ISO 923:1975
(Main)Coal cleaning tests — Expression and presentation of results
Coal cleaning tests — Expression and presentation of results
Essais d'épuration du charbon — Expression et représentation des résultats
Preskusi priprave separiranja premoga - Prikaz rezultatov
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INTERNATIONAL STANDARD
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION .MEX)JYHAPOAHASl OPrAHM3AUMJl no CTAHAAPTM3AL@iM.ORGANISATION INTERNATIONALE DE NORMALISATION
Coal cleaning tests -
Expression and presentation of results
Essais d%pura tion du charbon
- Expression et rep&en ta tion des rkultats
First edition - 1975-12-01
UDC 662.66 : 622.7 : 620.1 : 001.818
- Ref. No. IS0 923-1975 (E)
Descriptors : coal, coal preparation, tests, cleaning, test results.
Price based on 21 pages
---------------------- Page: 1 ----------------------
IS0 (the International Organization for Standardization) is a worldwide federation
of national standards institutes (IS0 Member Bodies). The work of developing
International Standards is carried out through IS0 Technical Committees. Every
Member Body interested in a subject for which a Technical Committee has been set
up 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.
Draft International Standards adopted by the Technical Committees are circulated
to the Member Bodies for approval before their acceptance as International
Standards by the IS0 Council.
Prior to 1972, the results of the work of the Technical Committees were published
as IS0 Recommendations; these documents are now in the process of being
transformed into International Standards. As part of this process, Technical
Committee lSO/TC 27 has reviewed IS0 Recommendation R 923 and found it
technically suitable for transformation.
International Standard IS0 923 therefore
replaces IS0 Recommendation R 9234969 to which it is technically identical.
IS0 Recommendation R 923 was approved by the Member Bodies of the following
countries :
Australia
Greece Spain
Austria Switzerland
India
Belgium I ran Thailand
Bulgaria
Japan Turkey
Canada Korea, Rep. of United Kingdom
Czechoslovakia Netherlands U.S.A.
Denmark
New Zealand U.S.S.R.
Egypt, Arab Rep. of
Poland Yugoslavia
France
Romania
Germany South Africa, Rep. of
No Member Body expressed disapproval of the Recommendation.
The Member Bodies of the following countries disapproved the transformation of
ISO/R 923 into an International Standard :
Czechoslovakia
Japan
0 International Organization for Standardization, 1975 l
Printed in Switzerland’
---------------------- Page: 2 ----------------------
IS0 923-1975 (E)
INTERNATIONAL STANDARD
Expression and presentation of results
Coal cleaning tests -
4 STANDARD EXPRESSION OF EFFICIENCY
0 INTRODUCTION
4.1 Many different formulae have been proposed to
A number of formulae have been used in different countries
express the results of coal cleaning tests and the efficiency
for expressing the results of coal cleaning tests and for
of the separation processes. Those commonly used are
determining the efficiency of the separation processes (see
listed in annex A. For the purpose of meeting the
annex A). Bearing in mind the different purposes for which
requirements stated in clause 2, no one of these formulae,
such tests are carried out, it is considered that no one of
by itself, suffices.
these formulae, taken by itself, is adequate. It is, therefore,
recommended that four formulae should be used in
conjunction for expressing the basic data (see 4.2). In
4.2 For a standard expression of efficiency, the following
addition, recommendations are made for standard methods
formulae should be used in conjunction :
of presenting these data in tabular and graphical form (see
annexes B and C).
4.2.1 Separation density expressed as
The general adoption of these formulae, tables and graphs
partition density, and/or
a)
should simplify the exchange of information relating to the
equal errors cut-point (density).
efficiency and performance of coal preparation plant, and b)
the accumulation of data resulting from their use on a
variety of coals treated in different types of machine in 4.2.2 Total of correctly placed material at the separation
different parts of the world should enable them to be density, expressed as a percentage of the reconstituted feed,
simplified at a later date. and, where required, the misplaced material in each product
at the separation density, expressed as a percentage of the
product.
1 SCOPE
4.2.3 &art probable (moyen) and imperfection.
This International Standard outlines the principles on
which the expression of the efficiency of operation of coal
4.2.4 Ash error or organic efficiency
cleaning plant should be based, states the criteria,
coefficients and formulae to be used and also gives methods
for tabulation and graphical presentation of the test data.
5 TABULATION AND GRAPHICAL PRESENTATION
OF TEST RESULTS
The formulae for the expression of efficiency are derived
by standard methods of calculation from the basic test
2 FIELD OF APPLICATION
data; for convenience, the tables and graphs in which these
Expressions of the efficiency of coal cleaning processes are
data are presented should also follow a standard pattern.
required for
Annexes B and C describe and exemplify recommended
a) the indication of the accuracy (or inaccuracy) of a
methods for the tabulation and graphical presentation of
given separating operation on a particular coal;
test results.
b) the prediction of the probable results of treating
different coals by a given separating operation;
6 SIZE OF COAL
c) the comparison of different separating processes.
In expressing efficiency, it is essential to state the nominal
size limits of the coal to which the calculations refer.
3 DEFINTIONS 7 MULTIPLE-PRODUCT SEPARATION
In multiple-product separation, the criteria should be
The terms used in this International Standard are defined in
ISO/R 1213, Vocabulary of terms relating to solid mineral expressed at each separation density (see also annex B,
fuels - Part I : Terms relating to coal preparation. clause B.2).
1
---------------------- Page: 3 ----------------------
IS0 923-1975 (E)
ANNEX A
METHODS OF EXPRESSING EFFICIENCY
Formula Derived from Remarks
I
I
,A.1 Separation density Describes one characteristic of the separation, but does not indicate its
accuracy
Partition curves
a) Partition density
M-curves
b) Equal errors cut-
Washability curves
point (density)
. Misplaced material M-curves Measure of quantity of misplaced material (without reference to its quality)
iA 2
Washability curves at the separation density
Measure of quantity of correctly placed material (without reference to its
~A.3 Total of correctly M-curves
quality) at the separation density
placed material Washability curves
A.4 Ash error M-curves Reflects both the quantity and quality of misplaced material in terms of the
Washability curves specific property of coal (percentage of ash) which the separation is designed
to control; measures qualitative efficiency
A.5 Yield error M-curves Reflects both the quantity and quality of misplaced material and measures
Washability curves quantitative efficiency
Related to yield error but expressed as a percentage
A.6 Organic efficiency M-curves
Washability curves
A.7 Error area Partition curves Measure of quantity of misplaced material in terms of density
I
A.8 Partition coefficients Partition curves Special applications only
A.9 &art probable (moyen) Partition curves Gives an indication of the quantitative errors inherent in the separating
process at a given separation density
A.10 Imperfection Partition curves Modification of &art probable (moyen) to include effect of varying
separation density
States results without reference to accuracy of separation
A.11 Yield loss Product samples
NOTES
1 M-curves and washability curves describe graphically the character of the raw coal and of the products, in terms of mass and ash content.
