GOST 1953.9-79
GOST 1953.9−79 Bronze tin. Methods for determination of silicon (with Amendments No. 1, 2)
GOST 1953.9−79
Group B59
INTERSTATE STANDARD
BRONZE TIN
Methods for determination of silicon
Tin bronze.
Methods for the determination of silicon
AXTU 1709
Date of introduction 1981−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from
3. The standard fully complies ST SEV 1539−79
4. REPLACE GOST 1953.9−74
5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
The designation of the reference document, to which this links |
Section number, paragraph, sub-paragraph |
GOST 8.315−97 |
2.4.4, 3.4.4 |
GOST 61−75 |
4.2 |
GOST 83−79 |
2.2 |
GOST 195−77 |
4.2 |
GOST 244−76 |
4.2 |
GOST 613−79 |
Chapeau |
GOST 614−97 |
Chapeau |
GOST 859−2001 |
3.2 |
GOST 1953.1−79 |
1.1 |
GOST 3118−77 |
2.2 |
GOST 3652−69 |
2.2, 3.2 |
GOST 3760−79 |
2.2, 3.2 |
GOST 3765−78 |
2.2, 3.2 |
GOST 4160−74 |
4.2 |
GOST 4207−75 |
2.2 |
GOST 4332−76 |
2.2 |
GOST 4461−77 |
2.2, 3.1, 4.2 |
GOST 5017−74 |
Chapeau |
GOST 6006−78 |
2.2 |
GOST 6552−80 |
3.2 |
GOST 6691−77 |
2.2, 3.2 |
GOST 9428−73 |
2.2, 3.2 |
GOST 9656−75 |
3.2 |
GOST 10484−78 |
2.2, 3.2 |
GOST 18300−87 |
2.2, 3.2, 4.2 |
GOST 19627−74 |
4.2 |
GOST 25086−87 |
1.1, 2.4.4, 3.4.4 |
6. Limitation of actions taken by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (ICS 11−12−94)
7. EDITION with Amendments No. 1, 2 approved in February 1983, August 1990 (IUS 6−83, 11−90)
This standard specifies the extraction-photometric method for the determination of silicon (from 0.001% to 0.1%), a photometric method for the determination of silicon (from 0.01% to 0.3%) and the spectral semi-quantitative method for determination of silicon (from 0.0005% to 0.003%) in tin bronze according to GOST 5017, GOST GOST 614 and 613.
(Changed edition, Rev. N 2).
1. GENERAL REQUIREMENTS
1.1. General requirements for methods of analysis GOST 25086 with the Supplement according to claim 1.1 GOST 1953.1.
(Changed edition, Rev. N 1, 2).
2. EXTRACTION-PHOTOMETRIC METHOD for the DETERMINATION of SILICON (from 0.001% to 0.1%)
2.1. 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.
The method is applicable for determination of silicon in the presence of phosphorus not exceeding 5-fold excess relative to the silicon.
2.2. Apparatus, reagents and solutions
a pH meter.
Nitric acid according to GOST 4461 and diluted 1:2 (boiled).
Sulfuric acid according to GOST 4207* diluted 1:9.
____________
* Probably a mistake of the original. Should read GOST 4204. — Note the CODE.
Hydrochloric acid according to GOST 3118 and diluted 1:1.
A mixture of acids: hydrochloric acid is mixed with nitrogen in a ratio of 3:1.
Hydrofluoric acid.
Citric acid according to GOST 3652, a solution of 500 g/DM.
Boric acid, saturated solution: 60 g of boric acid was dissolved 1 DMof hot water and after cooling, use the supernatant solution.
Ammonia is water-based.h. and according to GOST 3760, diluted 1:1 and 1:100.
Ammonium molybdate according to GOST 3765, recrystallized, solution 100 g/DM.
The recrystallization is carried out: 250 g molibdenovogo ammonium dissolved in 400 cmof water when heated to 70−80 °C, ammonia is added to a clear smell and the hot solution is filtered twice through the same dense filter into a glass contains 300 cmof ethyl alcohol.
The solution was cooled to 10 °C and allowed to settle for 1 h. Precipitated crystals are filtered off on a Buchner funnel under vacuum created a water vacuum pump. The crystals are washed 2−3 times with ethanol, portions at 20−30 cm, was dried in air.
