GOST 22536.14-88

• gost-2253614-88.pdf (310.35 KiB)
  ГОСТ 22536.14-88

GOST 22536.14−88 carbon Steel and unalloyed cast iron. Method for the determination of zirconium

GOST 22536.14−88

Group B09

STATE STANDARD OF THE USSR

CARBON STEEL AND UNALLOYED CAST IRON

Method for the determination of zirconium

Сaгbon steel and unalloyed cast iron.
Methods for determination of zirconium

AXTU 0809

Valid from 01.01.90
to 01.07.95*
______________________________
* Expiration removed
Protocol N 4−93 inter-state Council
for standardization, Metrology and certification.
(IUS N 4, 1994). — Note the CODE.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR

PERFORMERS

D. K. Nesterov, PhD. tech. Sciences; S. I. Rudyuk, PhD. tech. Sciences; S. V. Spirina, PhD. chem. Sciences (head of subject); V. F. Kovalenko, PhD. tech. science; N. N. Gritsenko, PhD. chem. Sciences; V. P. Danilenko; L. I. birch

2. APPROVED AND put INTO EFFECT by decision of the USSR State Committee for standards from 25.08.88 N 3019

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

This standard sets the photometric method for the determination of zirconium (at a mass fraction of zirconium from 0.005 to 0.10%).

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 22536.0−87.

1.2. The error of the result of the analysis (under confidence probability =0,95) does not exceed the limit given in table. 1, when the conditions are met:

the discrepancy between the results of two (three) parallel dimensions should not exceed (with a confidence probability =0,95) of the values () given in table. 1;

played in the standard sample, the value of the mass fraction of zirconium should not differ from the certified more than acceptable (at a confidence level =0,85) the value given in table.1.

If any of the above conditions, a second measurement of the mass fraction of Zirconia. If in repeated measurements the precision requirement of the results are not met, the results of the analysis recognize the incorrect measurements cease to identify and establish the causes of the violation of the normal course of analysis.

The divergence of the two middle results of an analysis performed under different conditions (for example, when the control intralaboratory reproducibility) shall not exceed (at p = 0.95) values are given in table. 1.

Table 1

2. THE PHOTOMETRIC METHOD FOR THE DETERMINATION OF ZIRCONIUM, ARSENAZO III

2.1. The essence of the method

The method is based on formation of colored complex compounds of zirconium (IV) with arsenazo III and measurement of optical density at a wavelength of 665 nm.

When the mass fraction of zirconium of 0.005−0.05% determination carried out in the environment of nitric acid in the presence of perchloric acid, at a mass fraction of zirconium of 0.05−0.10% in the environment of hydrochloric acid. The interfering influence of iron in the first case can be eliminated by restoring it with a solution azotistykh sodium and urea in the second — ascorbic acid solution.

2.2. Equipment and reagents

Spectrophotometer or photoelectrocolorimeter.

Hydrochloric acid by the GOST 3118−77, diluted 1:1, 1:20 and solution with molar concentration of equivalent to 6 mol/DM.

Nitric acid GOST 4461−77.

A mixture of hydrochloric and nitric acids in the ratio 3:1, prepare before use.

Sulfuric acid GOST 4204−77, diluted 1:1.

Acid chloride, of qualification «Kh. CH.».

Hydrofluoric acid according to GOST 10484−78, with a density of 1.50 g/cm.

Potassium preservatory according to GOST 7172−76.

Sodium carbonate according to GOST 83−79.

Sodium tetraborate 10-water according to GOST 4199−76.

Sodium atomistically according to GOST 4197−74, a solution with a mass concentration of 10 g/DM.

Urea according to GOST 6691−77, a solution with a mass concentration of 100 g/DM.

Ascorbic acid, a solution with a mass concentration of 50 g/l, 5 g of ascorbic acid dissolved in 100 cmof a hydrochloric acid solution with molar concentration of equivalent of 2 mol/DM.

Zirconium (IV) chloroxide 8-water.

Radio engineering carbonyl iron according to GOST 13610−79.

Salt is the disodium Ethylenediamine-, , , -tetraoxane acid (Trilon B) according to GOST 10652−73, solution with molar concentration of the equivalent 0,1 mol/DM.

Sodium hydroxide according to GOST 4328−77, a solution with a mass concentration of 10 g/DM.

Ammonium chloride according to GOST 3773−72, a solution with a mass concentration of 20 g/DM.

Ammonia water according to GOST 3760−79.

