1、BSI Standards PublicationBS ISO 4696-2:2015Iron ores for blast furnacefeedstocks Determinationof low-temperature reduction-disintegration indices by staticmethodPart 2: Reduction with CO and N2BS ISO 4696-2:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 4
2、696-2:2015. Itsupersedes BS ISO 4696-2:2007 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/58, Iron ores.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include a
3、ll the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 79285 4ICS 73.060.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British St
4、andard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2015.Amendments issued since publicationDate Text affectedBS ISO 4696-2:2015 ISO 2015Iron ores for blast furnace feedstocks Determination of low-temperature reduction-disintegration indices by static
5、method Part 2: Reduction with CO and N2Minerais de fer pour charges de hauts fourneaux Dtermination des indices de dsagrgation par rduction basse temprature par mthode statique Partie 2: Rduction avec CO et N2INTERNATIONAL STANDARDISO4696-2Third edition2015-09-01Reference numberISO 4696-2:2015(E)BS
6、ISO 4696-2:2015ISO 4696-2:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, 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, i
7、ncluding 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 ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandT
8、el. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 4696-2:2015ISO 4696-2:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Sampling, sample preparation and preparation of test portions 25.1 Sampling and sample preparat
9、ion . 25.2 Preparation of test portions 26 Apparatus . 26.1 General 27 Test conditions . 37.1 General . 37.2 Reducing gas . 37.2.1 Composition . 37.2.2 Purity . 37.2.3 Flow rate . 47.3 Heating and cooling gas 47.4 Temperature of the test portion . 48 Procedure. 48.1 Number of determinations for the
10、test 48.2 Reduction . 48.3 Tumbling 48.4 Sieving 59 Expression of results 59.1 Calculation of the reduction-disintegration index (RDI22,8) 59.2 Repeatability and acceptance of test results . 510 Test report . 611 Verification . 6Annex A (normative) Flowsheet of the procedure for the acceptance of te
11、st results .10 ISO 2015 All rights reserved iiiContents PageBS ISO 4696-2:2015ISO 4696-2:2015(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 carri
12、ed 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. I
13、SO 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
14、 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
15、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).A
16、ny 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 ISOs adherence to the WTO principles in
17、the Technical Barriers to 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 3, Physical testing.This third edition cancels and replaces the second edition (ISO 4696-2:200
18、7), which has been technically revised to address the care needed during hand sieving, to introduce the mechanical sieving and to exclude the reference to ISO 4701.ISO 4696 consists of the following parts, under the general title Iron ores for blast furnace feedstocks Determination of low-temperatur
19、e reduction-disintegration indices by static method: Part 1: Reduction with CO, CO2, H2and N2 Part 2: Reduction with CO and N2iv ISO 2015 All rights reservedBS ISO 4696-2:2015ISO 4696-2:2015(E)IntroductionThis part of ISO 4696 concerns one of a number of physical test methods that have been develope
20、d to measure various physical parameters and to evaluate the behaviour of iron ores, including reducibility, disintegration, crushing strength, apparent density, etc. This method was developed to provide a uniform procedure, validated by collaborative testing, to facilitate comparisons of tests made
21、 in different laboratories.The results of this test have to be considered in conjunction with other tests used to evaluate the quality of iron ores as feedstocks for blast furnace and direct reduction processes.This part of ISO 4696 can be used to provide test results as part of a production quality
22、 control system, as a basis of a contract, or as part of a research project. ISO 2015 All rights reserved vBS ISO 4696-2:2015BS ISO 4696-2:2015Iron ores for blast furnace feedstocks Determination of low-temperature reduction-disintegration indices by static method Part 2: Reduction with CO and N2CAU
23、TION This International Standard can involve hazardous operations and equipment. This International Standard does not purport to address all of the safety issues associated with its use. It is the responsibility of the user of this International Standard to establish appropriate safety and health pr
24、actices and determine the applicability of regulatory limitations prior to its use.1 ScopeThis part of ISO 4696 specifies a method to provide a relative measure for evaluating the degree of size degradation of iron ores when reduced with carbon monoxide and nitrogen, under conditions resembling thos
25、e prevailing in the low-temperature reduction zone of a blast furnace.This part of ISO 4696 is applicable to lump ores, sinters and hot-bonded pellets.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its applica
26、tion. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3082, Iron ores Sampling and sample preparation proceduresISO 3310-1, Test sieves Technical requirements and testing Part 1: Test s
27、ieves of metal wire clothISO 3310-2, Test sieves Technical requirements and testing Part 2: Test sieves of perforated metal plateISO 11323, Iron ore and direct reduced iron Vocabulary3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 11323 apply.4 Princi
28、pleThe test portion is isothermally reduced in a fixed bed, at 550 C, using a reducing gas consisting of CO and N2, for 30 min. The reduced test portion is tumbled in a specific tumble drum for 900 revolutions and then sieved with a sieve having square openings of 2,8 mm. The reduction-disintegratio
29、n index (RDI) is calculated as the mass percentage of material 2,8 mm.INTERNATIONAL STANDARD ISO 4696-2:2015(E) ISO 2015 All rights reserved 1BS ISO 4696-2:2015ISO 4696-2:2015(E)5 Sampling, sample preparation and preparation of test portions5.1 Sampling and sample preparationSampling of a lot and pr
