1、BS ISO 13909-4:2016Hard coal and coke Mechanical samplingPart 4: Coal Preparation of test samplesBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 13909-4:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 13909-4:2016.It
2、 supersedes BS ISO 13909-4:2001 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/16, Solid mineral fuels.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all
3、 the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 83177 5ICS 73.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standar
4、d was published under the authority of theStandards Policy and Strategy Committee on 30 June 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 13909-4:2016 ISO 2016Hard coal and coke Mechanical sampling Part 4: Coal Preparation of test samplesHouille et coke chant
5、illonnage mcanique Partie 4: Charbon Prparation des chantillons pour essaiINTERNATIONAL STANDARDISO13909-4Second edition2016-07-01Reference numberISO 13909-4:2016(E)BS ISO 13909-4:2016ISO 13909-4:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll
6、 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 fr
7、om either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 13909-4:2016ISO 13909-4:2016(E)Foreword vIntroduction vi
8、1 Scope . 12 Normative references 13 Terms and definitions . 14 Precision of sample preparation . 15 Constitution of a sample . 25.1 Introduction 25.2 Combination of increments 25.2.1 Time-basis sampling . 25.2.2 Mass-basis sampling . 25.3 Combination of samples . 36 Division . 36.1 General . 36.2 M
9、echanical methods . 106.2.1 General. 106.2.2 Mass of cut 106.2.3 Interval between cuts .106.2.4 Division of individual increments 106.2.5 Division of samples .136.3 Manual methods . 146.3.1 Riffle method 146.3.2 Flattened-heap method . 156.3.3 Strip-mixing and splitting method 177 Reduction 197.1 Ge
10、neral 197.2 Reduction mills 198 Mixing199 Air-drying 1910 Preparation of samples for specific tests .2010.1 Types of test samples . 2010.2 Preparation of samples for determination of total moisture only .2010.2.1 General. 2010.2.2 Storage . 2210.2.3 Sample reduction2210.2.4 Sample division 2310.3 Pr
11、eparation of samples for general analysis only 2310.3.1 General. 2310.3.2 Air-drying 2310.3.3 Reduction and division 2310.4 Common samples . 2410.4.1 General. 2410.4.2 Extraction of moisture sample by mechanical division.2510.4.3 Extraction of moisture sample by manual method .2510.5 Preparation of
12、size-analysis sample 2610.6 Preparation of samples for other tests 2711 Reserve sample .2812 Design of equipment for preparation 2812.1 Dividers 28 ISO 2016 All rights reserved iiiContents PageBS ISO 13909-4:2016ISO 13909-4:2016(E)12.2 Design of cutters for falling-stream dividers . 2812.2.1 General
13、. 2812.2.2 Cutter velocity .2912.3 Preparation systems 2912.3.1 General. 2912.3.2 Design criteria .2912.3.3 Abnormal operation .3012.4 Provision for checking for precision . 3012.5 Provision for testing for bias 30Bibliography .31iv ISO 2016 All rights reservedBS ISO 13909-4:2016ISO 13909-4:2016(E)F
14、orewordISO (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 tec
15、hnical 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 o
16、f 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
17、 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 p
18、atent 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 no
19、t constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information
20、.The committee responsible for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 4, Sampling.This second edition cancels and replaces the first edition (ISO 13909-4:2001), which has been technically revised.ISO 13909 consists of the following parts, under the general title Hard coal a
21、nd coke Mechanical sampling: Part 1: General introduction Part 2: Coal Sampling from moving streams Part 3: Coal Sampling from stationary lots Part 4: Coal Preparation of test samples Part 5: Coke Sampling from moving streams Part 6: Coke Preparation of test samples Part 7: Methods for determining t
22、he precision of sampling, sample preparation and testing Part 8: Methods of testing for bias ISO 2016 All rights reserved vBS ISO 13909-4:2016ISO 13909-4:2016(E)IntroductionThe objective of sample preparation is to prepare one or more test samples from the primary increments for subsequent analysis.