Partition curves describe only the products and in terms of mass and density; they can be constructed without the necessity to determine ash
content.
2 M-curves have wider direct applications than washability curves, especially, for example, in three-product separations.
3 The &cart probable (moyen) and imperfection reflect the influence of changes in the separation process rather than in the raw coal, in
contrast to the formuke derived from M-curves or washability curves, which reflect changes in the raw coal as well as in the separation process.
4 The separation density, although not a measure of efficiency, is an important characteristic of the separation and is essential to any
comprehensive statement of the results of a given test.
5 The misplaced material and the total of correctly placed material at the separation density, the ash error, the yield error, the organic
efficiency and the error area can all be used for guarantee tests and occasional control tests to give an indication of the accuracy of a given
separation on a given coal, and hence of economic efficiency; but they are of little value in the prediction of probable results of cleaning a range
of coals by one specific process.
6 Partition coefficients, &art probable (moyen) and imperfection are valuable for the purpose of prediction but do not give an adequate
indication of the accuracy of a given separating operation on a particular coal.
2
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IS0 923-1975 (E)
ANNEX B
RECOMMENDATIONS FOR STANDARD METHODS OF PRESENTING COAL
CLEANING TEST DATA
B.l.6 The figures in the tables headed “two-product
B.l DESCRIPTION OF THE TABLES
separation” have been calculated from these same figures
on the assumption that the products from both elevators
B.l.l Two sets of tables are required (see clause B.4) :
(i.e. the middlings and the reject) were combined so that
there were two products only : cleaned coal and a single
a) for three-product separation (cleaned coal, middlings
reject.
and reject);
b) for two-product separation (cleaned coal and reject).
B.2 EXPRESSION OF EFFICIENCY IN THE THREE-
For convenience, an identical layout has been adopted for
PRODUCT SEPARATION
both sets of tables, but in those intended for use with
two-product separations, the columns which relate only to
B.2.1 Three-product separation may be regarded as a
three-product separation have been struck through so as to
combination of two distinct two-product separations (i.e. a
avoid confusion.
low-density cut and a high-density cut), whether these two
stages are in fact carried out in different separating vessels
8.12 Each set of tables is presented in two ways :
or in different parts of the same vessel.
a) blank tables, to show the method of printing (see
The following diagrams illustrate different combinations of
Form 1 and Form 3 in clause B.4);
the two stages :
b) tables completed, by way of example, by filling in
Diagram
the figures relating to the results of a test on a Baum jig
No.
washer (see Form 2 and Form 4 in clause B.4).
l)F+rj--[+R
B.l.3 For the test described in this example, the washer
was supplied with coal sized from 152 mm to 0 (6 in to 0).
The figures used refer to the fraction sized between
,,,+yJ - f, ---+ c
12,7 mm (l/2 in) and 0,5 mm. The fine material below
0,5 mm was removed from the samples before carrying out
+
float and sink tests, because this fine material presents i
difficulties in testing. hnoreover, the jig is not expected to
3IF‘l+l -c
clean material smaller than 0,5 mm.
R
M
+
+
B.1.4 For a full analysis of the test, tables similar to those
given for the 12,7 mm (l/2 in) - 0,5 mm size would be
where
required for the other sizes of the raw coal, in this instance
152 - 51 mm (6 - 2 in), 51 - 25,4 mm (2 - 1 in), and
F is the feed (reconstituted raw coal);
25,4 - 12,7 mm (1 - l/2 in). Such tables would enable the
performance on the different sizes to be compared. By
C is the cleaned coal;
adding together the results on the four individual sizes, a
further set of tables could be constructed representing the R is the reject;
whole of the 152 mm (6 in) - 0,5 mm coal.
M is the intermediate product (middlings).
B.1.5 In this test, three products were made : cleaned
coal, middlings and reject. The reject is the material Diagrams 1 and 2 represent typical arrangements for a
removed by the primary reject elevator and the middlings is two-stage dense medium separation, the only difference
the reject from the secondary reject elevator. The tables being that the low-density cut comes first in diagram 1 and
headed “three-product separation” are built up from float second in diagram 2, while diagram 3 represents a normal
and sink tests at various relative densities from I,30 to 2,00 three-product jig (or a three-product dense medium
on samples of each of these three products. Although separation). The middlings M may be collected as a separate
intervals of 0,l relative density have been used for the product, or recirculated, or otherwise dealt with, but
example, different ranges and intervals may be required in provided that any recirculated middlings are included in the
other cases. reconstituted feed F, the argument is unaffected.
3
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IS0 923-1975 (E)
8.2.2 The efficiency of a three-product separation may be combination of the cleaned coal C and middlings M, and it
is this combination which becomes the feed to the second
calculated in two different ways :
stage of the separation.
by regarding it as two distinct and
a) Method A,
individual separations, each with its own feed;
B.2.2.3 Method A enables the efficiency of each of the
two separations to be studied individually, for only the
b) Method B, by regarding it as a single comprehensive
material actually admitted to the separation is included in
separation, the feed for which is the reconstituted raw
the calculation. This is of advantage when considering the
coal.
performance of each machine or stage in the separation
process.
B.2.2.1 In order to calculate the partition coefficients, the
appropriate formulae for these two methods, for the
8.2.2.4 Method B does not show up so emphatically the
combinations of plant illustrated in the diagrams, are as
actual performance of the second machine or stage, but by
follows :
referring each separation back to the reconstituted raw feed
it facilitates comparisons of the efficiency of the whole
B.2.2.1.1 For diagram 1
separation process in terms of the results on the original
100 (M+ R) raw coal. (The sequence of operations included in this
a) Method A
low-density cut
complete process may include steps not shown in
C+M+R
diagrams 1 to 3, for example crushing of the middlings and
IOOR
its recirculation to the feed, which is common in jig
high-density cut
washing and may also occur in dense medium separation.)
M+R
100 (M+ R)
B.2.3 It is essential, whenever the efficiency of a
low-density cut
b) Method B
C+M+R
three-product separation is expressed (for example in
descriptions of plant and efficiency statements and
IOOM
guarantees), that it should be clearly stated which of these
high-density cut
C+M+R
two bases has been used for the calculation. To facilitate
this, it is proposed that Method A should be described as
the equipment performance basis, and Method B as the coal
B.2.2.1.2 For diagram 2 performance basis.