30、eparation of a test sample shall be in accordance with ISO 3082.The size range for pellets shall be 12,5 mm + 10,0 mm.The size range for sinters and lump ores shall be 20,0 mm + 16,0 mm.A test sample of at least 2 kg, on a dry basis, of the sized material shall be obtained.Oven-dry the test sample t
31、o constant mass at 105 C 5 C and cool it to room temperature before preparation of the test portions.NOTE Constant mass is achieved when the difference in mass between two subsequent measurements becomes less than 0,05 % of the initial mass of the test sample.5.2 Preparation of test portionsCollect
32、each test portion by taking ore particles at random.NOTE Manual methods of division recommended in ISO 3082, such as riffling, can be applied to obtain the test portions.At least four test portions, each of approximately 500 g ( the mass of one particle) shall be prepared from the test sample.Weigh
33、the test portions to the nearest 0,1 g and register the mass of each test portion on its recipient label.6 Apparatus6.1 General The test apparatus shall comprise the following:a) ordinary laboratory equipment, such as an oven, hand tools and safety equipment;b) reduction-tube assembly;c) furnace;d)
34、system to supply the gases and regulate the flow rates;e) tumble drum;f) test sieves;g) weighing device.Figure 1 shows an example of the test apparatus.6.2 Reduction tube, made of non-scaling, heat-resistant metal to withstand temperatures higher than 600 C, and resistant to deformation. The interna
35、l diameter shall be 75 mm 1 mm. A removable perforated plate made of non-scaling, heat-resistant metal to withstand temperatures higher than 600 C shall be mounted in the reduction tube to support the test portion and to ensure uniform gas flow through it. The perforated plate shall be 4 mm thick, w
36、ith its diameter 1 mm less than the internal 2 ISO 2015 All rights reservedBS ISO 4696-2:2015ISO 4696-2:2015(E)diameter of the tube. The holes in the plate shall be 2 mm to 3 mm in diameter at a pitch centre distance of 4 mm to 5 mm.Figure 2 shows an example of a reduction tube.6.3 Furnace, having a
37、 heating capacity and temperature control able to maintain the entire test portion, as well as the gas entering the bed at 550 C 5 C.6.4 Gas-supply system, capable of supplying the gases and regulating gas flow rates.6.5 Tumble drum, made of steel, at least 5 mm thick, having an internal diameter of
38、 130 mm and an inside length of 200 mm. Two equally spaced steel lifters (200 mm long, 20 mm high, and 2 mm thick) shall be mounted longitudinally inside the drum. These can be mounted on a frame that can be inserted inside the vessel from one end. One end of the drum shall be closed and the other o
39、pen. A close-fitting lid shall be held in place on the opening to ensure a dust-tight seal. The drum shall be replaced in any case when the thickness of the vessel wall is reduced to 3 mm in any area, and the lifters when their height is reduced to less than 18 mm.Figure 3 shows an example of a tumb
40、le drum.6.6 Rotation equipment, capable of ensuring that the drum attains full speed in one revolution, rotates at a constant speed of 30 r/min 1 r/min and stops within one revolution. The equipment shall be fitted with a revolution counter and with an automatic device for stopping the drum after a
41、predetermined number of revolutions.6.7 Test sieves, conforming to ISO 3310-1 or ISO 3310-2 and having square apertures of 2,8 mm nominal size.6.8 Weighing device, capable of weighing the test sample and test portions to an accuracy of 0,1 g.7 Test conditions7.1 GeneralVolumes and flow rates of gase
42、s are as measured at a reference temperature of 0 C and at a reference atmospheric pressure of 101,325 kPa (1,013 25 bar).7.2 Reducing gas7.2.1 CompositionThe reducing gas shall consist of the following:CO 30,0 % 0,5 % (volume fraction)N270,0 % 0,5 % (volume fraction)7.2.2 PurityImpurities in the re
43、ducing gas shall not exceed the following:H20,01 % (volume fraction)Total impurities 0,1 % (volume fraction) ISO 2015 All rights reserved 3BS ISO 4696-2:2015ISO 4696-2:2015(E)7.2.3 Flow rateThe flow rate of the reducing gas, during the entire reducing period, shall be maintained at 15 L/min 0,5 L/mi
44、n.7.3 Heating and cooling gasNitrogen (N2) shall be used as the heating and cooling gas. Impurities shall not exceed 0,1 % (volume fraction).The flow rate of N2shall be maintained at 5 L/min until the test portion reaches 550 C, and at 15 L/min during the temperature-equilibration period. During coo
45、ling, it shall be maintained at 5 L/min.7.4 Temperature of the test portionThe temperature of the entire test portion shall be maintained at 550 C 5 C during the entire reducing period and, as such, the reducing gas shall be preheated before entering the test portion.8 Procedure8.1 Number of determi
46、nations for the testCarry out the test as many times as required by the procedure in Annex A.8.2 ReductionTake, at random, one of the test portions prepared in 5.2. Place it in the reduction tube (6.2) and level its surface.NOTE In order to achieve a more uniform gas flow, a double-layer bed of porc
47、elain balls can be placed between the perforated plate and the test portion.Close the top of the reduction tube. Connect the thermocouple, ensuring that its tip is in the centre of the test portion.Insert the reduction tube into the furnace (6.3).Connect the gas-supply system (6.4).Pass a flow of N2
48、through the test portion at a rate of at least 5 L/min and commence heating. When the temperature of the test portion approaches 550 C, increase the flow rate to 15 L/min. Continue heating while maintaining the flow of N2until the test portion reaches 550 C 10 C. Allow a period of 15 min for tempera
49、ture equilibration at 550 C.DANGER Carbon monoxide and the reducing gas, which contains carbon monoxide, are toxic and therefore hazardous. Testing shall be carried out in a well-ventilated area or under a hood. Precautions should be taken for the safety of the operator, in accordance with the safety codes of each country.Introduce the reducing gas at a flow rate of 15 L/min 0,5 L/min to replace the N2. After 30 min of reduction, turn off the power. Replace the reducing gas with N2
