ASTM D4438-24

Standard Test Method for Particle Size Distribution of Catalysts and Catalyst Carriers by Electronic Counting

SIGNIFICANCE AND USE
4.1 This test method can be used to determine particle size distributions for material specifications, manufacturing control, and research and development work in the particle size range usually encountered in fluidizable cracking catalysts.
SCOPE
1.1 This test method covers the determination of particle size distribution of catalyst and catalyst carrier (see Terminology D3766) particles using an electroconductive sensing method and is one of several valuable methods for the measurement of particle size.  
1.2 The range of particle sizes investigated was 20 μm to 150 μm (see IEEE/ASTM SI 10) equivalent spherical diameter. The technique is capable of measuring particles above and below this range. The instrument used for this method is an electric current path of small dimensions that is modulated by individual particle passage through an aperture, and produces individual pulses of amplitude proportional to the particle volume.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 14-Mar-2024
• ICS: 19.120 - Particle size analysis. Sieving
• Technical Committee: D32 - Catalysts
• Drafting Committee: D32.02 - Physical-Mechanical Properties

Relations

• Replaces: ASTM D4438-13(2018)e1 - Standard Test Method for Particle Size Distribution of Catalysts and Catalyst Carriers by Electronic Counting
• Effective Date: 15-Mar-2024
• Refers: ASTM E456-13a(2022)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022
• Refers: ASTM E456-13a(2022) - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022

Overview

ASTM D4438-24: Standard Test Method for Particle Size Distribution of Catalysts and Catalyst Carriers by Electronic Counting defines a precise procedure to determine the particle size distribution of catalyst and catalyst carrier materials using an electroconductive sensing method. This test covers the particle size range typically encountered in fluidizable cracking catalysts, providing a standardized approach for material quality control, research, and manufacturing environments.

Electronic counting methods, as outlined in the ASTM D4438-24 standard, are valued for their accuracy and ability to deliver reproducible and objective measurements. These results support specification compliance and quality assurance for catalyst producers and users in various industrial sectors.

Key Topics

• Test Scope: Applies to catalyst and catalyst carrier particles in the 20 μm to 150 μm equivalent spherical diameter range, with capabilities to measure slightly outside this range.
• Measurement Principle: Utilizes a small-aperture electric current path, where individual particles passing through the aperture are detected as pulses proportional to their volume.
• Sample Preparation: Involves dispersing and suspending the test sample in an electrolyte, ensuring particles remain uniformly suspended for analysis.
• Instrument Calibration: Requires systematic calibration of the particle counter and apertures in accordance with manufacturer specifications for accurate results.
• Data Expression: Particle distribution data can be presented as cumulative or differential volume/weight percent. Median diameter is determined at the 50th percentile of the cumulative volume distribution.
• Precision and Reproducibility: The method provides defined repeatability and reproducibility parameters based on multilaboratory studies, fostering consistent results across different settings.
• Safety and Good Laboratory Practices: Users must establish appropriate safety, health, and environmental protocols and comply with regulatory requirements before conducting the method.

Applications

ASTM D4438-24 is essential in industries where accurate characterization of catalyst and catalyst carrier particle size is critical:

• Material Specifications: Assists suppliers and users in verifying that catalysts meet required particle size distribution specifications.
• Manufacturing Quality Control: Supports continuous monitoring and quality assurance in the production of catalysts, helping maintain optimal performance in end-use applications.
• Research and Development: Facilitates R&D by providing reproducible data for developing new catalyst materials or improving existing formulations.
• Fluidized Catalytic Cracking (FCC): Especially relevant for catalysts used in FCC units, where precise particle size distribution directly impacts process efficiency and catalyst performance.

The electroconductive sensing technique detailed in ASTM D4438-24 is particularly useful for spherical particles but may yield variable results for non-spherical shapes. Data interpretation should consider particle morphology when comparing alternative measurement methodologies.

Related Standards

ASTM D4438-24 refers to several related ASTM and international standards that provide supporting procedures and definitions:

• ASTM D3766: Terminology Relating to Catalysts and Catalysis
• ASTM D1193: Specification for Reagent Water
• ASTM B215: Practices for Sampling Metal Powders
• ASTM E105: Guide for Probability Sampling of Materials
• ASTM E122: Practice for Calculating Sample Size
• IEEE/ASTM SI 10: Standard for Use of the International System of Units (SI)
• ASTM E691: Practice for Conducting Interlaboratory Study for Test Method Precision

Compliance with these related standards ensures proper sample handling, data accuracy, and traceability, supporting the overall value of ASTM D4438-24 in catalyst characterization workflows.