IOOR
high-density cut
a) Method A
for the three-product
B.2.4 The attached tables
C+M+R
separations are drawn up on the coal performance basis.
IOOM When calculations are made on the equipment performance
low-density cut
basis, it is recommended that two-product tables should be
C+M
used (one for each stage). It is possible, however, to deduce
IOOR
the results from the three-product table; thus, partition
high-density cut
b) Method B
coefficients for the second cut would be calculated on the
C-I-M-I-R
equipment performance basis as follows :
IOOM
low-density cut -
For diagram 1 (see B.2.1), column (12) would be
C+M+R
calculated from (7)/(g) instead of (7)/(10).
-
For diagrams 2 and 3 (see B.2.1), column (13) would
B.2.2.1.3 For diagram 3 be calculated from (6)/(8) instead of (9)/(10).
100 R
a) Method A
high-density cut
C+M+R
B.3 DESCRIPTION OF THE GRAPHS (see annex C)
IOOM
low-density cut
B.3.1 In order to calculate the efficiency by the four
C+M
formulae proposed (see 4.2), the data in these tables must
100 R
be represented in graphs. Graphs relating to the test results
high-density cut
b) Method B
are shown in figures 1 to 4. The graphs have been prepared
C+M+R
from the data for three-product separation; but the curves
100 (M+ R
for the low-density cut apply to the two-product example.
low-density cut
C+M+R
8.3.2 Figure 1 has been drawn to a scale such that 0,2 unit
B.2.2.2 While for Method A the formulae are identical for on the relative density axis equals 10 % on the partition
coefficient axis. It is proposed to standardize this relation
diagrams 2 and 3, in the latter case there is no sharp
for drawing partition curves, when using (as in figure 1)
dividing line between the first and second cuts. The first
linear co-ordinates, but similar standard scales for the other
(high-density) cut separates the reject R from the
4
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IS0 923-1975 (E)
curves are not at present considered to be practicable. the curve as 94,60 %. The organic efficiency is derived
The curves can also be drawn using other than linear from the ratio of these two yields.
co-ordinates.
B.3.3.2.4 Similar considerations apply to point Y.
B.3.3 The following sub-clauses explain the construction
B.3.3.3 Correctly placed (and misplaced) material - high-
and use of the graphs in figures 1 to 4 :
density cut (see figure 3)
B.3.3.1 Partition curves (three-product) (see figure 1)
B.3.3.3.1 The two lower curves show the amounts of
misplaced material in the reject (column 18) and the
B.3.3.1.1 The partition coefficients in columns (12) and
cleaned coal plus middlings product (column 17) - the
(13) are plotted against the mean of the relative densities
fraction which in this example goes forward for further
shown in the table for each fraction.
treatment. The upper curve shows the sum or total of the
misplaced material in these two products combined
B.3.3.1.2 The curve on the right represents the
(column 19). The total amount (percentage) of correctly
high-density cut because it refers to the removal of the final
placed material (100 minus misplaced material) is read from
reject.
the scale on the right-hand side of the graph.
B.3.3.1.3 The table columns from which the coefficients
B.3.3.3.2 The equal errors cut-point (density) is the
are extracted are shown on each curve.
relative density at which the two lower curves intersect; in
this example this density is 1,770. The partition density
B.3.3.1.4 The relative density at which the curves cross
is 1,835.
50 % is by definition the partition density. Similarly &art
probable (moyen) (Epm) is defined in terms of the relative
B.3.3.3.3 The relative densities of 1,770 and 1,835
densities d 25 and d75 at which the curves cross 25 % an
...
SLOVENSKI STANDARD
SIST ISO 923:1998
01-februar-1998
Preskusi priprave separiranja premoga - Prikaz rezultatov
Coal cleaning tests -- Expression and presentation of results
Essais d'épuration du charbon -- Expression et représentation des résultats
Ta slovenski standard je istoveten z: ISO 923:1975
ICS:
73.040 Premogi Coals
SIST ISO 923:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST ISO 923:1998
---------------------- Page: 2 ----------------------
SIST ISO 923:1998
INTERNATIONAL STANDARD
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION .MEX)JYHAPOAHASl OPrAHM3AUMJl no CTAHAAPTM3AL@iM.ORGANISATION INTERNATIONALE DE NORMALISATION
Coal cleaning tests -
Expression and presentation of results
Essais d%pura tion du charbon
- Expression et rep&en ta tion des rkultats
First edition - 1975-12-01
UDC 662.66 : 622.7 : 620.1 : 001.818
- Ref. No. IS0 923-1975 (E)
Descriptors : coal, coal preparation, tests, cleaning, test results.
Price based on 21 pages
---------------------- Page: 3 ----------------------
SIST ISO 923:1998
IS0 (the International Organization for Standardization) is a worldwide federation
of national standards institutes (IS0 Member Bodies). The work of developing
International Standards is carried out through IS0 Technical Committees. Every
Member Body interested in a subject for which a Technical Committee has been set
up 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.
Draft International Standards adopted by the Technical Committees are circulated
to the Member Bodies for approval before their acceptance as International
Standards by the IS0 Council.
Prior to 1972, the results of the work of the Technical Committees were published
as IS0 Recommendations; these documents are now in the process of being
transformed into International Standards. As part of this process, Technical
Committee lSO/TC 27 has reviewed IS0 Recommendation R 923 and found it
technically suitable for transformation.
International Standard IS0 923 therefore
replaces IS0 Recommendation R 9234969 to which it is technically identical.
IS0 Recommendation R 923 was approved by the Member Bodies of the following
countries :
Australia
Greece Spain
Austria Switzerland
India
Belgium I ran Thailand
Bulgaria
Japan Turkey
Canada Korea, Rep. of United Kingdom
Czechoslovakia Netherlands U.S.A.
Denmark
New Zealand U.S.S.R.
Egypt, Arab Rep. of
Poland Yugoslavia
France
Romania
Germany South Africa, Rep. of
No Member Body expressed disapproval of the Recommendation.
The Member Bodies of the following countries disapproved the transformation of
ISO/R 923 into an International Standard :
Czechoslovakia
Japan
0 International Organization for Standardization, 1975 l
Printed in Switzerland’
---------------------- Page: 4 ----------------------
SIST ISO 923:1998
IS0 923-1975 (E)
INTERNATIONAL STANDARD
Expression and presentation of results
Coal cleaning tests -
4 STANDARD EXPRESSION OF EFFICIENCY
0 INTRODUCTION
4.1 Many different formulae have been proposed to
A number of formulae have been used in different countries
express the results of coal cleaning tests and the efficiency
for expressing the results of coal cleaning tests and for
of the separation processes. Those commonly used are
determining the efficiency of the separation processes (see
listed in annex A. For the purpose of meeting the
annex A). Bearing in mind the different purposes for which
requirements stated in clause 2, no one of these formulae,
such tests are carried out, it is considered that no one of
by itself, suffices.
these formulae, taken by itself, is adequate. It is, therefore,
recommended that four formulae should be used in
conjunction for expressing the basic data (see 4.2). In
4.2 For a standard expression of efficiency, the following
addition, recommendations are made for standard methods
formulae should be used in conjunction :
of presenting these data in tabular and graphical form (see
annexes B and C).
