ISO 11722:2013

Solid mineral fuels - Hard coal - Determination of moisture in the general analysis test sample by drying in nitrogen

ISO 11722:2013 specifies a method for determining the moisture in the general analysis test sample of hard coal by drying in nitrogen.

Combustibles minéraux solides — Houille — Détermination de l'humidité de l'échantillon pour analyse par dessiccation en atmosphère d'azote

General Information

• Status: Published
• Publication Date: 14-Jul-2013
• ICS: 73.040 - Coals
• Technical Committee: ISO/TC 27/SC 5 - Methods of analysis
• Drafting Committee: ISO/TC 27/SC 5/WG 1 - Moisture, volatile matter and ash
• Current Stage: 9092 - International Standard to be revised
• Start Date: 10-Nov-2025
• Completion Date: 13-Dec-2025

Relations

• Consolidated By: ISO 5832-2:2018 - Implants for surgery - Metallic materials - Part 2: Unalloyed titanium
• Effective Date: 06-Jun-2022
• Revises: ISO 11722:1999 - Solid mineral fuels - Hard coal - Determination of moisture in the general analysis test sample by drying in nitrogen
• Effective Date: 10-Aug-2012

Overview

ISO 11722:2013 specifies a laboratory method for the determination of moisture in the general analysis test sample of hard coal by drying in a stream of nitrogen. The method provides a standardized procedure to obtain moisture values used to correct other analytical results (e.g., volatile matter and hydrogen) and to report results on a dry basis.

The method is applicable to equilibrated general analysis test samples and is designed to minimise rehydration or oxidation during drying by using moisture-free nitrogen and a minimum-free-space oven.

Key Topics

• Principle: A known mass of coal is heated in nitrogen at 105 °C to 110 °C until constant mass; moisture is the loss in mass.
• Reagent: Nitrogen, moisture-free, with an oxygen volume fraction < 30 µl/l. Commercial nitrogen with water content < 5 µl/l normally requires no further drying.
• Apparatus highlights:
  • Analytical balance readable to 0.1 mg.
  • Oven controlled at 105–110 °C with nitrogen flow approximately 15 times the oven volume per hour and minimum free space (Annex A gives an example).
  • Shallow weighing dishes with well-fitting covers; coal layer not to exceed 0.20 g/cm².
  • Cooling vessel (desiccator) without desiccant; metal plate for initial cooling.
• Sample and procedure:
  • Use the general analysis test sample equilibrated with the laboratory atmosphere and mixed thoroughly for at least 1 min.
  • Weigh dish + cover, add 1 g ± 0.1 g coal in an even layer, dry in nitrogen for at least 60 min, cool and reweigh.
  • If needed, reheat for further 30 min intervals until mass change ≤ 1 mg.
• Expression of results: Report moisture mass fraction w (%) calculated from pre- and post-drying masses and report the mean of duplicate determinations to the nearest 0.1 %.
• Precision: Repeatability limits are provided: differences between duplicates should not exceed 0.10% (for moisture < 5%) or 0.15% (for moisture ≥ 5%). Reproducibility limits are not fixed because laboratory humidity varies.

Applications

• Routine laboratory determination of moisture content in hard coal general analysis samples.
• Correction of analytical results (volatile matter, hydrogen) to a dry basis.
• Quality control and comparative reporting across laboratories when the prescribed procedure is followed.

Practical tips: ensure samples are equilibrated to lab humidity, avoid opening the oven during drying, use covers immediately after removal, and perform duplicate determinations for reliable reporting.

Related Standards

• ISO 1213-2 - Vocabulary: terms relating to sampling, testing and analysis (normative reference used by ISO 11722).
• ISO/TC 27 (Solid mineral fuels) provides the technical committee and context for this method.

This summary highlights the practical steps and value of ISO 11722:2013 for consistent, comparable moisture determination in hard coal using nitrogen drying.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11722
Second edition
2013-07-01
Solid mineral fuels — Hard coal —
Determination of moisture in the
general analysis test sample by
drying in nitrogen
Combustibles minéraux solides — Houille — Détermination
de l’humidité de l’échantillon pour analyse par dessiccation en
atmosphère d’azote
Reference number
©
ISO 2013
© ISO 2013
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ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normatives references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagent . 1
6 Apparatus . 1
7 Preparation of the test sample . 2
8 Procedure. 2
9 Expression of results . 2
10 Precision . 2
10.1 Repeatability limit . 2
10.2 Reproducibility limit . 2
11 Test report . 3
Annex A (informative) Example of a suitable oven . 4
Foreword
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The committee responsible for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 5,
Methods of analysis.
This second edition cancels and replaces the first edition (ISO 11722:1999), of which it constitutes a
minor revision.
iv © ISO 2013 – All rights reserved

Introduction
The determination of the moisture in the general analysis test sample is required to correct the results
of certain analytical determinations, e.g. volatile matter and hydrogen, for the effect of water in the
determinatio
...