GOST 1219.3-74
GOST 1219.3−74 calcium Babbits. Method for determination of aluminium (with Change No. 1)
GOST 1219.3−74
Group B59
INTERSTATE STANDARD
CALCIUM BABBITS
Method for determination of aluminium content
Lead-calcium bearing alloys.
Method for determination of aluminium content
ISS 77.160.20*
____________________
* In the index «National standards» 2006
ISS
Date of introduction 1975−01−01
The decision of the State standards Committee of the Council of Ministers of the USSR from January 17, 1974 N 150 date of introduction is established 01.01.75
Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)
REPLACE GOST 1219−60 in part of sec. IV
EDITION (September 2003) with amendment No. 1, approved in November 1979 (ICS 1−80).
This standard applies to calcium babbits and sets the volumetric method chelatometric determination of aluminium (with a mass fraction of aluminum from 0.05 to 0.25%) and photocolorimetric method (when the mass fraction of aluminum from 0.01 to 0.05%).
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 1219.0−74.
A. Volumetric method chelatometric determination of aluminium
The essence of the method
The method is based on the formation of complex compounds of aluminum and other impurities with Trilon B, the latter given in excess. With the help of buffer solution to create a pH of 5.5−6.0 and an excess Trilon titrated with a solution of zinc chloride in the presence of an indicator xrenovo orange. Then the aluminium is displaced from the complex compound of sodium fluoride and vacated the number of Trilon B, is equivalent to the aluminium content, is titrated with a solution of zinc chloride. Interfering components are removed by precipitation with ammonium sulfate.
(Changed edition, Rev. N 1).
2. REAGENTS AND SOLUTIONS
Nitric acid GOST 4461−77 diluted 1:4.
Hydrochloric acid by the GOST 3118−77, diluted 1:4.
Ammonia water according to GOST 3760−79 diluted 1:1.
Ammonium sulfate according to GOST 3769−78 by 12.8% solution.
Sodium fluoride according to GOST 4463−76, 4% saturated solution.
Trilon B (disodium salt of ethylenediaminetetraacetic acid) according to GOST 10652−73, 0.05 M solution.
Phenolphthalein on the other 6−09−5360−87, 1% solution (alcohol).
Indicator kylinalove orange; prepared as follows:
0.1 g of the indicator is triturated with 10 g of sodium chloride.
Ammonium acetate according to GOST 3117−78.
Acetic acid GOST 61−75.
Buffer solution; prepared as follows: 500 g ammonium acetate and dissolve in 1 DMof water and add 20 cm
of acetic acid.
Zinc GOST 3640−94 brand C0, 0.1 M solution is prepared as follows: to 6 538 g of zinc is dissolved in 50 cmof hydrochloric acid diluted 1:1, put the solution in a volumetric flask with a capacity of 1 DM
and bring to mark.
0.02 M solution of zinc; prepared as follows: accurately measured 200 cmof 0.1 M solution of zinc is placed in a volumetric flask with a capacity of 1 DM
and adjusted to the mark with water.
3. ANALYSIS
A portion of the babbit 5 g, taken with an accuracy of at least 0.001 g, was dissolved with heating in 30 cmof nitric acid, diluted 1:4. At the time of the dissolution beaker cover watch glass. After dissolution of the alloy added to the sample 40 cm
of warm water and with constant stirring 25 cm
of a solution of ammonium sulfate, measured with a graduated cylinder. Provide sediment to settle 10 min, and then filtered through a filter of medium density. Precipitate was washed in the beaker and on the filter 3 times with cold water and drop. The filtrate and the washings collected in a conical flask with a capacity of 750 cm
, add 20 cm
to 0.05 M solution of Trilon B, measured by a pipette, and boil for 2 minutes, Cool the solution to a temperature of 30−40 °C, add 2−3 drops of phenolphthalein and ammonia, diluted 1:1, before the appearance of pink color. Then added dropwise hydrochloric acid, diluted 1:4, until the disappearance of color and 20 cm
buffer solution. Heat the solution to boiling. To the hot solution poured 100 cm
of cold water and cool the sample to room temperature. Injected 0.05−0.1 g of the indicator xrenovo orange and octarepeat excess Trilon B with 0.02 M solution of zinc chloride until the color of solution from yellow to pink. To the solution add 30 cm
of a saturated solution of sodium fluoride and heated to boiling (the color again becomes yellow), boiled for 2−3 min, quickly cool the solution in running water to room temperature and freed of Trilon B titrated with 0.02 M solution of zinc chloride till the appearance of pink color.
(Changed edition, Rev. N 1).
4. PROCESSING OF THE RESULTS OF THE ANALYSIS
4.1. Mass fraction of aluminium () in percent is calculated by the formula
where a titer of 0.02 M solution of zinc, expressed in g/cm
of aluminum. Take the theoretical titer equal to 0,0005394 g/cm
of aluminum;
— the amount of 0.02 M solution of zinc consumed in the second titration, cm
;
— hanging Babbitt,
4.2. The allowable divergence between the extreme results of the analysis shall not exceed 0,001 abs. % when the mass fraction of aluminum from 0.05 to 0.1% and 0.01% when the mass fraction of aluminum from 0.1 to 0.25%.