23、 The requisite mass and particle size of the test sample depend on the test to be carried out.The process of sample preparation may involve constitution of samples, reduction, division, mixing and drying, or all or a combination of these.Primary increments may be prepared individually as test sample
24、s or combined to constitute samples either as taken or after having been prepared by reduction and/or division. Samples may either be prepared individually as test samples or combined on a weighted basis to constitute a further sample.When difficulty in handling the coal or coals being sampled is ex
25、pected at a particular stage in sample preparation, or if there is a likelihood of losing moisture by evaporation, it is necessary to withdraw the sample or increment from the on-line system at the stage immediately prior to the point of difficulty and proceed off-line.vi ISO 2016 All rights reserve
26、dBS ISO 13909-4:2016Hard coal and coke Mechanical sampling Part 4: Coal Preparation of test samples1 ScopeThis part of ISO 13909 describes the preparation of samples of coal from the combination of primary increments to the preparation of samples for specific tests.2 Normative referencesThe followin
27、g documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 589, Hard coal D
28、etermination of total moistureISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire clothISO 13909-1, Hard coal and coke Mechanical sampling Part 1: General introductionISO 13909-2, Hard coal and coke Mechanical sampling Part 2: Coal Sampling from moving stream
29、sISO 13909-3, Hard coal and coke Mechanical sampling Part 3: Coal Sampling from stationary lotsISO 13909-7, Hard coal and coke Mechanical sampling Part 7: Methods for determining the precision of sampling, sample preparation and testingISO 13909-8, Hard coal and coke Mechanical sampling Part 8: Meth
30、ods of testing for bias3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 13909-1 apply.4 Precision of sample preparationFrom the equations given in ISO 13909-7, the estimated absolute value of the precision of the result obtained for the lot at the 95 %
31、 confidence level, PL, for sampling is given by Formula (1):PVnVmLIPT=+2 (1)whereINTERNATIONAL STANDARD ISO 13909-4:2016(E) ISO 2016 All rights reserved 1BS ISO 13909-4:2016ISO 13909-4:2016(E)PLis the estimated overall precision of sampling, sample preparation and testing for the lot at a 95 % confi
32、dence level, expressed as a percentage absolute;VIis the primary increment variance;VPTis the preparation and testing variance for both off-line and on-line systems;n is the number of increments to be taken from a sub-lot;m is the number of sub-lots in the lot.The procedures given in this part of IS
33、O 13909 are designed to achieve levels of VPTof 0,2 or less for both ash and moisture tests. Better levels are expected when using mechanical dividers.For some preparation schemes, however, practical restrictions may prevent the preparation and testing variance being as low as this. Under these circ
34、umstances, the user should decide whether to achieve the desired overall precision by improving the preparation scheme or by dividing the lot into a greater number of sub-lots.The errors occurring in the various stages of preparation and analysis, expressed in terms of variance, may be checked by th
35、e method given in ISO 13909-7.5 Constitution of a sample5.1 IntroductionPrimary increments shall be taken in accordance with the procedures specified in ISO 13909-2 and ISO 13909-3.Individual increments are usually combined to form a sample. A single sample may be constituted by combination of incre
36、ments taken from a complete sub-lot or by combining increments taken from individual parts of a sub-lot. Under some circumstances, e.g. size analysis or bias testing, the sample consists of a single increment which is prepared and tested. Examples of the constitution of samples are shown in Figure 1
37、.The procedures for increment combination (5.2) may vary according to whether the primary increments were taken using a time-basis (5.2.1) or a mass-basis (5.2.2) sampling scheme.Samples may also be prepared by the combination of other samples (see 5.3).5.2 Combination of increments5.2.1 Time-basis
38、samplingThe mass of the primary increments shall be proportional to the flow rate at the time of sampling. The primary increments may be combined into a sample either directly as taken or after having been prepared individually to an appropriate stage by fixed-ratio division (see Clause 6).5.2.2 Mas
39、s-basis samplingIf the primary increments are of almost uniform mass (see note), they may be combined into a sample, either directly as taken or after having been prepared individually to an appropriate stage by fixed-ratio division (see Clause 6).NOTE Almost uniform mass has been achieved if the co
40、efficient of variation of the increment masses is less than 20 % and there is no significant correlation between the flow rate at the time of taking the increment and the mass of the increment (see ISO 13909-2:2016, Annex A).2 ISO 2016 All rights reservedBS ISO 13909-4:2016ISO 13909-4:2016(E)If the
41、primary increments are not of almost uniform mass, they may only be combined into samples after having been divided individually by fixed-mass division (see Clause 6).a) Example 1b) Example 2Figure 1 Examples of the constitution of samples5.3 Combination of samplesWhen combining samples, the mass of
42、 the individual samples shall be directly proportional to the mass of the coal from which they were taken in order to obtain a weighted mean of the quality characteristic for the sub-lot. Prior to combination, division shall be by fixed-ratio division (see Clause 6).6 Division6.1 GeneralDivision can
43、 be on-line mechanically, or off-line mechanically or manually.Whenever possible, mechanical methods are preferred to manual methods to minimize human error. Examples of dividers are shown in Figure 2. ISO 2016 All rights reserved 3BS ISO 13909-4:2016ISO 13909-4:2016(E)Mechanical dividers are design
44、ed to extract one or more parts of the coal in a number of cuts of relatively small mass. When the smallest mass of the divided sample that can be obtained in one pass through the divider is greater than that required further passes through the same divider or subsequent passes through further divid
45、ers may be necessary.If coal does not run freely through a sample divider it may be necessary to air-dry the sample as described in Clause 10 before sample division is undertaken.Manual division is normally applied when mechanical methods would result in loss of integrity, e.g. loss of moisture or s
46、ize degradation. Manual methods may themselves result in bias, particularly if the mass of coal to be divided is large.a) Rotating disc type b) Rotating cone typeKey Key1 feed 1 feed2 reject 2 rotating cone3 divided sample 3 adjustable slot4 divided sample5 rejectThe material from a mixing container
47、 is fed by scrapers to the centre of the dividing disc. From there it is discharged over the range of the disc through special clearing arms. The sample falls through adjustable slots into chutes; the reject is carried away through a cleaning conduit. The whole interior space is cleaned by scrapers.
48、A stream of coal is allowed to fall onto a rotating cone; the adjustable slot with lips in the cone allows the stream to fall directly onto the sample receiver for part of each revolution.Figure 2 Examples of dividers4 ISO 2016 All rights reservedBS ISO 13909-4:2016ISO 13909-4:2016(E)c) Container ty
49、peKey1 feed2 divided sample in rotating receiversThe coal stream flows to the hopper and this flow is intercepted by the top edge of a number of sector-shaped containers dividing the flow into equal parts. Either the hopper or the containers may rotate. The machine can be controlled for the following operations:1) for dividing;2) for collecting duplicates;3) for collecting replicates.Figure 2 Examples of dividers (continued) ISO 2016 All rights reserved 5BS ISO 1
