ISO 10752:2025
(Main)Coal sizing equipment — Performance evaluation
Coal sizing equipment — Performance evaluation
This document describes the principles and methods for the expression of results of performance tests on sizing equipment used in coal preparation and includes methods for the evaluation of performance parameters. Performance test procedures and size measurement techniques are recommended. This document applies to all types of sizing equipment, categorized as follows: a) screens; b) classifiers; c) others. The procedure described in this document applies to two-product separations. Performance assessment of multiproduct separations can be achieved by consideration of a series of two-product separations.
Équipement pour la granulométrie du charbon — Évaluation de l'aptitude à l'emploi
General Information
Relations
Standards Content (Sample)
International
Standard
ISO 10752
Third edition
Coal sizing equipment —
2025-12
Performance evaluation
Équipement pour la granulométrie du charbon — Évaluation de
l'aptitude à l'emploi
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms .1
3.2 Performance parameters terms .2
4 Performance criteria . 2
5 Performance parameters . 3
6 Performance test procedures . 3
7 Analytical procedures . . 4
8 Evaluation and presentation of performance characteristics . 5
8.1 General .5
8.2 Basic data .5
8.3 Reconstituted feed size distribution .5
8.4 Partition curve .6
8.5 Partition size .6
8.6 Sharpness of separation .6
8.7 Misplaced material curves .6
8.8 Misplaced material .7
8.9 Equal errors size .7
8.10 Theoretical yield .7
8.11 Material placement efficiency .7
8.12 Near-size material .8
8.13 Test and equipment data .8
9 Tabular and graphical presentation . 8
Annex A (informative) Calculation of the yield of each product of a size separation from size
analyses of feed and product materials .16
Annex B (informative) Worked example — Vibrating screen . 19
Annex C (informative) Worked example — Cyclone .27
Annex D (informative) Worked example — Deduster .34
Bibliography . 41
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by Technical Committee ISO/TC 27, Coal and coke, Subcommittee SC 1, Coal
preparation: Terminology and performance.
This third edition cancels and replaces the second edition (ISO 10752:2019), which has been technically
revised.
The main changes are as follows:
— Clause 2 normative references updated;
— data sheets converted to tables.
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
Introduction
A standard expression of performance is used to define the accuracy of separation of a particular item, to
assist in the comparison of the performance of different items of coal sizing equipment and in the prediction
of separation results.
v
International Standard ISO 10752:2025(en)
Coal sizing equipment — Performance evaluation
1 Scope
This document describes the principles and methods for the expression of results of performance tests
on sizing equipment used in coal preparation and includes methods for the evaluation of performance
parameters. Performance test procedures and size measurement techniques are recommended.
This document applies to all types of sizing equipment, categorized as follows:
a) screens;
b) classifiers;
c) others.
The procedure described in this document applies to two-product separations. Performance assessment of
multiproduct separations can be achieved by consideration of a series of two-product separations.
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 1213-1, Coal and coke — Vocabulary — Part 1: Terms relating to coal preparation
ISO 13909-2, Coal and coke — Mechanical sampling — Part 2: Sampling of coal from moving streams
ISO 13909-4, Coal and coke — Mechanical sampling — Part 4: Preparation of test samples of coal
ISO 18283, Coal and coke — Manual sampling
ISO 20904, Hard coal — Sampling of slurries
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General terms
3.1.1
actual feed
F
material fed to the sizing equipment during the test period and including any recirculated material
3.1.2
coarser material
material that is coarser than the reference size
3.1.3
finer material
material that is finer than the reference size
3.1.4
product
material discharged from the sizing equipment prior to any further treatment or recirculation
3.1.5
coarser product
c
product of size separation that contains a greater proportion of coarser material than the feed
3.1.6
finer product
f
product of size separation that contains a greater proportion of finer material than the feed
3.1.7
sharpness of separation
E
p
assessment of the deviation from a perfect separation
Note 1 to entry: Usually expressed in terms of mean probable error (often identified in technical reports as E .
pm )
3.2 Performance parameters terms
3.2.1
theoretical yield
maximum yield of a product at a reference size, as determined from the size distribution curve for the
reconstituted feed
3.2.2
coarser material placement efficiency
E
c
percentage of coarser material in the reconstituted feed that reports to the coarser product
3.2.3
finer material placement efficiency
E
f
percentage of finer material in the reconstituted feed that reports to the finer product
3.2.4
overall separation index
sum of the coarser material placement efficiency and the finer material placement efficiency minus 100
4 Performance criteria
The following criteria should be determined where applicable:
a) feed rate;
b) reference size of separation;
c) sharpness of separation;
d) misplaced material;
e) material placement efficiencies;
f) the degree of difficulty of separation;
g) material characteristics.
