GOST 6689.7-92
GOST 6689.7−92 Nickel, alloys Nickel and copper-Nickel. Methods for determination of silicon
GOST 6689.7−92
Group B59
STATE STANDARD OF THE USSR
NICKEL, ALLOYS NICKEL AND COPPER-NICKEL
Methods for determination of silicon
Nickel, nickel and copper-nickel alloys.
Methods for the determination of silicon
AXTU 1709
Date of introduction 1993−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR
DEVELOPERS
V. N. Fedorov, Y. M. Leybov, Boris Krasnov, A. N. Bulanova, I. A. Vorobyev
2. APPROVED AND promulgated by the Decree of Committee of standardization and Metrology of the USSR from
3. REPLACE GOST 6689.7−80
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
This standard specifies the gravimetric method for determination of silicon (with a mass fraction of silicon of from 0.1 to 1.6%) and photometric methods for determination of silicon (with a mass fraction of silicon of from 0.001 to 0.1 and 0.01 to 0.3%) in Nickel, Nickel and copper-Nickel alloys according to GOST 492* and GOST 19241.
______________
* On the territory of the Russian Federation GOST 492−2006. — Note the manufacturer’s database.
1. GENERAL REQUIREMENTS
General requirements for methods of analysis GOST 25086 with the addition of sec. 1 GOST 6689.1.
2. GRAVIMETRIC METHOD FOR DETERMINATION OF SILICON
2.1. The essence of the method
The method is based on the isolation of silicon in the form silicic acid, calcining it to silicon dioxide and removal in the form of silicon tetrafluoride. The silicon content calculated by the mass difference of sludge before and after treatment hydrofluoric acid.
2.2. Reagents, solutions
Nitric acid according to GOST 4461.
Hydrochloric acid according to GOST 3118 and diluted 1:100.
Sulfuric acid according to GOST 4204, and diluted 1:1 and 1:4.
Mixture of nitric and hydrochloric acids in a ratio of 1:3 to dissolve.
Hydrofluoric acid according to GOST 10484.
Potassium ferrocyanide according to GOST 4207, a solution of 30 g/DM.
Sodium hydroxide according to GOST 4328, solution 100 g/DM.
Dimethylglyoxime according to GOST 5828, a solution of 10 g/DMsolution of sodium hydroxide.
Potassium, anhydrous sodium carbonate according to GOST 4332.
2.3. Analysis
A portion of the alloy weight 2 g (for mass fraction of silicon is less than 1%) and 1 g (in mass percentage of silicon in excess of 1%) was placed in a quartz glass with a capacity of 250 cm, adding 20−30 cm
of a mixture of acid, cover with watch glass, glass or plastic plate and dissolved by heating. After dissolution of the alloy or glass plate and the walls of the beaker rinse with water, add 20−30 cm
of sulphuric acid (1:1) and evaporated to release a thick white smoke of sulfuric acid. The residue is cooled, rinse walls of beaker with water and again repeat the evaporation to release a thick white smoke of sulfuric acid. To the cooled residue add 3−5 cm
of concentrated hydrochloric acid, 150−200 cm
of hot water and heated to dissolve the salts. The precipitate was filtered off on a medium density filter, washed with hot hydrochloric acid (1:100) until a negative reaction of wash water on copper (sample with solution of ferrocyanide of potassium) and Nickel (sample with an alkaline solution dimethylglyoxime), and then the precipitate is washed 3−4 times with hot water. The filtrate is evaporated until a white smoke of sulfuric acid, the residue is diluted with water to 150−200 cm
, the precipitate of silicic acid is filtered off on another medium density filter and washed as above. Both of the filter with sediment was placed in a platinum crucible, dried, incinerated and calcined in a muffle furnace at 1000−1100 °C to constant weight. To the residue in a platinum crucible add 2−3 drops of concentrated sulfuric acid, 1 cm
hydrofluoric acid and cautiously evaporated to dryness. The residue is calcined at 1000−1100 °C in a muffle furnace to constant weight.
At the same time through the analysis of spend control experience and found the content of silicon is introduced by an appropriate amendment.
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 after treatment with hydrofluoric acid, g;
0,4672 — the ratio of the mass of silicon dioxide in bulk silicon; — the weight of the portion of alloy,
2.4.2. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.1.
Table 1
2.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) of Nickel, Nickel and copper-Nickel alloys, approved under GOST 8.315* in accordance with GOST 25086.
________________
* On the territory of the Russian Federation GOST 8.315−97. Here and further. — Note the manufacturer’s database.
3. EXTRACTION-PHOTOMETRIC METHOD for the DETERMINATION of SILICON (from 0.001 to 0.1%)
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
Spectrophotometer or photoelectrocolorimeter.
a pH meter.
Nitric acid according to GOST 4461 and diluted 2:1, 1:2 (boiled) and 1:100.
Sulfuric acid according to GOST 4204, diluted 1:9.
Hydrochloric acid according to GOST 3118 and diluted 1:1.
Hydrofluoric acid, OS.h.
