SH/T 0340-1992 NaY Molecular sieve crystallinity determination method

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Card type: Test method

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

• Standard number: SH/T 0340-92 (confirmed in 2004)
• Chinese name: NaY Molecular sieve crystallinity determination method
• English name: not provided in the available source
• Replacement relationship: replaces ZBE 49002-88
• Reference adoption: ASTM D3906-91 "Molecular sieve relative diffraction intensity determination method" (the original text states "reference adoption")

2. Scope of application and non-applicability

• This standard specifies the determination method for the crystallinity of NaY molecular sieves. Molecular sieve crystallinity refers to the percentage content of the molecular sieve crystalline phase in the sample.
• This standard applies to NaY molecular sieves.
• Not applicable: not provided in the available source.

3. Method principle

Based on the principle that the X ray diffraction intensity of a certain crystalline phase in the sample is proportional to the content of that crystalline phase, the X ray diffraction method is used for quantitative analysis. Under the same conditions, collect the X ray diffraction patterns of the molecular sieve sample to be tested and the standard sample, with CuKα radiation, take the sum of the peak heights of eight diffraction peaks with 2θ between 14°—35°, multiply by the half-height width of the (533) diffraction peak (2θ approximately 23.5°) as the diffraction intensity of the molecular sieve, and use the external standard method to calculate the molecular sieve crystallinity of the sample to be tested.

4. Reagents and materials (purity / preparation)

• Standard sample: should meet the requirements of GSB G 75004. Produced by Changling Refinery Catalyst Plant, calibrated by the Research Institute of Petroleum Processing.
• Calcium chloride supersaturated solution for constant humidity chamber (see 5.3, 4.3).
• Other reagents: not provided in the available source.

5. Instruments and equipment

• 4.1 X ray diffractometer: CuKα radiation, slits: DS 1/2°, RS 0.15mm, SS 1/2° (the original text source-text extraction is "DS 1/20, RS 0.15mrn, SS 1/200", requires confirmation against the source standard (source-text extraction))
• 4.2 Constant-temperature drying oven: controlled at 110℃±5℃
• 4.3 Constant humidity chamber: laboratory glass desiccator, containing calcium chloride supersaturated solution, temperature between 18—28℃

6. Recommended operating conditions

• 6.1 Scanning range 14°—35°(2θ), scanning speed 1°/min, paper speed 10mm/min (the original text source-text extraction is "10/min" "l0nun/min", requires confirmation against the source standard (source-text extraction)); the selection of X tube voltage, current and recorder range is the same as in clause 6.2.
• 6.2 Record (533) diffraction peak, scanning range 22.5°—25.0°(2θ), scanning speed 0.25°/min, paper speed 20mm/min; the selection of X tube voltage, current and recorder range should make the (533) peak height of the standard sample lie between 50%—100% of full scale.

7. Sampling and sample preparation

• 5.2 Grind the sample until no particles can be felt by hand.
• 5.3 Take an appropriate amount of the sample to be tested and the standard sample, place them in a constant-temperature drying oven, dry at 110℃±5℃ for more than 1h, transfer to a constant humidity chamber to absorb water for more than 16h, maintaining the temperature at 18—28℃.
• 6.1 Press the sample after water absorption treatment into the sample holder, and record the diffraction spectrum.

8. Analysis procedure

For the sample to be tested and the standard sample, under the same test conditions, perform the following steps in sequence:

• 6.1 Press the sample after water absorption treatment into the sample holder, and record the diffraction spectrum. Test conditions are: scanning range 14°—35°(2θ), scanning speed 1°/min, paper speed 10mm/min, the selection of X tube voltage, current and recorder range is the same as in clause 6.2. The test result is shown in Figure 1.
• 6.2 Record (533) diffraction peak, scanning range 22.5°—25.0°(2θ), scanning speed 0.25°/min, paper speed 20mm/min, the selection of X tube voltage, current and recorder range should make the (533) peak height of the standard sample lie between 50%—100% of full scale, as shown in Figure 2.

9. Qualitative and quantitative and calculation formula

• 7.1 From the diffraction pattern obtained in clause 6.1, measure the heights of the eight diffraction peaks (331), (511, 333), (440), (533), (642), (822, 660), (555, 751), (664), and calculate the sum of the peak heights of the eight peaks for the sample and the standard sample respectively.

• 7.2 From the diffraction pattern obtained in clause 6.2, measure the half-height width of the (533) peak of the sample to be tested and the standard sample.

• 7.3 The crystallinity of NaY molecular sieve is calculated according to the following formula:

  Long = XR × (Ren · Cheng / IR · WR)

  The original text source-text extraction formula symbols have many doubtful points, requires confirmation against the source standard (source-text extraction). According to the original symbol explanations:

  • XR— crystallinity of the standard sample;
  • Ren—sum of peak heights of the sample;
  • IR— sum of peak heights of the standard sample;
  • W_i— half-height width of the (533) peak of the sample;
  • WR— half-height width of the (533) peak of the standard sample.

  Note: In some cases, omitting the step in clause 6.1 and using only the peak height of one (533) peak obtained in clause 6.2 multiplied by its half-height width as the diffraction intensity can also give good results, but it may not necessarily be completely consistent with the results of the eight-peak method, and cannot be used as the basis for product release, commodity inspection, or arbitration.

10. Precision

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

• 8.1 Repeatability: In the same laboratory, by the same operator, the difference between two results of repeated determinations on the same sample should not be greater than 4%.
• 8.2 Reproducibility: The difference between two results of determinations on the same sample by different laboratories should not be greater than 5%.
• Note: This precision data was determined by statistical analysis of the measurement results of 6 samples in 11 laboratories.

11. Report

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

12. Referenced documents

• GSB G 75004 Determination of NaY molecular sieve crystallinity standard sample NaY molecular sieve
• ASTM D3906-91 "Molecular sieve relative diffraction intensity determination method" (reference adoption)

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 Q&A