ISO 23499:2026

Coal — Determination of bulk density of coal as it is handled in industrial practices

This document specifies a cone procedure for determining an uncompacted bulk density of crushed coal up to −45 mm nominal top size, as it is handled in industrial practices. It focuses on the uncompacted bulk density of coal resulting from flowing the material into a measuring container (box) in the absence of compacting forces. The determination of the bulk density of coal charged into coke ovens is a typical example. This document also provides a method for determining the bulk density of dry powdered coal at −63 micrometres for boiler or utility application. It does not cover the determination of bulk density of coal in storage piles.

Charbon — Détermination de la masse volumique en vrac du charbon tel qu'il est traité dans les pratiques industrielles

General Information

• Status: Published
• Publication Date: 05-Feb-2026
• ICS: 73.040 - Coals
• Technical Committee: ISO/TC 27/SC 1 - Coal preparation: Terminology and performance
• Drafting Committee: ISO/TC 27/SC 1 - Coal preparation: Terminology and performance
• Current Stage: 6060 - International Standard published
• Start Date: 06-Feb-2026
• Due Date: 25-Mar-2026
• Completion Date: 06-Feb-2026

Relations

• Revises: ISO 23499:2013 - Coal — Determination of bulk density for the use in charging of coke ovens
• Effective Date: 20-Apr-2024

Overview

ISO 23499:2026 – Coal - Determination of Bulk Density of Coal as It Is Handled in Industrial Practices is an international standard developed by ISO Technical Committee ISO/TC 27. This standard provides tested and reliable methods for determining the uncompacted bulk density of crushed coal and dry powdered coal as they are commonly handled in industrial operations. It ensures uniformity and accuracy in quantifying coal bulk density, which is crucial for efficient material handling, storage, transportation, and processing in sectors such as power generation, steel manufacturing, and cement production.

Key Topics

• Cone Procedure for Crushed Coal: Details a method for measuring uncompacted bulk density of crushed coal up to a nominal top size of 45 mm using a cone and box apparatus, simulating industrial charging (e.g., into coke ovens).
• Bulk Density for Fine Powdered Coal: Introduces a procedure for dry powdered coal with a nominal top size of −63 micrometres, vital for fuel applications in boilers and utility plants.
• Sampling and Preparation: Outlines representative sampling practices and sample preparation requirements for accurate bulk density determination.
• Measurement Apparatus: Specifies design and calibration of measuring boxes, cones, tripods, and other required equipment.
• Procedural Steps: Provides detailed instructions from sample acquisition through filling, leveling, weighing, and data reporting.
• Data Expression and Reporting: Guides on calculating and reporting bulk density, considering moisture content and repeatability of results.
• Test Precision: Establishes criteria for repeatability and the process for confirmatory testing when initial results differ.

Applications

ISO 23499:2026 has broad application across coal and energy industries, supporting:

• Coke Oven Charging: Precise bulk density measurements are critical for controlling the mass and uniformity of coal charged into coke ovens, directly impacting coke quality.
• Boiler Fuel Management: Accurate assessment of powdered coal bulk density helps optimize feed rates and combustion efficiency in pulverized fuel-fired boilers.
• Coal Storage and Handling: Reliable measurement reduces handling uncertainties and aids in designing conveyors, silos, and hoppers by providing a consistent basis for volume-weight conversions.
• Trade and Logistics: Standardized bulk density figures facilitate fair and transparent transactions in coal trading, supporting accurate quantity declarations.
• Quality Control: Enables producers and users to monitor and maintain product consistency and process performance by integrating routine bulk density checks.

Note: This standard expressly does not cover the determination of bulk density in coal storage piles, focusing instead on coal as handled during processing or before storage.

Related Standards

ISO 23499:2026 references and complements several key coal testing and handling standards, including:

• ISO 589: Hard coal - Determination of total moisture
• ISO 1213-1: Coal and coke - Vocabulary (coal preparation terms)
• ISO 1213-2: Coal and coke - Vocabulary (sampling, testing, and analysis)
• ISO 1953: Coal - Size analysis by sieving
• ISO 13909-2: Coal and coke - Mechanical sampling of coal from moving streams
• ISO 13909-4: Coal and coke - Preparation of test samples of coal
• ISO 18283: Coal and coke - Manual sampling Additional referenced practices include ASTM D291 for cubic foot weight of crushed bituminous coal and AS 3899 for bulk density of higher rank coal and coke.

Practical Value

The implementation of ISO 23499:2026 supports safer, more efficient, and scientifically consistent handling of coal throughout the supply chain. Manufacturers, energy producers, and laboratories applying this standard will benefit from:

• Enhanced process efficiency
• Improved quality assurance
• Reliable material accounting
• Compliance with international best practices

Keywords: ISO 23499, coal bulk density, uncompacted bulk density, cone procedure, powdered coal density, industrial coal handling, standard test method, coal sampling, coke oven bulk density, coal processing standards.

