GB/T 15076.6-2020Methods for chemical analysis of tantalum and niobium—Part 6:Determination of silicon content—Inductively coupled plasma atomic emission spectrometry (English PDF)

Foreword

GB/T 15076 "Methods for Chemical Analysis of Tantalum and Niobium" is divided into 16 parts.

---Part 1: Determination of tantalum content in niobium by inductively coupled plasma atomic emission spectrometry;

---Part 2: Determination of the amount of niobium in tantalum inductively coupled plasma atomic emission spectrometry and chromatography gravimetric method;

---Part 3: Determination of copper content by flame atomic absorption spectrometry;

---Part 4: Determination of iron content 1,10-phenanthroline spectrophotometry;

---Part 5: Determination of the amount of molybdenum and tungsten by inductively coupled plasma atomic emission spectrometry;

---Part 6: Determination of silicon content by inductively coupled plasma atomic emission spectrometry;

---Part 7: Determination of phosphorus content in niobium 4-methyl-pentanone-[2] extraction separation phosphomolybdenum blue spectrophotometry and inductively coupled plasma Bulk atomic emission spectroscopy;

---Part 8: Determination of carbon and sulfur content by high-frequency combustion infrared absorption method;

---Part 9: Determination of the amount of iron, chromium, nickel, manganese, titanium, aluminum, copper, tin, lead and zirconium in tantalum by DC arc atomic emission spectrometry;

---Part 10: Determination of the content of iron, nickel, chromium, titanium, zirconium, aluminum and manganese in niobium by DC arc atomic emission spectrometry;

---Part 11: Determination of arsenic, antimony, lead, tin and bismuth in niobium by DC arc atomic emission spectrometry;

---Part 12: Determination of Phosphorus in Tantalum by Ethyl Acetate Extraction and Separation of Phosphomolybdenum Blue Spectrophotometry;

---Part 13: Determination of nitrogen content inert gas fusion thermal conductivity method;

---Part 14: Determination of oxygen content inert gas melting infrared absorption method;

---Part 15: Determination of hydrogen content inert gas fusion thermal conductivity method;

---Part 16: Determination of sodium and potassium content by flame atomic absorption spectrometry.

This part is Part 6 of GB/T 15076.

This section was drafted in accordance with the rules given in GB/T 1.1-2009.

This part replaces GB/T 15076.6-1994 "Methods for chemical analysis of tantalum and niobium-Determination of silicon content in tantalum". This part is consistent with GB/T 15076.6- Compared with.1994, the main technical changes except for editorial changes are as follows.

---The measurement method was changed from "spectrophotometry" to "inductively coupled plasma atomic emission spectrometry";

---Expanded the measurement range, the measurement range was changed from "0.0005%~0.070%" to "0.0005%~0.50%" (see Chapter 1, Chapter 1 and Chapter 9 of the 1994 edition);

---The reference standard is deleted (see Chapter 2 of the 1994 edition);

---Add sample clause (see Chapter 5);

--- Added precision clause (see Chapter 8);

---Added the test report clause (see Chapter 9).

1 Scope

This part of GB/T 15076 specifies the determination of silicon content in tantalum and niobium by inductively coupled plasma atomic emission spectrometry.

This section applies to the determination of silicon content in tantalum, niobium and their hydroxides, oxides, carbides and potassium fluorotantalate. Measuring range. 0.0005%~0.50%.

2 Principle

The sample is dissolved in nitric acid and hydrofluoric acid, in a dilute acid medium, using argon plasma as the ionization source, and direct inductively coupled plasma Atomic emission spectrometry.

3 Reagents or materials

Unless otherwise stated, only reagents confirmed to be MOS grade and laboratory grade 2 water are used in the analysis.

3.1 Nitric acid (rho=1.42g/mL).

3.2 Hydrofluoric acid (rho=1.14g/mL).

3.3 Metal tantalum (wTa>=99.99%, wSi<=0.0001%).

3.4 Niobium metal (wNb>=99.99%, wSi<=0.0001%).

3.5 Silicon standard storage solution. Weigh 2.1394g silica (wSiO2>=99.99%) into a platinum crucible, add 10g sodium carbonate-potassium carbonate Mix the flux, mix well, melt on the blowtorch until it is clear, then burn for 10 minutes. After cooling, immerse with hot water, heat until the solution is clear, and move after cooling Put it into a 1000mL volumetric flask, dilute to the mark with water, and mix well. 1mL of this solution contains 1mg of silicon. Store in a polyethylene bottle.

3.6 Silicon standard solution. Pipette 10.00mL silicon standard stock solution (3.5) in a 100mL volumetric flask, dilute to the mark with water, and mix. 1mL of this solution contains 100µg of silicon. Store in a polyethylene bottle.

3.7 Argon (volume fraction not less than 99.99%).

4 Equipment

4.1 Inductively coupled plasma atomic emission spectrometer, equipped with hydrofluoric acid resistant sampling system, resolution < 0.006nm (200nm).

4.2 The recommended silicon analysis line is 251.612nm.

5 Samples

5.1 The particle size of tantalum powder is less than 700µm; the particle size of niobium powder is less than 180µm; the particle size of tantalum-niobium carbide is less than 150µm.

5.2 Tantalum powder should be dried in vacuum at 80°C~150°C for 4h in advance, cooled to room temperature, and vacuum packaged in a composite aluminum foil bag; Substances, oxides and potassium fluorotantalate should be pre-baked at 105°C~110°C for 2h, and placed in a desiccator to cool to room temperature for later use.

5.3 From the top 10cm of the niobium ingot to any part of the middle, use a planer to remove the skin and sample the shavings. The size of the shavings should be uniform, and And the particles should be as small as possible.

6 Test procedure

7 Test data processing

The silicon content is calculated as the mass fraction of silicon wSi, calculated according to formula (1).

When wSi< 0.010%, the result obtained is kept to four decimal places; when wSi>=0.010%, the result obtained keeps three significant digits.

8 Precision

9 Test report

The test report should include the following.

---Test object;

---This part number;

---result;

--- Anomalies observed;

---Test date.