Citric acid according to GOST 3852, a solution of 500 g/DM.
Boric acid according to GOST 9656, saturated solution: 60 g of boric acid is treated with 1 DMof hot water and after cooling, use the supernatant solution.
Ammonia water according to GOST 3760, OS.CH., diluted 1:1 and 1:100.
Ammonium molybdate according to GOST 3765, recrystallized, solution 100 g/l250 g ammonium molybdate are dissolved in 400 cm
of water at 70−80 °C, ammonia is added to a clear smell and the hot solution is filtered twice through the same filter into the beaker containing 300 cm
of 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, sucking mother liquor. The crystals are washed 2−3 times with ethanol in batches of 20−30 cm
, after which they are dried in air.
The technical rectified ethyl alcohol according to GOST 18300.
Tin dichloride on the other 6−09−5384−88, a solution of 100 g/DM; prepared: 10 g of tin dichloride dissolved in 100 cm
of hydrochloric acid (1:1) when heated to 80−90 °C.
Wash solution: to 50 cmof sulphuric acid are added 1.5 cm
of a solution of molybdate of ammonium.
Potassium-sodium carbonate according to GOST 4332.
Sodium hydroxide according to GOST 4328, solution 0,1 mol/DM.
Sodium carbonate according to GOST 83, a solution of 50 g/DM.
Sodium meta silicate according to GOST 4239.
Normal butyl alcohol according to GOST 6006.
Silicon dioxide according to GOST 9428.
Standard solutions of silicon.
Silicate of sodium: 0.5 g sodium silicate dissolved in 20 cmof sodium carbonate solution in a platinum plate, cooled, placed in a plastic vessel, dilute with water to 500 cm
and mixed.
1 cmof the solution contains 0.0001 gram of silicon.
The exact content of the set of silicon by gravimetric method.
Of silicon dioxide: 0,2143 g of calcined silicon dioxide is fused in a platinum crucible with 2 g of sodium-potassium 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 gravimetrics
them method.
3.3. Analysis
3.3.1. For alloys not containing tungsten
A portion of the alloy (see table.2) is placed in a polyethylene or Teflon or Teflon beaker with a capacity of 100 cm, add 15−30 drops of hydrofluoric acid, 15 cm
of nitric acid (2:1), covered with plastic or Teflon cap and dissolve in 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. After dissolution, the solution was cooled, added 30 cm
boric acid, after 20 min the mixture is transferred through a polyethylene funnel into a measuring flask with a capacity of 100 cm
, containing 30 cm
of boric acid, made up to the mark with water and mix. The solution is immediately transferred into the glass, which had a dissolution.
Table 2
Pre-set pH in solutions alikvotnih parts in pH-meter: in a polyethylene beaker with a capacity of 50 cmis placed aliquot part of the solution (see table.2) add water to a volume of approximately 50 cm
and with solution of ammonia (OS.h.) set pH=1,0−1,2 by adding ammonia solution drop by drop, recording the number of drops consumed to the surgery. Aliquot part of the solution (see table.2) for analysis is placed in a separating funnel with a capacity of 200 cm
, topped up the water to about 50 cm
and set pH=1,0−1,2 using preliminary data. To the solution was dropwise added with stirring 5 cm
of ammonium molybdate solution and allowed to stand 10 min. Then add 5 cm
of citric acid, 10 cm
boiled nitric acid (1:2), 30 cm
butyl alcohol and extracted silica-molybdenum heteropolyacid, carefully turning the funnel 30. After separation the aqueous layer is discarded and to the organic layer add 50 cm
wash 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, is added to the labels of 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 the thickness of the light 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 of p
robe.
3.3.2. For alloys containing tungsten
A portion of the alloy (see table.2) is placed in a beaker with a capacity of 250 cm, adding 10 cm
of nitric acid (1:2). Cover the watch glass, glass or plastic plate and dissolved by heating. Glass or plate and the side of the Cup then rinsed with water, the solution is evaporated to a syrupy condition, with water diluted to 60 cm
and incubated for 20−30 min in a warm place until clarification of the solution.
The precipitate tungsten acid is filtered off on a double thick filter, a glass and a precipitate was washed 3−4 times with hot nitric acid (1:100) and the filtrate leave. The filter cake is dissolved in 4−6 cmof hot ammonia solution (1:1) in a glass, in which were dissolving, and the filter washed with ammonia solution (1:100). The resulting solution was poured to the previously obtained filtrate with rapid stirring. The filter is placed in a platinum crucible, incinerated, add 0.3 g of potassium-sodium carbonate and fused at 1000−1100 °C. After cooling, the melt leached with water with addition of 1−2 drops of concentrated nitric acid, the resulting solution was attached to the combined filtrate and evaporated to 70−80 cm
. After cooling, the solution was placed in a volumetric flask with a capacity of 100 cm
and then filled to the mark with water.
Aliquot part of the solution (see table.2) is placed in a beaker with a capacity of 50 cm, made up to a volume of 50 cm
of water and then do as described in claim 3.3.
