SH/T 0339-1992 NaY Method for determination of molecular sieve unit cell parameters

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: SH/T 0339-92
• Chinese name: NaY Method for determination of molecular sieve unit cell parameters
• English name: not provided in the available source
• Replacement relationship: replaces ZBE 49001-88
• Year confirmation: the source marks "(confirmed in zap)", specific year requires confirmation against the source standard (source-text extraction)
• Reference adoption: ASTM D3942-91 "Method for determination of faujasite-type molecular sieve unit cell size"

2. Scope of application and non-applicability

• Scope of application: This standard applies to NaY molecular sieves.
• Non-applicability: not provided in the available source.

3. Method principle

Mix the molecular sieve sample to be tested with silicon powder (internal standard substance), collect the X-ray diffraction pattern of the mixed sample, use the silicon powder as the internal standard to correct the positions of the molecular sieve diffraction peaks, and calculate the unit cell parameters of the molecular sieve.

4. Reagents and materials (purity / preparation)

• Silicon powder: Shanghai Institute of Testing Technology X-ray diffraction silicon powder standard sample (standard number: XSI-FBY).
• Other reagents: not provided in the available source.

5. Instruments and equipment

• 5.1.1 X-ray diffractometer: CuKα radiation, slit: DS1°, RS 0.3mm, SS1° (the source text is "DSl0, RS0.3mm, SSI0o", requires confirmation against the source standard (source-text extraction)).
• 5.1.2 Constant-temperature drying oven: controlled at 110℃±5℃.
• 5.1.3 Constant-humidity chamber: laboratory glass desiccator, containing saturated calcium chloride solution, temperature 18~28℃ (the source text is "18.28`Ca", requires confirmation against the source standard (source-text extraction)).

6. Recommended operating conditions

• Diffraction pattern 2θ range: approximately 5°~60° (the diffraction-angle range is unclear in the source transcription and remains unverified), such that the background of the two molecular sieve peaks can be drawn.
• Scanning speed: 0.25°/min (the source text is ".250/min", requires confirmation against the source standard (source-text extraction)).
• Paper speed: 20mm/min.

7. Sampling and sample preparation

• 4.1 Weigh approximately 1g of the sample to be tested and 0.05g of silicon powder, grind and mix uniformly, place in a constant-temperature drying oven at 110℃±5℃, dry for more than 1h, then place in a constant-humidity chamber to absorb water for 16~20h.

8. Analysis procedure

• 4.2 Press the water-absorbed sample into the sample holder and record the diffraction pattern.
• 4.3 Measure the molecular sieve diffraction angles of 2θ near 54° and 58.3°, and the silicon powder diffraction angle near 56.1°, reading values to three decimal places, and use the 2θ value corresponding to the midpoint at the peak height 3/4 as the diffraction peak angle.

9. Qualitative and quantitative determination and calculation formulas

• 5.1 Use the difference between the theoretically calculated value of the silicon powder CuKα diffraction angle (2θ = 56.123°) and the measured value to correct the positions of the molecular sieve diffraction peaks.
• 5.2 Convert the corrected molecular sieve diffraction angles into interplanar spacings d, calculated according to formula (1): d = λ / (2 sinθ) ………………(1) Where: λ—CuKα-ray wavelength 1.5405×10⁻¹⁰ m (the source text is "1.5405 x 10' '0, .o", requires confirmation against the source standard (source-text extraction)).
• 5.3 The unit cell parameter a₀ of the NaY molecular sieve is calculated according to formula (2): a₀ = d_hkl × (h²+k²+l²)^(1/2) ………………(2) Where: h²+k²+l²—the sum of squares of the Miller indices of the molecular sieve diffraction peak; for the peak near the 2θ angle 54° it is equal to 211, and for the peak near 58.3° it is equal to 2430 (the source text is "2430", requires confirmation against the source standard (source-text extraction)).
• 5.4 Calculate the average value of a₀ from the two diffraction peaks.

10. Precision

Judge the reliability of the results according to the following provisions (95% confidence level).

• 6.1 Repeatability: within the same laboratory, by the same operator, the difference between two results of repeated determination on the same sample shall not be greater than 2×10⁻¹² m (0.02Å).
• 6.2 Reproducibility: the difference between two results of determination on the same sample by different laboratories shall not be greater than 4×10⁻¹² m (0.04Å).
• Note: This precision data was determined by statistical analysis of measurement results from 6 samples and 12 laboratories.

11. Report

Take the arithmetic mean of the two results of repeated determination and report the data.

12. Referenced documents

• ASTM D3942-91 "Method for determination of faujasite-type molecular sieve unit cell size" (reference adoption)
• Other referenced documents: not provided in the available source.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick reference Q&A