BS ISO 10835-2007 Direct reduced iron and hot briquetted iron - Sampling and sample preparation《直接还原铁和热压铁 取样和制样》.pdf

1、BRITISH STANDARDBS ISO 10835:2007Direct reduced iron and hot briquetted iron Sampling and sample preparationICS 73.060.10g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g4

2、4g42g43g55g3g47g36g58BS ISO 10835:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2007 BSI 2007ISBN 978 0 580 60937 4National forewordThis British Standard is the UK implementation of ISO 10835:2007.The UK participation in its

3、 preparation was entrusted to Technical Committee ISE/58, Iron ores.A list of organizations 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 applica

4、tion.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsReference numberISO 10835:2007(E)INTERNATIONAL STANDARD ISO10835Second edition2007-02-15Direct reduced iron and hot briquetted iron Sampling and sample prep

5、arationMinerais de fer prrduits et fer briquet chaud chantillonnage et prparation des chantillons BS ISO 10835:2007ii iiiContents Page Foreword. v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 General considerations for sampling and sample preparation . 3 4.1 Basic requirements

6、. 3 4.2 Establishing a sampling scheme 4 4.3 System verification. 5 5 Fundamentals of sampling and sample preparation 5 5.1 Minimization of bias 5 5.1.1 General. 5 5.1.2 Minimization of particle-size degradation 5 5.1.3 Extraction of increments 5 5.1.4 Increment mass. 6 5.2 Overall precision. 7 5.3

7、Quality variation 9 5.4 Sampling precision and number of primary increments 9 5.4.1 Mass-basis sampling 9 5.4.2 Time-basis sampling 9 5.5 Precision of sample preparation and overall precision 11 5.5.1 General. 11 5.5.2 Preparation and measurement of gross sample . 11 5.5.3 Preparation and measuremen

8、t of partial samples 11 5.5.4 Preparation and measurement of each increment 11 6 Methods of sampling 12 6.1 Mass-basis sampling 12 6.1.1 Mass of increment 12 6.1.2 Quality variation 13 6.1.3 Number of primary increments . 13 6.1.4 Sampling interval 13 6.1.5 Methods of taking increments. 13 6.2 Time-

9、basis sampling 14 6.2.1 Mass of increment 14 6.2.2 Quality variation 14 6.2.3 Number of increments 14 6.2.4 Sampling interval 14 6.2.5 Methods of taking increments. 14 6.3 Stratified random sampling within fixed mass or time intervals . 15 6.3.1 General. 15 6.3.2 Fixed mass intervals. 15 6.3.3 Fixed

10、 time intervals 15 7 Sampling from moving streams 15 7.1 General. 15 7.2 Safety of operations . 16 7.3 Robustness of sampling installation 16 7.4 Versatility of sampling system 16 7.5 Primary samplers 16 7.5.1 Location . 16 7.5.2 Types of primary sampler 17 BS ISO 10835:2007iv 7.5.3 General design c

11、riteria for primary cutters 17 7.5.4 Cutter aperture of primary sampler. 21 7.5.5 Cutter speed of primary sampler. 21 7.6 Secondary and subsequent samplers 22 7.7 On-line sample preparation 22 7.7.1 Arrangement for sample preparation 22 7.7.2 Crushers. 22 7.7.3 Dividers 22 7.7.4 Dryers . 27 7.8 Chec

12、king precision and bias . 27 7.9 Cleaning and maintenance. 27 7.10 Example of a flowsheet 27 8 Sampling from stationary situations. 29 9 Stopped-belt reference sampling 29 10 Sample preparation. 30 10.1 Fundamentals 30 10.1.1 General . 30 10.1.2 Crushing and grinding 30 10.1.3 Mixing. 30 10.1.4 Samp

13、le division. 30 10.1.5 Mass of divided sample 31 10.1.6 Split use and multiple use of sample 33 10.2 Method of constituting partial samples or a gross sample 33 10.2.1 General . 33 10.2.2 Method of constitution for mass-basis sampling 33 10.2.3 Method of constitution for time-basis sampling 34 10.3

