

Methods for determination of lead

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

AXTU 1709**
_____________
* The name of the standard. Changed the wording, Rev. N 1, 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 1380.11−70

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 804 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 with 01.07.83

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 the volumetric method for determination of lead (with lead content of 1 to 3%) and atomic absorption method for determination of lead (with lead content of from 0.05 to 3%).

(Changed edition, Rev. N 1, 2).

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 21877.0−76.

2A. VOLUMETRIC METHOD FOR THE DETERMINATION OF LEAD CONTENT

2A.1. The essence of the method

The method is based on dissolution of babbit in the mixture bromatological acid and bromine, separation of lead in the form of sulfate, and (after the dissolution in the ammonium acetate) titration at pH 5.5 with a solution of Trilon B with indicator kylinalove orange.

Section 2A. (Added, Rev. N 1).

2. REAGENTS AND SOLUTIONS

Sulfuric acid GOST 4204−77, diluted 1:1 and 1:50.

Bromatologia acid according to GOST 2062−77.

Bromine according to GOST 4109−79.

Nitric acid GOST 4461−77 diluted 1:1.

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

Ammonium acetate according to GOST 3117−78, a solution of 250 g/DM.

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

Lead according to GOST 3778−77*, not below grade.
_______________
* On the territory of the Russian Federation GOST 3778−98. Here and hereinafter. — Note the manufacturer’s database.

Selenology orange, a mixture of sodium chloride in the ratio of 1:100 aqueous solution is 1 g/DM.

Salt is the disodium Ethylenediamine — N, N, N', N'-tetraoxane acid, 2-water (Trilon B) according to GOST 10652−73, solution concentrations of 0.025 mol/l; prepared as follows: 9,305 g Trilon B dissolved in water, the solution is transferred into a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water and mix.

(Changed edition, Rev. N 1, 2).

3. ANALYSIS

3.1. A portion of the babbit weighing 0.5 g is placed in a tall glass with a capacity of 400 cm, add 30 cmof the mixture for dissolution, dissolve at a moderate heat and evaporated to dryness. To the dry residue add a 10 cmmixture for dissolving and re-evaporated to dryness. The processing mixture, repeat twice more, each time rinsing the walls of the beaker, add 15 cmof sulphuric acid diluted 1:1, gently bring the water up to 150 cmand heated to dissolve the salts (except salts of lead). The solution was cooled, added 40 cmof ethyl alcohol and leave you without heating for at least 4 h. the Precipitate of lead sulfate is filtered on pad of filtrowanie mass, washed 5−6 times with sulfuric acid, diluted 1:50, and twice with water. Filtrowanie mass of sediment transferred to a glass, which conducted the deposition, added 40 cmof a solution of acetate of ammonia, and gently heated to boiling. The solution was transferred into a flask with a capacity of 500 cm, dilute with hot water up to 150 cm, then cooled (solution pH should be 5,5−5,8), add a little kylinalove orange and titrated with a solution of Trilon B before transition of colouring from red-violet to yellow.

(Changed edition, Rev. N

1).

3.2. The installation of the mass concentration of 0.025 m solution of Trilon B

The mass concentration of the solution Trilon B set on the metal lead. 0.1 g of lead dissolved in 15 cm.of nitric acid diluted 1:1, evaporated to 1−2 cm, add 15 cmof sulphuric acid diluted 1:1, and evaporated until the appearance of white fumes of sulphuric anhydride. The solution was cooled, the side of the Cup is washed with a small amount of water and again evaporated to the appearance of sulphuric acid fumes, then cooled, carefully add 150 cmof water and further analysis are as indicated in claim 3.1.

The mass concentration of the solution Trilon B (T) on lead, expressed in g/cm, is calculated by the formula

,

where is the mass of lead, g;

 — volume of a 0.025 M solution of Trilon B, spent on titration, sm.

(Changed edition, Rev. N 1, 2).

4. PROCESSING OF THE RESULTS

4.1. Lead content () in percent is calculated by the formula

,

where  — volume of a 0.025 M solution of Trilon B, used for titration, cm;

T — mass concentration of the solution Trilon B on lead, g/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 0.10%.

(Changed edition, Rev. N 2).

5. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF LEAD CONTENT

5.1. The essence of the method

The method is based on selective absorption of light from a standard source of lead atoms. The solution is sprayed in an acetylene-air flame atomic absorption spectrometer and measure the absorbance at the wavelength 283,8 nm.

5.2. 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.

Lead according to GOST 3778−77.

Standard solutions of lead.

Solution a: prepared as follows: 0,5000 g of metallic lead is dissolved in 30 cmof nitric acid, diluted 1:4, heated to remove oxides of nitrogen, cooled, transferred into a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water and mix. 1 cmof solution A contains 0.5 cmof lead.

Solution B, prepared as follows: 20 cmsolution And placed in a volumetric flask with a capacity of 100 cm, adjusted to the mark with water and mix. 1 cmof solution B contains 0.1 cmpig

CA.

5.3. Analysis

5.3.1. A portion of the Babbitt weight specified in the table.1, 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 is carried out according to GOST 21877.3−76.

Table 1

The obtained solution is sprayed in air-acetylene flame atomic absorption spectrometer and photometric at a wavelength 283,8 nm under the conditions specified in GOST 21877.3−76.

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

5.3.2. To build a calibration curve in a volumetric flask with a capacity of 50 cm, measure off microburette 0; 1,0; 2,0; 4,0; 6,0 cmstandard solution and 2,0; 3,0; 4,0; 5,0; 6,0 cmstandard solution And poured 10 cmof the mixture for dissolution, adjusted to the mark with water and mix. Photometric, as specified when defining the content of copper (GOST 21877.3−76).

5.4. Processing of the results

5.4.1. Lead content () in percent is calculated by the formula

,

where is the concentration fotometricheskogo solution, µg/cm;

 — volume fotometricheskogo solution, cm;

 — the mass of sample, g;

 — conversion factor from micrograms to grams.

5.4.2. Permissible discrepancies in the results of the analysis at a confidence level of 0.95, should not exceed the values given in table.2.

Table 2