Solid mineral fuels — Determination of phosphorus content — Reduced molybdophosphate photometric method

ISO 622:2016 specifies a reduced molybdophosphate photometric method for the determination of the total phosphorus content of hard coal, lignites and coke. Two methods for taking the phosphorus into solution are specified, namely extraction from the coal or coke ash with acid or by repeated oxidation of the coal or coke, by acid, to remove carbonaceous matter.

Combustibles minéraux solides — Dosage du phosphore — Méthode photométrique au molybdophosphate réduit

General Information

Status
Published
Publication Date
17-Nov-2016
Current Stage
9020 - International Standard under periodical review
Start Date
15-Oct-2021
Ref Project

RELATIONS

Buy Standard

Standard
ISO 622:2016 - Solid mineral fuels -- Determination of phosphorus content -- Reduced molybdophosphate photometric method
English language
6 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 622
Second edition
2016-11-15
Solid mineral fuels — Determination
of phosphorus content — Reduced
molybdophosphate photometric
method
Combustibles minéraux solides — Dosage du phosphore — Méthode
photométrique au molybdophosphate réduit
Reference number
ISO 622:2016(E)
ISO 2016
---------------------- Page: 1 ----------------------
ISO 622:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, 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. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 622:2016(E)
Contents Page

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

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

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

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

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

4.1 Extraction .................................................................................................................................................................................................... 1

4.2 Determination ......................................................................................................................................................................................... 1

5 Reagents ........................................................................................................................................................................................................................ 2

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

7 Sample preparation ........................................................................................................................................................................................... 3

8 Procedure..................................................................................................................................................................................................................... 3

8.1 Dry oxidation method ....................................................................................................................................................................... 3

8.2 Wet oxidation method ...................................................................................................................................................................... 4

8.3 Determination ......................................................................................................................................................................................... 5

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

9.1 Method of calculation and formulae ..................................................................................................................................... 5

10 Precision of the method ................................................................................................................................................................................ 6

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

10.2 Reproducibility ....................................................................................................................................................................................... 6

© ISO 2016 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 622:2016(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 on 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 the following URL: www.iso.org/iso/foreword.html.

The committee responsible for this document is ISO/TC 27, Solid minerals fuels, Subcommittee SC 5,

Methods of analysis.

This second edition cancels and replaces the first edition (ISO 622:1981), which has been technically

revised. This document incorporates changes related to references and other minor items following its

systematic review.
iv © ISO 2016 – All rights reserved
---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 622:2016(E)
Solid mineral fuels — Determination of phosphorus content
— Reduced molybdophosphate photometric method
1 Scope

This document specifies a reduced molybdophosphate photometric method for the determination of the

total phosphorus content of hard coal, lignites and coke. Two methods for taking the phosphorus into

solution are specified, namely extraction from the coal or coke ash with acid or by repeated oxidation of

the coal or coke, by acid, to remove carbonaceous matter.
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 383, Laboratory glassware — Interchangeable conical ground joints

ISO 565, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes

of openings
ISO 1171, Solid mineral fuels — Determination of ash
ISO 18283, Hard coal and coke — Manual sampling
3 Terms and definitions
No terms and definitions are defined in this document.

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

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

Method 1: Removal of carbonaceous material by ashing in a muffle furnace under specified conditions,

and extraction of phosphorus by treatment with hydrofluoric and sulphuric acids.

Method 2: Removal of carbonaceous material by repeated oxidation with nitric acid in the presence of

sulphuric acid.
4.2 Determination

Addition of ammonium molybdate and ascorbic acid solution to the acid solution. Measurement of the

absorbance of the resulting blue solution by a suitable optical instrument.
© ISO 2016 – All rights reserved 1
---------------------- Page: 5 ----------------------
ISO 622:2016(E)
5 Reagents

During the analysis, use only reagents of recognized analytical grade and only distilled water or water

of equivalent purity.
5.1 Hydrofluoric acid, approximately 400 g/l solution.

WARNING — Aqueous hydrofluoric acid is a highly corrosive liquid which attacks glass; the

vapour is irritant and toxic. Its action on the skin and eyes is strongly corrosive, producing

severe and painful burns which may not be immediately evident and which respond slowly to

treatment. The solution should be handled only inside a well-ventilated fume cupboard. In the

event of contact or suspected contact, flood with water and seek immediate medical attention.

The manufacturer’s literature should be consulted for further information.
5.2 Sulphuric acid, approximately 490 g/l solution.

5.3 Sulphuric acid, concentrated, ρ 1,84 g/ml, approximately 98 % (m/m) solution.

5.4 Nitric acid, concentrated, ρ 1,42 g/ml, approximately 70 % (m/m) solution.
5.5 Ammonium molybdate, 60 g/l solution.
5.6 Ascorbic acid, 50 g/l solution.
Prepare the solution fresh daily.
5.7 Antimony potassium tartrate (KSbO·C H O ), 1,36 g/l solution.
4 4 6
5.8 Reagent solution.
Mix 25 ml of the sulphuric acid solution (5.2), 10 ml of the
...

Questions, Comments and Discussion

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