ISO 3087:2020

DRAFT INTERNATIONAL STANDARD
ISO/DIS 3087
ISO/TC 102/SC 1 Secretariat: JISC
Voting begins on: Voting terminates on:
2019-12-03 2020-02-25
Iron ores — Determination of the moisture content of a lot
Minerais de fer — Détermination de l'humidité d'un lot
ICS: 73.060.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
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STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
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WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 3087:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019

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ISO/DIS 3087:2019(E)

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ISO/DIS 3087:2019(E)
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 . 5
10 Test report . 7
Annex A (normative) 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

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ISO/DIS 3087:2019(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.
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 technical changes to this edition are as follows:
— Confirmation that the existing two 105 °C moisture determination methods are to serve as reference
methods;
— Allowing for alternative moisture determination methods if they can be shown to result in equivalent
moisture contents as the reference methods;
— Changing weighing device readability requirement from 0,05 % to 0,01 % equivalent of test portion mass;
— Revising clause 9: Calculation and expression of results;
— Updating Annex D with new example reports.
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ISO/DIS 3087:2019(E)
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 International Standard 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, Iron ores — Determination of hygroscopic moisture in analytical
samples — Gravimetric, Karl Fischer and mass-loss methods.

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DRAFT INTERNATIONAL STANDARD ISO/DIS 3087:2019(E)
Iron ores — Determination of the moisture content of a lot
1 Scope
This International Standard 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 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 3082, Iron ores — Sampling and sample preparation procedures
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.
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 capacity of the weighing device shall be enough for the combined mass of the drying pan and the initial
mass of the test portion.
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ISO/DIS 3087:2019(E)
6 Samples
Test samples which 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,
clause 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.
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,
according to the conditions of preparation of the test sample.
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
3 to 7 2 minimum per partial sample
From partial sample
 8 1 minimum per partial sample
From increment — 1 minimum per increment

