ISO 4695:2007
(Main)Iron ores for blast furnace feedstocks — Determination of the reducibility by the rate of reduction index
Iron ores for blast furnace feedstocks — Determination of the reducibility by the rate of reduction index
ISO 4695:2007 specifies a method to provide a relative measure for evaluating the extent to and ease with which oxygen can be removed from iron ores, when reduced under conditions resembling those prevailing in the reduction zone of a blast furnace. ISO 4695:2007 is applicable to lump ores, sinters and hot-bonded pellets.
Minerais de fer pour charges de hauts fourneaux — Détermination de la réductibilité à partir de la vitesse de réduction
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 4695
Third edition
2007-11-01
Iron ores for blast furnace feedstocks —
Determination of the reducibility by the
rate of reduction index
Minerais de fer pour charges de hauts fourneaux — Détermination de la
réductibilité à partir de la vitesse de réduction
Reference number
ISO 4695:2007(E)
©
ISO 2007
---------------------- Page: 1 ----------------------
ISO 4695:2007(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2007
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2007 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 4695:2007(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Principle. 1
5 Sampling, sample preparation and preparation of test portions. 2
6 Apparatus . 2
7 Test conditions . 3
8 Procedure . 4
9 Expression of results . 5
10 Test report . 6
11 Verification . 7
Annex A (normative) Flowsheet of the procedure for the acceptance of test results . 10
Annex B (informative) Derivation of equation for reducibility. 11
© ISO 2007 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 4695:2007(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.
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. 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 patent rights.
ISO 4695 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommittee
SC 3, Physical testing.
This third edition cancels and replaces the second edition (ISO 4695:1995), which has been revised to
homogenise with other physical test standards.
iv © ISO 2007 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 4695:2007(E)
Introduction
This International Standard concerns one of a number of physical test methods that have been developed 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 in different laboratories.
The results of this test should be considered in conjunction with other tests used to evaluate the quality of iron
ores as feedstocks for blast furnace processes.
This International Standard may be used to provide test results as part of a production quality control system,
as a basis of a contract, or as part of a research project.
© ISO 2007 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 4695:2007(E)
Iron ores for blast furnace feedstocks — Determination of the
reducibility by the rate of reduction index
CAUTION — This International Standard may involve hazardous materials, operations and equipment.
This 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
practices and determine the applicability of regulatory limitations prior to its use.
1 Scope
This International Standard specifies a method to provide a relative measure for evaluating the extent to and
ease with which oxygen can be removed from iron ores, when reduced under conditions resembling those
prevailing in the reduction zone of a blast furnace.
This International Standard is applicable to lump ores, sinters and hot-bonded pellets.
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 latest edition of the referenced
document (including any amendments) applies.
ISO 2597-1:2006, Iron ores — Determination of total iron content — Part 1: Titrimetric method after tin(II)
chloride reduction
1)
ISO 3082:2000 , Iron ores — Sampling and sample preparation procedures
ISO 9035:1989, Iron ores — Determination of acid-soluble iron(II) content — Titrimetric method
ISO 9507:1990, Iron ores — Determination of total iron content — Titanium(III) chloride reduction methods
ISO 11323:2002, Iron ore and direct reduced iron — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11323 apply.
4 Principle
The test portion is isothermally reduced in a fixed bed, at 950 °C, using a reducing gas consisting of CO and
N , and is weighed at specified time intervals until its degree of reduction reaches 65 %. The rate of reduction
2
is calculated at the oxygen/iron ratio of 0,9.
1) Under revision, to incorporate ISO 10836, Iron ores — Method of sampling and sample preparation for physical
testing.
© ISO 2007 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 4695:2007(E)
5 Sampling, sample preparation and preparation of test portions
5.1 Sampling and sample preparation
Sampling of a lot and preparation of a test sample shall be in accordance with ISO 3082.
The size range for pellets, sinters and lump ores shall be − 12,5 mm + 10,0 mm.
A test sample of at least 2,5 kg, on a dry basis, of the sized material shall be obtained.
Oven-dry the test sample to 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 portions
Collect 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 5 test portions, each of approximately 500 g (± the mass of 1 particle) shall be prepared from the test
sample: 4 test portions for testing and 1 for chemical analysis.
Weigh the test portions to the nearest 1 g and register the mass of each test portion on its recipient label.
6 Apparatus
6.1 General
The test apparatus shall comprise:
a) ordinary laboratory equipment, such as an oven, hand tools, time-control device and safety equipment;
b) a reduction-tube assembly;
c) a furnace, equipped with a balance for permitting the mass loss of the test portion to be read at any time
during the test;
d) a system to supply the gases and regulate the flow rates;
e) a 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
950 °C and resistant to deformation. The internal diameter shall be 75 mm ± 1 mm. A removable perforated
plate, made of non-scaling, heat-resistant metal to withstand temperatures higher than 950 °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, with its diameter 1 mm less than the tube internal diameter. The holes in
the plate shall be 2 mm to 3 mm in diameter, at a pitch center distance of 4 mm to 5 mm.
Figure 2 shows an example of a reduction tube.
6.3 Furnace, having a heating capacity and temperature control able to maintain the entire test portion, as
well as the gas entering the bed, at 950 °C ± 10 °C.
2 © ISO 2007 – All rights reserved
---------------------- Page: 7 ----------
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.