14、Mechanical methods of division 34 10.3.1 Mechanical increment division 34 10.3.2 Other mechanical-division methods . 35 10.4 Manual methods of division. 35 10.4.1 Manual increment division. 35 10.4.2 Fractional shoveling . 38 10.4.3 Manual riffle division method 39 10.5 Preparation of test sample fo

15、r physical testing. 40 10.6 Preparation of test sample for moisture determination 40 10.7 Preparation of test sample for chemical analysis .41 10.7.1 Mass and particle size 41 10.7.2 Preparation to 250 m 41 10.7.3 Final preparation to 160 m 42 10.7.4 Distribution of samples for chemical analysis. 42

16、 10.8 Example of sample-preparation process 43 11 Packing and marking of sample 43 Annex A (informative) Inspection of mechanical sampling systems 45 Annex B (normative) Equation for number of increments . 49 Annex C (normative) Riffle dividers 52 BS ISO 10835:2007vForeword ISO (the International Or

17、ganization 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 establ

18、ished 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 standardizati

19、on. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.

20、 Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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 pa

21、tent rights. ISO 10835 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 1, Sampling. This second edition cancels and replaces the first edition (ISO 10835:1995), which has been technically revised. BS ISO 10835:2007blankDirect reduced iron and hot bri

22、quetted iron Sampling and sample preparation WARNING This International Standard may involve hazardous materials, operations and equipment, and does not purport to address all of the safety issues associated with its use. It is the responsibility of the user of this standard to establish appropriate

23、 health and safety practices and determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard gives a) the underlying theory, b) the basic principles for sampling and preparation of samples, and c) the basic requirements for the design, installation and ope

24、ration of sampling systems, for mechanical sampling, manual sampling and preparation of samples taken from a lot under transfer, to determine the chemical composition, moisture content and physical properties of the lot. The methods specified in this International Standard are applicable to both the

25、 loading and discharging of direct reduced iron (DRI) and hot briquetted iron (HBI), by means of belt conveyors and other ore handling equipment to which a mechanical sampler may be installed or where stopped-belt sampling may safely be conducted. In this International Standard, DRI includes both re

26、duced pellets and reduced lump ores. CAUTION Direct reduced iron (DRI) and, in some cases, hot briquetted iron (HBI), for example, with low density or high fines content, may react with water and air to produce hydrogen and heat. The heat produced may cause ignition. Therefore, due consideration sha

27、ll be given to the safety of operators by respecting applicable regulations or international codes. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the late

28、st edition of the referenced document (including any amendments) applies. ISO 565:1990, Test sieves Metal wire cloth, perforated metal plate and electroformed sheet Nominal sizes of openings ISO 3084:1998, Iron ores Experimental methods for evaluation of quality variation ISO 3085:2002, Iron ores Ex

29、perimental methods for checking the precision of sampling, sample preparation and mesasurement ISO 3086:1998, Iron ores Experimental methods for checking the bias of sampling ISO 3087:1998, Iron ores Determination of moisture content of a lot 1BS ISO 10835:20072 ISO 3534-1:2006, Statistics Vocabular

30、y and symbols Part 1: General statistical terms and terms used in probability ISO 4701:1999, Iron ores Determination of size distribution by sieving ISO 11323:2002, Iron ores and direct reduced iron Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given

31、 in ISO 11323 and the following apply. 3.1 lot discrete and defined quantity of DRI or HBI for which quality characteristics are to be assessed 3.2 increment quantity of DRI or HBI collected in a single operation of a sampling device 3.3 sample relatively small quantity of DRI or HBI, taken from a l

32、ot so as to be representative in respect of the quality characteristics to be assessed 3.4 partial sample sample consisting of less than the complete number of increments needed for a gross sample 3.5 gross sample sample comprising all increments, entirely representative of all quality characteristi

33、cs of a lot 3.6 test sample sample prepared to meet all specific conditions for a test 3.7 test portion part of a test sample that is actually and entirely subjected to the specific test 3.8 stratified sampling sampling of a lot carried out by taking increments from systematically specified position

34、s and in appropriate proportions from identified parts called strata NOTE Examples of strata, based on time, mass or space, include production periods (e.g. 5 min), production masses (e.g. 1 000 t), holds in vessels, wagons in a train, or containers. 3.9 systematic sampling selection of increments a