1.
3.3.3. Construction of calibration curve
Five of six plastic, Teflon or Teflon cups were placed 1,0; 2,0; 3,0; 4,0 and 5,0 cmstandard solution silicon (0.0001 g/cm
) or 0,5; 1,0; 1,5 and 2.0 and 2.5 cm
standard solution silicon (0.0002 g/cm
). All cups add 15 drops of hydrofluoric acid, 15 cm
of nitric acid (2:1), 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.
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 in the sample was found in the 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,
3.4.2. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.1.
3.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) Nickel and copper-Nickel alloys, approved under GOST 8.315, or by a method of additives in accordance with GOST 25086.
4. The PHOTOMETRIC METHOD for the DETERMINATION of SILICON (from 0.01 to 0.3%)
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
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 1:2.
Sulfuric acid according to GOST 4204, diluted 1:1.
Hydrofluoric acid, OS.h.
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: 60 g of boric acid are dissolved in 1000 cmof hot water. Before administration, the solution is cooled to a temperature of 20 °C.
Ammonia water according to GOST 3760, diluted 1:1.
Carbamide (urea) GOST 6691, a solution of 100 g/DM.
Ammonium molybdate according to GOST 3765, recrystallized, solution 100 g/DM. Keep the solution in a plastic vessel. The recrystallization of ammonium molybdate is carried out as specified in clause 3.2.
Potassium-sodium carbonate according to GOST 4332.
Copper, OS.CH., with a mass fraction of silicon of less than 3−10%.
The copper solution to prepare a solution of comparison: 1 g of copper is placed in a platinum Cup or PTFE, is added 0.6 cmhydrofluoric acid, 11 cm
of nitric acid (1:2), cover with a lid and dissolve in a water bath at a temperature not exceeding 60 °C. After dissolution, the cover is removed and while stirring, and remove the nitrogen oxides.
The solution was cooled, added to 50 cmof a solution of boric acid, the solution transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix.
The copper solution to prepare the solution in the reference experiment: 1 g of copper is placed in a platinum Cup and dissolved in 0.6 cmhydrofluoric acid and 11 cm
of nitric acid (1:2) when heated. Then add 2.5 cm
of sulphuric acid (1:1) and the solution is heated to remove free sulfuric acid.
After cooling, the residue is dissolved, adding a small amount of water, 10 cmof nitric acid (1:2) and 0.6 cm
hydrofluoric acid. To the solution was added to 50 cm
of a solution of boric acid, the solution transferred to a volumetric flask with a capacity of 100 cm
, top up to the mark with water and mix.
Silicon dioxide according to GOST 9428.
Standard solutions of silicon
Solution a: 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 and placed in 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: 10 cmsolution And placed in 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 0,0
0002 g of silicon.
4.3. Analysis
4.3.1. A sample of alloy weighing 1 g is placed in a platinum or Teflon crucible, add 0.6 cmhydrofluoric acid and 11 cm
of nitric acid (1:2), cover with a lid and dissolve in a water bath at a temperature not exceeding 60 °C. After dissolution, the cover is removed and while stirring, and remove the nitrogen oxides. The solution was cooled, added to 10 cm
of boric acid solution and the solution is transferred through a polyethylene funnel into a measuring flask with a capacity of 100 cm
, containing 40 cm
of boric acid, made up to the mark with water and mix.
Depending on the mass fraction of silicon is taken aliquot part of the solution (see table.3), placing it in a volumetric flask with a capacity of 50 cmand added are given in table.3 the number of solution of nitric acid.
Table 3
The solution in the flask is diluted with water to 20 cmand add, while mixing after adding each reagent, 5 cm
urea solution, 5 cm
of molybdenic acid ammonium solution and leave for 10 minutes Then add 5 cm
of the citric acid solution, 3 cm
of a solution of orthophosphoric acid, made up to the mark with water and mix. After 15 min measure the optical density of the solution on the spectrophotometer or photoelectrocolorimeter at a wavelength of 400 nm in a cuvette with the thickness of the light absorbing layer 5 cm relative to the solution in the reference experiment. The solution in the reference experiment is prepared simultaneously with the sample and the copper solution (see p.4.2) take this number as the analyzed solution.
4.3.2. Construction of calibration curve
In seven volumetric flasks with a capacity of 50 cmplaced at 10 cm
of copper solution (reference solution), add 0.6 cm
of a solution of nitric acid, and then in six flasks add 1,0; 2,0; 4,0; 6,0; 8,0 and 10,0 cm
standard solution B of silicon.
The solutions in all flasks is poured with water to a volume of 20 cm, add 5 cm
of the urea solution and further analysis is carried out as given in claim
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. Discrepancies in the results of three parallel measurements (rate of convergence) and the results of the two tests
(index of reproducibility) shall not exceed the values of permissible differences given in table.1.
4.4.3. Control of accuracy of analysis results is carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) of Nickel, Nickel and copper-Nickel alloys, approved under GOST 8.315, or by a method of additives in accordance with GOST 25086.