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.
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.
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ISO/DIS 3087:2019(E)
7.2.2 Normal reference method
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 determine the total mass immediately. Record the total mass, the mass of the drying pan, the
initial mass of the test portion (m ) and the numerical value of 0,05 % of m .
1 1
b) Place the drying pan with the test portion in the drying oven (5.2) set at 105 °C, and maintain this
temperature for not less than 4 h. Remove the drying pan with the test portion from the drying oven and
weigh it immediately while still hot in order to minimize any reabsorption of moisture. Otherwise, weigh
the test portion after cooling in air in a container having a close-fitting airtight lid. In each case, report the
method of weighing.
c) Once more, place the drying pan with the test portion in the drying oven, heat for a further 1 h, and then
repeat the weighing.
d) Repeat the procedure described in item c) until the difference in mass between subsequent
measurements becomes 0,05 % or less of the initial mass of the test portion.
NOTE 1 The weighing device should be protected from the influence of heat.
NOTE 2 To reduce drying time, it is recommended that layer-thickness of the sample be kept as low as possible. It
should be specified for particular ores by check experiments carried out beforehand.
NOTE 3 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.
7.2.3 Optional reference method for ores of high combined water content
For ores containing 8 % or more combined water, the following procedure may be applied.
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 determine the total mass immediately. Record the total mass, the mass of the drying pan and
the initial mass of the test portion (m1).
b) Place the drying pan with the test portion in the drying oven (5.2) set at 105 °C and maintain this
temperature for not less than 24 h. Remove the drying pan with the test portion from the drying oven and
weigh it immediately while still hot in order to minimize any reabsorption of moisture. Otherwise, weigh
the test portion after cooling in air in a container having a close-fitting airtight lid. Record the total mass
after drying. In each case, report the method of weighing.
NOTE The notes in 7.2.2 apply to this subclause
7.3 Alternative methods
7.3.1 General
Alternative methods refer to the potential use of different technology, such as ovens that do not rely on
convection drying alone or to procedures that potentially differ in terms of oven temperature (up to 140 °C)
and time from what is described in clause 7.2, but which do not deviate from the conditions stipulated in
Clause 6 and Clause 7.1 (minimum mass of test portion and number of portions to be tested).
Such alternative methods or modifications for determining the moisture content are allowed where check
experiments carried out beforehand, demonstrate satisfactorily to all parties concerned, that an equivalent
moisture result is obtained when compared to the applicable reference method specified in 7.2. This
demonstration shall include ISO 3086 bias testing using a relevant bias of no more than 0,05 % moisture and
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ISO/DIS 3087:2019(E)
where the confidence interval includes the zero. Further, the precision of the alternative method needs to be
demonstrated by ISO 3085 to be the same or better than achieved by the applicable reference method.
If the sample is subsequently to be utilized for multiple use, the chemistry, LOI and size distribution of the
dried remains shall be checked by means of ISO 3086 to ensure they are not different to dried remains from
equivalent reference moisture testing methods. If any changes are identified, the alternative method must be
discarded.
7.3.2 Adjustment of drying time only
In the case where an alternative method changes only the drying times specified in 7.2.2 in order to eliminate
repeat weighings for verification of constant mass, then it is only necessary to demonstrate equivalence of
precision and moisture result.
NOTE The notes in 7.2.2 apply to this subclause
8 Verification
Regular checking of apparatus and procedures is essential to verify the test results. Checks shall be carried
out prior to the commencement of a routine test in accordance with this International Standard and at regular
intervals thereafter. The frequency of checking is a matter for each laboratory to determine. A detailed record
of all verification activities shall be maintained for the following items:
a) Sprinkled water measurement
— volumenometer;
b) Rainfall measurement
— rain gauge;
c) Moisture test
— oven temperature/temperature regulation;
— circulation and change of air in oven;
— weighing device.
9 Calculation and expression of results
9.1 Test portion
The result of the determination of the moisture content, w , expressed as a mass fraction (%), for each test
i
portion, is given by Formula (1) and reported to the second decimal place.
mm−
12
(1)
w=100
i
m
1
where
m is the initial mass, in grams, of the test portion;
1
m is the mass, in grams, of the test portion after drying.
2
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ISO/DIS 3087:2019(E)
An illustration of moisture determination of a random test portion is shown in an example test report in
Annex D, Table D.1.
9.2 Lot
The moisture content of a lot is given by one of the Formulas (2) to (6) as the occasion may demand, and
reported to the first decimal place.
Sprinkled water and/or rainwater over iron ore during loading and/or unloading operation, in other words
moisture added after/before the point where sampling has taken place, shall be corrected according to the
procedure specified in Annex B.
9.2.1 When moisture determination is conducted on the gross sample from the lot, the moisture of the lot is
determined as follows.
When the range of the four test results does not exceed 1,3r as given in Table 3, the arithmetic mean, w , of
the four results shall be the moisture content, expressed as a mass fraction (%), of the lot as given by
Formula (2).
w+++w w w
1 2 3 4
w = (2)
4
where w , w , w and w are the results of the determinations of the moisture contents, expressed as a mass
1 2 3 4
fraction (%), on each of the four test portions.
When the range of the four test results exceeds 1,3r as given in Table 3, the median shall be taken as the
moisture content of the lot. The median of four test results is defined as the mean of the two non-extreme test
results.
Table 3 — Repeatability limit of moisture determination on the gross sample
Average of moisture content Repeatability limit Repeatability limit
a
w
r 1,3r


mass fraction (%) mass fraction (%)
mass fraction (%)
w  3 0,20 0,26
36w 0,25 0,33
6 w 0,31 0,40
a
The theoretical background of the repeatability limit is shown in Annex C.

