GOST 1652.10-77
GOST 1652.10−77 Alloys copper-zinc. Methods for determination of aluminium (with Amendments No. 1, 2, 3, adjusted)
GOST 1652.10−77
Group B59
STATE STANDARD OF THE USSR
ALLOYS COPPER-ZINC
Methods for determination of aluminium
Copper-zinc alloys.
Methods for the determination of aluminium
AXTU 1709
Date of introduction 1978−07−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
Y. F. Chuvakin, M. B. Taubkin, A. A. Nemodruk, N. In. Egiazarov (supervisor), I. A. Vorobyev
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. REPLACE GOST 1652.10−71
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph |
| GOST 8.315−91 |
2.4.4, 3.4.4, 4.4.4, 5.4.4, 6.4.4 |
| GOST 61−75 |
2.2, 3.2, 5.2 |
| GOST 199−78 |
3.2 |
| GOST 435−77 |
2.2 |
| GOST 859−78 |
2.2 |
| GOST 1020−77 |
Chapeau |
| GOST 1652.1−77 |
1.1, 3.3.1, 3.3.2, |
| GOST 3117−78 |
2.2, 3.2, 5.2 |
| GOST 3118−77 |
2.2, 3.2, 4.2, 5.2, 6.2 |
| GOST 3760−79 |
2.2, 3.2, 4.2, 5.2, 6.2 |
| GOST 3773−72 |
3.2, 4.2 |
| GOST 4147−74 |
3.2 |
| GOST 4204−77 |
2.2, 3.2, 4.2 |
| GOST 4233−77 |
6.2 |
| GOST 4237−77* | 4.2 |
| ________________ * Probably, the error of the original. Should read: GOST 4234−77, here and hereafter. — Note the manufacturer’s database. | |
| GOST 4328−77 |
3.2, 5.2 |
| GOST 4461−77 |
2.2, 3.2, 4.2, 5.2, 6.2 |
| GOST 4463−76 |
2.2 |
| GOST 4518−75 |
2.2, 6.2 |
| GOST 5475−69 |
4.2 |
| GOST 5841−74 |
3.2 |
| GOST 6563−75 |
3.2, 6.2 |
| GOST 6691−77 |
2.2, 3.2 |
| GOST 10484−78 |
3.2, 4.2 |
| GOST 10521−78 |
5.2 |
| GOST 10652−73 |
2.2, 6.2 |
| GOST 10928−90 |
4.2 |
| GOST 10929−76 |
2.2 |
| GOST 11069−74 |
2.2, 3.2, 4.2, 5.2 |
| GOST 15527−70 |
Chapeau |
| GOST 17711−93 |
Chapeau |
| GOST 18300−87 |
2.2, 3.2, 5.2 |
| GOST 20478−75 |
3.2 |
| GOST 25086−87 | 1.1, 2.4.4, 3.4.4, 4.4.4, 5.4.4, 6.4.4 |
| GOST 27068−86 |
3.2 |
5. Resolution of the state standard from
6. REPRINT (July 1997) with Amendments No. 1, 2, 3, approved in October 1981 and November 1987, October 1989, December 1992 (IUS 12−81, 2−88, 2−90, 3−93)
(Amendment. ICS N 4−2008).
AMENDED, published in the IUS N 4, 2008
An amendment made by the manufacturer of the database
This standard establishes titrimetric methods for the determination of aluminum (with a mass fraction of aluminum from 0.5 to 8%), a photometric method for the determination of aluminum (with a mass fraction of aluminum from 0.005 to 0.5%) and atomic absorption method for the determination of aluminum (with a mass fraction of aluminum from 0.01 to 8%) in copper-zinc alloys according to GOST 15527, GOST and GOST 17711 1020.
(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 1652.1.
(Changed edition, Rev. N 2).
2. TITRIMETRIC CHELATOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM (FROM 0.5 TO 8%).
2.1. The essence of the method
The method is based on the introduction of the sample solution and excess Trilon B solution that forms complex with all the components of the alloy, the titration of an excess of solution of nitrate of copper, the decomposition of complexonate of aluminium by adding ammonium fluoride or sodium and the titration of Trilon B emitted in a quantity equivalent to the aluminium content.
2.2. Apparatus, reagents and solutions
pH meter with all accessories (type LPU-01 or pH-340, etc.).
Potentiometer-type of LSM-60 with a scale interval of 5 mV.
Microammeter M-95 with a scale of 25 mA.
Battery voltage 2 V or dry battery of the same voltage.
AC resistance 1 mω.
Two platinum electrode, made of wire with diameter 0,8−1 mm, sealed in a glass tube. Length of the working part of the electrodes 30−35 mm.
Magnetic stirrer.
Burette with a capacity of 25 cmwith Moncoutant spout.
Microburette with a capacity of 1 cmis drawn with a spout.
The mixture to dissolve; preparing by mixing three volumes of concentrated hydrochloric acid with one volume of concentrated nitric acid.
Sulfuric acid according to GOST 4204.
Methenamine (hexamethylenetetramine).