Arsenazo III, the solution with a mass concentration of 1 g/DM:

when the mass fraction of zirconium of 0.05−0.10%;

a portion of arsenazo III equal to 0.1 g, placed in a volumetric flask with a capacity of 100 cm, dissolved in 40−50 cmof warm water, add 15 cmof a hydrochloric acid solution with molar concentration of equivalent of 2 mol/DM. The solution was then cooled, diluted to the mark with water and allowed to stand 48 hours, stirring occasionally. The solution was then filtered through a layer of compacted cotton, discarding first portion of filtrate. The solution is usable for 5−7 days;

when the mass fraction of zirconium 0,005−0,05%;

a portion of arsenazo III equal to 0.1 g, placed in a volumetric flask with a capacity of 100 cm, is dissolved in 50 cmof water, add sodium hydroxide solution until blue color of the solution and an excess of 5 drops. The solution is mixed well until complete dissolution, arsenazo III, then the solution is poured dropwise a solution of hydrochloric acid diluted 1:1 until the color of the solution from blue to red-purple, diluted to the mark with water and mix well. The solution is usable for 10−12 days.

Standard solution zirconium

Solution a: 3,533 g chloroxide Zirconia is placed in a beaker with a capacity of 300 cmand dissolved in 150−200 cmof a hydrochloric acid solution with molar concentration of equivalent to 6 mol/DM, the solution is transferred to a volumetric flask with a capacity of 1 DM, made up to the mark with hydrochloric acid of the same concentration, and stirred.

1 cmof the solution contains 0.001 g of zirconium.

Solution B: 10 cmstandard solution zirconium And transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with the hydrochloric acid solution with molar concentration of equivalent of 2 mol/land stirred. The solution is prepared before use.

1 cmof a solution contains 0.0001 g of zirconium.

Solution: 10 cmstandard solution zirconium B is transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with the hydrochloric acid solution with molar concentration of equivalent of 2 mol/land stirred. The solution is prepared before use.

1 cmof the solution contains 0,00001 g of zirconium.

The mass concentration of a standard solution of Zirconia And set in the following way: 50 cmsolution is placed in a beaker with a capacity of 250−300 cm, add 100 cmof water, 3 g of ammonium chloride and ammonia until the precipitation of zirconium hydroxide and an excess of 3−5 cm. The resulting solution was heated to boiling, allowed to settle for 20−25 min, then the precipitate was filtered off on filter «white ribbon» and washed 7−8 times with hot solution of ammonium chloride with a mass concentration of 20 g/DM. The filter with precipitate was placed in a weighed platinum crucible, dried, incinerated, and calcined at a temperature of 1000−1050 °C for 2 h to constant weight, cooled and weighed. Simultaneously conduct control experience for contamination of reagents.

Mass concentration (), expressed in grams of zirconium per 1 cmof a solution is calculated by the formula

,

where is the mass of the crucible with the precipitate of zirconium dioxide, g;

 — weight of crucible without the precipitate of zirconium dioxide, g;

 — the mass of the crucible with the sediment in a control experiment, g;

 — weight of crucible without the sediment in a control experiment, g;

0,7403-the ratio of zirconium dioxide to zirconium;

 — the volume of a solution of zirconium chloroxide taken for analysis, cm.

2.3. The analysis for the mass concentration of zirconium and 0.05−0.1%

2.3.1. A portion of the sample weighing 1.0 g was placed in a beaker with a capacity of 300 cmand dissolved in 30−50 cmof hydrochloric acid (density 1,19 g/cm) under low heat. After complete dissolution of the sample poured nitric acid until the termination of foaming solution and in excess of 2−3 cm, the solution was heated and evaporated to dryness. Pour 10 cmof hydrochloric acid and again evaporated to dryness. Operation of evaporation with 10 cmof hydrochloric acid again.

The dry residue is dissolved in 20 cmof hydrochloric acid (density 1,19 g/cm) when heated. Then pour 20−30 cmof hot water and filtered off the precipitate of silicic acid to the filter medium density, containing a little filter-paper pulp, into a measuring flask with a capacity of 200 cm. The filter and the glass washed 4−5 times with hot water. The filtrate is saved. The filter with precipitate was placed in a platinum crucible, incinerated and calcined at a temperature of 600−700 °C. the Residue in the crucible is slightly moisten with water, add 3−4 drops of sulfuric acid (1:1), 2−3 cmhydrofluoric acid and evaporated to dryness. The residue is calcined at a temperature of 600−700 °C and fused with 1 g of potassium peacemaking. The smelt is leached in 10−20 cmof a hydrochloric acid solution with molar concentration of equivalent of 2 mol/DMand added to the main solution. To the obtained solution poured 20 cmof hydrochloric acid (density 1,19 g/cm), adjusted to the mark with water, mix. Filter part of the solution through a dry filter medium density in a dry conical flask, discarding first portion of filtrate.

Aliquot part of the solution 10 cmis placed in a conical flask with a capacity of 100 cm, flow 10 cmof hydrochloric acid with molar concentration of equivalent of 2 mol/l, heated to boiling and boiled for 1 min. the Solution was cooled, poured 5cmof ascorbic acid solution and allowed to stand until reduction of iron (III). The solution was then transferred to a volumetric flask with a capacity of 100 cm, pour 5 cmof arsenazo III, adjusted to the mark with the hydrochloric acid solution with molar concentration of equivalent of 2 mol/land stirred.