Rectified ethyl alcohol according to GOST 18300.
Tin dichloride, solution 100 g/lprepared: 10 g of tin dichloride dissolved in 100 cmof hydrochloric acid (1:1) when heated to 80−90 °C.
Wash solution: to 50 cmof sulphuric acid are added 1.5 cmof a solution of molybdate of ammonium.
Potassium-sodium carbonate according to GOST 4332.
Sodium carbonate according to GOST 83, a solution of 50 g/DM.
Sodium meta silicate.
Normal butyl alcohol according to GOST 6006.
Silicon dioxide according to GOST 9428.
Standard solutions of silicon:
Preparation of silicate of sodium: 0.5 g dissolved in 20 cmof sodium carbonate solution in a platinum plate, cooled, placed in a plastic vessel, dilute with water to 500 cmand mixed.
1 cmof the solution contains 0.0001 gram of silicon.
The exact content of the set of silicon by gravimetric method.
Trade of silicon dioxide: 0,2143 g of calcined silicon dioxide is fused in a platinum crucible with 2 g of potassium-sodium carbonate. The smelt is leached with water, transferred to a volumetric flask with a capacity of 500 cm, made up to the mark with water, mixed and immediately transferred to a plastic vessel.
1 cmof the solution contains 0.0002 g of silicon.
The exact content of the silicon set gravimetrically
m method.
2.3. Analysis
2.3.1. The weight of bronze (PL.1) is placed in a polyethylene or Teflon or Teflon beaker with a capacity of 100 cm, add 15−30 drops of hydrofluoric acid, 15 cmacid mixtures, cover with plastic or forestablishing cover and dissolve the cold, and then in a water bath heated to 60 °C and kept at this temperature for 20−30 min Then open the lid and keep for another 15 min.
Table 1
Mass fraction of silicon, % |
The mass of charge, g |
The volume aliquote part of the solution, cm |
The weight of the portion corresponding to aliquote part of the solution, g |
From 0.001 to 0.01 incl. |
1 |
50 |
0,5 |
SV. The 0.01 «to 0.025 « |
0,5 |
20 |
0,1 |
«Of 0.025» to 0.05 « |
0,5 |
10 |
0,05 |
«0,05» 0,1 « |
0,25 |
10 |
0,025 |
After dissolution, the solution was cooled, added 30 cmboric acid, after 20 min the mixture is transferred through a polyethylene funnel into a measuring flask with a capacity of 100 cmcontaining 30 cmof boric acid, made up to the mark with water and mix. The solution is immediately transferred into the glass, which had a dissolution. Pre-set pH in solutions alikvotnih parts in pH-meter in the following way: in a plastic beaker with a capacity of 50 cmis placed aliquot part of the solution (table.1) add water to a volume of ~50 cmand with solution of ammonia (OS.h.) set pH=1,0−1,2, add ammonia solution drop by drop, recording the number of drops that went for the operation.
Aliquot part of the solution (table.1) for analysis was placed in a separating funnel with a capacity of 200 cm, topped up the water to ~50 cmand set pH=1,0−1,2 using preliminary data. To the solution was dropwise added with stirring 5 cmmolibdenovogo solution of ammonia and allowed to stand 10 min. Then add 5 cmof citric acid, 10 cmboiled nitric acid (1:2), 30 cmbutyl alcohol and extracted kriminalistov the heteropolyacid, carefully turning the funnel 30. After separation the aqueous layer is discarded and to the organic layer add 50 cmwash liquid and washed, the funnel inverting 10−15 times. The aqueous layer is discarded and the organic is transferred to a volumetric flask with a capacity of 50 cm, add butyl alcohol, 7−8 drops of solution of tin dichloride, made up to the mark butyl alcohol and vigorously shaken. Within 5 min, measure the optical density of the solution on a photoelectrocolorimeter with a red light filter (=600−630 nm) or on a spectrophotometer at 635 nm in a cuvette with a thickness of absorbing layer 1 cm as a solution of comparison, using butyl alcohol. At the same time through all stages of the analysis carried out control experience and found in it the value of optical density is subtracted from the value of optical density
and samples.