Hydrogen peroxide according to GOST 10929, 30% solution.
Blend to refresh the surface of the electrodes; prepared by adding hydrochloric acid diluted 1:5, a few drops of hydrogen peroxide.
A solution of sulphate of manganese GOST 435 containing 1 mg/cmof manganese; prepared as follows: a 2.75 g of salt dissolved in 1 DM
of water.
The installation for the titrimetric determination of aluminium with amperometrical indication of the titration end (see drawing).
The installation for the titrimetric determination of aluminium with amperometrical indication end of titration
The installation consists of the following elements: Cup 1 with a capacity of 250−300 cmfor the test solution; two platinum indicator electrodes 2 with a length of 17−20 mm and diameter 0,8−1 mm; magnetic stirrer 3; battery or dry battery 4; the variable resistance 1 Mω 5 to establish a polarizing current of 2−10 mA; microammeter 6. potentiometer 7 for measuring voltage across the electrodes; burettes 8.
The scale value of the potentiometer should be less than 5 mV, that the jump in potential at the equivalence point provides a deflection on the scale of the device is not less than 20−25 divisions.
This jump is fixed with high accuracy. The titrant (copper sulfate solution) is supplied in glass burettes with a capacity of 25 cm; close to the equivalence point the titrant is served drop by drop from microburette.
The pH value of the titrated solution at the set pH-meter. The establishment of the pH on the acid-basic indicator or indicator paper does not provide the necessary precision of the titration, especially in the case of the titration of colored solutions.
For the titrimetric determination of aluminium you can use the setup PAT.
Determination of the mass concentration of a standard solution of copper
A sample of copper with a mass of 0.2 g were placed in a glass with a capacity of 250 cm, add 10 cm
to the standard solution of aluminium and copper is dissolved in 3 cm.
of nitric acid diluted 1:1. After dissolution, the sample solution was evaporated to a volume of about 1 cm
, add a 40 cm
water, 1 cm
of solution of manganese and 20 cm
of a solution of Trilon B.
Establish a pH 6,0−6,2 (silver-chloride electrode on a pH meter) by adding hexamine in small portions. The solution was heated 5 minutes, cooled, set the beaker on the magnetic stirrer, immerse in a solution of platinum electrodes in the variable resistance set circuit current is in the range of 2−10 µa include a potentiometer and set the arrow on the scale potentiometer so that she was in the middle of the scale. Octarepeat excess Trilon B with a standard copper solution, constantly stirring the solution. The titrant enters the Cup approximately at the speed of 10 cm/min By the end of the titration a standard solution of copper is added dropwise. The titration is complete when by adding one drop of titrant (a solution of copper) hand potentiometer is deflected to the left by at least 20 divisions of the scale (100 mV).
After the first titration the solution was added 20 cmof a solution of sodium fluoride, establish a pH 6,0−6,2 by adding a few drops of nitric acid, diluted 1:1, or hexamine solution and boil for 2 min.
After cooling, the solution was titrated with standard copper solution in the same way as in the case of binding of an excess Trilon B. Last portion of the titrant in the range of 1 cmis added from microburette and determine the endpoint of a titration amperometric, as described above.
To establish the mass concentration of the standard copper solution in the above definition is repeated at least five times.
The mass concentration of the standard solution expressed in g/cm
of aluminum, calculated according to the formula
where — the volume of a standard solution of copper consumed in the second titration, sm
.
Nitric acid according to GOST 4461 and diluted 1:1.
Hydrochloric acid according to GOST 3118 and diluted 1:1 and 1:5.
Ammonia according to GOST 3760, diluted 1:1.
Acetic acid according to GOST 61.
Ammonium acetate according to GOST 3117, a solution of 200 g/DM.
1-(2-pyridylazo)-2-naphthol (PAN), ethanolic solution of 1 g/DM.
The technical rectified ethyl alcohol according to GOST 18300.
Urea according to GOST 6691, a solution of 100 g/DM.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B) according to GOST 10652, a solution of 100 g/DM.
Ammonium fluoride according to GOST 4518.
Sodium fluoride according to GOST 4463 and a solution of 25 g/DM.
Copper according to GOST 859 brand M0k and M00k.
The copper standard solution, 0.005 M solution; prepared as follows: 3,177 g of copper metal is dissolved in 20 cmof nitric acid, diluted 1:1. Once dissolved, boil the solution to remove the oxides of nitrogen, cooled, neutralized with ammonia before the advent of the stable precipitate, which is dissolved by adding acetic acid and diluted to 1 DM
.
Aluminum brand А999 according to GOST 11069.
A solution of aluminium standard; prepared as follows:
1 g of aluminum was dissolved in 10 cmof hydrochloric acid, transferred to a volumetric flask with a capacity of 1 DM
and topped to the mark with water.
1 cmof the solution contains 0.001 g of aluminium.
