ISO 5074:2015

Hard coal - Determination of Hardgrove grindability index

ISO 5074:2015 specifies the method for determining the grindability index of hard coal using the Hardgrove machine. It also specifies the procedure for calibrating the test machine and for preparing the standard reference coal samples. NOTE In this International Standard, the term "hard coal" is used as an indication of maturity or rank in the coalification sequence and is not related to the physical properties of the coal.

Houille — Détermination de l'indice de broyabilité Hardgrove

Črni premog - Določanje meljivosti - Hardgroveov indeks

Ta mednarodni standard določa metodo za določevanje meljivosti črnega premoga s Hardgroveovo napravo. Določa tudi postopek za umerjanje preskusne naprave in pripravo standardnih referenčnih vzorcev premoga.
OPOMBA: Zveza »črni premog« se v tem mednarodnem standardu uporablja kot oznaka za zrelost oziroma stopnjo v zaporedju nastajanja premoga in ni povezana s fizikalnimi lastnostmi premoga.

General Information

• Status: Published
• Publication Date: 28-Sep-2015
• ICS: 73.040 - Coals
• Technical Committee: ISO/TC 27/SC 5 - Methods of analysis
• Drafting Committee: ISO/TC 27/SC 5/WG 12 - Miscellaneous methods
• Current Stage: 9093 - International Standard confirmed
• Start Date: 09-Apr-2021
• Completion Date: 13-Dec-2025
• Ref Project: SIST ISO 5074:2016 - Hard coal - Determination of Hardgrove grindability index

Relations

• Revises: ISO 5074:1994 - Hard coal - Determination of Hardgrove grindability index
• Effective Date: 08-Dec-2012

Overview

ISO 5074:2015 - "Hard coal - Determination of Hardgrove grindability index" is the ISO method for measuring the relative grindability of hard coal using the Hardgrove machine. The third edition (2015) defines the test principle, machine calibration, and preparation of standard reference coal samples. The standard clarifies that the term hard coal refers to coal rank (gross calorific value > 24 MJ/kg, moist, ash‑free) and not to physical hardness.

Key topics and requirements

• Test principle: Controlled milling of a prepared coal sample in a calibrated Hardgrove machine followed by sieve analysis of the ground product to derive the Hardgrove grindability index (HGI).
• Calibration: Procedures for calibrating the Hardgrove machine and generating the calibration chart using standard reference materials.
• Sample preparation & sampling: Mandates use of ISO 13909 and ISO 18283 for mechanical and manual sampling and details preparation steps needed to obtain a representative test sample.
• Reporting and equipment: Requires conformity with equipment, test procedure and reporting conventions, referencing ASTM D409 for related apparatus and procedural details.
• Definitions: Clear definition of “hard coal” based on calorific value and other relevant terms used in grindability testing.

Applications and users

• Pulverizer design and selection: Engineers use HGI values to estimate pulveriser throughput and power consumption for a specified product fineness.
• Power plants and utilities: Fuel characterization to optimize combustion performance and mill operation.
• Coal suppliers and traders: Quality assessment and specification of coal lots for sale or blending.
• Laboratories and QA/QC: Routine analytical testing of coal for process control and compliance.
• Research and standards bodies: Comparative studies of coal physical properties, grindability correlations, and method development.

Practical value

• Provides a reproducible, industry‑accepted grindability metric (HGI) to predict milling behaviour.
• Enables consistent communication of coal grindability across suppliers, plant operators, and equipment manufacturers.
• Supports plant energy-efficiency assessments and mill capacity planning through empirical relationships between HGI and pulverizer performance.

Related standards

• ISO 13909 - Hard coal and coke: Mechanical sampling
• ISO 18283 - Hard coal and coke: Manual sampling
• ASTM D409 - Standard Test Method for Grindability of Coal by the Hardgrove‑Machine Method (referenced for equipment and procedural alignment)

Keywords: ISO 5074, Hardgrove grindability index, Hardgrove machine, hard coal grindability, coal testing standard, grindability test, calibration, sample preparation, pulverizer power consumption.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 5074
Third edition
2015-10-01
Hard coal — Determination of
Hardgrove grindability index
Houille — Détermination de l’indice de broyabilité Hardgrove
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
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 ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified
...

SLOVENSKI STANDARD
01-maj-2016
1DGRPHãþD
SIST ISO 5074:1998
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Hard coal - Determination of Hardgrove grindability index
Houille - Détermination de l'indice de broyabilité Hardgrove
Ta slovenski standard je istoveten z: ISO 5074:2015
ICS:
73.040 Premogi Coals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 5074
Third edition
2015-10-01
Hard coal — Determination of
Hardgrove grindability index
Houille — Détermination de l’indice de broyabilité Hardgrove
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
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 ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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 documents should be noted. This document wa
...