GOST 15027.6-77
GOST 15027.6−77 Bronze without tin. Methods for determination of silicon (with Amendments No. 1, 2)
GOST 15027.6−77
Group B59
INTERSTATE STANDARD
BRONZE WITHOUT TIN
Methods for determination of silicon
Non-tin bronze.
Methods for the determination of silicon
AXTU 1709
Date of introduction 1979−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 28.06.77 N 1614
3. REPLACE GOST 15027.6−69
4. The standard fully complies ST SEV 1539−79
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| |
|
The designation of the reference document referenced
|
Section number, paragraph, sub-paragraph |
GOST 493−79
|
Chapeau |
GOST 614−97
|
Chapeau |
GOST 859−2001
|
4.2 |
GOST 3118−77
|
2.2, 3.2 |
GOST 3652−69
|
3.2, 4.2 |
GOST 3760−79
|
3.2, 4.2 |
GOST 3765−78
|
3.2, 4.2 |
GOST 4166−76
|
3.2 |
GOST 4204−77
|
2.2, 3.2, 4.2 |
GOST 4207−75
|
2.2 |
GOST 4332−76
|
3.2, 4.2 |
GOST 4461−77
|
2.2, 3.2, 4.2 |
GOST 6006−78
|
3.2 |
GOST 6552−80
|
4.2 |
GOST 6691−77
|
3.2, 4.2 |
GOST 9428−73
|
3.2, 4.2 |
GOST 9656−75
|
3.2, 4.2 |
GOST 10484−78
|
2.2, 3.2, 4.2 |
GOST 11293−89
|
2.2 |
GOST 18175−78
|
Chapeau |
GOST 18300−87
|
3.2 |
GOST 25086−87
|
1.1, 2.4.4 |
THAT 6−09−5384−88
|
3.2 |
6. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
7. EDITION with Amendments No. 1, 2 approved in February 1983, March 1988 (IUS 6−83, 6−88)
This standard specifies the gravimetric method in siliceous bronze (at a mass fraction of silicon of from 0.5% to 4%), extraction-photometric method in bronze with a mass fraction of iron in excess of 1% (mass fraction of silicon of from 0.01% to 0.25%) and photometric method in the bronze the other brands (at a mass fraction of silicon of from 0.01% to 0.3%) in the tin bronze according to GOST 18175, GOST and GOST 614 493.
(Changed edition, Rev. N 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 25086 with the addition of sec. 1 GOST 15027.1.
(Changed edition, Rev. N 1, 2).
2. GRAVIMETRIC METHOD FOR DETERMINATION OF SILICON IN SILICEOUS BRONZE
2.1. The essence of the method
The method is based on the allocation of silicic acid by precipitation with gelatin from hydrochloric acid solution.
2.2. Reagents and solutions
Nitric acid according to GOST 4461.
Sulfuric acid according to GOST 4204, and diluted 1:4.
Hydrochloric acid according to GOST 3118 and diluted 5:95.
Hydrofluoric acid according to GOST 10484.
The mixture of acids to dissolve; prepared as follows: mix one part nitric acid and three parts hydrochloric acid.
Gelatin food according to GOST 11293, a solution of 10 g/DM
.
Potassium ferrocyanide according to GOST 4207, a solution of 30 g/DM.
(Changed edition, Rev. N 2).
2.3. Analysis
The weight of bronze stamps Bcmcs-1 mass of 1 g of bronze stamps Brkn1−3 weighing 2 g were placed in a glass with a capacity of 250 cm, add 20 cmof water, 20 cmof a mixture of acids and dissolved by heating. The solution was evaporated to dryness, moisten the residue in 10 cmof concentrated hydrochloric acid and evaporated to dryness, then twice evaporated to dryness, by evaporation before adding 10 cmof concentrated hydrochloric acid. After that, the residue is moistened with 10 cmof concentrated hydrochloric acid and after 3−5 minutes pour the 70−80 cmof hot water, 5 cmof a solution of gelatin and heated until complete dissolution of salts. Filter the residue on the filter medium density, compacted filtrowanie ground and first washed 8−10 times with hot hydrochloric acid solution (5:95) to the disappearance of the reaction of copper (sample with a solution of ferric sinergistom potassium), and then hot water until the disappearance of the reaction to the chloride ion. The filter with precipitate was placed in a platinum crucible, dried, incinerated, moistened with 0.5 cmof concentrated nitric acid, dried and calcined at 1000−1050 °C to constant weight, then cooled in a desiccator and weighed. The contents of the crucible moistened with a few drops of water, add 3−4 drops of sulphuric acid, 1−2 cmhydrofluoric acid, carefully evaporated to dryness and the residue calcined at 1000−1050 °C to constant weight, cooled in a desiccator and weighed.