2.3.2. Construction of calibration curve
Five of six plastic, Teflon or Teflon cups were placed 1,0; 2,0; 3,0; 4,0; 5,0 cmstandard solution silicon (0.0001 g/DM) or 0,5; 1,0; 1,5; 2,0 and 2,5 cmstandard solution silicon (0.0002 g/DM). All cups add 15 drops of hydrofluoric acid, at 7−8 cmof the mixture of acids, placed in a water bath, heated to 60 °C and then act as described in section
Aliquota part of the solution taken for measurement, for each point of calibration curve is 10 cm.
As a solution comparison, using a solution not containing silicon. Calibration curve is based on its mass fraction in aliquote part of the solution.
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 silicon in the sample is found by calibration schedule g;
— the mass of silicon in the solution in the reference experiment, was found in the calibration schedule g;
— the weight of the portion corresponding to aliquote part of the solution,
2.4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3) specified in table.2.
Table 2
Mass fraction of silicon, % |
, % |
, % |
From 0.001 to 0.005 incl. |
0,0008 |
0,001 |
SV. 0,005 «0,01 « |
0,001 |
0,001 |
«0,01» 0,02 « |
0,002 |
0,003 |
«0,02» 0,05 « |
0,005 |
0,007 |
«0,05» 0,10 « |
0,008 |
0,01 |
«To 0.10» to 0.20 « |
0,012 |
0,02 |
«To 0.20» to 0.30 « |
0,02 |
0,03 |
2.4.3. Discrepancies in the results analysis, 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 specified in table.2.
2.4.4. Control of accuracy of analysis results is carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or by a method of additives in accordance with GOST 25086.
Sec. 2 (Modified edition, Rev. N 2).
3. PHOTOMETRIC METHOD FOR DETERMINATION OF SILICON
3.1. The essence of the method
The method is based on formation of yellow kremneftoristogo acid and measuring the optical density of the resulting solution.
3.2. Apparatus, reagents and solutions
Spectrophotometer or photoelectrocolorimeter.
a pH meter.
Nitric acid according to GOST 4461, diluted 1:2.
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.
Ammonia water according to GOST 3760, diluted 1:1.
Copper according to GOST 859, mark M0 or M00.
Urea according to GOST 6691, a solution of 100 g/DM.
Crystal violet aqueous solution 1 g/DM.
The technical rectified ethyl alcohol according to GOST 18300.
Ammonium molybdate according to GOST 3765, recrystallized, a freshly prepared solution of 100 g/DM(see section 2 recrystallization.2).
Sodium-potassium carbonate.
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 for 1 h at 1100 °C. the Melt leached with water, the solution transferred to a volumetric flask with a capacity of 500 cm, is poured 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 cream
niya.
3.3. Analysis
3.3.1. The sample of bronze with a weight of 1 g was placed in Teflon or platinum crucible, add 1 cmhydrofluoric acid; 10 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 at 60 °C. after dissolution in a crucible add 10 cmof boric acid solution and the solution transferred (via a plastic funnel) into a measuring flask with a capacity of 100 cm, which has added 20 cmof boric acid, made up to the mark with water and mix.
20 cmof the resulting solution (with a mass fraction of silicon of from 0.01% to 0.07%), 10 cm(with a mass fraction of silicon from 0.07% to 0.15%) and 5 cm(with a mass fraction of silicon from 0.15% to 0.30%) were placed in a glass with a capacity of 50 cmand neutralized with ammonia under constant stirring to a pH of 1.0−1.2. In the solution having a pH of 1.0−1.2, add 5 cmof a solution of urea and leave it for 10 minutes, then add 2.5 cmof molybdenic acid ammonium solution and leave for 10 mins then insert 5 cmof a solution of citric acid, 3 cmof phosphoric acid, the solution transferred to a volumetric flask with a capacity of 50 cmand up to the mark and top up with water. The solution was stirred and after 15 minutes measure the optical density on a photoelectrocolorimeter with a blue filter in a cell with thickness of the absorbing layer 3 or 5 cm, or on the spectrophotometer at a wavelength of 400 nm in a cuvette with a thickness of absorbing layer 1 cm.
A solution of comparison, using the solution of the same sample without the addition of molybdate ammonium solution.
