GOST 22974.8-96

• gost-229748-96.pdf (276.13 KiB)
  ГОСТ 22974.8-96

GOST 22974.8−96 fused welding Fluxes. Methods for determination of zirconium oxide

GOST 22974.8−96

Group B09

INTERSTATE STANDARD

FUSED WELDING FLUXES

Methods for determination of zirconium oxide

Melted welding fluxes.
Methods of zirconium oxide determination

ISS 77.040
AXTU 0809

Date of implementation 2000−01−01

Preface

1 DEVELOPED by the Interstate technical Committee for standardization MTK 72; the Institute of electric them. E. O. Paton of NAS of Ukraine

SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification

2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)

The adoption voted:

3 Resolution of the State Committee of the Russian Federation for standardization and Metrology, dated April 21, 1999 N 134 inter-state standard GOST 22974.8−96 introduced directly as state standard of the Russian Federation from January 1, 2000

4 REPLACE GOST 22974.8−85

1 Scope

This standard sets the photometric method for the determination of zirconium oxide at a content of from 0.5 to 5%, and titrimetric chelatometric method for the determination of zirconium oxide at a content of from 3.0 to 25%.

2 Normative references

The present standard features references to the following standards:

GOST 3118−77 hydrochloric Acid. Specifications

GOST 3760−79 Ammonia water. Specifications

GOST 3773−72 Ammonium chloride. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4328−77 Sodium hydroxide. Specifications

GOST 4461−77 nitric Acid. Specifications

GOST 5456−79 of Hydroxylamine hydrochloride. Specifications

GOST 10652−73 Salt is the disodium Ethylenediamine-N, N, N', N'-tetraoxane acid 2-water (Trilon B)

GOST 18300−87 ethyl rectified technical. Specifications

GOST 22974.0−96 fused welding Fluxes. General requirements for methods of analysis

GOST 22974.1−96 fused welding Fluxes. Methods of flux decomposition

GOST 22974.4−96 fused welding Fluxes. Method for the determination of aluminium oxide

GOST 22974.9−96 fused welding Fluxes. Methods for determination of titanium oxide (IV)

3 General requirements

General requirements for methods of analysis GOST 22974.0.

4 Photometric method for the determination of zirconium oxide

4.1 the essence of the method

The method is based on the formation of complex compounds of zirconium, arsenazo III, painted in blue color. The optical density of colored solution is measured at a wavelength of 665 nm (red filter).

4.2 Equipment, reagents and solutions

Spectrophotometer or photoelectrocolorimeter.

Nitric acid according to GOST 4461.

Sulfuric acid according to GOST 4204, diluted 1:4, 1:10.

Hydrochloric acid according to GOST 3118, diluted 1:1, 1:5, with molar concentration of equivalent of 2 mol/DM.

Ammonia water according to GOST 3760.

Ammonium chloride according to GOST 3773, solution mass concentration of 0.2 g/CCand 0.03 g/cm.

Hydroxylamine hydrochloride according to GOST 5456, solution mass concentration of 0.2 g/cm.

The technical rectified ethyl alcohol according to GOST 18300.

Methyl red (indicator), an alcoholic solution of the mass concentration of 0.001 g/cm.

Arsenazo III, solution mass concentration of 0.001 g/cm: 0.1 g, arsenazo III dissolved in water, add 15 cmof hydrochloric acid (1:5), transferred to a volumetric flask with a capacity of 100 cmwater and bring to mark.

Standard solutions of zirconium oxide.

Solution a: 2,77 g of zirconium chloroxide 8-water is dissolved in water, add 70 cmof hydrochloric acid is poured in volumetric flask to 1000 cmwater, and stirred. Solution a has a mass concentration of oxides of zirconium 0.001 g/cm.

Check the mass concentration of a standard solution A: 25 cmsolution is placed in a beaker with a capacity of 250−300 cmand conduct the deposition of zirconium hydroxide with ammonia. Solution and the precipitate leave for 20−25 min, then the precipitate was filtered off on filter «white ribbon» and washed 4−5 times with ammonium chloride solution the mass concentration of 0.03 g/cm.