If after the removal of silicic acid in the crucible remains a black precipitate of silicon carbide, it is fused with anhydrous sodium carbonate and the alloy is treated with sulphuric acid, diluted 1:4, the solution was evaporated until a white smoke of sulfuric acid, cooled, poured 5cmof hydrochloric acid, 80 cmof hot water and boil it. Allocated an additional precipitate of silicic acid is filtered off, washed and further analysis are as described above.
At the same time through all stages of the analysis carried out control experience and found the content of silicon is introduced by an appropriate amendment.
(Changed edition, Rev.
N 2).
2.4. Processing of the results
2.4.1. Mass fraction of silicon (
) in percent is calculated by the formula
,
where 
is the mass of the crucible with the precipitate of silicon dioxide prior to processing hydrofluoric acid, g;
— weight of crucible with residue after treatment with hydrofluoric acid, g;
— weight alloy, g;
0,4672 — the ratio of silicon dioxide to silicon.
2.4.2. The absolute discrepancies in the results of parallel measurements (
the rate of convergence) must not exceed the permissible values given in the table.
| |
|
|
Mass fraction of silicon, %
|
, % |
 , %
|
From 0.01 to 0.02
|
0,002 |
0,005 |
SV. 0,02 «0,05
|
0,005 |
0,01 |
«0,05» 0,10
|
0,008 |
0,02 |
«To 0.10» to 0.20
|
0,012 |
0,03 |
«To 0.20» to 0.30
|
0,02 |
0,05 |
«Of 0.30» to 0.40
|
0,03 |
0,07 |
«To 0.50» to 1.0
|
0,05 |
0,1 |
Is 2.5 to 4.0
|
0,10 |
0,2 |
(Changed edition, Rev. N 2).
2.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in the table.
2.4.4. Control of accuracy of analysis results
Control of accuracy of analysis results is carried out according to State standard samples without tin bronzes, certified in the prescribed manner, in accordance with GOST 25086.
2.4.3, 2.4.4. (Added, Rev. N 2).
3. EXTRACTION-PHOTOMETRIC METHOD FOR THE DETERMINATION OF SILICON
3.1. The essence of the method
The method is based on the formation kremneftoristogo acid, extraction of its butyl alcohol, the recovery in the extract to kremneftoristogo blue and measuring the intensity of the resulting color.
3.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 1:2.
Sulfuric acid according to GOST 4204, diluted 1:9.
Hydrochloric acid according to GOST 3118, diluted 1:1.
Hydrofluoric acid according to GOST 10484.
Citric acid according to GOST 3652, a solution of 500 g/DM.
Boric acid according to GOST 9656, saturated solution; prepared as follows: about 60 g boric acid dissolve in 1 DMof hot water.
Ammonia water according to GOST 3760, diluted 1:1.
Ammonium molybdate according to GOST 3765, recrystallized a solution of 100 g/DM.
For recrystallization of ammonium molybdate, 70 g of drug is dissolved in 400 DMwater at low heat (70−80 °C). The solution was filtered two times through a dense filter, the filtrate cooled and added to 250 cmof ethyl alcohol. After standing for 1 h the separated crystals are aspirated. Received ammonium molybdate is dissolved in water and repeat the recrystallization.
After the second suction, the crystals washed several times with mixture of alcohol and water (5:8) and dried in air.