The obtained values of optical density of the test solution subtract the value of optical density of control experiment through all stages of the analysis and measured against water.
(Changed edition, Rev.
N 1, 2).
3.3.2. Construction of calibration curve
In glasses with a capacity of 50 cmis placed 0; 1,0; 2,0; 4,0; 6,0 and 8,0 cmof a solution of silicon, diluted with water to 20 cmand further analysis are as indicated in claim
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;
— mounting of bronze, suitable aliquote part of the solution,
3.4.2. Discrepancies in the results of parallel definitions should not exceed the values of permissible differences (the rate of convergence for 3) specified in table.2.
(Changed edition, Rev. N 2).
3.4.3. Discrepancies in the results analysis, obtained in two different laboratories or two of the results obtained in the same laboratory but under different conditions (a measure of reproducibility) shall not exceed the values specified in table.2.
3.4.4. Control of accuracy of analysis results is carried out according to State standard samples of tin bronzes, re-approved by GOST 8.315, or by a method of additives in accordance with GOST 25086.
3.4.3,
4. SEMI-QUANTITATIVE SPECTRAL METHOD FOR DETERMINATION OF SILICON
4.1. The essence of the method
Samples or ground (0,50±0,05) g subjected to preliminary oxidation of the melt at the cathode of the DC arc in an oxygen atmosphere.
The oxidized sample is placed on a graphite stand between him and the dummy electrode of pure copper or coal excite the arc DC. Spectrum arc photographed with the spectrograph, the measured intensity of the analytical lines and the background, and by the method of «three standards» find the concentration of silicon. If the line of the analyzed element in the sample is missing or much weaker in intensity lines in the standard sample, estimation of the concentration of silicon is POLYOLESTER.
4.2. Apparatus, reagents and solutions
Spectrograph ISP-22.
A constant current source to power the arc, providing a voltage of 200−400 V and currents up to 10 A.
Device for high-frequency ignition of the DC arc from the generator of any system (PS-39, DG, IG).
Microphotometer designed for measuring optical densities of spectral lines and background.
Press oil, hydraulic, or any other, providing the force on the rod is 1.5−2 g press paper, providing the compressed tablets of metal with a diameter of 5−7 mm and a mass of (0,50±0,05) g.
Electrodes-foot graphite with a diameter of 8−10 mm.
The electrodes are made of copper of the mark Mob or from coal of high purity in the form of bars with diameter 6−7 mm, sharpened to a hemisphere, or a truncated cone with an area of diameter 1.5−1.7 mm.
A device for grinding coal or copper electrodes, for example the machine model CP-35.
Oxygen chamber for oxidation of co and samples.
Oxygen cylinder fitted with reducer.
Spectrographic plates type 1 or type 2 sensitivity 0,5−5 units. Monochromatic sensitivity 10−60 units.
Hot plate or sand bath.
Analytical scale 200 g with weights of type ADV-200 etc.
Boxy or porcelain crucibles for storage of oxidized pills.
Forceps for grasping tablets.
Caps, glass or plastic to protect from dust sharpened electrodes.
Magnet type MVM-63.
A stopwatch or timer.
Nitric acid according to GOST 4461, diluted 1:1.
Rectified ethyl alcohol according to GOST 18300.
Metol (para-metilaminofenazon).
Hydroquinone (paradoxians) according to GOST 19627.
Sodium sanitarily according to GOST 195.
Sodium carbonate according to GOST 83.
Potassium bromide according to GOST 4160.
Chernovetskiy crystalline sodium (thiosulfate) according to GOST 244.
Acetic acid according to GOST 61.
Developer for plates the spectral type 1, 2 and «Micro» is prepared by mixing equal volumes of solutions 1 and 2 before use.
Solution 1: 2.5 g of metol 12 g of hydroquinone and 100 g of sodium semitecolo dissolved in 500−700 cmof water and add water to 1 DM.
Solution 2: 100 g of sodium carbonate and 7 g of potassium bromide dissolved in 500−700 cmof water and topped up to 1 cm.
You can also use other high contrast developers.
Fixing solution: 300 g sodium thiosulfate, 25 g of sodium semitecolo and 8 cmof acetic acid are dissolved in 1 DMdistilled water.