The filter with precipitate was placed in a calcined to constant weight porcelain or platinum crucible, dried, incinerated and calcined at a temperature of 1000−1050 °C to constant weight. Simultaneously conduct control experience for contamination of reagents. The mass concentration of the solution of zirconium oxide , g/cm, is calculated by the formula

, (1)

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

 — weight of crucible without the precipitate of zirconium oxide, 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;

 — the volume of solution A taken for analysis, cm.

Solution B: 10 cmsolution And transferred into a measuring flask with volume capacity of 1000 cm, adjusted to the mark with water and mix. Solution B has a mass concentration of zirconium oxide 0,00001 g/cm

.

4.3 analysis

After the decomposition flux according to GOST 22974.1 aliquot part of the solution is 20−50 cmwere placed in a glass with a capacity of 300−400 cm(if the sample decomposition was carried out by melting), add 3−5 cmof concentrated nitric acid and carefully pour 10 cmof concentrated sulfuric acid. The solution is evaporated to dense fumes of sulfuric acid. The glass solution was cooled, a well-washed walls of glass with water and the evaporation repeated. The solution was then cooled, poured 20 cmof hydrochloric acid (1:1), 10 cmof water and heated until complete dissolution of sulfate salts. The solution is poured 20 cmof a solution of ammonium chloride mass concentration of 0.2 g/cm, heated to 70−80 °C, add 2−3 drops of methyl red and the solution of ammonia until a color change of the indicator. For separation of the precipitate the solution is heated for 3−5 min without boiling. The precipitate was filtered off on filter «white ribbon», washed 2−4 times with hot water. The precipitate sesquioxides oxides washed from the filter with hot hydrochloric acid with molar concentration of equivalent of 2 mol/DMin the glass, which made the deposition. The solution is heated to complete dissolution of the precipitate, transferred to a volumetric flask with a capacity of 500 cmand was adjusted to the mark with hydrochloric acid 2 mol/DM.

Select aliquot part of the solution is 0.5−5.0 cm(depending on the mass fraction of zirconium oxide in the flux) in a volumetric flask with a capacity of 50 cm, add 10 cmof hydrochloric acid 2 mol/DM, 0.5 cmof a solution of hydroxylamine hydrochloride, heated to boiling. The solution in the flask is cooled, add from burette 1 cmof the solution, arsenazo III, adjusted to the mark with hydrochloric acid 2 mol/DM. The optical density measured on the spectrophotometer at a wavelength of 665 nm on a photoelectrocolorimeter with a red light filter. As a solution comparison solution is used in the reference experiment, carried out through all stages of the analysis. The mass of zirconium oxide in grams find the calibration

WMD graphics.

4.4 Construction of calibration curve

Nine volumetric flasks with a capacity of 50 cmis consistently making from microburette 0,3; 0,5; 0,7; 0,9; 1,1; 1,3; 1,5; 1,7 and 1.9 cmstandard solution B, which corresponds to 0,000003; 0,000005; 0,000007; 0,000009; 0,000011; 0,000013; 0,000015; 0,000017; 0,000019 g of zirconium dioxide, in the tenth bulb make a 2−3 cmof hydrochloric acid 2 mol/DM. Then pour 10 cmof hydrochloric acid 2 mol/DMand further analysis are on 4.3. Solution comparison is the solution without standard solution of zirconium oxide.

4.5 Processing of results

4.5.1 Mass fraction of zirconium oxide , %, is calculated by the formula

, (2)

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

 — the weight of the portion of the flux corresponding to aliquote part of the solution,

4.5.2 Standards of accuracy and standards for monitoring the accuracy of determining the mass fraction of zirconium oxide are given in table 1.


Table 1

Percentage

5 Titrimetric chelatometric method for the determination of zirconium oxide

5.1 the essence of the method

The method is based on titration of ions of zirconium (IV) with Trilon B in the presence of an indicator kylinalove orange at 80−90 °C. in a solution of 30 mg of aluminum, titanium, up to 10 mg of iron determination of zirconium does not interfere.

5.2 Reagents and solutions

Nitric acid according to GOST 4461.

Sulfuric acid according to GOST 4204, diluted 1:1.

Hydrochloric acid according to GOST 3118, diluted 1:1.

Ammonia water according to GOST 3760.

Sodium hydroxide according to GOST 4328, solutions of the mass concentration of 0.2 g/cmand 0.01 g/cm.