The above criteria can be influenced by test conditions which should therefore be fully reported.
The prediction of separation results should consider the influence of test conditions.
It is important also that test conditions are made compatible to ensure valid comparisons.
Conditions should be kept uniform during a test.
5 Performance parameters
For the standard expression of performance of a separation, the criteria given in Clause 4 should be
determined by the following parameters:
a) the feed rate, expressed on mass or volume bases, or both;
b) the reference size, preferably expressed as both partition size and equal errors size. It is recognized
that partition size is not always obtainable from the results of a size separation and that an alternative
reference size therefore must be employed. To allow comprehensive comparison of performance, it is
recommended that parameters based on equal errors size as the reference be included, in addition to
those based on partition size;
c) the sharpness of separation, expressed in terms of probable error;
d) the distribution of misplaced material in each product, presented graphically with respect to size, and
the values of misplaced material in each product on both feed and product bases, are each determined at
the reference size of separation;
e) the material placement efficiencies expressed as:
1) coarser material placement efficiency, E ;
c
2) finer material placement efficiency, E ;
f
3) overall separation index derived from 1) and 2);
f) the degree of difficulty of separation, expressed in terms of near size material;
g) other relevant characteristics of the feed material.
6 Performance test procedures
The equipment to be tested, the actual feed composition, and the means of handling the feed and products
vary widely. A single standard procedure is not applicable. The following general provisions are provided:
a) the average feed rate and product flow rates should be determined by the most accurate method possible
in the circumstances;
Typical procedures that may be used are:
1) direct assessment of the mass and volume of the whole of the feed or product during the test.
2) continuous assessment by means of a calibrated belt mass determinator or flowmeter and
integration during the test;
3) determine the mass of timed increments by weighing taken at regular intervals during the test.
b) where possible in coal preparation plants, sampling techniques, initial number of increments and
minimum mass of each increment shall be chosen so that all samples taken are representative. Sampling
and preparation of samples, shall be in accordance with ISO 13909-2, ISO 13909-4, and ISO 18283
for solids and with ISO 20904 for slurries. Some manual sampling of piped liquids and solids in coal
preparation plants can be quite difficult and achieving fully representative samples may not be easy. If
this is suspected, a manual sampling regime may be undertaken following strict plant safety guidelines.
However, samples produced in this manner shall be clearly recorded as such in all test reports:
c) representative samples should be taken from all relevant streams to and from the equipment to be
tested, to facilitate checking of results and assessment of the effects of degradation;
d) representative samples should be taken from all relevant streams to determine their total moisture
mass fraction in accordance with ISO 589 or solids mass fractions as appropriate, so that the results can
be reported on a dry basis;
e) it is recommended that the feed rate and the actual yield of each product be determined on a dry basis in
accordance with ISO 1170.
This should be achieved in accordance with one of the following procedures:
1) The mass of each product should be determined by one or more of the following methods:
i) direct determination of mass of the whole of each product collected over the duration of the test
or through continuous determination of mass and integration over the duration of the test;
ii) taking regular timed increments over the duration of the test;
iii) determination of mass of each product collected simultaneously over a selected timed period
during the test;
iv) in all circumstances, the method used to determine the actual mass (yield) of each product should
be reported with each respective value in Table 3.
NOTE 1 The methods given in 1) are listed in order of reliability.
NOTE 2 If it is feasible to measure both the mass of the feed (by calibrated belt mass determinator, by
calibrated hopper mass determinator, flowmeter, etc.) and the mass of the products, this provides a check.
NOTE 3 If the mass of one of the products cannot be measured, it can be obtained from a mass balance
between the feed and products.
NOTE 4 Where the solids are conveyed by a fluid, it can be more convenient to make volumetric meas-
urements.
2) In circumstances that prevent the determination of mass of sufficient streams, size analyses of feed
and products can be used to determine the mass and mass fraction as a percent of each product, as
described in Annex A.
7 Analytical procedures
The method and procedure of size analysis should be selected, as far as possible, to agree with the principle
of the equipment under test, to produce results in compatible terms. For example, the results of size
analysis by sieving should be compatible with vibrating screens, and the results of size analysis by a series
of small cyclones would be compatible with cyclone separators. Size analysis by sieving should be carried
out in accordance with ISO 1953. ISO 1953 however, advocates a hand placing technique during sizing
above 22,4 mm so direct comparison with vibratory screens can prove difficult for these sizes. However,
comparisons with vibratory screens with particles less than 22,4 mm should be much better particularly
if you use the mechanical methods for sizes −22,4 mm x 4,0 mm and −4 mm as indicated in ISO 1953. The
method and apparatus used, and the basis of the percentages (by mass or volume), shall be stated in Tables 1
and 2.