Keywords: ASTM D4438-24, particle size distribution, catalyst, catalyst carrier, electronic particle counting, electroconductive sensing, material specification, quality control, fluidized catalytic cracking, laboratory testing.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4438 − 24
Standard Test Method for
Particle Size Distribution of Catalysts and Catalyst Carriers
by Electronic Counting
This standard is issued under the fixed designation D4438; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E122 Practice for Calculating Sample Size to Estimate, With
Specified Precision, the Average for a Characteristic of a
1.1 This test method covers the determination of particle
Lot or Process
size distribution of catalyst and catalyst carrier (see Terminol-
E177 Practice for Use of the Terms Precision and Bias in
ogy D3766) particles using an electroconductive sensing
ASTM Test Methods
method and is one of several valuable methods for the
E456 Terminology Relating to Quality and Statistics
measurement of particle size.
E691 Practice for Conducting an Interlaboratory Study to
1.2 The range of particle sizes investigated was 20 μm to
Determine the Precision of a Test Method
150 μm (see IEEE/ASTM SI 10) equivalent spherical diameter.
E1272 Specification for Laboratory Glass Graduated Cylin-
The technique is capable of measuring particles above and
ders
below this range. The instrument used for this method is an
IEEE/ASTM SI 10 Standard for Use of the International
electric current path of small dimensions that is modulated by
System of Units (SI): The Modern Metric System
individual particle passage through an aperture, and produces
individual pulses of amplitude proportional to the particle
3. Summary of Test Method
volume.
3.1 A carefully dispersed, dilute suspension of the represen-
1.3 This standard does not purport to address all of the
tative sample in a beaker filled with an electrolyte is placed in
safety concerns, if any, associated with its use. It is the
the counting position on the instrument sample stand. The
responsibility of the user of this standard to establish appro-
suspension is forced through a restricting aperture. Each
priate safety, health, and environmental practices and deter-
passing particle is recorded on an electronic counter, and the
mine the applicability of regulatory limitations prior to use.
data are accumulated according to selected particle size inter-
1.4 This international standard was developed in accor-
vals for subsequent processing.
dance with internationally recognized principles on standard-
3.2 The instrument response is proportional to liquid dis-
ization established in the Decision on Principles for the
placement by the particle volume. Equivalent spherical diam-
Development of International Standards, Guides and Recom-
eter is commonly used to express the particle size.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Significance and Use
2. Referenced Documents 4.1 This test method can be used to determine particle size
distributions for material specifications, manufacturing control,
2.1 ASTM Standards:
and research and development work in the particle size range
B215 Practices for Sampling Metal Powders
usually encountered in fluidizable cracking catalysts.
D1193 Specification for Reagent Water
D3766 Terminology Relating to Catalysts and Catalysis
5. Apparatus
E105 Guide for Probability Sampling of Materials
5.1 Electronic Particle Counter, with sample stand and
stirring motor.
This test method is under the jurisdiction of ASTM Committee D32 on
5.2 Aperture Tubes, with varying diameters. The diameter
Catalysts and is the direct responsibility of Subcommittee D32.02 on Physical-
required is dependent upon the particle size distribution of the
Mechanical Properties.
Current edition approved March 15, 2024. Published March 2024. Originally
sample. Generally, any given tube will cover a particle size
ɛ1
approved in 1985. Last previous edition approved in 2018 as D4438 – 13 (2018) .
range from 2 % to 40 % of its aperture diameter.
DOI: 10.1520/D4438-24.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Supporting data have been filed at ASTM International Headquarters and may
the ASTM website. be obtained by requesting Research Report RR:D32-1011.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4438 − 24
5.3 Ultrasonic Tank, 100 W. 8. Procedure
8.1 Follow instrument manufacturer’s instruction manual
5.4 Beaker, 100-mL.
for instrument settings.
5.5 Graduated Glass Pipet, 5-mL.
8.2 Follow the manufacturer’s instructions for calibrating
5.6 Wash Bottles.
each aperture and electrolyte combination that will be used.
5.7 Membrane Filtering Device with 0.22-μm filters.
8.3 Before each analysis, using the wash bottle and filtered
5.8 Round-Bottom Sample Beakers, 250-mL. wash water, wash all surfaces coming in contact with the
sample.
5.9 Micro-Riffler or Chute Riffler.
8.4 Place 150 mL to 200 mL of electrolyte in a round-
bottom beaker on the sample stand with the stirring rod turning
6. Reagents
moderately fast. Position the stirring blades near the bottom of
6.1 Purity of Reagents—Reagent grade chemicals shall be
the beaker and increase the stirrer speed to a rate just below air
used in all tests. Unless otherwise indicated, it is intended that
bubble formation (Note 2). Follow the instruction manual and
all reagents shall conform to the specifications of the Commit-
take several background counts. If they exceed the limit in the
tee on Analytical Reagents of the American Chemical Society,
manual for the aperture in use, refilter the electrolyte and flush
where such specifications are available. Other grades may be
the glassware. If the background is due to electrical
used, provided it is first ascertained that the reagent is of
interference, the instrument manufacturer’s recommendations
sufficiently high purity to permit its use without lessening the
for sample should not be used when it can disintegrate fragile
accuracy of the determination.
primary particles.
6.2 Purity of Water—Unless otherwise indicated, references
NOTE 2—Proper adjustment of the position and speed of the stirrer will
to water shall be understood to mean reagent water conforming
prevent the loss of large particles by settling and formation of air bubbles
to Specification D1193, Type II.
during counting.
6.3 Electrolyte—Dissolve 10.0 g of reagent grade sodium
8.4.1 Transfer the sample into a 250-mL round-bottom
chloride (NaCl) in 1 L of distilled or deionized water and filter beaker containing about 200 mL of clean electrolyte. Be sure
twice through a 0.22-μm filter. (See Specification E1272)
all the sample is transferred.
8.4.2 Place the sample and beaker (from 8.4.1) in the
NOTE 1—Com
...