Hydroxylamine hydrochloride according to GOST 5456, solution mass concentration of 0.1 g/cm.

Selenology orange (indicator), the solution of the mass concentration of 0.002 g/cm.

Salt is the disodium Ethylenediamine-N, N, N', N' -tetraoxane acid 2-water (Trilon B) according to GOST 10652, a solution with a concentration equivalent to 0.05 mol/DM: 9,30 g Trilon B dissolved in 300 cmof water, transferred into a measuring flask with volume capacity of 1000 cmand dilute to the mark with water.

A standard solution of zirconium oxide prepared according to 4.2.

A standard solution of aluminum oxide prepared according to GOST 22974.4.

A standard solution of titanium oxide (IV) is prepared according to GOST 22974.9.

Mass concentration of Trilon B, expressed in g/cmzirconium oxide, establish a standard solution of zirconium oxide: three conical flasks with a capacity of 250−300 cmtaken at 10 cmstandard solution And zirconium oxide and aliquote part of standard solutions of aluminium oxide and titanium oxide (IV) based on their mass fraction in the sample. The solution was diluted to 100−110 cmand precipitated Zirconia with a solution of sodium hydroxide mass concentration of 0.2 g/cmprior to the deposition of zirconium hydroxide, giving an excess of sodium hydroxide of 15 cm. Solution and the precipitate was heated to boiling and boiled for 3−5 min.

The precipitate of zirconium hydroxide is filtered off on the filter «white ribbon», washed 3−4 times with hot sodium hydroxide solution the mass concentration of 0.01 g/cmand 3−4 times with hot water. Hydroxide precipitate from the filter washed in the same flask, where he made the deposition, the filter is washed with 50 cmof hot hydrochloric acid (1:1) (total volume of water and acid 70−80 cm). The solution in the flask is heated to boiling, pour 5 cmof a solution of hydrochloric acid hydroxylamine, in the boiling solution while stirring gently poured 20 cmof sodium hydroxide solution mass concentration of 0.2 g/cm, six drops of orange kylinalove and titrated with a solution of Trilon B to switch the color of the solution from yellow to crimson.

Mass concentration of Trilon B , g/cmzirconium oxide calculated by the formula

, (3)

where  — the weight of the portion corresponding to aliquote part of the solution, g;

 — volume of solution Trilon B, spent on titration, sm.

5.3 analysis

After the decomposition flux according to GOST 22974.1 50 cmof the solution was placed in a beaker with a capacity of 300−400 cm(if the sample decomposition was carried out by melting), pour 5 cmof nitric acid, carefully pour 10 cmof concentrated sulfuric acid and evaporate until dense fumes of sulphuric acid. The glass is cooled, wash the side of the Cup with water and the evaporation repeated. A glass of cool, add water up to 100 cmand precipitated hydroxides with a solution of sodium hydroxide mass concentration of 0.2 g/cmprior to the deposition of zirconium hydroxide, giving an excess of sodium hydroxide of 15 cm. Solution and the precipitate was heated to boiling and boiled for 3−5 min.

The precipitate of hydroxides is filtered at the filter «white ribbon», washed 3−4 times with hot sodium hydroxide solution the mass concentration of 0.01 g/cmand 3−4 times with hot water. The precipitate from the filter washed into the glass, which made the deposition, the filter is washed with 50 cmof hot hydrochloric acid (1:1) and several times with water.

The solution is heated until the precipitate has fully dissolved, bring to the boil, pour 5 cmof a solution of hydrochloric acid hydroxylamine, and then add (in portions) 20 cmof sodium hydroxide solution mass concentration of 0.2 g/cm, poured six drops of orange kylinalove and titrated with a solution of Trilon B to switch the color of the solution from raspberry well

eltoy.

5.4 processing of the results

5.4.1 Mass fraction of zirconium oxide , %, is calculated by the formula

, (4)

where  — the volume of Trilon B, used for titration, cm;

 — mass concentration of the solution Trilon B, expressed in g/cmof zirconium oxide;

 — the weight of the portion of the flux corresponding to aliquote part of the solution,

5.4.2 Norms of accuracy and norms control the accuracy of determining the mass fraction of zirconium oxide are given in table 1.