ISO 3087:2020
(Main)Iron ores — Determination of the moisture content of a lot
Iron ores — Determination of the moisture content of a lot
This document specifies a method for the determination of the moisture content of a lot of iron ore. This method is applicable to all iron ores, whether natural or processed.
Minerais de fer — Détermination de l'humidité d'un lot
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 3087
Fifth edition
2020-07
Iron ores — Determination of the
moisture content of a lot
Minerais de fer — Détermination de l'humidité d'un lot
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 1
6 Samples . 2
7 Procedure. 2
7.1 Number of moisture measurements . 2
7.2 Reference methods . 2
7.2.1 General. 2
7.2.2 Normal reference method . 3
7.2.3 Optional reference method for ores of high combined water content . 3
7.3 Alternative methods . 3
7.3.1 General. 3
7.3.2 Adjustment of drying time only . 4
8 Verification . 4
9 Calculation and expression of results . 4
9.1 Test portion . 4
9.2 Lot . 4
10 Test report . 7
Annex A (informative) Determination of moisture content of adhesive or wet iron ores .8
Annex B (normative) Corrections for sprinkled water and/or rainwater .10
Annex C (informative) Precision of moisture measurement .15
Annex D (informative) Examples of test reports .16
Bibliography .35
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
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ISO 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 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 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).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
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expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron,
Subcommittee SC 1, Sampling.
This fifth edition cancels and replaces the fourth edition (ISO 3087:2011), which has been technically
revised. The main changes compared with the previous edition are as follows:
— the existing two 105 °C moisture determination methods have been confirmed to serve as reference
methods;
— alternative moisture determination methods are now allowed if they can be shown to result in
equivalent moisture contents as the reference methods;
— the weighing device readability requirement has been changed from 0,05 % to 0,01 % equivalent of
test portion mass;
— Clause 9 has been revised;
— Annex D has been updated with new example reports.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
Introduction
Currently, large tonnages of iron ore are traded internationally and a small error in the measured
moisture content [mass fraction (%)] of a lot has a considerable effect on the commercial transaction.
The correct determination of moisture content of a lot is, therefore, a matter of importance for both the
purchaser and the vendor.
This document does not address the determination of the hygroscopic moisture content of a test sample
for chemical analysis. If the hygroscopic moisture content is required to be determined, reference
should be made to ISO 2596:2006.
INTERNATIONAL STANDARD ISO 3087:2020(E)
Iron ores — Determination of the moisture content of a lot
1 Scope
This document specifies a method for the determination of the moisture content of a lot of iron ore. This
method is applicable to all iron ores, whether natural or processed.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 3082, Iron ores — Sampling and sample preparation procedures
ISO 3085, Iron ores — Experimental methods for checking the precision of sampling, sample preparation
and measurement
ISO 3086, Iron ores — Experimental methods for checking the bias of sampling
ISO 11323, 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.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Principle
Dry the test portion in air at 105 °C and measure the loss in mass. Express the moisture content as the
mass loss relative to the original mass of the sample as a mass fraction (%).
5 Apparatus
5.1 Drying pan, with a smooth surface, free from contamination and capable of accommodating the
specified quantity of a test portion in a layer of nominal thickness not greater than 31,5 mm.
5.2 Drying oven, equipped with a temperature indicator and control apparatus capable of regulating
the temperature at any point in the oven at 105 °C ± 5 °C and so designed as to maintain this temperature
with a current of air to ensure efficient drying but without any loss of sample, and fitted with a fan that
allows for both the circulation and change of air.
5.3 Weighing device, with readability equivalent to at least 0,01 % of the Table 1 minimum test
portion mass. The weighing device should be protected from the influence of heat.
The capacity of the weighing device shall be enough for the combined mass of the drying pan and the
initial mass of the test portion.
6 Samples
Test samples that have been taken and prepared in accordance with ISO 3082 shall be used. The
mass of a test portion, in relation to its nominal top size, is specified in Table 1, in accordance with
ISO 3082:2017, 10.6.
The nominal top size of the moisture test sample shall be 31,5 mm or less. Samples with a nominal
top size greater than 31,5 mm shall be crushed prior to extraction of test samples for moisture
determination. When it is difficult to conduct crushing and dividing owing to a sample being adhesive
or excessively wet, the sample may be partially dried in accordance with the procedure in Annex A.
For convenience, the test portion of mass 10 kg for ore of particle size less than 31,5 mm may be divided
into two portions, each of which is subjected to moisture measurement. In calculating the results, the
mean of the two values of initial mass and the mean of the two values of the drying loss in mass should
be used.
Table 1 — Minimum mass of test portion
Nominal top size of test Minimum mass of test
portion portion
mm kg
Over Up to and
including
22,4 31,5 10
10,0 22,4 5
― 10,0 1
7 Procedure
7.1 Number of moisture measurements
Carry out one moisture measurement per test portion on the number of test portions specified in
Table 2, in accordance with the conditions of preparation of the test sample.
In order to minimize losses of moisture to the atmosphere, it is necessary to perform all the initial
weighings of the test portions as quickly as possible after obtaining those test portions.
Table 2 — Number of test portions
Preparation of test sample Number of partial samples per lot Number of test portions to be tested
From gross sample — 4 per gross sample
2 4 per partial sample
From partial sample 3 to 7 2 minimum per partial sample
≥ 8 1 minimum per partial sample
From increment — 1 minimum per increment
7.2 Reference methods
7.2.1 General
The moisture determination shall be conducted in accordance with 7.2.2 or, optionally for ores with
8 % or more of combined water, in accordance with 7.2.3.
2 © ISO 2020 – All rights reserved
7.2.2 Normal reference method
Apply the following procedure.
a) Spread the test portion in a layer of nominal thickness not greater than 31,5 mm in the tared drying
pan (5.1) and
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