1、Designation: D4464 10D4464 15Standard Test Method forParticle Size Distribution of Catalytic MaterialMaterials byLaser Light Scattering1This standard is issued under the fixed designation D4464; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the particle size distribution of catalyst, catal
3、yst and catalyst carrier carrier,and catalytic raw material particles and is one of several found valuable for the measurement of particle size. The range of averageparticle sizes investigated was from 1 to 300 m equivalent spherical diameter. The technique is capable of measuring particlesabove and
4、 below this range. The angle and intensity of laser light scattered by the particles are selectively measured to permitcalculation of a volume distribution using light-scattering techniques.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included i
5、n this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2
6、. Referenced Documents2.1 ASTM Standards:2D3766 Terminology Relating to Catalysts and CatalysisE105 Practice for Probability Sampling of MaterialsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting
7、an Interlaboratory Study to Determine the Precision of a Test MethodE1617 Practice for Reporting Particle Size Characterization Data3. Terminology3.1 Definitions and recommended nomenclature pertaining to catalysts and to materials used in their manufacture can be foundin Terminology D3766.3.2 Defin
8、itions of Terms Specific to This Standard:3.2.1 backgroundextraneous scattering of light by material present in the dispersion fluid other than the particles to bemeasured. It includes scattering by contamination in the measurement path.3.2.2 Fraunhofer Diffractionthe optical theory that describes t
9、he low-angle scattering of light by particles that are largecompared to the wavelength of the incident light.3.2.3 Mie Scatteringthe complex electromagnetic theory that describes the scattering of light by spherical particles. It isapplied when the sample includes particles with diameters that are c
10、lose to the wavelength of the incident light. The real andimaginary indices of light refraction of the particles are needed.3.2.4 multiple scatteringthe re-scattering of light by a particle in the path of light scattered by another particle. This usuallyoccurs in heavy concentrations of a particle d
11、ispersion.1 This test method is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.02 on Physical-MechanicalProperties.Current edition approved Oct. 15, 2010April 1, 2015. Published January 2011May 2015. Originally approved in 1985. Last pr
12、evious edition approved in 20052010 asD446400(2005).D4464 10. DOI: 10.1520/D4464-10.10.1520/D4464-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Do
13、cument Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM
14、 recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summa
15、ry of Test Method4.1 A prepared sample of particulate material is dispersed in water or a compatible organic liquid and is circulated through thepath of a laser light beam or some other suitable source of light. The particles pass through the light beam and scatter it.Photodetector arrays collect th
16、e scattered light which is converted to electrical signals to be analyzed using Fraunhofer Diffraction,or Mie Scattering, or both. Scattering information, typically, is analyzed assuming a spherical geometry for the particles. Calculatedparticle sizes are, therefore, presented as equivalent spherica
17、l diameters.5. Significance and Use5.1 It is important to recognize that the results obtained by this test method or any other method for particle size determinationutilizing different physical principles may disagree. The results are strongly influenced by physical principles employed by eachmethod
18、 of particle size analysis. The results of any particle sizing method should be used only in a relative sense and should notbe regarded as absolute when comparing results obtained by other methods. Particularly for fine materials (that is, average particlesize 20 m), significant differences are ofte
19、n observed for laser light scattering instruments of different manufacturers. Thesedifferences include lasers of different wavelengths, detector configuration, and the algorithms used to convert scattering to particlesize distribution. Therefore, comparison of results from different instruments may
20、be misleading.35.2 Light scattering theories (Fraunhofer Diffraction4 and Mie Scattering5) that are used for determination of particle size havebeen available for many years. Several manufacturers of testing equipment now have units based on these principles. Althougheach type of testing equipment u
21、tilizes the same basic principles for light scattering as a function of particle size, differentassumptions pertinent to application of the theory and different models for converting light measurements to particle size, may leadto different results for each instrument. Furthermore, any particles whi
22、ch are outside the size measurement range of the instrumentwill be ignored, causing an increase in the reported percentages within the detectable range.Aparticle size distribution which endsabruptly at the detection limit of the instrument may indicate that particles outside the range are present. T
23、herefore, use of this testmethod cannot guarantee directly comparable results from different types of instruments.5.3 This test method can be used to determine particle size distributions of catalysts and supports for materials catalysts,supports, and catalytic raw materials for specifications, manu
24、facturing control, and research and development work.5.4 For fine materials (that is, average particle size 20 m), it is critical that Mie Scattering Theory be applied. This involvesentering an “optical model” consisting of the “real” and “imaginary” refractive indices of the solid at the wavelength
25、 of the laser.The “imaginary” refractive index is also referred to as the “absorbance,” as it has a value of zero for transparent materials suchas glass beads. For common materials and naturally occurring minerals (for example, kaolin), these values are known andpublished, and usually included in th