35、t regular intervals from a lot 3.10 mass-basis sampling sampling carried out so that increments are taken at equal mass intervals, increments being, as near as possible, of uniform mass BS ISO 10835:200733.11 time-basis sampling sampling carried out so that increments are taken from free-falling str

36、eams, or from conveyors, at uniform time intervals, the mass of each increment being proportional to the mass flow rate at the instant of taking the increment 3.12 proportional sample division division of samples or increments such that the mass of each retained divided portion is a fixed proportion

37、 of the mass being divided 3.13 constant-mass division division of samples or increments such that the retained divided portions are of almost uniform mass, irrespective of variations in mass of the samples or increments being divided NOTE This method is required for sampling on a mass basis. “Almos

38、t uniform” means that variations in mass are less than 20 % in terms of the coefficient of variation. 3.14 split use of sample separate use of parts of a sample, as test samples for separate determinations of quality characteristics 3.15 multiple use of sample use of a sample in its entirety for the

39、 determination of one quality characteristic, followed by the use of the same sample in its entirety for the determination of one or more other quality characteristics 3.16 nominal top size of DRI smallest aperture size, within the range of the R20 Series (in ISO 565, square opening), such that no m

40、ore than 5 % by mass of the DRI is retained on the sieve 3.17 nominal top size of HBI prior to crushing, the largest average dimension of HBI briquettes, or, after crushing, the smallest aperture size, within the range of the R20 Series (in ISO 565, square opening), such that no more than 5 % by mas

41、s of the HBI is retained on the sieve 4 General considerations for sampling and sample preparation 4.1 Basic requirements The basic requirement for a correct sampling scheme is that all of the DRI or HBI in the lot has an equal opportunity of being selected and becoming part of the partial sample or

42、 gross sample for analysis. Any deviation from this basic requirement can result in an unacceptable loss of accuracy and precision. An incorrect sampling scheme cannot be relied on to provide representative samples. The best sampling location to satisfy the above requirement is at a transfer point b

43、etween conveyor belts. Here, the full cross-section of the DRI or HBI stream can be conveniently intercepted at regular intervals, enabling representative samples to be obtained. Alternatively, samples may be taken from a stopped conveyor belt, provided a full cross-section of DRI or HBI of adequate

44、 length is taken from the conveyor (see Clause 9). In situ sampling of ships, stockpiles, wagons, containers and bunkers is not permitted, because there is no suitable sampling device that can be driven down to the bottom and then extract the full column of DRI or HBI. Consequently, all parts of the

45、 lot do not have an equal opportunity of being sampled. The only effective procedure is sampling from a conveyor belt when the DRI or HBI is being conveyed to or from the ship, stockpile, container or bunker. BS ISO 10835:20074 Sampling shall be carried out by systematic sampling or stratified rando

46、m sampling either on a mass basis (see 6.1 or 6.3.2) or on a time basis (see 6.2 or 6.3.3). However, if periodic variations in quality or quantity are present, sampling shall be restricted to stratified random sampling within fixed mass or time intervals (see 6.3.2 or 6.3.3). The methods used for sa

47、mpling and sample preparation depend on the final choice of the sampling scheme, and on the steps necessary to minimize possible biases and obtain acceptable overall precision. Moisture samples shall be processed as soon as possible and test portions weighed immediately. If this is not possible, sam

48、ples shall be stored in impervious airtight containers with a minimum of free air space to minimize any change in moisture content, but should be prepared without delay. 4.2 Establishing a sampling scheme The procedure for establishing a sampling scheme is as follows: a) identify the lot to be sampl

49、ed and the quality characteristics to be determined; b) ascertain the nominal top size; c) determine the mass of increment considering the nominal top size, the DRI- or HBI-handling equipment and the device for taking increments; d) specify the precision required; e) ascertain the quality variation, W, of the lot in accordance with ISO 3084, or, if this is not possible, assume a “large” quality variation as specified in 5.3; f) determine the minimum number of primary increments, n1, to be taken from the lot for systematic or stratified random sam