1、BS ISO 16742:2014Iron ores Sampling ofslurriesBS ISO 16742:2014Incorporating corrigendum July 2016BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2014Iron ores Sampling of slurriesMinerais de fer chantillonnage des schlammsINTERNATIONAL STANDARDISO16742First edi
2、tion2014-03-01Reference numberISO 16742:2014(E)Corrected version2015-09-15BS ISO 16742:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 16742:2014.The UK participation in its preparation was entrusted to Technical Committee ISE/58, Iron ores.A list of organ
3、izations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 20
4、16ISBN 978 0 580 95262 3ICS 73.060.10Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2014.Amendments/corrigenda issued since publicationDate Text affect
5、ed31 July 2016 Implementation of ISO corrected text 15 September 2015: Table 3 corrected ISO 2014Iron ores Sampling of slurriesMinerais de fer chantillonnage des schlammsINTERNATIONAL STANDARDISO16742First edition2014-03-01Reference numberISO 16742:2014(E)Corrected version2015-09-15ISO 16742:2014(E)
6、ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014, Published in SwitzerlandAll 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
7、 on the internet or an intranet, without prior written permission. Permission can be requested from 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 74
8、9 09 47copyrightiso.orgwww.iso.orgBS ISO 16742:2014ISO 16742:2014(E)Foreword v1 Scope . 12 Normative references 13 Terms and definitions . 24 General considerations for sampling slurries . 24.1 Basic requirements . 24.2 Sampling errors 34.3 Establishing a sampling scheme 45 Fundamentals of sampling
9、and sample preparation 65.1 Minimization of bias . 65.2 Volume of increment for falling stream samplers to avoid bias . 75.2.1 Linear cross-stream cutter 75.2.2 Vezin cutter . 85.3 Volume of increment for manual sampling to avoid bias . 85.4 Overall precision 95.5 Quality variation . 105.6 Sampling
10、precision and number of primary increments 115.7 Precision of sample preparation and overall precision 116 Minimum mass of solids in gross and partial samples 126.1 General 126.2 Minimum mass of solids in gross samples . 126.3 Minimum mass of solids in partial samples 137 Time-basis sampling .137.1
11、General 137.2 Sampling interval . 137.3 Cutters . 137.4 Taking of increments 147.5 Constitution of gross or partial samples 147.6 Division of increments and partial samples . 147.7 Division of gross samples 147.8 Number of cuts for division 148 Stratified random sampling within fixed time intervals1
12、49 Mechanical sampling from moving streams .159.1 General 159.2 Design of the sampling system . 159.2.1 Safety of operators 159.2.2 Location of sample cutters . 159.2.3 Provision for duplicate sampling 159.2.4 System for checking the precision and bias.159.2.5 Minimizing bias 169.3 Slurry sample cut
13、ters . 169.3.1 General. 169.3.2 Falling-stream cutters 179.3.3 Cutter velocities .179.4 Mass of solids in increments 179.5 Number of primary increments 179.6 Routine checking 1810 Manual sampling from moving streams 1810.1 General 1810.2 Choosing the sampling location 1810.3 Sampling implements 18 I
14、SO 2014 All rights reserved iiiContents PageBS ISO 16742:2014ISO 16742:2014(E)10.4 Volume of increments 1810.5 Number of primary increments 1910.6 Sampling procedures 1911 Sampling of stationary slurries 1912 Sample preparation procedures .2012.1 General 2012.2 Grinding mills 2012.3 Sample division
15、2012.4 Chemical analysis samples . 2012.5 Physical test samples 2013 Packing and marking of samples 20Annex A (informative) Examples of correct slurry sampling devices .22Annex B (informative) Examples of incorrect slurry sampling devices 25Annex C (normative) Manual sampling implements 28Bibliograp
16、hy .29iv ISO 2014 All rights reservedBS ISO 16742:2014ISO 16742:2014(E)ForewordISO (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 techni
17、cal 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 w
18、ith 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
19、 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 rig
20、hts. 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 thi
21、s 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 ISOs adherence to the WTO principles in the Technical Barriers to
22、 Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 1, Sampling.This corrected version of ISO 16742:2014 incorporates the following correction: In Table 3, third row, the
23、values in the second column (“Up to”) have been correctly aligned with the corresponding values in the first column (“Over”). ISO 2014 All rights reserved vBS ISO 16742:2014BS ISO 16742:2014Iron ores Sampling of slurriesWARNING This International Standard may involve hazardous materials, operations,
24、 and equipment, and does not purport to address all the safety issues associated with its use. It is the responsibility of the user of this International Standard to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use.1 ScopeThis I
25、nternational Standard sets out the basic methods for sampling fine iron ore of nominal top size W 1,5 WW 1,5 WW 0,4 WW 0,011 WW 2,25 W 2,25For iron ore slurries whose quality variation is unknown, measurements shall be conducted at the earliest opportunity in accordance with ISO 3084 to determine th
26、e quality variation. Prior to the determination of quality variation, the classification adopted shall be as follows:a) when no prior information exists on the quality variation of the slurry or similar slurries, the slurry shall be considered to have “large” quality variation;b) when prior informat
27、ion exists on the quality variation of a similar slurry, the quality variation classification of that slurry shall be adopted as the starting point.10 ISO 2014 All rights reservedBS ISO 16742:2014ISO 16742:2014(E)When separate samples are taken for the determination of chemical composition, moisture
28、 content and size distribution, the quality variation for the individual characteristics shall be adopted. When separate samples are taken for the determination of other physical characteristics or metallurgical properties not specified in Table 2, large quality variation should be used. When the sa
29、mple is used for the determination of more than one quality characteristic, the largest classification category for quality variation in Table 2 shall be adopted.For small lots, it cannot be possible to take the number of increments specified by Formula 8 for large quality variation. In this case, t