Determination of the mass concentration of copper solution
Take 20 cmof a standard solution of aluminum in a conical flask with a capacity of 500 cm
, is diluted with water up to 50−60 cm
, neutralized with ammonia before formation of a stable precipitate, which is dissolved by adding hydrochloric acid in excess of that and give two drops in excess. Add 20 cm
of the solution Trilon B, 100−150 cm
of hot water and heated to boiling. In the hot solution is poured 10 cm
of a solution of ammonium acetate, 0.5 cm
of the solution PAN and the hot solution titrated with standard copper solution until the transition of the green color of the solution blue, then add 1 g of sodium fluoride (or ammonium), boiled for 5 min and again titrate with the copper solution until the transition of the green color of the solution blue.
The mass concentration of copper solution , expressed in g/cm
of aluminum, calculated according to the formula
where is the mass of aluminium, suitable aliquote part, taken for titration, g;
— the volume of a standard solution of copper consumed in the second titration, sm
.
2.3. Analysis
2.3.1. With amperometric indication of the endpoint of the titration
A sample of alloy weighing 0.5 g (for the mass concentration of aluminum of up to 5%) and 0.2 g (for a mass fraction of aluminum, more than 5%) was dissolved in 3 cmof a mixture of acids to dissolve. After dissolution, add 1.5 cm
of sulphuric acid and evaporate the solution to start the selection, the dense white smoke of sulfuric acid. The solution volume after evaporation should not exceed 1 cm
. A glass of cool, add 40 cm
of water, 20 cm
of solution Trilon B and further analysis are as indicated in claim 2.2.
2.3.2. With a visual indication of the titration end point
A sample of alloy weighing 0.5 g (for the mass concentration of aluminum of up to 5%) and 0.25 g (when the mass fraction of aluminum, more than 5%) is dissolved by heating in 20 cmof nitric acid in the conical flask with a capacity of 500 cm
, add 50−60 cm
of water and boil to remove oxides of nitrogen, then cooled, added to 10 cm
of urea solution and neutralize the solution with ammonia until the formation of a stable precipitate, which is then dissolved by adding hydrochloric acid in excess and in addition gives in excess of two drops. Further analysis are as indicated in claim 2.2.
2.4. Processing of the results
2.4.1. Mass fraction of aluminium in percent is calculated by the formula
where is the volume of copper solution consumed in the second titration, cm
;
— mass concentration of copper solution, expressed in g/cm
of aluminum;
— the weight of the portion of alloy,
2.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.1*.
_______________
* Table.1 in the original paper are not given, here and hereafter. — Note the manufacturer’s database.
(Changed edition, Rev. N 1, 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 (the reproducibility) shall not exceed the values specified in table.1.
(Changed edition, Rev. N 2, 3).
2.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved under GOST 8.315, or by additives or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 3).
3. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM
3.1. The essence of the method
The method is based on formation of colored complex compounds with eryhromycin R (or chromazurol S) after prior separation of the elements from aluminum by electrolysis on a mercury cathode, or platinum electrode and subsequent separation of the aluminum by coprecipitation with ferric hydroxide.
3.2. Apparatus, reagents and solutions
Installation for electrolysis with platinum electrodes according to GOST 6563.
Installation for electrolysis with a mercury cathode.
Spectrophotometer or photoelectrocolorimeter pH meter.
Nitric acid according to GOST 4461 and diluted 1:1.
Hydrochloric acid according to GOST 3118, diluted 1:1 and 0.1 mol/DM.
Chloric acid, diluted 1:1, 1:4 and 1:99.
Sulfuric acid according to GOST 4204, diluted 1:1.
Hydrofluoric acid according to GOST 10484.
A mix of acids for dissolving: mix the salt (1:1) and nitrogen (1:1) acid at a ratio of 1:1.
Ammonium neccersarily according to GOST 20478, a solution of 100 g/DM.
Iron chloride according to GOST 4147, a solution of 15 g/DM: 1.5 g of ferric chloride was dissolved with heating in 30 cm
of hydrochloric acid (1:1).
The solution was then cooled, diluted to a volume of 100 cmand mixed.
Hydrazine sulfate according to GOST 5841.
Rectified ethyl alcohol according to GOST 18300.
Phenolphthalein, solution at 10 g/cmin ethanol.
Ammonia water according to GOST 3760 and a solution of 1:19.
Ascorbic acid, a solution of 10 g/cm, freshly prepared.
Sodium Chernovetskiy according to GOST 27068, a solution of 50 g/cm.
Urea according to GOST 6691.
Eryhromycin R, a solution of 0,7 g/DM: 0.7 g of erioglaucine dissolved in 2 cm
of concentrated nitric acid with constant stirring for 2 minutes, add 60 cm
of water, 0.3 g of urea and incubated for 24 h in a dark place. The solution was filtered in a volumetric flask with a capacity of 1 DM
, made up to the mark with water and mix. Solution store in a dark bottle.
Chromazurol S, a solution of 1 g/DM: 0.1 g of the reagent is dissolved in 30 cm
of warm water (maximum 60 °C) and 20 cm
of ethyl alcohol, filtered and made up to 100 cm
water.
Gelatin, a solution of 10 g/cm.
Sodium hydroxide according to GOST 4328, a solution of 40 g/DM.