26、e manufacturers instrument manual (for example, as an appendix). For example, kaolinitemeasured at 589.3 nm has a “real” refractive index of 1.55. The absorbance (imaginary component) for minerals and metal oxidesis normally taken as 0.001, 0.01 or 0.1. Many of the published values were measured at
27、589.3 nm (sodium light) but often valuesat other wavelengths are also given. Extrapolation, interpolation, or estimation to the wavelength of the laser being used cantherefore be made.66. Interferences6.1 Air bubbles entrained in the circulating fluid will scatter light and then be reported as parti
28、cles. Circulating fluids, typically,do not require degassing, but should be bubble-free on visual inspections.6.2 Contaminants, such as non-aqueous solvents, oil or other organic coatings on the sample may emulsify in an aqueous carrier,scatter light, and be reported as part of the particle size dis
29、tribution. Samples containing such contaminants may be analyzed ina non-aqueous carrier solvent to dissolve the contaminants or washed free of the contaminant with a compatible aqueous solvent.6.3 Reagglomeration or settling of particles during analysis will cause erroneous results. Dispersions shal
30、l be prepared such thata stable dispersion is maintained throughout the analysis.6.4 Insufficient sample loading may cause electrical noise interference and poor data reproducibility. High sample loading maycause excessive light attenuation and multiple scattering, resulting in erroneous particle si
31、ze distributions.7. Apparatus7.1 Particle Size Analyzer, based on Fraunhofer Diffraction or Mie Scattering, or both, light scattering analysis techniques.Ensure that the analyzer system or subsystem is optimum for the range of the powder being tested.7.2 Micro Sample Splitter, used in accordance wit
32、h MNL 327 to obtain the test portion of sample.3 Jillavenkatesa, A., et al., Particle Size Characterization, NIST Recommended Practice Guide SP 960-1, 2001.4 Born, M., and Wolf, E., Principles of Optics, Chapter 8, Pergamon Press, Oxford, 1957.5 van Hulst, H. C., Light Scattering by Small Particles,
33、 Chapter 9, John Wiley the details are given in ASTM Research Report RR:D32-1041.1010 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D32-1041.TABLE 1 Fraction Smaller than 10 volume %Material AverageDiameterA (m)Repeatability,S
34、tandard DeviationReproducibility,Standard DeviationRepeatabilityLimitReproducibilityLimitPrecisionSensitivityx sr SR r R R/rA 25.8 0.511 1.59 1.43 4.46 3.11B 39.6 2.70 5.06 7.57 14.2 1.87C 3.39 0.053 2.00 0.149 5.59 37.5D 2.27 0.073 1.26 0.205 3.52 17.2E 1.36 0.122 0.678 0.341 1.90 5.57F 1.39 0.033
35、0.975 0.093 2.73 29.4A The average of the laboratories calculated averages.D4464 15414.3.1 Repeatability Limit, (r)Two test results obtained within one laboratory shall be judged not equivalent if they differ bymore than the “r” value for that material; “r” is the interval representing the critical
36、difference between two test results for the samematerial, obtained by the same operator using the same equipment on the same day in the same laboratory.14.3.1.1 Repeatability limits are listed in Tables 1-3.14.3.2 Reproducibility Limit, (R)Two test results shall be judged not equivalent if they diff
37、er by more than the “R” value forthat material; “R” is the interval representing the critical difference between two test results for the same material, obtained bydifferent operators using different equipment in different laboratories.14.3.2.1 Reproducibility limits are listed in Tables 1-3.14.3.3
38、The above terms (repeatability limit and reproducibility limit) are used as specified in Practice E177.14.3.4 Any judgment in accordance with statements in 14.3.1 and 14.3.2 would normally have an approximate 95% probabilityof being correct, however, since all requested replicates were not consisten
39、tly reported, there may be times when differences greaterthan predicted by the ILS results arise, sometimes with considerably greater or smaller frequency that the 95% probability limitwould imply.14.3.4.1 The ratio of the reproducibility to repeatability (R/r) is reported. As this ratio increases i
40、t indicates that while theintralaboratory precision may be very good, the agreement among laboratories decreases. High ratios can indicate sensitivity ofprecision to different instruments and software, as well as any other procedural differences among different laboratories. The datashow that higher
41、 ratio values generally occur for the fine samples (C, D, E, F). As expected, differences among instruments areemphasized at smaller particle sizes.14.4 BiasAt the time of the study, there was no accepted reference material suitable for determining the bias for this testmethod; therefore, no stateme
42、nt on bias is being made.14.5 The precision statement was determined through statistical examination of 378 results, from eight data sets from sixdifferent organizations. The six materials tested were identified as the following:Material A: FCC Catalyst: X-5388Material B: FCC Catalyst: X-6705Materia
43、l C: Alumina Calcined: 5126Material D: Alumina Calcined: 6027Material E: Hydrous Kaolin: Ansilex-93Material F: Hydrous Kaolin: LustraTABLE 2 Fraction Smaller than 50 volume %Material AverageDiameterA (m)Repeatability,Standard DeviationReproducibility,Standard DeviationRepeatabilityLimitReproducibili
44、tyLimitPrecisionSensitivityx sr SR r R R/rA 50.1 1.61 2.02 4.52 5.64 1.25B 81.6 0.639 4.43 1.79 12.4 6.92C 9.4 0.108 1.84 0.301 5.16 17.1D 7.00 0.113 0.955 0.316 2.67 8.46E 3.12 0.064 0.813 0.179 2.28 12.7F 5.72 0.247 3.75 0.690 10.5 15.2A The average of the laboratories calculated averages.TABLE 3
45、Fraction Smaller than 90 volume %Material AverageDiameterA (m)Repeatability,Standard DeviationReproducibility,Standard DeviationRepeatabilityLimitReproducibilityLimitPrecisionSensitivityx sr SR r R R/rA 91.0 3.86 4.30 10.8 12.0 1.11B 136 1.10 10.7 3.07 30.1 9.79C 18.9 0.268 4.17 0.752 11.7 15.5D 20.
46、63 1.98 7.40 5.53 20.7 3.75E 9.65 0.253 3.77 0.709 10.6 14.9F 26.4 2.35 14.2 6.57 39.8 6.06A The average of the laboratories calculated averages.D4464 15515. Keywords15.1 catalyst; catalyst carrier; Fraunhofer Diffraction; laser light scattering; Mie ScatteringScattering; particle size distributionA
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