An illustration of moisture determination of a gross sampled lot with four test portions, where the range of the
four moistures do not exceed 1,3r, is shown in an example test report in Annex D, Table D.2.
An illustration of moisture determination of a gross sampled lot with four test portions, where the range of the
four moistures exceed 1,3r, is shown in an example test report in Annex D, Table D.3.
9.2.2 When mass-basis sampling has been performed and moisture determination is conducted on each
partial sample, the weighted mean, w̿, of the results from all the partial samples, considering the number of
increments for each partial sample, shall be the moisture content, expressed as a mass fraction (%), of the lot,
as given by Formula (3).
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ISO/DIS 3087:2019(E)
(3)
where
k is the number of partial samples;
N is the number of increments in the ith partial sample;
i
wi is the result of the determination of the moisture content, expressed as a mass fraction (%), of the ith
partial sample, according to Table 2 using as the number of test portions either 4 or 2.
NOTE: When partial samples are used and 4 test portions are conducted in any partial sample, the criteria established in
9.2.1 may be applied.
Illustrations of moisture determination of mass-basis sampled lots with two, four and eight partial samples are
shown in example test reports in Annex D, in respectively Table D.4, Table D.6 and Table D.8.
If it is impracticable to sample the lot as a whole, or desirable to sample a lot in separate parts of unequal
mass as in the case of time-basis sampling, the moisture content of each part shall be determined
independently and the weighted mean, w̿, of the results, expressed as a mass fraction (%), of the lot
calculated from the individual results using Formula (4).
k
m w
 i
i
i=1
w = (4)
k
m

i
i=1
where
k is the number of partial samples;
m is the mass of the ith part;
i
w is the result of the determination of the moisture content, expressed as a mass fraction (%), of the
i
ith part.
Illustrations of moisture determination of time-basis sampled lots with two, four and eight partial samples are
shown in example test reports in Annex D, in respectively Table D.5, Table D.7 and Table D.9.
9.2.3 When moisture determination is conducted on each increment during mass basis sampling, the
arithmetic mean, w , of the results for all increments obtained according to 9.1 shall be the moisture content,
expressed as a mass fraction (%), of the lot as given by Formula (5).
n
w
 i
i=1
w = (5)
n
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ISO/DIS 3087:2019(E)
where
n is the number of increments;
w is the result of the determination of the moisture content, expressed as a mass fraction (%), of the
i
ith increment.
An illustration of moisture determination of a mass-basis sampled lot where moisture is individually
determined for each of thirty increments, is shown in an example test report in Annex D, Table D.10.
When moisture determination is conducted on each increment during time basis sampling, the weighted mean,
,of the results for all increments obtained according to 9.1 shall be the moisture content, expressed as a
mass fraction (%), of the lot as given by Formula (6).
(6)
where
k is the number of increments;
m is the mass of the ith part that the increment represents;
i
w is the increment moisture content, expressed as a mass fraction (%).
i
An illustration of moisture determination of a time-basis sampled lot, where moisture is individually determined
for each of twenty-five increments, is shown in an example test report in Annex D, Table D.11.
10 Test report
The test report shall contain the following information. Examples of test reports are shown in Annex D.
a) A reference to this International Standard, i.e. ISO 3087:20--;
b) details necessary for the identification of the sample;
c) result of the test;
d) reference number of the result;
e) details of procedure (including apparatus, temperature and time used in the test);
f) any characteristics noticed during the determination, and any operation not specified in this International
Standard.
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ISO/DIS 3087:2019(E)
Annex A
(normative)

Determination of moisture content of adhesive or wet iron ores
Introduction
When it is difficult to conduct sieving, crushing and dividing, owing to a sample being adhesive or excessively
wet, the sample may be partially dried until preparation can be conducted without difficulty.
In this case, the moisture content of the lot shall be obtained by using the partial drying method according to
the procedure specified in this annex. In handling the test sample and weighing the initial mass and partially
dried mass of the test sample, attention shall be paid to ensuring the measurement precision of the partially
dried moisture content.
A.1 Determine the initial mass of the test sample.
A.2 Spread the test sample in a uniform thickness and dry it in air or in a drying apparatus at a temperature
no higher than 105 °C. The choice of temperature and time for this partial drying stage shall not exceed a
point where an ore is likely to reabsorb moisture during subsequent processing.
A.3 After partial drying, again determine the mass of the test sample.
A.4 Calculate the partially dried moisture content, wp, expressed as a mass fraction (%), of the test sample
using Formula (A.1).