Acetic acid according to GOST 61.
Ammonium acetate according to GOST 3117.
Sodium acetate according to GOST 199 and a solution of 2 mol/DM.
Buffer solution pH 6±0,1: 46 g ammonium acetate and 18 g of sodium acetate and dissolve in 1 DMof water. Set the pH of the solution on the pH meter, by adding sodium hydroxide solution or acetic acid.
Aluminum grade And 999 according to GOST 11069.
Standard solutions of aluminium
Solution a: 0.1 g of aluminium is dissolved by heating in 25 cmhydrochloric acid (1:1). The solution was transferred to a volumetric flask with a capacity of 1 DM
, made up to the mark with water and mix.
1 cmof the solution contains 0.0001 g of aluminum.
Solution B: 5 cmmortar And transferred to a volumetric flask with a capacity of 100 cm
, add 20 cm
of hydrochloric acid (1:1), made up to the mark with water and mix.
2 cmsolution B contains 0,000005 g of aluminum.
3.3. Analysis
3.3.1. The method of separation of aluminium from interfering elements by electrolysis at a mercury cathode.
The weight of the alloy (see table.2) is placed in a beaker with a capacity of 250 cm, and dissolved in 10 cm
of the mixture of acids to dissolve when heated.
Table 2
| Mass fraction of aluminum, % |
The mass of charge, g |
Aliquota part of the solution, see |
| From 0.005 to 0.01 incl. |
1,0 |
25 |
| SV. The 0.01 «to 0.05 « |
0,5 |
25 |
| «0,05» 0,1 « |
0,5 |
10 |
| «0,1» 0,5 « |
0,25 |
5 |
After dissolution of the sample add 6 or 3 cmof perchloric acid (1:1), respectively, for a sample weight of 0.5 and 0.25 g and the solution was evaporated until copious white fumes of perchloric acid. After cooling, rinse the walls of the glass 5−10 cm
of water and again heat to release white fumes. The residue is cooled, add 5 cm
of perchloric acid (1:4), 50 cm
of hot water and heated to dissolve the salts. The solution was cooled, top up with water to 100 cm
and transferred into the electrolytic cell with mercury cathode. The electrolysis is carried out at a current of 4−5 A (current density of 0.15 A/cm
, the voltage 5−6 V). After the bleaching solution and continue the electrolysis for another 15 min, then the solution was transferred to a beaker with a capacity of 250 cm
, the mercury washed with water and the washing solutions are combined with the main electrolyte. In the electrolyte add 5 cm
naternicola solution of ammonia and heated to a temperature of 70−80 °C. In case of precipitation of the manganese dioxide precipitate was filtered on a medium density filter and washed four times with a solution of perchloric acid (1:99). The precipitate is discarded, the filtrate evaporated to 80−100 cm
and after cooling, the solution is transferred to a volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix.
3.3.1.1. Fotometrirovanie using eryhromycin R
Depending on the mass fraction of aluminum in a beaker with a capacity of 100 cmis taken aliquot part of the solution (see table.2), top up with water to a volume of 25 cm
, add 2 cm
of ascorbic acid solution, 1 cm
of a solution of sodium servational 10 cm
of a solution of erioglaucine and sodium hydroxide solution set the pH value 6±0.1 na pH-meter.
Then add 30 cmbuffer solution and the solution transferred to a volumetric flask with a capacity of 100 cm
, made up to the mark with water and mix. After 20 minutes, measure the optical density of the solution on the spectrophotometer at a wavelength of 535 nm in a cuvette with a layer thickness of 1 cm or photoelectrocolorimeter with a green optical filter in a cuvette of 2 cm
. Solution comparison is the solution of the reference experiment.
3.3.1.2. Fotometrirovanie using chromazurol With
Depending on the mass fraction of aluminium in a volumetric flask with a capacity of 100 cmis taken aliquot part of the solution (see table.2), top up with water to a volume of 25 cm
, add 2 cm
of ascorbic acid, 5 cm
solution servational sodium and neutralized with sodium hydroxide solution to a pH of 5−6 on the universal indicator paper. Then add 5 cm
of hydrochloric acid (0.1 mol/DM
), water up to 50 cm
, 10 cm
gelatin solution, 2 cm
of a solution of chromazurol s, 5 cm
of a solution of sodium acetate and then filled to the mark with water. After 10 minutes measure the optical density of the solution on the spectrophotometer at 545 nm or photoelectrocolorimeter with a green optical filter in a cuvette with a layer thickness of 1 cm
. Solution comparison is the solution of the reference experiment.
