Solid mineral fuels -- Determination of carbonate carbon content -- Gravimetric method

This document specifies a gravimetric method of determining the carbon in the mineral carbonates associated with solid mineral fuels. NOTE The result obtained will include any carbon from atmospheric carbon dioxide absorbed by the fuel.

Combustibles minéraux solides -- Dosage du carbone sous forme de carbonate -- Méthode gravimétrique

General Information

Status
Published
Publication Date
15-Jul-2019
Current Stage
6060 - International Standard published
Start Date
13-Jun-2019
Completion Date
16-Jul-2019
Ref Project

RELATIONS

Buy Standard

Standard
ISO 925:2019 - Solid mineral fuels -- Determination of carbonate carbon content -- Gravimetric method
English language
8 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 925
Fourth edition
2019-07
Solid mineral fuels — Determination
of carbonate carbon content —
Gravimetric method
Combustibles minéraux solides — Dosage du carbone sous forme de
carbonate — Méthode gravimétrique
Reference number
ISO 925:2019(E)
ISO 2019
---------------------- Page: 1 ----------------------
ISO 925:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 925:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 1

5 Reagents ........................................................................................................................................................................................................................ 1

6 Apparatus ..................................................................................................................................................................................................................... 2

7 Preparation of the test sample ............................................................................................................................................................... 3

8 Procedure..................................................................................................................................................................................................................... 4

8.1 Check test ..................................................................................................................................................................................................... 4

8.2 Determination ......................................................................................................................................................................................... 5

8.2.1 Preparation ........................................................................................................................................................................... 5

8.2.2 Conditioning ........................................................................................................................................................................ 5

8.2.3 Reaction and completion .......................................................................................................................................... 5

9 Expression of results ........................................................................................................................................................................................ 5

10 Precision ....................................................................................................................................................................................................................... 6

10.1 Repeatability limit ................................................................................................................................................................................ 6

10.2 Reproducibility critical difference ......................................................................................................................................... 6

11 Test report ................................................................................................................................................................................................................... 7

Annex A (informative) Derivation of factors used in calculations in this document ..........................................8

© ISO 2019 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 925:2019(E)
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 during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions 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, Solid mineral fuels, Subcommittee

SC 5, Methods of analysis.

This fourth edition cancels and replaces the third edition (ISO 925:1997), of which it constitutes a minor

revision. The changes compared to the previous edition are as follows:
— the normative references have been updated and the dates removed;
— the references in Clause 7 have been updated.

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 © ISO 2019 – All rights reserved
---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 925:2019(E)
Solid mineral fuels — Determination of carbonate carbon
content — Gravimetric method
1 Scope

This document specifies a gravimetric method of determining the carbon in the mineral carbonates

associated with solid mineral fuels.

NOTE The result obtained will include any carbon from atmospheric carbon dioxide absorbed by the fuel.

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 687, Solid mineral fuels — Coke — Determination of moisture in the general analysis test sample

ISO 1170, Coal and coke — Calculation of analyses to different bases

ISO 5068-2, Brown coals and lignites — Determination of moisture content — Part 2: Indirect gravimetric

method for moisture in the analysis sample

ISO 11722, Solid mineral fuels — Hard coal — Determination of moisture in the general analysis test

sample by drying in nitrogen

ISO 13909-4, Hard coal and coke — Mechanical sampling — Part 4: Coal — Preparation of test samples

ISO 13909-6, Hard coal and coke — Mechanical sampling — Part 6: Coke — Preparation of test samples

ISO 18283, Hard coal and coke — Manual sampling
3 Terms and definitions
No terms and definitions are listed in this document.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Principle

A known mass of sample is treated with hydrochloric acid, which reacts with the carbonates present

to liberate carbon dioxide. The carbon dioxide resulting from the decomposition of the carbonates is

absorbed and weighed.
5 Reagents

WARNING — Care should be exercised when handling reagents, many of which are toxic and

corrosive.
© ISO 2019 – All rights reserved 1
---------------------- Page: 5 ----------------------
ISO 925:2019(E)

During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only

distilled water, or water of equivalent purity.

NOTE Distilled water can be freed from carbon dioxide by boiling gently for 15 min.

5.1 Hydrochloric acid, approximately 3 mol/l.
5.2 Hydrogen sulfide absorbent, any of the following:
a) copper(II) phosphate, granular, particle size 1,2 mm to 0,7 mm;
NOTE 1 Copper(II) phosphate granules can be prepared as follows.

Mix copper(II) phosphate powdered reagent to a stiff paste with 1 % starch solution. Press through a sheet

of metal, perforated with apertures of approximately 1 mm diameter. Dry the extruded material at 110 °C.

Sieve to recover the desired size fraction.
b) copper(II) sulfate, deposited on a supporting base of ground pumice;

NOTE 2 A suitable absorbent, based on copper(II) sulfate, can be prepared as follows.

Prepare pumice by crushing and sieving to obtain the 2,8 mm to 0,7 mm fraction. Transfer approximately

60 g of the prepared pumice to an evaporating basin, covering with a saturated solution of copper(II) sulfate,

evaporate to dryness with constant stirring, and heat at 150 °C to 160 °C for 3 h to 4 h. Cool in a desiccator

and store in a glass-stoppered bottle.
c) silver sulfate, granular.
5.3 Magnesium perchlorate, anhydrous, particle size 1,2 mm to 0,7 mm.
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.