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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D4438 − 13 (Reapproved 2018) D4438 − 24
Standard Test Method for
Particle Size Distribution of Catalysts and Catalyst Carriers
by Electronic Counting
This standard is issued under the fixed designation D4438; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Keywords revised editorially in May 2018.
1. Scope
1.1 This test method covers the determination of particle size distribution of catalyst and catalyst carrier (see Terminology D3766)
particles using an electroconductive sensing method and is one of several valuable methods for the measurement of particle size.
1.2 The range of particle sizes investigated was 20 to 150 μm 20 μm to 150 μm (see IEEE/ASTM SI 10) equivalent spherical
diameter. The technique is capable of measuring particles above and below this range. The instrument used for this method is an
electric current path of small dimensions that is modulated by individual particle passage through an aperture, and produces
individual pulses of amplitude proportional to the particle volume.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
B215 Practices for Sampling Metal Powders
D1193 Specification for Reagent Water
D3766 Terminology Relating to Catalysts and Catalysis
E105 Guide for Probability Sampling of Materials
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or
Process
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1272 Specification for Laboratory Glass Graduated Cylinders
IEEE/ASTM SI 10 Standard for Use of the International System of Units (SI): The Modern Metric System
This test method is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.02 on Physical-Mechanical
Properties.
Current edition approved May 1, 2018March 15, 2024. Published June 2018March 2024. Originally approved in 1985. Last previous edition approved in 20132018 as
ɛ1
D4438 – 13.D4438 – 13 (2018) . DOI: 10.1520/D4438-13R18E01.10.1520/D4438-24.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4438 − 24
3. Summary of Test Method
3.1 A carefully dispersed, dilute suspension of the representative sample in a beaker filled with an electrolyte is placed in the
counting position on the instrument sample stand. The suspension is forced through a restricting aperture. Each passing particle
is recorded on an electronic counter, and the data are accumulated according to selected particle size intervals for subsequent
processing.
3.2 The instrument response is proportional to liquid displacement by the particle volume. Equivalent spherical diameter is
commonly used to express the particle size.
4. Significance and Use
4.1 This test method can be used to determine particle size distributions for material specifications, manufacturing control, and
research and development work in the particle size range usually encountered in fluidizable cracking catalysts.
5. Apparatus
5.1 Electronic Particle Counter, with sample stand and stirring motor.
5.2 Aperture Tubes, with varying diameters. The diameter required is dependent upon the particle size distribution of the sample.
Generally, any given tube will cover a particle size range from 22 % to 40 % of its aperture diameter.
5.3 Ultrasonic Tank, 100 W.
5.4 Beaker, 100-mL.
5.5 Graduated Glass Pipet, 5-mL.
5.6 Wash Bottles.
5.7 Membrane Filtering Device with 0.22-μm filters.
5.8 Round-Bottom Sample Beakers, 250-mL.
5.9 Micro-Riffler or Chute Riffler.
6. Reagents
6.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
6.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to
Specification D1193, Type II.
6.3 Electrolyte—Dissolve 10.0 g of reagent grade sodium chloride (NaCl) in 1 L of distilled or deionized water and filter twice
through a 0.22-μm filter. (See Specification E1272)
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D32-1011.
“Reagent Chemicals, American Chemical Society Specifications,” Am. ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade
Reference Materials, American Chemical Soc.,Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see
“AnalarAnalar Standards for Laboratory U.K.Chemicals, Chemicals,” BDH Ltd., Poole, Dorset, U.K., and the “United States Pharmacopeia.”United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D4438 − 24
NOTE 1—Commercially available Electrolyte solution of the same concentration can also be used, but should be filtered for apertures smaller than 100
μm.100 μm.
6.4 Wash Water—Distilled or deionized water, twice filtered through a 0.22-μm filter. Electrolyte may also be used as wash water.
6.5 Calibration Spheres , Nearnear monosized, having a relative standard deviation from the mean of less than 5 %, or equivalent,
as certified by the manufacturer.
7. Sampling
7.1 Test sample(s) shall be obtained from larger composites by riffling or splitting in accordance with subsection 5.12 of STP
447A with the aim of obtaining a representative sample that mirrors the shape and size distribution of the larger composite
...