4.2.1 Separation density expressed as
The general adoption of these formulae, tables and graphs
partition density, and/or
a)
should simplify the exchange of information relating to the
equal errors cut-point (density).
efficiency and performance of coal preparation plant, and b)
the accumulation of data resulting from their use on a
variety of coals treated in different types of machine in 4.2.2 Total of correctly placed material at the separation
different parts of the world should enable them to be density, expressed as a percentage of the reconstituted feed,
simplified at a later date. and, where required, the misplaced material in each product
at the separation density, expressed as a percentage of the
product.
1 SCOPE
4.2.3 &art probable (moyen) and imperfection.
This International Standard outlines the principles on
which the expression of the efficiency of operation of coal
4.2.4 Ash error or organic efficiency
cleaning plant should be based, states the criteria,
coefficients and formulae to be used and also gives methods
for tabulation and graphical presentation of the test data.
5 TABULATION AND GRAPHICAL PRESENTATION
OF TEST RESULTS
The formulae for the expression of efficiency are derived
by standard methods of calculation from the basic test
2 FIELD OF APPLICATION
data; for convenience, the tables and graphs in which these
Expressions of the efficiency of coal cleaning processes are
data are presented should also follow a standard pattern.
required for
Annexes B and C describe and exemplify recommended
a) the indication of the accuracy (or inaccuracy) of a
methods for the tabulation and graphical presentation of
given separating operation on a particular coal;
test results.
b) the prediction of the probable results of treating
different coals by a given separating operation;
6 SIZE OF COAL
c) the comparison of different separating processes.
In expressing efficiency, it is essential to state the nominal
size limits of the coal to which the calculations refer.
3 DEFINTIONS 7 MULTIPLE-PRODUCT SEPARATION
In multiple-product separation, the criteria should be
The terms used in this International Standard are defined in
ISO/R 1213, Vocabulary of terms relating to solid mineral expressed at each separation density (see also annex B,
fuels - Part I : Terms relating to coal preparation. clause B.2).
1
---------------------- Page: 5 ----------------------
SIST ISO 923:1998
IS0 923-1975 (E)
ANNEX A
METHODS OF EXPRESSING EFFICIENCY
Formula Derived from Remarks
I
I
,A.1 Separation density Describes one characteristic of the separation, but does not indicate its
accuracy
Partition curves
a) Partition density
M-curves
b) Equal errors cut-
Washability curves
point (density)
. Misplaced material M-curves Measure of quantity of misplaced material (without reference to its quality)
iA 2
Washability curves at the separation density
Measure of quantity of correctly placed material (without reference to its
~A.3 Total of correctly M-curves
quality) at the separation density
placed material Washability curves
A.4 Ash error M-curves Reflects both the quantity and quality of misplaced material in terms of the
Washability curves specific property of coal (percentage of ash) which the separation is designed
to control; measures qualitative efficiency
A.5 Yield error M-curves Reflects both the quantity and quality of misplaced material and measures
Washability curves quantitative efficiency
Related to yield error but expressed as a percentage
A.6 Organic efficiency M-curves
Washability curves
A.7 Error area Partition curves Measure of quantity of misplaced material in terms of density
I
A.8 Partition coefficients Partition curves Special applications only
A.9 &art probable (moyen) Partition curves Gives an indication of the quantitative errors inherent in the separating
process at a given separation density
A.10 Imperfection Partition curves Modification of &art probable (moyen) to include effect of varying
separation density
States results without reference to accuracy of separation
A.11 Yield loss Product samples
NOTES
1 M-curves and washability curves describe graphically the character of the raw coal and of the products, in terms of mass and ash content.
Partition curves describe only the products and in terms of mass and density; they can be constructed without the necessity to determine ash
content.
2 M-curves have wider direct applications than washability curves, especially, for example, in three-product separations.
3 The &cart probable (moyen) and imperfection reflect the influence of changes in the separation process rather than in the raw coal, in
contrast to the formuke derived from M-curves or washability curves, which reflect changes in the raw coal as well as in the separation process.
4 The separation density, although not a measure of efficiency, is an important characteristic of the separation and is essential to any
comprehensive statement of the results of a given test.
5 The misplaced material and the total of correctly placed material at the separation density, the ash error, the yield error, the organic
efficiency and the error area can all be used for guarantee tests and occasional control tests to give an indication of the accuracy of a given
separation on a given coal, and hence of economic efficiency; but they are of little value in the prediction of probable results of cleaning a range
of coals by one specific process.
6 Partition coefficients, &art probable (moyen) and imperfection are valuable for the purpose of prediction but do not give an adequate
indication of the accuracy of a given separating operation on a particular coal.
2
---------------------- Page: 6 ----------------------
SIST ISO 923:1998
IS0 923-1975 (E)
ANNEX B
RECOMMENDATIONS FOR STANDARD METHODS OF PRESENTING COAL
CLEANING TEST DATA
B.l.6 The figures in the tables headed “two-product
B.l DESCRIPTION OF THE TABLES
separation” have been calculated from these same figures
on the assumption that the products from both elevators
B.l.l Two sets of tables are required (see clause B.4) :
(i.e. the middlings and the reject) were combined so that
there were two products only : cleaned coal and a single
a) for three-product separation (cleaned coal, middlings
reject.
and reject);
b) for two-product separation (cleaned coal and reject).
B.2 EXPRESSION OF EFFICIENCY IN THE THREE-
For convenience, an identical layout has been adopted for
PRODUCT SEPARATION
both sets of tables, but in those intended for use with
two-product separations, the columns which relate only to
B.2.1 Three-product separation may be regarded as a
three-product separation have been struck through so as to
combination of two distinct two-product separations (i.e. a
avoid confusion.
low-density cut and a high-density cut), whether these two
stages are in fact carried out in different separating vessels
8.12 Each set of tables is presented in two ways :
or in different parts of the same vessel.
a) blank tables, to show the method of printing (see
The following diagrams illustrate different combinations of
Form 1 and Form 3 in clause B.4);
the two stages :
b) tables completed, by way of example, by filling in
Diagram
the figures relating to the results of a test on a Baum jig
No.
washer (see Form 2 and Form 4 in clause B.4).
l)F+rj--[+R
B.l.3 For the test described in this example, the washer
was supplied with coal sized from 152 mm to 0 (6 in to 0).