mm−
12
(A.1)
w=100
p

m
1
where
m is the initial mass, in grams, of the test sample;
1
m is the mass, in grams, of the test sample after partial drying.
2
A.5 Prepare the test portions for moisture measurement from the partially dried sample according to the
procedure in ISO 3082.
A.6 Determine the drying loss of the test portion in accordance with 7.2 and calculate the additional
moisture content, expressed as a mass fraction (%), in accordance with 9.1.
A.7 Calculate the total (as received) moisture content, w , expressed as a mass fraction (%), of the test
pd
sample using Formula (A.2).
100 −w
p
w = w + w (A.2)
pd p d
100
where w is the additional moisture content obtained in accordance with 9.1 after partial drying, expressed as
d
a mass fraction (%).
A.8 Determine the moisture content, as a mass fraction (%), of the lot in accordance with 9.2.
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A.9 If the mass of the moisture sample is not large, the entire quantity of the sample may be dried in order
to conduct the moisture determination according to the method specified in the body of this International
Standard.
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ISO/DIS 3087:2019(E)
Annex B
(normative)

Corrections for sprinkled water and/or rainwater
Introduction
Nowadays, in many countries, strict environmental regulations must be observed in the iron ore and steel
industry. When water is sprinkled over iron ore during loading and/or unloading operations to prevent dust
evolution, the moisture content of a lot shall be corrected, according to the procedure specified in this annex,
for the mass of water sprinkled.
This annex also describes a method for correcting the moisture content of a lot containing rainwater.
B.1 General
B.1.1 Water is sprinkled for the following reasons:
a) environmental regulations at loading and/or unloading ports;
b) difficulty of handling iron ores due to ore characteristics, weather conditions, handling equipment, etc.
B.1.2 Correction for rainwater shall be made whenever rainfall occurs during the loading or unloading
operations, and the moisture content of the lot is known to have been affected.
B.2 Corrections for sprinkled water
General
In the case of unloading a lot, sprinkled water refers to water sprinkled (or sprayed) in the vessel holds and/or
on any sections extending to a point where samples are taken. In the case of loading of a lot, sprinkled water
refers to water sprinkled in the holds and/or on the loading conveyors located after the point where moisture
samples are taken.
Two methods of correction for sprinkled water are mentioned in this clause. One refers to water added before
the sampling point during unloading operations, the other to water added after the sampling point during
loading operations.
Measurement of sprinkled water
The measurement of sprinkled water shall be made with a volumenometer having an accuracy of  5 %. The
volume obtained shall be converted to a mass, m , in tonnes, by multiplying it by the density of the sprinkled
3
water.
3
NOTE Fresh water is assumed to have a density of 1 t/m .
Mass of lot
The mass of the lot, m4, in tonnes, as received or as despatched without sprinkled water or rainwater, or the
mass of the lot, m5, in tonnes as received or as despatched containing sprinkled water or rainwater, should be
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ISO/DIS 3087:2019(E)
determined by draught survey or by other internationally recognized means, such as weightometer or weigh
hopper.
NOTE In the examples given in B.2.4, B.2.5, B.3.6, B.3.7, B.4 and B.5 below, it is assumed that the mass of the lot
has been determined by draught survey. In these instances, the determination of mass is conducted either before any
sprinkled water or rainwater is added (unloading operations) or after all sprinkled water or rainwater has been added
(loading operations).
If a weightometer or weigh hopper is us
...