ISO/FDIS 23499

ISO/TC 27/SC 1
Secretariat: SA
Date: 2025-09-10-15
Coal — Determination of bulk density of coal as it is handled in
industrial practices
FDIS stage
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ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Method 1 . 1
5 Apparatus . 2
5.1 Measuring boxes . 2
5.2 Cones and tripod frame . 2
6 Sampling and preparation . 3
6.1 Sampling for bulk density of coal up to a 45 mm nominal top size . 3
6.2 Preparation of sample . 3
7 Procedure for bulk density of coal up to a 45 mm nominal top size . 3
8 Method 2 . 7
8.1 Principle . 7
8.2 Sampling and preparation . 7
9 Apparatus . 8
10 Procedure . 12
11 Expression of results . 13
11.1 Method 1 . 13
11.2 Method 2 . 14
12 Reporting of results . 14
12.1 Precision . 14
12.2 Repeatability for Method 1 and Method 2 . 14
12.3 Reproducibility . 15
13 Test report . 15
Bibliography . 16

iii
Foreword
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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 23499:2013), which has been technically
revised.
The main changes are as follows:
— addition of an alternate method using a smaller sized box of 0.02837,028 37 m for bulk density of coal up
to 45 mm nominal top size.;
— — addition of method for determining bulk density of a dry coal powder at minus 63 micrometres
nominal top size.
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
The StandardThis document describes two methods for determining the following: :
a) the bulk density for crushed coal of up to 45 mm nominal top size as that charged into coke ovens; and
b) 2 the bulk density for fine dry coal powders typically less than 63 micrometres nominal top size
used in pulverized fuel fired boilers and cement kilns.
v
Coal — Determination of bulk density of coal as it is handled in
industrial practices
1 Scope
This Standard provides description ofdocument specifies a cone procedure for determining an uncompacted
bulk density of crushed coal up to minus −45 mm nominal top size, as it is handled in industrial practices. It
focuses on the uncompacted bulk density of coal resulting from flowing the material into a measuring
container (box) in the absence of compacting forces. The determination of the bulk density of coal charged
into coke ovens is a typical example.
This Standarddocument also provides a method for determining the bulk density of dry powdered coal at
minus −63 micrometres for boiler or utility application. It does not cover the determination of bulk density of
coal in storage piles.
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 589, Hard coal — Determination of total moisture
ISO 1213--1, Coal and coke — Vocabulary — Part 1: Terms relating to coal preparation
ISO 1213--2, Coal and coke — Vocabulary — Part 2: Terms relating to sampling, testing and analysis
ISO 1953, Coal — Size analysis by sieving
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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213--1 and ISO 1213--2 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/
4 Method 1
Bulk density for coal up to a nominal 45 mm top size is determined by filling a container (measuring box) of
known mass and volume with coal and determining the increase in mass.
5 Apparatus
5.1 Measuring boxes
A cubical container of 0,1 m capacity and internal dimensions of 465 mm. see Figure 1 aFigure 1(a-1).). The
3 3
volume of the box is 0,465 x× 0,465 x× 0,465 = 0,1m 1 m
Note: For coals greater than 45 mm nominal top size, the internal edge dimension of the measuring box should
be approximately ten times nominal top size
An alternate cubic container of 0,02873 028 73 m capacity and internal dimensions of 305 mm may also be
used. see Figure 1 bFigure 1(a-2).). The volume of the box is 0,305 x× 0,305 x× 0,305 = 0,028 73 m (see
Reference [1reference ASTM D291 Bulk Density of Bituminous Coal.]).
The boxes shall be constructed of metal of sufficient thickness to ensure the rigidity of the walls and the base
of the container under the conditions of the test (minimum wall thickness of 3 mm is recommended). It is also
recommended that the boxes have a smooth inner surface, using stainless steel in their construction and be
fitted with handles.
The exact volume of the boxes, in cubic metres, shall be determined with a precision of 0,000 1 m (100 ml),
using water of known density.