The optical density of the solutions measured after 20−25 minutes on the spectrophotometer at a wavelength of 665 nm or photoelectrocolorimeter with a filter having a region of transmittance in the wavelength range of 655−675 nanometers.

As a solution comparison, using aliquot part of the solution of the sample, in which before adding a solution of arsenazo III add 5 cmof the solution Trilon B to bind zirconium.

Simultaneously conduct control experience through all stages of the analysis. From the values of optical density of analyzed solutions is subtracted the value of the optical density of the solution in the reference experiment.

The analysis results calculated by a calibration chart or by comparison with a standard sample similar in composition to the sample and carried through in

the CE stage of analysis.

2.3.2. Construction of calibration curve

Six glasses with a capacity of 300 cmwas placed 1.0 g of carbonyl iron and in five of them poured successively 4, 6, 8, 10 and 12 cmstandard solution of zirconium chloroxide B, which corresponds to 0.0004 inch; about 0.0006; 0.0008 inch; and 0,0012 0,0010 g of zirconium. The sixth glass is used for the reference experiment.

Liquid poured in the glasses at the 30−50 cmof hydrochloric acid and further analysis was carried out as given in claim 2.3.1.

The found values of optical density and corresponding values of the mass of the Zirconia build the calibration graph. Allowed construction of calibration curve in the coordinates: the optical density — mass fraction of zirconium.

2.4. The analysis for the mass concentration of the zirconium 0,005−0,05%

2.4.1. A portion of the sample depending on mass fraction of zirconium (table. 2) is placed in a beaker with a capacity of 250 cmand dissolved under moderate heating in 30−40 cmof hydrochloric acid. After dissolution of the sample poured nitric acid until the termination of foaming solution and in excess of 2−3 cm.

Table 2

Further analysis is carried out as specified in clause 2.3.1, filtering the solution into a glass with a capacity of 300 cm, before the operation of fusing the precipitate. The filtrate is saved.

The precipitate in a platinum crucible alloy with 0.5−1.0 g of a mixture of sodium carbonate and tetraborate sodium (3:1) at a temperature of 800−1000 °C for 10−15 minutes.

The filtrate is evaporated to a small volume (20−30 cm), pour 5−10 cmof nitric acid, boil until the destruction of organic substances, poured 20 cmof perchloric acid and evaporate to copious fumes of perchloric acid. All operations are carried out, covered with a glass watch glass. Salt dissolved in 25−30 cmwater when heated.

The cooled crucible with the melt is placed in a beaker with a capacity of 250 cm, flow 50 cmof water and heated until complete dissolution of the melt. The crucible is removed from the beaker and rinsed with water. A solution of videochannel afloat gently poured to the main filtrate with stirring.

The combined solution is evaporated to 30−40 cm, 25 cm pour thesolution azotistykh sodium, heated to boiling and boiled for 5 minutes. The contents of the Cup is cooled, transferred to a volumetric flask with a capacity of 100 cm, made up to the mark with water, mix. Filter part of the solution through a dry filter medium density in a dry conical flask, discarding first portion of filtrate.

Aliquot part of the solution 10 cmis placed in a volumetric flask with a capacity of 50 cm, flow 25 cmof nitric acid, 2.5 cmof a solution of urea, 5 cmsolution, arsenazo III, after the addition of each reagent solutions are mixed and cooled. Then the solutions were diluted to the mark with water and mix thoroughly.

The optical density of the solutions measured after 20−25 minutes on the spectrophotometer at a wavelength of 665 nm or photoelectrocolorimeter with a filter having a region of transmittance in the wavelength range of 655−675 nanometers.

Simultaneously conduct control experience through all stages of the analysis. A solution of comparison when measuring optical density of the analyzed solutions using solution control experience.

The analysis results calculated by a calibration chart or by comparison with a standard sample similar in composition to the sample and carried through all the stages

analysis.

2.4.2. Construction of calibration curve

In eight glasses with a capacity of 250 cmis placed a portion of carbonyl iron, corresponding to the portion of the sample. Seven of cups successively poured on 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 and 25,0 cmstandard solution of chloroxide of zirconium, which corresponds to 0,000050; 0,000075; 0,000100; 0,000125; 0,000150; 0,000200 and 0,000250 g of zirconium. The eighth glass is used for the reference experiment.

All the glasses are poured 30−50 cmof hydrochloric acid and further analysis is carried out as specified in clause 2.4.1.

The found values of optical density and corresponding values of the mass of the Zirconia build the calibration graph. Allowed construction of calibration curve in the coordinates: the optical density — mass fraction of zirconium.

2.5. Processing of the results

2.5.1. Mass fraction of zirconium () in percent is calculated by the formula:

,

where is the mass of zirconium in the sample was found in the calibration schedule g;

 — the weight of the portion,

2.5.2. Norms of accuracy and norms of accuracy control of determination of zirconium are given in table. 1.