3.3.2. The method of separation of copper from aluminium by electrolysis with platinum electrodes.
3.3.2.1. For alloys with a mass fraction of silicon and tin, more than 0,05% of lead to 0.05%.
The weight of the alloy (see table.2) is placed in a platinum Cup, add 10 cmof nitric acid (1:1), 3−5 cm
hydrofluoric acid and dissolved by heating. After dissolving, the solution was evaporated to wet salts, add 5 cm
of sulphuric acid and evaporated to start the selection of a white smoke of sulfuric acid. After cooling, dissolve the salt in 50 cm
of hot water and the solution transferred to a beaker with a capacity of 300 cm
. If necessary the solution is filtered through a dense filter with the addition of filtrowanie mass in a beaker with a capacity of 250 cm
. The sediment and filter washed with hot water. The solution in the beaker is diluted with water to 150 cm
, 8 cm add
boiled nitric acid (1:1) and produce copper by electrolysis according to GOST 1652.1.
In the electrolyte add 5 cmof a solution of ferric chloride (at a mass fraction of iron in the alloy is less than 0.5%), 2 drops of phenolphthalein solution, is heated to a temperature of 60−70 °C and poured ammonia to pink colouration of the solution and 2 cm
in excess. Solution and the precipitate leave in a warm place for 20−30 min and then filtered through a filter of medium density. The glass and the filter cake washed with hot ammonia solution (1:19). The precipitate is washed from the filter with a jet of hot water into the Cup, which was held a deposition, and the residue on the filter is dissolved in 5−10 cm
of hot hydrochloric acid (1:1). The filter is then washed with hot water, the solution was cooled, transferred to a volumetric flask with a capacity of 250 cm
, made up to the mark with water and mix.
In a glass or flask with a capacity of 100 cmis taken aliquot part of the solution according to the table.2, top up with water to a volume of 25 cm
and then do as described in the claims.3.3.1.1 and
3.3.2.2. For alloys with a mass fraction of silicon and tin up to 0.05%, and lead to more than 0.5%.
The weight of the alloy (see table.2) is placed in a beaker with a capacity of 300 cm, add 15 cm
of nitric acid (1:1) and dissolved by heating. After dissolution of the sample and removal of nitrogen oxides by boiling the solution was cooled, diluted with water to 150 cm
, isolated copper by electrolysis according to GOST 1652.1 and then do as described in claim
3.3.3. Construction of calibration curve
In five of the six beakers or volumetric flasks with a capacity of 100 cmis placed 1,0; 2,0; 3,0; 4,0 and 5,0 cm
standard solution B aluminum. All beakers or flasks, pour water to a volume of 25 cm
, add 2 cm
of ascorbic acid and then act as described in the claims.3.3.1.1 and
Solution comparison is the solution not containing aluminum. According to the obtained values of optical density of solutions and relevant content to build a calibration curve.
3.4. Processing of the results
3.4.1. Mass fraction of aluminium in percent is calculated by the formula
where is the mass of aluminum was found in the calibration schedule g;
— the weight of the portion corresponding to aliquote part of the solution,
3.1−3.3, 3.3.1,
3.4.2. Allowable absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the values given in table.3.
Table 3
| Mass fraction of aluminum, % |
|
|
| From 0,005 to 0,010 incl. |
0,002 |
0,003 |
| SV. Of 0.010 «to 0.025 « |
0,004 |
0,006 |
| «0,025» 0,050 « |
0,006 |
0,008 |
| «0,050» 0,10 « |
0,010 |
0,014 |
| «To 0.10» to 0.25 « |
0,015 |
0,021 |
| «0,25» 0,50 « |
0,025 |
0,035 |
| «To 0.50» and 1.0 « |
0,035 |
0,05 |
| «1,0» 2,0 « |
0,05 |
0,07 |
| «2,0» 3,0 « |
0,1 |
0,14 |
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 (the reproducibility) shall not exceed the values given in table.3.
3.4.2,
3.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved under GOST 8.315, or by additives or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 3).
4. ATOMIC ABSORPTION METHOD FOR THE DETERMINATION OF ALUMINIUM
4.1. The essence of the method
The method is based on dissolving the sample in nitric acid or in a mixture of nitric and hydrochloric acids and the measurement of atomic absorption of aluminium in the flame acetylene — nitrous oxide at a wavelength of 309,3 nm. When the mass fraction of aluminum to 0.1% atomic absorption of aluminium is measured after a preliminary coprecipitation it with the hydroxide of iron.
4.2. Apparatus, reagents and solutions
The atomic absorption spectrometer.
Lamp with a hollow cathode or other source of resonance radiation for aluminium.
Nitric acid according to GOST 4461 and diluted 1:1.
Hydrochloric acid according to GOST 3118 and diluted 1:1.
A mixture of nitric and hydrochloric acids in a ratio of 1:3.
Sulfuric acid according to GOST 4204, and diluted 1:1.
Hydrofluoric acid according to GOST 10484.
Acetylene according to GOST 5475.
Aluminium GOST 11069.
Standard aluminium solution: 1 g of aluminium is dissolved by heating in 10 cmof hydrochloric acid (1:1) and 2 cm
of nitric acid (1:1). The solution was cooled, transferred to a measuring flask with volume capacity of 1000 cm
and top up with water to the mark.
1 cmof the solution contains 0.001 g of aluminium.
Copper according to the GOST 859.
Standard copper solution: 10 g of copper was dissolved with heating in 80 cmof nitric acid (1:1). The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
and top up with water to the mark.
