GOST 22974.10-96

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  ГОСТ 22974.10-96

GOST 22974.10−96 fused welding Fluxes. Methods for determination of sodium oxide and potassium oxide

GOST 22974.10−96

Group B09

INTERSTATE STANDARD

FUSED WELDING FLUXES

Methods for determination of sodium oxide and potassium oxide

Melted welding fluxes. Methods of sodium and potassium oxides 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 22974.10−96 introduced directly as state standard of the Russian Federation from January 1, 2000

4 REPLACE GOST 22974.10−85

1 Scope

This standard specifies the flame photometric and atomic absorption methods for the determination of sodium oxide and potassium oxide at a content of 0.2 to 5%.

2 Normative references

The present standard features references to the following standards:

GOST 3118−77 hydrochloric Acid. Specifications

GOST 4204−77 sulfuric Acid. Specifications

GOST 4233−77 Sodium chloride. Specifications

GOST 4234−77 Potassium chloride. Specifications

GOST 5457−75 Acetylene, dissolved and gaseous. Specifications

GOST 10484−78 hydrofluoric Acid. Specifications

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

3 General requirements

General requirements for methods of analysis GOST 22974.0.

4 Flame photometric and atomic absorption methods for the determination of sodium oxide and potassium oxide

4.1 the Essence of the methods

4.1.1 Flame photometric method based on the introduction of the analyzed solution in aerosol form by spraying into a flame running on butane-propane. Arisen flame radiation of the analyzed element is separated by a filter or monochromator radiation from other elements and falling on the photocell, causes a photocurrent is measured by a galvanometer. Under certain conditions, the readings on the galvanometer proportional to the concentration of the element in solution.

4.1.2 Atomic absorption method is based on measuring the degree of absorption of resonance radiation by free atoms of sodium and potassium formed as a result of spraying the test solution into the flame acetylene-air.

4.2 Equipment, reagents and solutions

4.2.1 When flame photometric method

Flaming photometer.

The LPG cylinder.

4.2.2 the atomic-absorption method

Atomic absorption spectrophotometer with flame atomizer.

Lamp with hollow cathode for the determination of sodium and potassium.

Acetylene, dissolved and gaseous technical GOST 5457.

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

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

Hydrofluoric acid according to GOST 10484.

Potassium chloride according to GOST 4234, standard solution: 0,7915 g of potassium chloride, previously dried at a temperature of (100±5) °C to constant mass, dissolved in a volumetric flask with a capacity of 500 cm, was adjusted to the mark with water and mix. A standard solution has a mass concentration of potassium oxide 0.001 g/cm.

Sodium chloride according to GOST 4233, standard solution: 0,943 g of sodium chloride, dried at a temperature of (110±5) °C to constant mass, dissolved in a volumetric flask with a capacity of 500 cm, was adjusted to the mark with water and mix. A standard solution has a mass concentration of sodium oxide 0.001 g/cm.

4.3 Preparation for analysis

Before operation, the devices are configured on a resonant line: for sodium — 587,60 nm; potassium — 766,50 nm.

4.4 analysis

The linkage of flux with a mass of 0.1 g is placed in a dish of platinum or glassy carbon, moistened with 0.5−1.0 cmof water is added 5 cmhydrofluoric acid and 10−20 drops of sulfuric acid (1:1). Dried, heated until complete removal of sulphuric acid fumes. To the dry residue add 5 cmof hydrochloric acid (1:1) and 10 cmof water. The solution is heated until complete dissolution of sulfate salts.

The contents of the Cup is transferred to a volumetric flask with a capacity of 100 cmand adjusted to the mark with water.

The solutions were sprayed on the flame photometer or atomic absorption spectrophotometer to obtain constant readings for each solution. Before the suction of the measuring solution is sprayed with water for rinsing the system and zero the instrument.

According to the calibration schedule find the mass of potassium oxide and sodium oxide in the test solution, in grams.

4.5 Construction of calibration curve

Nine volumetric flasks with a capacity of 100 cmconsistently make 0,1; 0,2; 0,5; 1,0; 2,0; 3,0; 4,0; 5,0; 6,0 cmstandard solutions, which corresponds to 0,0001; 0,0002; 0,0005; 0,001; 0,002; 0,003; 0,004; 0,005; 0,006 g of sodium oxide and potassium oxide. Pour 5 cmof hydrochloric acid (1:1), adjusted to the mark with water and mix.

The solutions were sprayed on the flame photometer or atomic absorption spectrophotometer in order of increasing mass fraction. Before spraying each solution is sprayed water.

4.6 processing of the results

4.6.1 Mass fraction of sodium oxide and potassium oxide , %, is calculated by the formula

, (1)

where is the mass of sodium oxide or potassium oxide, was found in the calibration schedule g;

 — the weight of the portion of the flux,

4.6.2 Standards of accuracy and standards for monitoring the accuracy of determining the mass fraction of sodium oxide and potassium oxide are shown in table 1.


Table 1

Percentage