Foreword

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This document was prepared by Technical Committee ISO/TC 27, Coal and coke, Subcommittee SC 5, Methods of analysis.

This third edition cancels and replaces the second edition ( ISO 625:1996 ), which has been technically revised. It also incorporates the Technical Corrigendum ISO 625:1996/Cor. 1:1996 .

The main changes are as follows:

the normative references have been updated;
the mandatory terms and definitions clause (Clause 3) has been added and subsequent clauses have been renumbered;
Clause 5 has been updated;
Figures 1, 2, 3 and 4 have been updated;
Clause 9 has been updated;
Clause 11 has been revised;
the test report has been updated;
Annex A has been revised.

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.

Introduction

An alternative method to the one specified in this document is given in ISO 609 .

1 Scope

This document specifies a method of determining the total carbon and the total hydrogen in coal and coke, by the Liebig method.

2 Normative references

3 Terms and definitions

4 Principle

5 Reagents and materials

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

5.10

5.11

5.12

6 Apparatus

6.1

6.2

6.3

6.4

6.5

6.6

6.7

6.8

6.9

6.10

6.11

7 Preparation of the apparatus

7.1 Preparation of the combustion tube

7.2 Conditioning of the combustion tube

7.3 Conditioning of the absorption train

8 Preparation of test sample

9 Procedure

10 Blank test

11 Expression of results

11.1 Total carbon

11.2 Organic carbon

11.3 Total hydrogen

11.4 Total hydrogen mass fraction, less that present as moisture

11.5 Additional information

12 Precision

12.1 Repeatability limit

12.2 Reproducibility limit

13 Test report

Bibliography

ISO 625:2025

Coal and coke. Determination of carbon and hydrogen. Liebig method

Current

Published:

8 Aug 2025

1 Scope