1 cmof the solution contains 0.1 g of copper.
Hydrogen peroxide according to GOST 10928.
Ammonium chloride according to GOST 3773.
Iron chloride according to GOST 4147, a solution of 15 g/DM: 1.5 g of ferric chloride dissolved in 30 cm
of hydrochloric acid (1:1), the solution was cooled and diluted with water to a volume of 100 cm
.
Ammonia water according to GOST 3760 and diluted 1:19.
Potassium chloride according to GOST 4237, solution 200 g/DM.
4.1, 4.2. (Changed edition, Rev. N 2).
4.3. Analysis
4.3.1. When the mass fraction of aluminum from 0.01 to 0.1% taking a portion of the analyzed alloy with a mass of 3 g At a mass fraction of aluminum from 0.1 to 0.5% taking the sample analyzed alloy weighing 1 g.
(Changed edition, Rev. N 2).
4.3.1 a. Analysis of alloys containing aluminium up to 0.1%.
A portion of the alloy (see p.4.3.1) is placed in a beaker with a capacity of 600 cm, and dissolved in 30 cm
of a mixture of acids. After dissolution the solution is diluted with water to a volume of 200 cm
, add 3−4 g of ammonium chloride and 5 cm.
of solution of ferric chloride, if the alloy contains less than 0.5% iron. The solution is heated to 70−80 °C, ammonia is added to complete the transition of copper in a soluble ammonia complex, and the solution is kept in a warm place for 20 min. the solution was Then filtered through a medium density filter and washed with warm solution of ammonia (1:19). The filter cake is dissolved in 10 cm
of hydrochloric acid (1:1) with addition of 2−4 drops of hydrogen peroxide in a volumetric flask with a capacity of 100 cm
, the filter washed with hot water. The solution is cooled, add 2cm
of a solution of potassium chloride and add water to the mark. Measure the atomic absorption of aluminum in the sample solution in parallel with the solution to construct the calibration curve and the solution in the reference experiment in the flame acetylene — nitrous oxide at a wavelength of 309,3 nm.
(Added, Rev. N 2)
.
4.3.2. Analysis of alloys not containing tin and silicon
A portion of the alloy (see p.4.3.1) was dissolved with heating in 10 cmof nitric acid (1:1). The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
, add 2 cm
of a solution of potassium chloride and add water to the mark.
4.3.3. Analysis of alloys containing tin
A portion of the alloy (see p.4.3.1) dissolved in 10 cmof a mixture of acids. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
, add 2 cm
of a solution of potassium chloride and add water to the mark.
4.3.4. Analysis of alloys containing silicon
A portion of the alloy (see p.4.3.1) is placed in a platinum Cup and dissolved by heating in 10 cmof nitric acid (1:1) and 3 cm
hydrofluoric acid. After dissolution, add 10 cm
sulphuric acid (1:1) and evaporated until a white smoke of sulfuric acid. Cup cooled and the residue is dissolved in 50 cm
of water when heated. The solution was cooled, transferred to a volumetric flask with a capacity of 100 cm
, add 2 cm
of a solution of potassium chloride and add water to the mark.
4.3.5. Construction of calibration graphs.
When the mass fraction of aluminum from 0.01 to 0.1% in four of the five volumetric flasks with a capacity of 100 cmis placed 0,3; 1,0; 2,0 and 3,0 cm
standard solution aluminum. To all flasks add 5 cm
of hydrochloric acid (1:1), 2 cm
of a solution of potassium chloride and fluids topped up to the mark with water.
When the mass fraction of aluminum, more than 0.1% in nine out of ten volumetric flasks with a capacity of 100 cmplaced 0,5; 1,0; 2,0; 3,0; 4,0; 5,0; 6,0; 7,0; 8,0 cm
standard solution aluminum. To all flasks add 5 cm
of the mixture of acids, the solution of copper with a volume according to its concentration in the analyzed sample solution, 2 cm
of a solution of potassium chloride and fluids topped up to the mark with water.
4.3.6. Measure the atomic absorption of aluminium calibration solutions immediately prior to and after the measurement of atomic absorption of aluminum in the analyzed sample solution. Upon receipt of the values of the nuclear absorption of the solutions after subtracting the atomic absorption reference experiment and their corresponding mass concentrations of aluminium build of the calibration graphs.
4.3.2−4.3.6. (Changed edition, Rev. N 2).
4.4. Processing of the results
4.4.1. Mass fraction of aluminium in percent is calculated by the formula
where is the concentration of aluminum in the analyzed solution samples, was found in the calibration schedule, g/cm
;
— the concentration of aluminium in solution in the reference experiment, was found in the calibration schedule, g/cm
;
— the volume of the analyzed solution, cm
;
— the weight of the portion of alloy,
4.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.3.
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 (the reproducibility) shall not exceed the values specified in table.3.
4.4.2,
4.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved under GOST 8.315, or by additives or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 3).
5. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM WITH ALUMININUM
5.1. The essence of the method
The method is based on measuring the optical density of the colored complex compound of aluminum with alumininum at pH=4,5−4,6 after separation of the aluminium from components of the alloy with sodium hydroxide solution.