5.2 Cones and tripod frame
5.2.1 General
3 3
Cones and tripod frame, for filling the 0.,1 m and 0.02837 ,028 37 m boxes, should conform to Figure 1
Figure 1 (a-1) and b).
See Figure 2Figure 1 ( for a-2). reference for the iron shutters (two) to fit the base of the cones.
See Figure 3 for a reference for the three adjustable legs on each tripod.
The dimensions of the cones and tripod frames shall be as follows:
5.2.15.2.2 0.,1 m Box box
Cone and tripod frame: 610 mm high with an inside diameter at the top of 510 mm and a circular opening of
203 mm in diameter at the bottom. A slide valve consisting of a slide-plate shutter and its supports shall be
welded to the bottom of the cone in such a manner that the valve can be opened and closed with ease by
removing or inserting the shutter in its supporting slides. The cone shall be supported in a tripod frame having
a circular opening at the top of 460 mm in diameter. This frame shall support the cone so that the top side of
the shutter shall be 718 mm from the inside bottom surface of the box. Dimension from the cone bottom to
the top edge of the box shall be a minimum of 250 mm.
5.2.25.2.3 0.02837 ,028 37 m Boxbox
Cone and tripod frame: 610 mm high with an inside diameter at the top of 510 mm and a circular opening of
203 mm in diameter at the bottom. A slide valve consisting of a slide-plate shutter and its supports shall be
welded to the bottom of the cone in such a manner that the valve can be opened and closed with ease by
removing or inserting the shutter in its supporting slides. The cone shall be supported in a tripod frame having
a circular opening at the top of 460 mm in diameter. This frame shall support the cone so that the top side of
the shutter shall be 560 mm from the inside bottom surface of the box. Dimension from the cone bottom to
the top edge of the box shall be a minimum of 250 mm.
5.2.35.2.4 Levelling bar
A steel strip approximately 760 mm long by 40 mm wide and 5 mm thick.
5.2.45.2.5 Weighing device
A weighing platform capable of determining mass by weighing up to 300 kg and sensitive to 0,05 kg.
6 Sampling and preparation
6.1 Sampling for bulk density of coal up to a 45 mm nominal top size
Take a representative sample of the coal in accordance with ISO 13909-2 or ISO 18283. During the sampling
for bulk density, the increments of the sample shall be consolidated and stored in an airtight container to
prevent loss of moisture.
The minimum mass at minus 45 mm is 50 kg for sizing at 2.,0 %. To make sure we have enough sample the
minimum mass was increased to 70 kg. The minimum mass of sample for bulk density shall be about 280 kg.
(4 x 70 kg replicates)
The bulk density of coal is influenced by its physical characteristics, such as relative density, shape, size
distribution of the coal particles, degree of compaction and on the total moisture of the coal as well as on the
dimensions of the measuring container.
Since the results for coal bulk density change according to variations in the above factors, a separate
representative sample shall be taken and prepared at the same time for total moisture in accordance with ISO
1953. It is also recommended that a separate representative sample be taken and prepared at the same time
for size analysis in accordance with ISO 589.
6.2 Preparation of sample
The total sample (280 kg) for bulk density shall be thoroughly mixed and subdivided, without crushing, in
accordance with ISO 13909--4 or ISO 18283. This operation shall be done as quickly as possible to avoid loss
of moisture, and the bulk density shall be determined immediately.
If the determination cannot be done immediately, the samples shall be kept in air-tight containers and
waterproof with minimum airspace and with tightly fitting covers until the time for carrying out the test. Air-
tight and waterproof plastic bags of sufficient strength may also be used.
The total sample shall be divided in accordance with ISO 13909--4 or ISO 18283 to form four replicate samples
of 70 kg for testing whether testing immediately or later. Two of the replicate samples are chosen initially to
be tested and the other two are kept in reserve.
7 Procedure for bulk density of coal up to a 45 mm nominal top size
a) Before fi
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