Tin dichloride on the other 6−09−5384, a solution of 20 g/DMis prepared as follows: 2 g of salt dissolved in 100 cmheated to 80−90 °With hydrochloric acid diluted 1:1.
Potassium-sodium carbonate according to GOST 4332.
The washing solutions.
Solution A, prepared as follows: to 50 cmof water was added 12 cmof concentrated nitric acid and 5 cmof molybdate ammonium solution.
Solution B is prepared as follows: to 50 cmof sulphuric acid, diluted 1:9, add 5 cmof ammonium molybdate solution and 5 cmof citric acid.
Crystal violet, an aqueous solution of 1 g/DM.
Phenolphthalein, alcohol solution 1 g/DM.
Normal butyl alcohol according to GOST 6006.
Rectified ethyl alcohol according to GOST 18300 and diluted 5:8.
Urea according to GOST 6691, a solution of 100 g/DM.
Sodium sulphate anhydrous according to GOST 4166.
Silicon dioxide according to GOST 9428.
Standard solutions of silicon.
Solution A, prepared as follows: 0,2143 g of calcined silicon dioxide is fused in a platinum crucible with 2 g of sodium-potassium carbonate. The alloy is leached with water and transferred to a volumetric flask with a capacity of 500 cm, top up to the mark with water and mix. The solution was immediately transferred into a plastic vessel.
1 cmof the solution contains 0.0002 g of silicon.
Solution B is prepared as follows: 2.5 cmmortar And placed in a separating funnel with a capacity of 200 cm, add 50 cmof water, 2−3 drops of solution of phenolphthalein and, drop by drop nitric acid diluted 1:2, to the disappearance of the pink coloration and then 1 cmin excess, pour 5 cmof ammonium molybdate solution, dilute with water to 100 cm, mix and leave for 10 mins then add 5 cmn-butyl alcohol, and 10 cmof nitric acid, diluted 1:2, stirred, turning over 2−3 times, add 25 cmof butyl alcohol and mix thoroughly, inverting the funnel 30. While criminalistica acid is extracted into butyl alcohol, colouring it yellow with a faint greenish tinge. After phase separation, the aqueous layer drained into another separatory funnel. Then repeat the extraction to obtain a colorless extract, using every time 10 cmof n-butyl alcohol.
The extracts are combined and washed with 50 cmwash solution A, inverting funnel gently 20−25 times. The aqueous layer was discarded and the remainder washed organic layer was transferred to volumetric flask with a glass stopper with a capacity of 100 cm, made up to the mark and butyl alcohol and mix.
1 cmof a solution with baking soda
RIT 0,000005 g of silicon.
3.3. Analysis
3.3.1. The weight of bronze weighing 0.2 g was placed in Teflon or platinum crucible, add 1 cmhydrofluoric acid, 5 cmof nitric acid, diluted 1:2, and is available in platinum or Teflon cover. Dissolution of the sample is carried out by heating in a water bath to 60 °C. After dissolution in a crucible add 10 cmof boric acid solution and the mixture was transferred to a beaker with a capacity of 100 cm, which has already added 20 cmof boric acid. The solution is diluted with water to 50 cmand add ammonia diluted 1:1 with constant stirring to a pH of 1.5. Set the pH drip test with a solution of crystal violet on white porcelain or PTFE disc. At a pH of less than 1.5 a drop of test solution, mixed with a drop of indicator is colored in green at a pH of 1.5, the mixture turns purple.