5.2. Apparatus, reagents and solutions
Photoelectrocolorimeter or spectrophotometer.
Nitric acid according to GOST 4461, diluted 1:1.
Hydrochloric acid according to GOST 3118, diluted 1:1.
Acetic acid according to GOST 61.
Benzoic acid according to GOST 10521.
Ammonia water according to GOST 3760, diluted 1:1.
Sodium hydroxide according to GOST 4328, a solution of 300 g/DM.
Ammonium acetate according to GOST 3117.
Rectified ethyl alcohol according to GOST 18300.
Phenolphthalein, solution at 10 g/lin ethanol.
Gelatin.
Aluminum, a solution of 0.25 g/DM.
Preparation of the solution of aluminon:
Solution 1: 125 g ammonium acetate are dissolved in 250 cmof water, add 20 cm
of acetic acid and stirred to dissolve ammonium acetate.
Solution 2 consists of two solutions:
a) 0.25 g of aluminon dissolved in 15 cmof water;
b) 0.5 g of benzoic acid dissolved in 10 cmof ethanol.
Solution 3: solution 2 (a) is introduced into the solution 1, mix, add a solution of 2 (b) is diluted with water to 500 cm.
Solution 4: dissolve 2.5 g of gelatin in 100 cmof hot water, cool and dilute with water to 250 cm
.
Solution 5: mix the solutions 3 and 4, top up with water to 1000 cmand transferred into a dark bottle. The solution is used within hours after preparation. The shelf life of the solution one month.
Aluminum brand А999 according to GOST 11069.
Solution a: 0.1 g of aluminium is dissolved by heating in 20 cmof hydrochloric acid. The solution is transferred into a measuring flask with volume capacity of 1000 cm
, made up to the mark with water and mix.
1 cmof the solution contains 0.0001 g of aluminum.
Solution B: 10 cmsolution And placed in a volumetric flask with a capacity of 100 cm
, 20 cm dilute
hydrochloric acid, made up to the mark with water and mix.
1 cmof solution B has the 0.00001 g of aluminum.
5.3. Analysis
5.3.1. A portion of the alloy (see table.4) is placed in a beaker with a capacity of 250 cm, adding 10 cm
of nitric acid and dissolved by heating.
Table 4
| Mass fraction of aluminum, % |
The mass of charge, g |
Aliquota part of the solution, see |
| From 0.05 to 0.1 incl. |
0,5 |
10 |
| SV. 0,1 «0,3 « |
0,5 |
5 |
| «Of 0.3» to 0.6 « |
0,2 |
5 |
| «0,6» 1 « |
0,2 |
2 |
After dissolution of the alloy and removal of nitrogen oxides by boiling the solution was cooled, added to water, the solution transferred to a volumetric flask with a capacity of 200 cm, which previously was placed 30 cm
when weighed 0.5 g and 20 cm
when weighed 0.2 g of a hot solution of sodium hydroxide. A solution of the residue in the flask is stirred, heated to boiling, cooled, made up to the mark with water, stirred and allowed sediment to settle for 20−30 min. the Solution was filtered through a double dry filter into a dry flask, discarding first portion of filtrate. Aliquot part of the solution (see table.4) is placed in a volumetric flask with a capacity of 100 cm
, add 10 cm
of water, 2−3 drops of phenolphthalein and neutralize with hydrochloric acid until discoloration of the solution. Then the solution was again neutralized with ammonia solution until pink, add acetic acid dropwise until discoloration of the solution and give 2−3 drops excess. To the thus prepared solution was added to 15 cm
of aluminon and put in a warm place for 15 min, avoiding boiling point of the solution. The solution was then cooled, diluted to the mark with water, mix and measure the optical density of the solution in the cell length of 30 mm on a photoelectrocolorimeter with a green filter or on spectrophotometer at a wavelength of 525 nm using the solution in the reference experiment as the solution comparison.
5.3.2. Construction of calibration curve
In a volumetric flask with a capacity of 100 cmis placed 0; 0,5; 1,0; 2,0; 3,0 and 4,0 cm
of a solution of aluminum is added to 10 cm
of water, 2−3 drops of phenolphthalein and then do as specified in clause
Solution comparison is the solution not containing aluminum.
On the found values of optical densities of solutions and their corresponding grades of aluminium to build the calibration graph.
5.4. Processing of the results
5.4.1. Mass fraction of aluminium in percent is calculated by the formula
where is the mass of aluminum was found in the calibration schedule g;
— the weight of the portion corresponding to aliquote part of the solution,
5.4.2. The absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the permissible values given in table.3.
5.4.3. 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 (the reproducibility) shall not exceed the values specified in table.3.
5.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved under GOST 8.315, or by additives or by comparing the results obtained by another method in accordance with GOST 25086.
5.4.2−5.4.4. (Changed edition, Rev. N 3).