The figures used refer to the fraction sized between
,,,+yJ - f, ---+ c
12,7 mm (l/2 in) and 0,5 mm. The fine material below
0,5 mm was removed from the samples before carrying out
+
float and sink tests, because this fine material presents i
difficulties in testing. hnoreover, the jig is not expected to
3IF‘l+l -c
clean material smaller than 0,5 mm.
R
M
+
+
B.1.4 For a full analysis of the test, tables similar to those
given for the 12,7 mm (l/2 in) - 0,5 mm size would be
where
required for the other sizes of the raw coal, in this instance
152 - 51 mm (6 - 2 in), 51 - 25,4 mm (2 - 1 in), and
F is the feed (reconstituted raw coal);
25,4 - 12,7 mm (1 - l/2 in). Such tables would enable the
performance on the different sizes to be compared. By
C is the cleaned coal;
adding together the results on the four individual sizes, a
further set of tables could be constructed representing the R is the reject;
whole of the 152 mm (6 in) - 0,5 mm coal.
M is the intermediate product (middlings).
B.1.5 In this test, three products were made : cleaned
coal, middlings and reject. The reject is the material Diagrams 1 and 2 represent typical arrangements for a
removed by the primary reject elevator and the middlings is two-stage dense medium separation, the only difference
the reject from the secondary reject elevator. The tables being that the low-density cut comes first in diagram 1 and
headed “three-product separation” are built up from float second in diagram 2, while diagram 3 represents a normal
and sink tests at various relative densities from I,30 to 2,00 three-product jig (or a three-product dense medium
on samples of each of these three products. Although separation). The middlings M may be collected as a separate
intervals of 0,l relative density have been used for the product, or recirculated, or otherwise dealt with, but
example, different ranges and intervals may be required in provided that any recirculated middlings are included in the
other cases. reconstituted feed F, the argument is unaffected.
3
---------------------- Page: 7 ----------------------
SIST ISO 923:1998
IS0 923-1975 (E)
8.2.2 The efficiency of a three-product separation may be combination of the cleaned coal C and middlings M, and it
is this combination which becomes the feed to the second
calculated in two different ways :
stage of the separation.
by regarding it as two distinct and
a) Method A,
individual separations, each with its own feed;
B.2.2.3 Method A enables the efficiency of each of the
two separations to be studied individually, for only the
b) Method B, by regarding it as a single comprehensive
material actually admitted to the separation is included in
separation, the feed for which is the reconstituted raw
the calculation. This is of advantage when considering the
coal.
performance of each machine or stage in the separation
process.
B.2.2.1 In order to calculate the partition coefficients, the
appropriate formulae for these two methods, for the
8.2.2.4 Method B does not show up so emphatically the
combinations of plant illustrated in the diagrams, are as
actual performance of the second machine or stage, but by
follows :
referring each separation back to the reconstituted raw feed
it facilitates comparisons of the efficiency of the whole
B.2.2.1.1 For diagram 1
separation process in terms of the results on the original
100 (M+ R) raw coal. (The sequence of operations included in this
a) Method A
low-density cut
complete process may include steps not shown in
C+M+R
diagrams 1 to 3, for example crushing of the middlings and
IOOR
its recirculation to the feed, which is common in jig
high-density cut
washing and may also occur in dense medium separation.)
M+R
100 (M+ R)
B.2.3 It is essential, whenever the efficiency of a
low-density cut
b) Method B
C+M+R
three-product separation is expressed (for example in
descriptions of plant and efficiency statements and
IOOM
guarantees), that it should be clearly stated which of these
high-density cut
C+M+R
two bases has been used for the calculation. To facilitate
this, it is proposed that Method A should be described as
the equipment performance basis, and Method B as the coal
B.2.2.1.2 For diagram 2 performance basis.
IOOR
high-density cut
a) Method A
for the three-product
B.2.4 The attached tables
C+M+R
separations are drawn up on the coal performance basis.
IOOM When calculations are made on the equipment performance
low-density cut
basis, it is recommended that two-product tables should be
C+M
used (one for each stage). It is possible, however, to deduce
IOOR
the results from the three-product table; thus, partition
high-density cut
b) Method B
coefficients for the second cut would be calculated on the
C-I-M-I-R
equipment performance basis as follows :
IOOM
low-density cut -
For diagram 1 (see B.2.1), column (12) would be
C+M+R
calculated from (7)/(g) instead of (7)/(10).
-
For diagrams 2 and 3 (see B.2.1), column (13) would
B.2.2.1.3 For diagram 3 be calculated from (6)/(8) instead of (9)/(10).
100 R
a) Method A
high-density cut
C+M+R
B.3 DESCRIPTION OF THE GRAPHS (see annex C)
IOOM
low-density cut
B.3.1 In order to calculate the efficiency by the four
C+M
formulae proposed (see 4.2), the data in these tables must
100 R
be represented in graphs. Graphs relating to the test results
high-density cut
b) Method B
are shown in figures 1 to 4. The graphs have been prepared
C+M+R
from the data for three-product separation; but the curves
100 (M+ R
for the low-density cut apply to the two-product example.
low-density cut
C+M+R
8.3.2 Figure 1 has been drawn to a scale such that 0,2 unit
B.2.2.2 While for Method A the formulae are identical for on the relative density axis equals 10 % on the partition
coefficient axis. It is proposed to standardize this relation
diagrams 2 and 3, in the latter case there is no sharp
for drawing partition curves, when using (as in figure 1)
dividing line between the first and second cuts. The first
linear co-ordinates, but similar standard scales for the other
(high-density) cut separates the reject R from the
4
---------------------- Page: 8 ----------------------
SIST ISO 923:1998
IS0 923-1975 (E)
curves are not at present considered to be practicable. the curve as 94,60 %. The organic efficiency is derived
The curves can also be drawn using other than linear from the ratio of these two yields.
co-ordinates.
B.3.3.2.4 Similar considerations apply to point Y.
B.3.3 The following sub-clauses explain the construction
B.3.3.3 Correctly placed (and misplaced) material - high-
and use of the graphs in figures 1 to 4 :
density cut (see figure 3)
B.3.3.1 Partition curves (three-product) (see figure 1)
B.3.3.3.1 The two lower curves show the amounts of
misplaced material in the reject (column 18) and the
B.3.3.1.1 The partition coefficients in columns (12) and
cleaned coal plus middlings product (column 17) - the
(13) are plotted against the mean of the relative densities
fraction which in this example goes forward for further
shown in the table for each fraction.
treatment. The upper curve shows the sum or total of the
misplaced material in these two products combined
B.3.3.1.2 The curve on the right represents the
(column 19). The total amount (percentage) of correctly
high-density cut because it refers to the removal of the final
placed material (100 minus misplaced material) is read from
reject.
the scale on the right-hand side of the graph.