The solution was transferred to a separatory funnel with a capacity of 200−250 cm, thoroughly washed with a glass of water in the solution in separating funnel was diluted to 100 cm. Then add 5 cmof a solution of urea, 5 cmof ammonium molybdate solution and mix. After 10 minutes give 5 cmof the citric acid solution and stirred. Pour 5 cmof n-butyl alcohol to saturate the solution, 20 cmof nitric acid, diluted 1:2 and stirred. To the mixture is added 15 cmof n-butyl alcohol and carefully, to avoid the formation of emulsion, stirred, turning over the funnel 30. Fluids are given to delaminate (the aqueous layer should be transparent). After separation of phases the aqueous layer is transferred to a second separatory funnel with a capacity of 200−250 cm, pour 10 cmof n-butyl alcohol and the funnel is gently inverted 30 times. After the separation of the liquids aqueous layer transferred into a third funnel, and the organic layer attached to the first portion of the butanol extract. The extraction is repeated once with 10 cmof n-butyl alcohol. The combined extracts are washed with 50 cmwash solution B, inverting funnel gently 20−25 times. After separation the aqueous layer is discarded and the organic layer decanted into a volumetric flask with a capacity of 50 cm, which has added 0.2 g of sodium sulfate, and topped to the mark n-butyl alcohol. Aliquot part of volume 20 cm(when the mass fraction of silicon of from 0.01% to 0.04%), 5 cm(with a mass fraction of silicon from 0.04% to 0.1%) and 2 cm(at a mass fraction of silicon of from 0.1% to 0.25%) was placed in a volumetric flask with a capacity of 50 cm, add n-butyl alcohol up to 45 cm, 2−3 drops of solution of tin dichloride, made up to the mark and butyl alcohol and mix. After 20−25 min, measure the optical density on the photoelectrocolorimeter in a ditch with a length of 2 cm with a red filter (
=610 nm), or on the spectrophotometer at a wavelength of 810 nm. A solution of comparison used n-butyl alcohol.
Through all stages of the analysis conducting
t control the experience.
3.3.2. Construction of calibration curve
Eight volumetric flasks with a capacity of 50 cmimpose 0,5; 1,0; 2,0; 3,0; 4,0; 5,0; 6,0 and 7.0 cmstandard solution B, add n-butyl alcohol up to 45 cmand further analysis are as indicated in claim 3.3.1.
3.4. Processing of the results
3.4.1. Mass fraction of silicon (
) in percent is calculated by the formula
,
where is the mass of silicon was found in the calibration schedule g;
— the weight of the portion corresponding to aliquote part of the solution,
3.4.2. The absolute discrepancies in the results of parallel measurements (the rate of convergence) must not exceed the permissible values given in the table.
(Changed edition, Rev. N 2).
3.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in the table.
3.4.4. Control of accuracy of analysis results is carried out according to claim 2.4.4.
3.4.3, 3.4.4. (Added, Rev. N 2).
4. PHOTOMETRIC METHOD FOR DETERMINATION OF SILICON
4.1. The essence of the method
The method is based on the formation of silicon yellow kremneftoristogo acid and measuring the optical density of colored solution.
4.2. Apparatus, reagents and solutions
Spectrophotometer or photoelectrocolorimeter.
Nitric acid according to GOST 4461, diluted 1:2.
Sulfuric acid according to GOST 4204, diluted 1:1.
Hydrofluoric acid according to GOST 10484.
Citric acid according to GOST 3652, a solution of 100 g/DM.
Orthophosphoric acid according to GOST 6552, diluted 1:9.
Boric acid according to GOST 9656, saturated solution; prepared as follows: about 60 g boric acid dissolve in 1 DMof hot water. Before administration, the solution is cooled to a temperature of about 20 °C.
Ammonia water according to GOST 3760, diluted 1:1.
Copper of mark M0 GOST 859.
Urea according to GOST 6691, a solution of 100 g/DM.
Crystal violet, an aqueous solution.
Ammonium molybdate according to GOST 3765, recrystallized (see p.3.2) a freshly prepared solution of 100 g/DM.
Sodium-potassium carbonate according to GOST 4332.
Silicon dioxide according to GOST 9428.
Standard solutions of silicon.
Solution A, prepared as follows: 0,2143 g of calcined silicon dioxide is fused in a platinum crucible with 2 g of potassium carbonate-sodium. The alloy is leached with water and transferred to a volumetric flask with a capacity of 500 cm, top up to the mark with water and mix. The solution was immediately transferred into a plastic vessel.
1 cmof the solution contains 0.0002 g of silicon.
Solution B is prepared as follows: 10 cmof the solution And transferred to a volumetric flask with a capacity of 100 cm, is diluted to the mark with water and mix. The solution was immediately transferred into a plastic vessel.