30、he maximum number of increments possible shall be taken, but in an attempt to compensate for the poorer sampling precision, the precision of sample preparation shall be improved to achieve the required overall precision SPM, e.g. by preparing and analysing more partial samples. The procedure adopted
31、 should be recorded in the sampling report.5.6 Sampling precision and number of primary incrementsWhen the value of Wis known, the number of primary increments, n1, can be calculated for the desired sampling precision, S, as follows:n122=()wS(8)This is the preferable method of determining the number
32、 of primary increments. However, when the value of Wis classified in terms of large, medium, or small quality, variation in accordance with Table 2 and Table 3 can be used to determine the minimum number of primary increments required for the sampling precision, S, specified. In Table 3, the levels
33、of sampling precision have been increased slightly for smaller lot sizes as a trade-off between sampling cost and the uncertainty in the value of the lot.Table 3 Example of minimum number of increments required, n1, for desired sampling precision, SMass of lot (1 000 t)Sampling precision SNumber of
34、primary increments n1Over Up toFe or SiO2contentAl2O3contentP contentPellet feed, 45 m fractionQuality variationLarge (L), medium (M), or small (S)L M S100704530150100704530150,350,370,390,420,450,500,100,110,110,120,130,140,002 60,002 70,002 90,003 10,003 40,003 70,530,560,590,630,680,7520018016014
35、01201001009080706050504540353025NOTE The values of n1can be increased or decreased to alter the sampling precision, e.g. if the number of increments is 2n1, then Swill be improved by a factor of 1/2 = 0,71; and if it is n1/2, then Swill be worsened by a factor of 2 = 1,4.5.7 Precision of sample prep
36、aration and overall precisionThe precision of sample preparation depends on the choice of the sample preparation scheme. It can be improved if sample preparation is carried out first on individual increments or partial samples at an appropriate stage of sample preparation and then the divided increm
37、ents or partial samples are combined into a gross sample. ISO 2014 All rights reserved 11BS ISO 16742:2014ISO 16742:2014(E)Where a very precise result is required and the sampling variance has been minimized, consideration has to be given to increasing the number of sample preparations and measureme
38、nts to reduce these components of the overall variance. This is achieved by carrying out multiple determinations on the contained solids in the lot sample, i.e. replicate analyses, analysing the contained solids in individual increments, or preparing a number of partial samples and analysing the con
39、tained solids in each partial sample.The overall variance in each case is then given by one of the following formulae.a) Where a single lot sample is constituted from a lot and n2replicate determinations on the contained solids are carried out on the lot sample,SPM2SPM=+2222n(9)b) Where n3partial sa
40、mples are prepared, each constituted from the contained solids of an equal number of increments, and n2replicate determinations are carried out on each partial sample,SPMSPM222223=+nn(10)c) Where all n1primary increments are prepared and a single determination is carried out on the contained solids
41、of each increment,SPMSPM222121=+nn(11)6 Minimum mass of solids in gross and partial samples6.1 GeneralIt is essential to ensure that the mass of solids contained in gross samples collected from the slurry is sufficient to obtain the required sampling precision. Subject to increments being taken in a
42、n unbiased manner (see 5.1, 5.2, and 5.3), the combination of the average mass of solids contained in a slurry increment and the number of increments determined in 5.6 will ensure that a slurry sample with sufficient mass of contained solids is collected at the primary sampling stage. However, durin
43、g subsequent reduction and division of increments (if required), partial samples and gross samples, it is important to ensure that sufficient mass of solids is retained at each stage of division to achieve the desired sampling variance.6.2 Minimum mass of solids in gross samplesThe minimum mass of s
44、olids in a sample is dependent on the nominal top size of the particles in the slurry, the precision required for the parameter concerned, and the heterogeneity of the particles as a function of particle size. Such a relationship applies at all stages of preparation. The attainment of this mass will
45、 not, in itself, guarantee the required precision, because precision is also dependent on the number of increments in the sample and their variability.However, given that the nominal top size of particles in a slurry are 1 mm (see Clause 1), in practice the minimum mass of solids in the gross sample
46、 is determined by the required mass of the chemical analysis sample (100 g) and the required number of samples, i.e. one for the seller, one for the buyer, one for the arbitrator, and one in reserve. Taking this into account, the minimum mass of solids in the gross sample shall be 0,5 kg.12 ISO 2014
47、 All rights reservedBS ISO 16742:2014ISO 16742:2014(E)When preparing samples for multiple use, account shall also be taken of the individual masses and size distribution of the test samples required for each test.6.3 Minimum mass of solids in partial samplesIt is essential that the combined mass of
48、solids contained in all partial samples prepared for the lot is, at each sampling stage, greater than the minimum mass of contained solids in the gross sample defined in 6.2.7 Time-basis sampling7.1 GeneralSampling of slurry streams is usually carried out on a time basis rather than a mass basis. Ti
49、me-basis sampling involves the following steps.a) Determine the size of the lot, e.g. an hour, a shift, or a days production.b) Distribute the required number of increments, on a uniform time basis, throughout the total time, tL, for sampling each lot.c) Extract slurry increments of volume proportional to the slurry flow rate at the time of taking each increment.7.2 Sampling intervalThe interval between taking increments for time-basis sampling is as follows:ttnL1(12)wheret is time inter
