ISO/TS 4667:2022

TECHNICAL ISO/TS
SPECIFICATION 4667
First edition
2022-08
Coal — Determination of the thermal
stability and thermal fragmentation
Reference number
ISO/TS 4667:2022(E)
© ISO 2022

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ISO/TS 4667:2022(E)
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ISO/TS 4667:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
4.1 Thermal stability . 2
4.2 Thermal fragmentation . 2
5 Apparatus . 2
6 Preparation of test sample . 3
7 Procedure .3
7.1 Thermal stability . 3
7.2 Thermal fragmentation . 4
8 Expression of result . 5
9 Precision . 6
9.1 Repeatability limit . 6
9.2 Reproducibility limit . 6
10 Test report . 6
Bibliography . 7
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ISO/TS 4667:2022(E)
Foreword
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This document was prepared by Technical Committee ISO/TC 27, Coal and coke, Subcommittee SC 5,
Methods of analysis.
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ISO/TS 4667:2022(E)
Introduction
Coal gasification is an important technology for clean coal conversion, which involves many factors.
The thermal stability of coal is one of the essential parameters for the gasification industry and its
relevant coal trade.
The thermal stability of coal is a measure of how much a coal retains its original size under high-
temperature reaction during the process of gasification or high-temperature combustion. The coal with
a better thermal stability can be gasified or burnt in its original size without being broken, or while
being only a little bit broken, during the process of gasification or combustion, while the coal with a
poor thermal stability will be broken into smaller piece or into powder. When using a coal with poor
thermal stability for the gasification or combustion, the materials being taken from the furnace will
increase, causing the resistance to increase, which in turn, affects the gasification or combustion and
decreases the efficiency of the gasification. So, the thermal stability of coal is a very important property
highly concerned by the gasification or combustion industry of utilizing the sized coal for gasification
or combustion.
The opposite property of thermal stability of coal is the thermal fragmentation. Thermal fragmentation
has a highly significant negative linear correlation with thermal stability.
This document is based on GB/T1573 and on an alternative laboratory method to determine thermal
fragmentation of coal sources during pyrolysis in the gasification process given in Reference [3]
including two parameters of thermal stability (TS ) and thermal fragmentation (TF), both of which
+6
can be used for guiding the coal gasification of fixed bed.
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TECHNICAL SPECIFICATION ISO/TS 4667:2022(E)
Coal — Determination of the thermal stability and thermal
fragmentation
1 Scope
This document specifies methods for the determination of thermal stability and thermal fragmentation
of coal. It is applicable to brown coal and lignites, anthracites and bituminous coal with a caking index
of zero (determined by ISO 15585).
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 1213-2, Solid mineral fuels — Vocabulary — Part 2: Terms relating to sampling, testing and analysis
ISO 18283, Coal and coke — Manual sampling
ISO 13909-4, Hard coal and coke — Mechanical sampling — Part 4: Coal — Preparation of test samples
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-2 and the following
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 .elec
...