1 cmof solution B contains 0,00002 g of silicon.
The copper solution to prepare the solution of the comparison; prepared as follows: 1 g of copper is placed in a platinum Cup, add 1 cmhydrofluoric acid, 11 cmof nitric acid, diluted 1:2. The dissolution is carried out under heating. Then add 2.5 cmof sulphuric acid diluted 1:1, and heat the solution to remove free sulfuric acid. After cooling the salt is dissolved, adding a small amount of water, 11 cmof nitric acid, diluted 1:2, and 1 cmhydrofluoric acid. Then add 30 cmof boric acid, the solution transferred to a volumetric flask with a capacity of 100 cm, top up to the mark with water and mix.
(Amended,
Izm. N 2).
4.3. Analysis
4.3.1. The sample of bronze with a weight of 1 g was placed in Teflon or platinum crucible, add 1 cmhydrofluoric acid, 11 cmof nitric acid, diluted 1:2, and is available in platinum or Teflon cover. The dissolution is carried out by heating in a water bath to 60 °C. After dissolution in a crucible add 10 cmof boric acid solution and the solution is transferred through a polyethylene funnel into a measuring flask with a capacity of 100 cmwith 20 cmsolution of boric acid, made up to the mark with water and mix.
Aliquot part of the solution is 20 cm(when the mass fraction of silicon of from 0.01% to 0.05%), 5 cm(with a mass fraction of silicon from 0.10% to 0.30%) or 10 cm(when the mass fraction of silicon from 0.05% to 0.1%) were placed in a glass with a capacity of 50 cm, is added nitric acid in quantity 0.2 cm(if aliquote part — 20 cm); 0.6 cm(at aliquote part — 10 cm) and 0.8 cm(when aliquote part — 5 cm), top up with water to 20 cmand check the pH of the solution on the pH meter and drip test with a solution of crystal violet on a white plate made of PTFE. The solution should have a pH of 1.5, if the solution has a pH of 1.5, pH is adjusted with ammonia solution or nitric acid. When the pH value is less than 1.5 a drop of test solution, mixed with a drop of indicator is colored in green, at pH equal to 1.5, mixed color drop becomes pure blue. If ammonia is introduced in excess, the combined drop has a purple color. In such cases, add nitric acid diluted 1:2, to obtain a coloration of the mixed a drop of green and then carefully repeat the neutralization with ammonia. In a solution having pH 1.5, add 5 cmof a solution of urea, 5 cmof molybdenic acid ammonium solution and leave for 10 mins then insert 5 cmof a solution of citric acid, 3 cmof a solution of phosphoric acid, the mixture is transferred into a measuring flask with a capacity of 50 cm, top up to the mark with water and mix. After 15 min measure the optical density of the solution at a wavelength of 400 nm in a cuvette with a length of 5 cm relative to the comparison solution. Reference solution prepared simultaneously with the sample, taking the copper solution (see p.4.2) in the same amount as the analyzed solution.
The silicon content found by the calibration schedule.
(Amended
, Edit. N 1, 2).
4.3.2. Construction of calibration curve
Six glasses with a capacity of 50 cmand add 10 cmof copper solution, containing silicon (reference solution), successively 0; 1,0; 2,0; 4,0; 6,0 and 8,0 cmstandard solution B.
The solutions were diluted with water to 20 cmand further analysis are as indicated in claim 4.3.1.
4.4. Processing of the results
4.4.1. Mass fraction of silicon (
) in percent is calculated by the formula
,
where is the mass of silicon was found in the calibration schedule g;
— the weight of the portion corresponding to aliquote part of the solution,
4.4.2. The absolute discrepancies in the results of parallel measurements (rate of convergence) must not exceed the permissible values given in table.1.
(Changed edition, Rev. N 2).
4.4.3. The absolute discrepancies of the analysis results obtained in two different laboratories or two of the results of analysis obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values given in table.1.
4.4.4. Control of accuracy of analysis results is carried out according to claim 2.4.4.
4.4.3, 4.4.4. (Added, Rev. N 2).