The feed sample and each of the product samples should be subjected to size analyses in which the ratio of
the upper and lower size limits does not exceed 2:1 for each size fraction. It is recommended that this ratio
for size limits be reduced to 21: for minimum of two fractions, both above and below the reference size.
NOTE 1 In some circumstances, a ratio of size limits closer than 21: can be necessary in the region of the
reference size, to ensure that each of the size fractions contains not more than 10 % of the sample.
NOTE 2 Size distribution curves for the products can be used for the following:
a) providing data for additional partition coefficients;
b) averaging analytically determined values to improve the derived partition curve.
8 Evaluation and presentation of performance characteristics
8.1 General
All data shall be evaluated and presented in four tables, and three figures as follows:
a) Table 1 — data sheet — test and equipment data;
b) Table 2 — size distribution of feed and products;
c) Table 3 — partition coefficients and misplaced material data;
d) Table 4 — statement of sizing equipment performance;
e) Figure 1 — partition curve;
f) Figure 2 — size distribution curve for the reconstituted feed;
g) Figure 3 — misplaced material curves.
The presentation of the test data may be accomplished by the procedure described below. The specified
tabular and graphical formats are given in Clause 9. Specific worked examples for all Tables and Figures
above are included in Annexes B, C and D.
NOTE 1 Primary calculation procedures are shown in Tables 2 and 3. A column number in parentheses denotes a
respective value taken from that column.
NOTE 2 The origins of plotted values are shown in Figures 1 and 2 by reference to table and column numbers.
NOTE 3 Reference to definitions of performance parameters in Clause 3 supports the brief explanation of their
derivation given in relevant subclauses and in Tables 2 and 3.
8.2 Basic data
The data obtained from a performance test comprise the size analyses of the actual feed and the coarser and
finer products and the proportion of material reporting to each product. These basic data are compiled in
Table 2, columns 1 to 8, and calculated on a reconstituted feed basis in columns 9 to 12.
8.3 Reconstituted feed size distribution
The size distribution curve for the reconstituted feed is constructed as shown in Figure 2, by plotting the
cumulative mass fraction, expressed as a percentage less than the upper size limit (column 12 of Table 2)
against the upper size limit (column 1 of Table 2).
NOTE It is convenient to use a logarithmic scale (Rosin-Rammler distribution) for particle size when plotting size
distribution curves, to cover a wide range of sizes and to cater for size limits that are in geometric progression.
8.4 Partition curve
The partition curve is constructed as shown in Figure 1, by plotting the value of each partition coefficient
against the corresponding mean size. It is recommended that each size fraction be represented by its
geometric mean size. Geometric mean sizes and partition coefficients are calculated in Table 3, columns 13
and 14. The recommended scales are:
— size: log 1 cycle = 50 mm;
— partition coefficient: 1 % = 2 mm.
NOTE 1 As an alternative to geometric mean size, each size fraction can be represented by its mid-mass particle
size, derived from a known functional relationship or estimated from the reconstituted feed curve.
NOTE 2 As an alternative method of construction, partition coefficients can be plotted as a histogram on
a reconstituted feed base, producing an area representative of mass. An intermediate curve is then drawn by
equalizing areas within each size fraction. Performance parameters are derived by applying values obtained from the
intermediate curve to the size distribution curve for the reconstituted feed.
8.5 Partition size
The partition size, S , is obtained directly from the partition curve and is entered as a performance
parameter in the statement of sizing equipment performance in Table 4.
NOTE The partition size can be determined from the misplaced material curves (see Figure 3) at the minimum
value of total misplaced material.
8.6 Sharpness of separation
The 25 %, S , and 75 %, S , intercepts are each read from the partition curve (see Figure 1) and are entered
25 75
as primary parameters in the statement of sizing equipment performance in Table 4. For symmetrical
partition curves, the sharpness of separation may be expressed in terms of the mean probable error (E ) as
pm
follows:
SS
75 25
E (1)
pm
In the more common case of skewed partition curves, the sharpness of separation may be expressed in terms
of the upper and lower probable errors as follows.
— Upper probable error = S − S
75 50
— Lower probable error = S − S
50 25
The upper probable error and lower probable error parameters may be used separately if one of the
intercepts is undefined.