B.3.3.1.3 The table columns from which the coefficients
B.3.3.3.2 The equal errors cut-point (density) is the
are extracted are shown on each curve.
relative density at which the two lower curves intersect; in
this example this density is 1,770. The partition density
B.3.3.1.4 The relative density at which the curve
...
NORME INTERNATIONALE 923
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION .MFj(i.IYHAPOLIHAR OPr4HM3AUMH no CTAH,lAPTII3AUMM .ORGANISATION INTERNATIONALE DE NORMALISATION
Essais d'épuration du charbon - Expression et représentation
-
des résultats
Coal cleaning tests - Expression and presentation of results
Premiere édition - 1975-12-01
CDU 662.66 : 622.7 : 620.1 : 001.818 Réf. no : IS0 923-1975 (FI
Descripteurs : charbon, préparation du charbon, essai, nettoyage, résuitats d'essai.
Prix basé sur 21 pages
---------------------- Page: 1 ----------------------
AVANT-PROPOS
L'ISO (Organisation Internationale de Normalisation) est une fédération mondiale
d'organismes nationaux de normalisation (Comités Membres ISO). L'élaboration de
Normes Internationales est confiée aux Comités Techniques ISO. Chaque Comité
Membre intéressé par une étude a le droit de faire partie du Comité Technique
correspondant. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec I'ISO, participent également aux travaux.
Les Projets de Normes Internationales adoptés par les Comités Techniques sont
soumis aux Comités Membres pour approbation, avant leur acceptation comme
Normes Internationales par le Conseil de I'ISO.
Avant 1972, les résultats des travaux des Comités Techniques étaient publiés comme
Recommandations ISO; maintenant, ces documents sont en cours de
transformation en Normes Internationales. Compte tenu de cette procédure, le
Comité Technique ISO/TC 27 a examiné la Recommandation ISO/R 923 et est
d'avis qu'elle peut, du point de vue technique, être transformée en Norme
Internationale. La présente Norme Internationale remplace donc la
Recommandation ISO/R 923-1 969 à laquelle elle est techniquement identique.
La Recommandation ISO/R 923 avait été approuvée par les Comités Membres des
pays suivants :
Afrique du Sud, Rép. d' Espagne Roy aume- U n i
Al lemagne France Suisse
Australie Grèce Thaïlande
Autriche Inde Tchécoslovaquie
Belgique I ran Turquie
Bulgarie Japon U.R.S.S.
Nouvelle-Zélande U.S.A.
Canada
Corée, Rép. de
Pays-Bas Yougoslavie
Danemark
Pologne
Roumanie
Egypte, Rép. arabe d'
Aucun Comité Membre n'avait désapprouvé la Recommandation.
Les Comités Membres des pays suivants ont désapprouvé la transformation de la
Recommandation ISO/R 923 en Norme Internationale :
Japon
Tchécoslovaquie
O Organisation Internationale de Normalisation, 1975 0
Imprimé en Suisse
---------------------- Page: 2 ----------------------
NORME INTERNATIONALE IS0 923-1975 (F)
Essais d'épuration du charbon - Expression et représentation
des résultats
O INTRODUCTION en tableaux et la présentation graphique des résultats
d'essai.
Un certain nombre de formules ont été utilisées dans
différents pays pour exprimer les résultats des essais
d'épuration du charbon et pour déterminer l'efficacité des
2 DOMAINE D'APPLICATION
A). Tout en ne perdant
procédés de séparation (voir annexe
Des expressions de l'efficacité des essais d'épuration du
pas de vue les différents objets pour lesquels de tels essais
charbon sont nécessaires pour
sont exécutés, on considère qu'aucune de ces formules,
prise isolément, ne convient. C'est pourquoi il est
a) l'indication du degré d'exactitude (ou du défaut
recommandé que quatre formules soient employées en
d'exactitude) d'une opération donnée de séparation
combinaison pour exprimer les informations fondamentales
effectuée sur un certain charbon,
. (voir 4.2). Des recommandations sont faites, en outre,
concernant des méthodes normalisées de présentation de b) la prévision des résultats probables du traitement de
charbons différents par une opération de séparation
ces informations sous forme de tableaux et de graphiques
donnée, et
(voir annexes B et C).
L'adoption générale de ces formules, tableaux et graphiques c) la comparaison de différents procédés de séparation.
devrait simplifier l'échange des informations relatives à
l'efficacité et aux performances d'un atelier de préparation
3 DÉFINITIONS
du charbon et l'accumulation des renseignements, résultant
de leur emploi sur différents charbons traités dans
Les termes utilisés dans la présente Norme Internationale
différents types de machine et dans différentes parties du
sont définis dans I'ISO/R 1213, Vocabulaire des termes
monde, devrait être susceptible de rendre possible,
relatifs aux combustibles minéraux solides - Première
Ultérieurement, une simplification de ces formules, tableaux
partie : Termes relatifs à la préparation du charbon.
et graphiques.
4 EXPRESSION NORMALISÉE DE L'EFFICACITÉ
1 OBJET
4.1 Plusieurs formules différentes ont été proposées pour
exprimer les résultats des essais d'épuration du charbon et
La présente Norme Internationale délimite les principes sur
lesquels devrait être basée l'expression de l'efficacité du l'efficacité des procédés de séparation. Ceux utilisés
fonctionnement d'un atelier de préparation du charbon, communément sont énumérés dans l'annexe A. Pour
établit des critères, des coefficients et des formules à satisfaire aux exigences exposées dans le chapitre 2, aucune
employer et indique aussi des méthodes pour la disposition de ces formules, prise isolément, ne suffit.
1
---------------------- Page: 3 ----------------------
IS0 923-1975 (F)
par des méthodes normalisées, des renseignements
4.2 Pour une expression normalisée de l'efficacité, les
fondamentaux d'essais. Pour des raisons de commodité, les
quatre formules suivantes devraient être utilisées en
tableaux et les graphiques dans lesquels ces renseignements
combinaison :
à une configuration
sont présentés devraient aussi obéir
normalisée.
4.2.1 Densité de séparation, exprimée sous forme de
a) densité de partage, et/ou
Les annexes B et C décrivent les méthodes recommandées
b) densité de coupure équivalente pour la tabulation et la représentation graphique des
résultats d'essais; ils en donnent également des exemples
d'application.