4.3. Preparation for assay
Sample and in tablet mass (0,5±0,05) g with a diameter of 5−7 mm and a height of 2 mm are machined on a lathe.
Samples may be pressed from the chips. Chips pre-atminciai. Then chips and a pill is cleaned from surface contamination — etching in nitric acid. Chips and tablets WITH washed in distilled water and dried. During the pressing of tablets from the chip matrix and the punch is carefully cleaned from the remnants of previously molded samples (washed with water and rubbing alcohol). Prepare at least two samples tablets WITH.
Carry out oxidation of co and of samples in an oxygen chamber: all the details of the hyperbaric chamber and graphite supports for samples and purified from oxides of copper. The rotary table is strengthened in the lower elektrodvigateli camera. To avoid cross contamination of samples on the graphite stand of the rotary table is placed the tablets of the same composition.
In the upper holder reinforcing dummy electrode made of copper, the working end of which is sharpened to a truncated cone with an apex angle of 45° and a platform with a diameter of 1.5−1.7 mm, or sharpened to a hemisphere. The interelectrode gap set to 1.5−2 mm. the Tablet serves as a cathode of the DC arc, the amperage set 6 A. air from the chamber being squeezed, compressed oxygen flowing through the chamber for 30 s. the oxidation of pills the oxygen pressure in the chamber is supported slightly above atmospheric. Tablet under the pressure of the arc for 5−8 with melts and turns into a drop of melted oxides. The current is turned off, and is supplied to the dummy electrode next pill.
4.4. Analysis
The mechanical part of graphite electrodes for removal of surface contaminants calcined in an arc of DC current for 20 s at 6−10 And including the electrode-stand as the anode of the arc.
Prepared samples and calcined is placed on a graphite holder. As a support electrode is used copper rods or coal.
To determine mass fraction of silicon in a graphite stand is composed of a cathode of the DC arc. The Wren after shooting at the anode. Getting exposure counts after the transition of the cathode spot of the arc on the molten portion of the bead.
Shooting conditions the spectrogram: the width of the slit of a spectrograph — 0.012 mm; illumination of the slit by using a three-lens Achromat condenser; the diaphragm is in the middle of the condenser lens is 5 mm; the arc gap is 3 mm; rated current 6 to 8 A; the firing of 20; the exposure time is 60−90 s.
Photographic plates show depending on their type in the appropriate developer at a temperature of 18−20 °C for 3−5 min. After washing the plates in tap water they are fixed in fixing solution, washed in running water and dried.
4.5. Processing of the results
4.5.1. The optical densities of the analytical lines and the internal standards in the spectrograms are measured with the aid of microphotometer. The slot width of the photocell shall be 0.10−0.25 mm; gap width between the green cheeks, as measured on the screen in front of the cell is 0.3−1.0 mm.
Use analytical line silicon 288,158 nm and the minimum value of the optical density of the background measured near the line on the side of shorter waves.
Calibration graphs constructed in the coordinates:
.
Accounting background (no *) is carried out according to the table (GOST 9717.3).
_______________
* Formula conforms to the original. — Note the CODE.
The basic method for graphing is a method of «three standards». In the absence of a line of silicon in the sample or if it is much weaker in intensity line in a standard sample with a minimum content of silicon, the evaluation is conducted POLYOLESTER, the difference between pucherani line silicon background ();
is the logarithm of the concentration of silicon in the standard sample.
Mass fraction of silicon find the calibration schedule.
4.5.2 discrepancies in the results of parallel measurements (the rate of convergence in 3) should not exceed 0,0003% when the mass fraction of silicon of from 0.0005% to 0.001% and ~0,0008% when the mass fraction of silicon of from 0.001% to 0.003%.
4.5.3. Discrepancies in the results analysis, 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 ~0,0004% when the mass fraction of silicon of from 0.0005% to 0.001% and ~0.001% at a mass fraction of silicon from 0.001% to 0.003%.
4.5.4. Control of accuracy of analysis results (POLYOLESTER) is carried out according to GSO 1516−79 (М246х) tin-zinc bronze or SOP 2186−86 type tin-zinc bronze (М246х).
Sec. 4. (Added, Rev. N 2).