GOST 25278.10-82. Alloys and ligatures of rare metals. Methods of determination of zirconium
Are you interested in
Definition of zirconium in alloys
- photometric:
- spectral (0.3 to 3%) - for alloys based on niobium and vanadium;
- complexometric:
Alloy alloying.
| The strained standards for Zr content |
Alloy base |
| 0.2 to 5% | niobium (aluminum content up to 20%, vanadium up to 0.5%, tungsten up to 25%, molybdenum up to 25%, carbon up to 0.2%) |
| 0.5 to 5% | vanadium (niobium content up to 40%, yttrium content up to 30%) |
| 1 to 5% | vanadium without niobium |
| 1 to 30% | niobium containing aluminum |
| 1 to 30% | vanadium containing niobium |
| 5 to 30% | niobium without aluminum |
| 80 to 90% | zirconium-aluminum binary alloys; |
Photometric method of niobium alloys
The method is based on the formation of a colored complex compound of zirconium with xylenol orange in a 0.2 mol/dm3 sulfuric acid solution. Hydrolysis of niobium (alloy base) is prevented by the introduction of hydrogen peroxide. Absorption of complexes of niobium, tungsten and molybdenum with xylenol orange is counted by measuring the total absorbance of complexes of Nb, W, Mo and Zr in relation to another equal aliquot of the sample to which added trilon B, masking only zirconium. Up to 2 mg aluminum, up to 7 mg yttrium, up to 10 mg molybdenum, up to 3 mg tungsten, and up to 50 µg vanadium in the photometric solution do not interfere with the determination.
Sequence of analysis
Suspension of the analyzed sample of niobium-based alloy weighing 0.1 g, depending on the carbon content is dissolved by heating in a heat-resistant beaker and fused in a muffle furnace at a temperature of 800 - 900 ° C. After complete decomposition of the sample, the smelt is cooled down, 10 cm3 of the solution is taken into a volumetric flask and the optical density of the solution is measured. The mass of zirconium is determined according to the graduation diagram. Evek GmbH offers to buy zirconium and its alloys at affordable producer prices. The supplier guarantees prompt delivery to any location specified by the customer.
Complementometry and spectrometry
The method is based on the formation of a colored zirconium complex compound with xylenol orange in a 0.2 mol/dm3 sulfuric acid solution. Up to 10 mg of yttrium and up to 5 mg of vanadium do not interfere with the determination if the zirconium content in the photometric volume is at least 25 µg. A sample weight is placed in a quartz crucible, 2 - 4 g of potassium pyrosulfate is added and fused in a muffle at 900 °C until a homogeneous fusion is obtained. The melt is dissolved by heating in 36 cm3 of sulfuric acid (1:5), the solution is cooled and transferred into a 200 cm3 volumetric flask, topped up to the mark with water. Aliquot of solution containing 25-35 mcg of Zr is taken into a 50 cm3 volumetric flask, diluted with 0.5 mol/dm3 sulfuric acid, 1 cm3 xylenol orange solution is added to 20 cm3 , water is added to the mark and mixed. After 20 minutes, the optical density of the solution is measured in a photoelectro-colorimeter at = 536 nm in a cuvette with the thickness of the light-absorbing layer 30 mm with respect to zero solution. The mass of zirconium is determined by the calibration table.
Spectral method
The method is based on the dependence of the intensity of spectral lines on the mass fraction of an element in the analyzed sample by excitation of a spectrum in a condensed spark discharge. A sample sample weight of 0.5 g shall be placed in a quartz crucible and calcined in the muffle until constant mass at 850 °C. The oxides are removed from the crucible or platinum cup as described in 5.2.2 and thoroughly crushed. Weigh 40 mg of the prepared sample on a torsion scale and mix it with Vaseline. The resulting mixture is applied with a spatula to three electrodes with a spherical depression at the end. The electrode with the sample is placed in the lower holder of the tripod. A carbon electrode sharpened into a convex hemisphere is placed in the upper holder. The wavelength scale index of the spectrograph is set so that the spectral region around 320 nm is in the middle of the spectrogram. The intermediate aperture on the condenser is selected so as to ensure normal blackening of the analytical lines. A spark is ignited between the electrodes.
IG-3 Generator
- The current strength in the transformer's primary circuit is 3 А.
- Voltage in the transformer's primary circuit is 220 V.
- Capacitance - 0,1 uF.
- The inductance is 0.15 mHg.
- Auxiliary gap - 2,5 mm.
- Analytical interval - 3.5 mm.
- Exposure - 15 sec.
Blackening of analytical zirconium line in each of the obtained spectrograms by photometry.
Buy, favorable price
Are you interested in