4.2.2 Total de la matière correctement placée à la densité
de séparation, exprimé sous la forme d'un pourcentage de
l'alimentation reconstitutée, et, lorsque c'est nécessaire, les
égarés dans chaque produit, à la densité de séparation, 6 CALIBRE DU CHARBON
exprimés sous la forme d'un pourcentage du produit.
Dans l'expression de l'efficacité, il est essentiel de spécifier
les limites nominales de calibre du charbon auquel
4.2.3 Écart probable et imperfection.
s'applique le calcul.
4.2.4 Erreur sur cendres ou rendement organique.
7 SÉPARATION EN PRODUITS MULTIPLES
5 TABULATION ET PRESENTATION GRAPHIQUES
Dans ces séparations, les formules devraient être exprimées
DES RÉSULTATS D'ESSAIS
à chaque densité de séparation (voir aussi l'annexe B,
Les formules destinées à exprimer l'efficacité sont déduites. chapitre B.2).
2
---------------------- Page: 4 ----------------------
IS0 923-1975 (F)
ANNEXE A
MÉTHODES POUR EXPRIMER L-EFFICACITÉ
Formule Déduite de Observations
I
A.l Densité de séparation Décrit un caractère de la séparation, mais n'indique pas son degré d'exactitude
a) Densité de partage Courbes de partage
b) Densité de coupure Courbes M
équivalente Courbes de lavabilité
Courbes M Mesure de la quantité des égarés (sans référence à leur qualité) à la densité de
Courbes de lavabilité séparation
A.2 I Égarés
A.3 Total de la matière Courbes M Mesure de la quantité correctement placée (sans référence à sa qualité) à la
correctement placée Courbes de lavabilité densité de séparation
_____
Reflète à la fois la quantité et la qualité des égarés sous la forme du caractere
A.4 Erreur sur cendres Courbes M
Courbes de lavabilité considéré du charbon (pourcentage en cendres) que la séparation est destinée
à contrôler : mesure une efficacité qualitative
A.5 Erreur de rendement Courbes M Reflète à la fois la quantité et la qualité des égarés et mesure une efficacité
Courbes de lavabilité quantitative
__-
A.6 Rendement organique M En relation avec l'erreur de rendement, mais exprimé sous forme de
Courbes
Courbes de lavabilité pourcentage
Surface d'erreur 1 Mesure de la quantité des égarés en fonction de la densité
A.7 Courbes de partage
A.8 Coefficientsde partage Courbes de partage I seulement pour applications spéciales
-
A.9 Écart probable (moyen) Courbes de partage Donne une indication des erreurs quantitatives dues au procédé de séparation
à une densité de séparation donnée
Courbes de partage Modification de l'écart probable (moyen) destinée à y inclure l'effet d'une
densité de séparation variable
Échantillons du produit Indique les résultats sans référence au degré d'exactitude de la séparation
NOTES
1 Les courbes M et les courbes de lavabilité décrivent graphiquement le caractère du charbon brut et des produits en fonction de la masse et du
taux de cendres. Les courbes de partage décrivent seulement les produits, et ce en fonction de la masse et de la densité: elles peuvent être cons-
truites sans qu'il soit nécessaire de déterminer le taux de cendres.
2 Les courbes M ont des applications directes plus larges que les courbes de lavabilité, en particulier, par exemple, dans les séparations en trois
produ its.
3 L'écart probable et l'imperfection reflètent l'influence de changements plutôt dans le procédé de séparation que dans le charbon brut, ce qui
contraste avec les formules déduites des courbes M ou des courbes de lavabilité, qui reflètent des changements dans le charbon brut ainsi que
dans le procédé de séparation.
4 La densité de séparation, bien qu'elle ne soit pas une mesure de l'efficacité, est une caractéristique importante de la séparation et est
essentielle pour tout exposé complet des résultats d'un essai donné.
5 Les égarés et le total de la matière correctement placée à la densité de séparation, l'erreur sur cendres, l'erreur de rendement, le rendement
organique et la surface d'erreur peuvent tous ëtre employés pour des essais de garantie de et des contrôles occasionnels d'essais, afin de donner
une indication sur le degré d'exactitude d'une séparation donnée sur un charbon déterminé et, par conséquent, sur l'efficacité économique. Mais
ils n'ont que peu de valeur pour la prévision de résultats probables d'épuration d'une étendue de charbons selon un procédé déterminé.
Les coefficients de partage, l'écart probable (moyen) et l'imperfection sont utiles pour la prévision mais ne donnent pas une indication
6
convenable du degré d'exactitude d'une opération de séparation donnée sur un charbon déterminé.
3
---------------------- Page: 5 ----------------------
IS0 923-1975 (F)
ANNEXE B
RECOMMANDATIONS CONCERNANT DES METHODES NORMALISEES DE PRESENTATION
DES RENSEIGNEMENTS OBTENUS LORS D'UN ESSAI D-ÉPURATION DE CHARBON
B.l DESCRIPTION DES TABLEAUX trois produits)) sont établis d'après des essais aux liqueurs
denses, à des densités relatives allant de 1,30 à 2,00,
effectués sur des échantillons de chacun de ces trois
B.l.l Deux jeux de tableaux sont nécessaires (voir
produits. Bien que des intervalles de 0.1 de densité relative
chapitre 6.4);
aient été employés dans cet exemple, des gammes et des
a) l'un pour la séparation en trois produits (charbon
intervalles différents peuvent être employés dans d'autres
épuré, mixtes et rejets),
cas.
b) l'autre pour la séparation en deux produits (charbon
B.1.6 Les valeurs des tableaux du modèle 4, ((Séparation
épuré et rejets).
en deux produits)), ont été calculées à partir des mêmes
Par mesure de commodité, une disposition identique a été
données en admettant que les produits des deux élévateurs
adoptée pour les deux jeux de tableaux; mais pour ceux
(c'est-à-dire des mixtes et des rejets) ont été combinés de
à être employés pour la séparation en deux
destinés
facon qu'il n'y ait que deux produits seulement, c'est-à-dire
produits, les colonnes qui sont relatives uniquement aux
le charbon épuré et un seul rejet.
séparations en trois produits sont barrées pour évi-ter toute
confusion.
B.2 EXPRESSION DE L'EFFICACITE DANS LA
B.1.2 Chaque jeu de tableaux est présenté de deux facons,
SÉPARATION EN TROIS PRODUITS
à savoir :
B.2.1 Une séparation en trois produits peut être
a) tableaux en blanc pour indiquer le mode
considérée comme une combinaison de deux séparations
d'impression (voir modèle 1 et modèle 3 au
distinctes en deux produits (c'est.a-dire une coupure à
chapitre B.4);
faible densité et une autre à densité élevée), que ces deux
b) tableaux complétés, à titre d'exemple, par
phases soient réalisées dans des séparateurs différents ou
l'inscription des chiffres relatifs à un essai dans un bac
dans des parties différentes d'un même séparateur.
