GOST 21877.5-76
GOST 21877.5−76 Babbit tin and lead. Method for determination of iron (with Amendments No. 1, 2)
GOST 21877.5−76
Group B59
STATE STANDARD OF THE USSR
BABBIT TIN AND LEAD
Method for determination of iron
Tin and lead babbits. Method for the determination of iron*
AXTU 1709**
_______________
* The name of the standard. Changed the wording, Rev. N 2.
** Code standard. Introduced later, 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. ministra, 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 1380.4−70
MADE: the Change in N 1, approved and put into effect by the Decree of the USSR State Committee for standards from
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 method for determination of iron content (with Fe content of from 0.002 to 0.1%).
The method is based on dissolving the sample in a mixture bromatological acid with bromine with the addition of perchloric acid. Tin and antimony is distilled off in the form of bromides, copper is removed by reduction to lead metal. In mildly acidic conditions, measure the optical density of the colored complex of iron with ortofenantrolinom at a wavelength of 510 nm.
(Changed edition, Rev. N 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 21877.0−76.
2. APPARATUS, REAGENTS AND SOLUTIONS
Photoelectrocolorimeter or spectrophotometer with all accessories.
Hydrochloric acid by the GOST 3118−77.
Nitric acid GOST 4461−77 diluted 1:1.
Bromatologia acid according to GOST 2062−77.
The acid chloride.
Bromine according to GOST 4109−79.
Mix to dissolve: 90 cmbromatological acid is mixed with 10 cm
of bromine.
Hydroxylamine hydrochloric acid according to GOST 5456−79.
On-fenantrolin.
Sodium acetate (trihydrate) according to GOST 199−78.
Acetic acid GOST 61−75.
The reaction mixture for colorimetrically: a mixture of solutions A, B, C in the ratio 1:1:3.
Solution A, prepared as follows: 10 g of hydroxylamine hydrochloride dissolved in a small amount of water and adjusted with water to 1 L.
Solution B is prepared as follows: 1.5 g of o-phenanthroline dissolved in water and adjusted with water to 1 L.
Solution; prepared as follows: 272 g sodium acetate and dissolve in about 500 cmof water, poured 240 cm
acetic acid, filtered (if necessary) and adjusted with water to 1 L.
Lead granulated GOST 3778−77*.
______________
* On the territory of the Russian Federation GOST 3778−98. — Note the manufacturer’s database.
Iron metal standard solutions.
Solution A, prepared as follows: 0.5 g of iron was dissolved in a beaker with a capacity of 250 cmto 25 cm
of nitric acid, diluted 1:1, and remove the oxides of nitrogen by boiling. The solution was 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 0.5 mg of iron.
Solution B is prepared as follows: 20 cmsolution And transferred to a volumetric flask with a capacity of 500 cm
, was adjusted to the mark with water and mix.
1 cmof the solution contains 0.02 mg of iron.
(Changed edition, Rev. N 1).
3. ANALYSIS
3.1. Iron determination without separation of copper and lead
A portion of the babbit weighing 0.5 g were placed in a glass with a capacity of 250 cmand dissolved in 15 cm
of the mixture for dissolving at a moderate heat. After complete dissolution add 5 cm
of perchloric acid and evaporated until the appearance of white vapors. If the solution is cloudy, add another 5 cm
mixture for dissolution and again evaporated until the appearance of fumes of perchloric acid.
If the sample contains a large amount of lead, you may fall in the precipitate of lead bromide. In this case, the solution add a few drops of concentrated nitric acid to decompose the precipitate of lead bromide. The solution was evaporated to a volume of about 2 cm, cooled and diluted with water to 40 cm
, the solution level in the glass note with a pencil on the glass.
To the solution add 5 g of granulated lead, and boil for 15 minutes, adding water up to the mark as evaporation of the solution. Then add 1 g of lead, and again boiled for 10 min If the surface is newly added lead clean, not painted precipitated copper, recovery can be considered complete. The solution is poured over the lead and lead is washed by decantation. If the solution is turbid, it is filtered through a dense filter and washed 3−4 times with water.
The solution was transferred to volumetric flask with a capacity of 100 cm, dilute with water to 50 cm
, 25 cm pour the
reaction mixture and was adjusted to the mark with water.
If the iron content of the alloy exceeds 0.04%, solution in a volumetric flask was adjusted to the mark with water, mix, take 10 cmof the solution into another volumetric flask with a capacity of 100 cm
, was diluted to 50 cm
, 25 cm pour the
reaction mixture and was adjusted to the mark with water.
After 30 min, measure the optical density of the solution at a wavelength of 510 nm using cuvettes with a layer thickness of 3 cm with a Solution of comparison is water.
(Changed edition, Rev. N 1, 2).
3.1. The determination of iron after separation of copper and lead by electrolysis. The decomposition of babbit and separation of copper and lead by electrolysis is carried out according to GOST 21877.3−76. The solution after electrolysis is placed in a volumetric flask with a capacity of 200 cmand was adjusted to the mark with water, mix. In a volumetric flask with a capacity of 100 cm
is taken 50 cm
of the solution, pour 10 cm
sulfosalicylic acid concentration of 100 g/DM
, is added dropwise an aqueous ammonia solution until yellow color and then 5 cm
of excess. The solution was adjusted to the mark with water and mix. After 30 min measure the optical density in the cuvette at a wavelength of 520−550 nm thick light absorbing layer of 20 mm. with a Solution of comparison is water.
(Added, Rev. N 2).
3.2. Construction of calibration curve
Five volumetric flasks with a capacity of 100 cmmake 0,0; 1,0; 2,0; 3,0 and 5,0 cm
standard solution B, dilute with water to 50 cm
, 26 cm added to
the reaction mixture and further analysis are as indicated in claim 3.1.
On the found values of optical densities and their corresponding iron concentrations to build calibration curve.
(Changed edition, Rev. N 1).
4. PROCESSING OF THE RESULTS
4.1. The iron content () in percent is calculated by the formula
where — the amount of iron was found in the calibration schedule g;
— volume of initial solution, cm
;
— volume aliquote part of the solution, cm
;
— the weight of the portion of the sample,
(Changed edition, Rev. N 1).
4.2. Allowable absolute differences the results of the analysis shall not exceed the values given in the table.
| The content of iron, % |
Allowable absolute differences, % |
| From 0.002 to 0.005 |
0,001 |
| SV. A 0.005 «0.010 is |
0,002 |
| «Of 0.010» to 0.025 |
0,004 |
| «Of 0.025» to 0.05 |
0,008 |
| «0,05» 0,10 |
0,01 |
(Changed edition, Rev. N 2).