6. TITRIMETRIC CHELATOMETRIC METHOD FOR THE DETERMINATION OF ALUMINIUM (FROM 0.5 TO 3%)
6.1. The essence of the method
Method includes separation of aluminium from other elements by electrolysis at a mercury cathode or by separation of copper by electrolysis with platinum electrodes, the formation of the complex of aluminum with Trilon B, the titration of its excess of solution of nitrate of lead, the subsequent decomposition of the complex aluminium ammonium fluoride and titration Trilon B emitted in a quantity equivalent to the aluminum solution of nitrate of lead in the presence kylinalove orange.
(Added, Rev. N 2).
6.2. Apparatus, reagents and solutions
Installation for electrolysis with platinum electrodes according to GOST 6563.
Installation for electrolysis with a mercury cathode.
Nitric acid according to GOST 4461, diluted 1:1.
Hydrochloric acid according to GOST 3118, diluted 1:1.
A mix of acids for dissolving: mix the nitrogen (1:1) and hydrochloric (1:1) acid at a ratio of 1:1.
Chloric acid, diluted 1:1 and 1:4.
Ammonia water according to GOST 3760, diluted 1:1.
Sodium chloride according to GOST 4233.
Methenamine (hexamethylenetetramine).
Selenology orange.
Indicator mixture: selenology orange with sodium chloride in a ratio of 1:100.
Ammonium fluoride according to GOST 4518, solution 200 g/DM. The solution was stored in a plastic container.
Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B) according to GOST 10652, a solution of 0.05 mol/DM: 18,61 g Trilon B dissolved in water by heating, the solution was cooled, transferred to a volumetric flask with a capacity of 1 DM
, made up to the mark with water and mix.
Lead (II) nitrate according to GOST 4236, solution 0,05 mol/DM: 16,5615 g of lead nitrate dissolved in water, the solution transferred to a volumetric flask with a capacity of 1 DM
, made up to the mark with water and mix.
(Changed edition, Rev. N 2, 3).
6.3. Analysis
6.3.1. The method of separation of aluminium from interfering elements at a mercury cathode.
A portion of the alloy weight 2 g (for mass fraction of aluminium to 1%) or 1 g (in mass fraction of aluminium in excess of 1%) was placed in a beaker with a capacity of 250 cm, add 20 or 10 cm
of the mixture of acids to dissolve and dissolve when heated. After dissolution of the sample was added 12 or 6 cm
(according to hitch) perchloric acid (1:1) and then received, as indicated in paragraph
After completion of the electrolysis, the solution was filtered through a medium density filter, the filter washed with hot water, collecting the filtrate in a conical flask with a capacity of 500 cm.
The solution is diluted with water to a volume of 150 cm, neutralized with ammonia solution before the formation of stable precipitate, which is dissolved by adding nitric acid and added to an excess of two drops. Then add 30 cm
of the solution Trilon B, the solution is heated to boiling and boiled for 2 min; after cooling add a pinch of spatula of the mixture of indicator and hexamine in small portions until obtaining the yellow color of the solution and establishing a pH of 5.5−6 on universal indicator paper.
The solution is titrated with a solution of nitrate of lead to obtain a pink-purple color. After that, the solution was added 20 cmof a solution of ammonium fluoride, boil for 2 minutes, cooled, set to pH 5.5−6 by adding nitric acid or hexamine and again titrated solution of nitrate of lead to get a pink-violet color of the solution.
6.3.2. The method of separation of copper from aluminium by electrolysis with platinum electrodes.
A portion of the alloy weight 2 g (for mass fraction of aluminium to 1%) and 1 g (in mass fraction of aluminium in excess of 1%) was placed in a beaker with a capacity of 300 cmadd 30 cm or 15
nitric acid and dissolved by heating. After dissolution, the sample solution is boiled to remove oxides of nitrogen. In case of sedimentation metalbands acid solution is filtered through a dense filter with a small amount filtrowanie mass and the filter thoroughly washed with hot water. The solution is diluted with water to a volume of 150 cm
and produce copper by electrolysis according to GOST 1652.1. After electrolysis the solution was transferred to a conical flask with a capacity of 500 cm
, is neutralized with ammonia solution before the formation of stable precipitate, and then do as specified in clause
6.4. Processing of the results
6.4.1. Mass fraction of aluminium in percent is calculated by the formula
where is the volume of solution of nitrate of lead consumed in the second titration, cm
;
0,001340 is the mass of aluminium in grams, corresponding to 1 cmof solution of nitrate of lead;
— the weight of the portion of alloy,
6.3, 6.3.1, 6.3.2, 6.4,
6.4.2. Allowable absolute discrepancies in the results of parallel measurements ( — convergence) must not exceed the values given in table.3.
6.4.3. 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 (the reproducibility) shall not exceed the values specified in table.3.
6.4.2,
6.4.4. The control accuracy of the analysis carried out according to State standard samples (GSO) or industry standard sample (CCA), or by standard samples of the enterprise (SOP) copper-zinc alloys, approved under GOST 8.315, or by additives or by comparing the results obtained by another method in accordance with GOST 25086.
(Changed edition, Rev. N 3).