Baum (voir modèle 2 et modèle 4 au chapitre B.4). .
Les schémas suivants représentent différentes combinaisons
des deux phases :
B.1.3 Pour les essais décrits dans cet exemple, le bac a été
Schéma
alimenté par du charbon de calibre de 152 à O mm (6 à
no
O in). Les chiffres utilisés se réfèrent à la tranche calibrée
entre 12,7 mm (1/2 in) et 0.5 mm. La matière fine
inférieure à 0,5 mm a été enlevée des échantillons avant que
soient effectués la flottation et les essais aux liqueurs
sc
denses, étant donné que les matières fines présentent des
difficultés aux essais. De plus, on ne peut prévoir qu'un bac
à pistonnage épure une matière dont la finesse est inférieure
à 0,5 mm.
3)F-q I - c
B.1.4 Pour une analyse complète de l'essai, des tableaux
analogues à ceux donnés pour le calibre 12,7 mm (1/2 in) à JIR +M
Où
0.5 mm seraient nécessaires pour les autres calibres de
charbon brut, en l'occurrence ceux de 152 à 51 mm (6 a
F est l'alimentation (brut reconstitué);
2 in), 51 à 25.4 mm (2 à 1 in) et 25,4 à 12,7 mm (1 à
1/2 in). De tels tableaux permettraient de comparer le
C est le charbon épuré;
résultat 'obtenu sur les divers calibres. En additionnant
R est le rejet;
ensemble les résultats relatifs aux quatre calibres, on
pourrait établir un nouveau jeu de tableaux représentant
M est le produit intermédiaire (mixtes).
l'ensemble du charbon de 152 mm (6 in) à 0.5 rnm.
Les schémas 1 et 2 représentent des dispositions types pour
une séparation par milieu dense en deux phases, la seule
B.1.5 Dans cet essai, trois produits furent obtenus, à
différence étant que la coupure à basse densité est faite en
savoir : le charbon épuré, les mixtes et les rejets. Les rejets
premier lieu dans le schéma 1 et en second lieu dans le
représentent la matière enlevée par l'élévateur à rejets
schéma 2, alors que le schéma 3 représente un bac à
primaires et les mixtes sont les rejets provenant de
pistonnage normal à trois produits (ou bien une séparation
l'élévateur à rejets secondaires. Les tableaux ((Séparation en
4
---------------------- Page: 6 ----------------------
I
IS0 923-1975 (F)
B.2.2.2 Tandis que, pour la méthode A, les formules sont
par milieu dense en trois produits). Les mixtes M peuvent
être recueillis sous forme de produit séparé ou être recyclés, identiques pour les schémas 2 et 3, dans le dernier cas il n'y
ou bien être traités ailleurs, mais, à condition que tous les a pas de séparation nette entre les première et seconde
mixtes recyclés soient compris dans l'alimentation coupures. La première (haute densité) séparé le rejet R de la
reconstituée F, le raisonnement ne change pas. combinaison du charbon épuré C et les mixtes M, et c'est
cette combinaison qui devient l'al imentation de la seconde
phase de préparation.
B.2.2 L'efficacité d'une séparation en trois produits peut
être calculée de deux facons différentes, à savoir :
B.2.2.3 La méthode A permet d'étudier séparément
a) MéthodeA, en la considérant comme deux
l'efficacité de chacune des deux séparations, car seule la
séparations distinctes et individuelles, chacune ayant sa
matière effectivement admise à la séparation est comprise
propre alimentation;
dans le calcul. C'est un avantage lorsque l'on considère la
performance de chaque machine ou de chaque phase dans le
b) Méthode B, en la considérant comme une séparation
traitement de séparation.
intégrée unique, dont l'alimentation est le brut
reconstitué.
B.2.2.4 La méthode B n'insiste pas autant, dans sa
représentation, sur la performance effective de la seconde
B.2.2.1 Pour calculer les coefficients de partage, les
machine ou phase, mais, en rapportant chaque séparation à
formules appropriées pour ces deux méthodes, pour les
l'alimentation brute reconstitutée, cette méthode facilite les
combinaisons illustrées dans les schémas, sont les suivantes :
I
comparaisons d'efficacité de tout le traitement de
séparation, sous la forme de résultats sur le charbon brut
B.2.2.1 .I Pour le schéma 1
original. (La succession d'opérations comprises dans ce
100 (M + R) traitement complet peut comprendre des étapes non
a) Méthode A coupure à faible densité
représentées dans les schémas 1 à 3; par exemple : un
C+M+R
concassage des mixtes et leur recyclage dans l'alimentation,
100 R
ce qui est courant dans le lavage au bac à pistonnage et peut
coupure à haute densité -
aussi se produire dans une séparation en milieu dense).
M+R
100 (M + R)
B.2.3 II est essentiel, quelle que soit la facon dont une
b) Méthode B coupure à faible densité
séparation en trois produits est exprimée (par exemple,
C+M+R
dans les descriptions d'atelier et les énonciations d'efficacité
100 R
et les garanties), qu'il soit explicitement mentionné laquelle
coupure à haute densité
de ces deux bases a été utilisée pour le calcul. Pour faciliter
C+M+R
cela, il est proposé que la méthode A soit appelée base de
performance d'équipement (Equipment performance
B.2.2.1.2 Pour le schéma 2
basis) et la méthode B, base de performance du charbon
100 R
(Coal performance basis).
a) Méthode A coupure à haute densité
C+M+R
8.2.4 Les tableaux pour séparation en trois produits (voir
100 M
coupure à faible densité -
modèles 1 et 2) sont établis sur la base de performance du
C+M
charbon. Lorsque des calculs sont effectués sur la base de
100 R
performance de l'équipement nous recommandons que des
b) Méthode B coupure à haute densité
tableaux pour deux produits soient utilisés (un pour chaque
C+M+R
phase). II est possible, toutefois, de déduire les résultats de
100 M
tableaux à trois produits; c'est ainsi que les coefficients de
coupure à faible densité
partage pour la seconde coupure seraient calculés sur la base
C+M+R
de performance d'équipement de la facon suivante :
B.2.2.1.3 Pour le schéma 3
- Pour le schéma 1 (voir B.2.1), la colonne (12) serait
calculée au moyen des colonnes (7)/(9) au lieu de l'être
100 R
au moyen des colonnes (7)/(10).
a) Méthode A coupure à haute densité
C+M+R
- Pour les schémas 2 et 3 (voir B.2.1). l
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