8.7 Misplaced material curves
The misplaced materials in the coarser and finer products are calculated, as a mass fraction, expressed as a
percent of the reconstituted feed, in Table 3, columns 15 and 16. Corresponding values are summed to give
total misplaced material tabulated in column 17 of Table 3. The misplaced material curves are constructed,
as shown in Figure 3, by plotting values for coarser products (column 15 of Table 3), finer products (column
16 of Table 3) and total misplaced materials (column 17 of Table 3), each against the corresponding upper
size limit S1 (column 1 of Table 2). The recommended scales are:
— size: log 1 cycle = 50 mm;
— misplaced material: 1 % = 5 mm.
If it is necessary to use an alternative scale, this should be a simple multiple of the recommended scale; for
an example see Figure C.3.
8.8 Misplaced material
The misplaced material is read from each respective curve at the reference size, or sizes (see NOTE 1),
and the values are inserted into the statement of sizing equipment performance in Table 4. The value of
misplaced material for each respective product is converted to a mass fraction expressed as a percent of
that product (see NOTE 2), and the converted values are inserted into the statement in Table 4.
NOTE 1 It is convenient to construct an ordinate on the curves, at the reference size, or sizes, being considered (e.g.
S , S , S ), to assist in reading the three intercepting misplaced values.
d 50 e
NOTE 2 All values of misplaced material obtained from the curves are in terms of mass fraction expressed as a
percent of the reconstituted feed. Conversion to the mass fraction expressed as a percent of the respective product
can be obtained by multiplying the corresponding curve by 100 and dividing by the yield value of the product under
consideration (i.e. Y or Y ).
c f
NOTE 3 The procedure can be repeated for any other reference size.
8.9 Equal errors size
The equal errors size, S , is determined by reading the size that corresponds to the point of intersection of
e
the misplaced material curves for coarser and finer products. Alternatively, the equal errors size can be
determined from the size distribution curve for the reconstituted feed, as the size corresponding to the yield
of the finer product. The equal errors size is inserted into the statement of sizing equipment performance in
Table 4.
8.10 Theoretical yield
The theoretical yield value at the reference size, or sizes, is determined, for each of the products, from the
size distribution curve for the reconstituted feed. Alternatively, each respective theoretical yield value can
be determined by subtracting the misplaced material in the product under consideration from the actual
yield (Y or Y ) and adding the misplaced material in the complementary product.
c f
EXAMPLE:
YY MM (2)
c,tc cf
where
Y is the theoretical yield of the coarser product;
c,t
Y is the yield value of the coarser product;
c
M is the misplaced material in the coarser product;
c
M is the misplaced material in the finer product.
f
Theoretical yield values are inserted into the statement of sizing equipment performance in Table 4.
NOTE 1 Misplaced material values are in terms of mass fractions expressed as a percent of reconstituted feed.
NOTE 2 The theoretical yield of the complementary product can be obtained by difference from 100 %.
8.11 Material placement efficiency
Material placement efficiencies are evaluated and inserted into the statement of sizing equipment
performance in Table 4. The calculations are as follows.
a) Coarser material placement efficiency, E :
c
YM
cc
E 100 (3)
c
Y
c,t
where Y , M and Y are as defined in 8.10.
c c c,t
b) Finer material placement efficiency, E :
f
YM
ff
E 100 (4)
f
Y
f,t
where
Y is the yield value of the finer product;
f
Y is the theoretical yield of the finer product;
f,t
M is defined in 8.10.
f
c) Overall separation index (S )
i
SE E 100 (5)
if c
NOTE 1 Misplaced material values are in terms of mass and mass fractions expressed as a percent of reconstituted
feed.
NOTE 2 Alternative methods are available for the evaluation of the material placement efficiencies.
8.12 Near-size material
The near-size material, i.e. material within ±25 % of the reference size or sizes, is determined from the
size distribution curve for the reconstituted feed in Figure 2 and is inserted into the statement of sizing
equipment performance in Table 4.
Other relevant characteristics of the feed material that influence the degree of difficulty of separation are
inserted into Table 1, the test and equipment data sheet, which varies according to the type of equipment
under consideration. However, an example is included on page 11. Actual worked examples of data sheets
with different equipment are presented in Table 1 in Annexes B, C and D.
8.13 Test and equipment data
The presentation of the results of performance tests on coal sizing equipment shall include a report of the
equipment details, test conditions and characteristics of the feed material, particularly those that influence
the degree of difficulty involved in the separation. This information is inserted into Table 1, the test and
equipment data sheet with actual worked examples presented in Table 1 of Annexes B, C an
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