Standards Content (Sample)

International
Standard
ISO 23499
Third edition
Coal — Determination of bulk
2026-02
density of coal as it is handled in
industrial practices
Charbon — Détermination de la masse volumique en vrac du
charbon tel qu'il est traité dans les pratiques industrielles
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Method 1 . 1
4.1 Principle .1
4.2 Apparatus .2
4.2.1 Measuring boxes .2
4.2.2 Cones and tripod frame .2
4.3 Sampling and preparation .3
4.3.1 Sampling for bulk density of coal up to a 45 mm nominal top size .3
4.3.2 Preparation of sample .3
4.4 Procedure for bulk density of coal up to a 45 mm nominal top size .3
5 Method 2 . 5
5.1 Principle .5
5.2 Sampling and preparation .6
5.3 Apparatus .6
5.4 Procedure .8
6 Expression of results . 9
6.1 Method 1 .9
6.2 Method 2 .9
7 Reporting of results .10
7.1 Precision . . .10
7.2 Repeatability for Method 1 and Method 2 .10
7.3 Reproducibility .10
8 Test report .10
Bibliography .12

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 27, Coal and Coke, Subcommittee SC 1, Coal
preparation: Terminology and performance.
This third edition cancels and replaces the second edition (ISO 23499:2013), which has been technically
revised.
The main changes are as follows:
— addition of an alternate method using a smaller sized box of 0,028 37 m for bulk density of coal up to
45 mm nominal top size;
— addition of method for determining bulk density of a dry coal powder at minus 63 micrometres nominal
top size.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document describes two methods for determining:
a) the bulk density for crushed coal of up to 45 mm nominal top size as that charged into coke ovens;
b) the bulk density for fine dry coal powders typically less than 63 micrometres nominal top size used in
pulverized fuel fired boilers and cement kilns.

v
International Standard ISO 23499:2026(en)
Coal — Determination of bulk density of coal as it is handled
in industrial practices
1 Scope
This document specifies a cone procedure for determining an uncompacted bulk density of crushed coal
up to −45 mm nominal top size, as it is handled in industrial practices. It focuses on the uncompacted
bulk density of coal resulting from flowing the material into a measuring container (box) in the absence
of compacting forces. The determination of the bulk density of coal charged into coke ovens is a typical
example.
This document also provides a method for determining the bulk density of dry powdered coal at
−63 micrometres for boiler or utility application. It does not cover the determination of bulk density of coal
in storage piles.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 589, Hard coal — Determination of total moisture
ISO 1213-1, Coal and coke — Vocabulary — Part 1: Terms relating to coal preparation
ISO 1213-2, Coal and coke — Vocabulary — Part 2: Terms relating to sampling, testing and analysis
ISO 1953, Coal — Size analysis by sieving
ISO 13909-2, Coal and coke — Mechanical sampling — Part 2: Sampling of coal from moving streams
ISO 13909-4, Coal and coke — Mechanical sampling — Part 4: Preparation of test samples of coal
ISO 18283, Coal and coke — Manual sampling
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-1 and ISO 1213-2 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Method 1
4.1 Principle
Bulk density for coal up to a nominal 45 mm top size is determined by filling a container (measuring box) of
known mass and volume with coal and determining the increase in mass.

4.2 Apparatus
4.2.1 Measuring boxes
A cubical container of 0,1 m capacity and internal dimensions of 465 mm. see Figure 1 a). The volume of the
box is 0,465 × 0,465 × 0,465 = 0,1 m
For coals greater than 45 mm nominal top size, the internal edge dimension of the measuring box should be
approximately ten times nominal top size
An alternate cubic container of 0,028 73 m capacity and internal dimensions of 305 mm may also be used.
see Figure 1 b). The volume of the box is 0,305 × 0,305 × 0,305 = 0,028 73 m (see Reference [1]).
The boxes shall be constructed of metal of sufficient thickness to ensure the rigidity of the walls and the
base of the container under the conditions of the test (minimum wall thickness of 3 mm is recommended). It
is also recommended that the boxes have a smooth inner surface, using stainless steel in their construction
and be fitted with handles.
The exact volume of the boxes, in cubic metres, shall be determined with a precision of 0,000 1 m (100 ml),
using water of known density.
4.2.2 Cones and tripod frame
4.2.2.1 General
3 3
Cones and tripod frame, for filling the 0,1 m and 0,028 37 m boxes, should conform to Figure 1 a) and b).
See Figure 2 for a reference for the iron shutters (two) to fit the base of the cones.
See Figure 3 for a reference for the three adjustable legs on each tripod.
The dimensions of the cones and tripod frames shall be as follows:
4.2.2.2 0,1 m box
Cone and tripod frame: 610 mm high with an inside diameter at the top of 510 mm and a circular opening
of 203 mm in diameter at the bottom. A slide valve consisting of a slide-plate shutter and its supports shall
be welded to the bottom of the cone in such a manner that the valve can be opened and closed with ease by
removing or inserting the shutter in its supporting slides. The cone shall be supported in a tripod frame
having a circular opening at the top of 460 mm in diameter. This frame shall support the cone so that the
top side of the shutter shall be 718 mm from the inside bottom surface of the box. Dimension from the cone
bottom to the top edge of the box shall be a minimum of 250 mm.
4.2.2.3 0,028 37 m box
Cone and tripod frame: 610 mm high with an inside diameter at the top of 510 mm and a circular opening
of 203 mm in diameter at the bottom. A slide valve consisting of a slide-plate shutter and its supports shall
be welded to the bottom of the cone in such a manner that the valve can be opened and closed with ease by
removing or inserting the shutter in its supporting slides. The cone shall be supported in a tripod frame
having a circular opening at the top of 460 mm in diameter. This frame shall support the cone so that the
top side of the shutter shall be 560 mm from the inside bottom surface of the box. Dimension from the cone
bottom to the top edge of the box shall be a minimum of 250 mm.
4.2.2.4 Levelling bar
A steel strip approximately 760 mm long by 40 mm wide and 5 mm thick.
...