B. Photocolorimetric method for the determination of aluminium
The essence of the method
The method is based on formation of colored in red-violet color complex compound of aluminum with indicator arsenazo 1 at a pH of 4.7 to 5.1. The influence of impurities is eliminated by adding ascorbic acid. The main components of the alloy are separated from the aluminium by precipitation by sodium sulfate.
5. APPARATUS, REAGENTS AND SOLUTIONS
Photoelectrocolorimeter FEK-M or other similar devices providing the same measurement accuracy.
Nitric acid GOST 4461−77 diluted 1:1.
Hydrochloric acid by the GOST 3118−77, diluted 1:1 and 1:10.
Sodium sulfate according to GOST 4166−76, 20% solution.
Sodium hydroxide according to GOST 4328−77, 10% solution.
Ascorbic acid, 5% solution.
Methenamine, 25% solution.
Methyl red, 0,001% solution.
Arsenazo, 1, 0.001 M solution: 0.6 g of the indicator, arsenazo 1 is dissolved in 1 DMdistilled water. If the solution turned turbid, it is filtered off.
Standard solutions of aluminium.
Solution a: 0.5 g of aluminium stamps A-999, A-995, A-97 and a-95 And GOST 11069−2001 placed in a beaker with a capacity of 250 cm, flow 20 cm
of hydrochloric acid diluted 1:1, and dissolve in low heat. The solution was cooled and transferred into a measuring flask with volume capacity of 1000 cm
, adjusted to the mark with water and mix.
1 cmof solution contains 0.5 mg of aluminum.
Solution B: 10 cmsolution And taken in a measuring flask with volume capacity of 1000 cm
, adjusted to the mark with water and mix.
1 cmof a solution contains 0.005 mg of aluminium.
6. ANALYSIS
6.1. A portion of the babbit weighing 1 g is placed in a beaker with a capacity of 250 cmand dissolved in 15 cm
of nitric acid (1:1) at low heating to complete decomposition of the alloy and removal of nitrogen oxides.
The solution was cooled, poured 30 cmof water and 20 cm
of a solution of sulphate of sodium. The contents of the beaker stirred with a glass rod, the precipitate is allowed to settle for 30−40 min. the Precipitate was filtered off on a tight filter «blue ribbon» with small amounts of paper pulp made from ash-free filter. The solution is collected in a volumetric flask with a capacity of 100 cm
. Precipitate was washed in the beaker and on the filter 3−4 times with cold water, bring the flask to the mark with water and mix thoroughly.
Aliquot part of the solution was 10 cmwhen the mass fraction of aluminum from 0.005% to 0.03% and 5 cm
for the mass concentration of aluminum in excess of 0.03% is transferred to a volumetric flask with a capacity of 50 cm
. To the solution add 2−3 drops of 0.001% solution of methyl red and neutralize dropwise 10% sodium hydroxide solution until yellow color. Then added dropwise to the solution diluted 1:10 hydrochloric acid until the pink color. In order to better establish the pH of the test solution neutralization operation is carried out again, watching the colour change of the indicator from one drop of alkali and acid. The solution was added 1−2 drops of 5% solution of ascorbic acid, poured with a pipette 6 cm
water of 0.001 M solution of arsenazo 1, 8−10 drops of a 25% strength solution of hexamine and stirred. Bring the contents of the flask to the mark with water and mix thoroughly. In 10−15 min the solution photometered in cuvettes with a length of 20 cm
with the orange filter in
=595 nm. Through all stages of the analysis carried out control experience with all reagents, solution control experience serves as a solution.
eniya.
6.2. Construction of calibration curve
In a volumetric flask with a capacity of 50 cmis administered consistently 0; 1,0; 2,0; 4,0; 6,0; 10,0 cm
standard solution B, which corresponds to 0; 0,005; 0,01; 0,02; 0,03; 0,05 mg of aluminium. The solution volume in all flasks was adjusted with water to 15 cm
and mixed. Further analysis is carried out as specified in clause 6.1.
According to the measurement of the optical density of solutions to build the calibration graph.
7. PROCESSING OF THE RESULTS
7.1. Mass fraction of aluminium () in percent is calculated by the formula
where is aluminum found on a calibration schedule, mg;
— the weight of the portion of the babbit, the corresponding aliquote part of the solution, g;
— a conversion factor of milligrams to grams.
7.2. Allowable absolute differences between the extreme results of the analysis should not exceed 0.001% at a mass fraction of aluminum from 0.01 to 0.02% and 0.002% when the mass fraction of aluminum of more than 0.02 to 0.05%.
Sec. B. (Added, Rev. N 1).
