ASTM D409-02

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D409–02
Standard Test Method for
1
Grindability of Coal by the Hardgrove-Machine Method
This standard is issued under the fixed designation D409; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 2. Referenced Documents
2
1.1 This test method covers the determination of the 2.1 ASTM Standards:
3
relative grindability or ease of pulverization of coals in D2013 Method of Preparing Coal Samples for Analysis
3
comparison with coals chosen as standards. A prepared and D2234 Practice for Collection of a Gross Sample of Coal
sized sample receives a definite amount of grinding energy in D4749 Test Method for Performing the Sieve Analysis of
3
a miniature pulverizer, and the size consist of the pulverized Coal and Designating Coal Size
product is determined by sieving. The resultant size consist is E11 Specification for Wire-Cloth Sieves for Testing Pur-
4
used to produce an index relative to the ease of grinding poses
(Hardgrove Grindability Index (HGI)).
3. Significance and Use
1.1.1 Some coals, such as some high-volatile bituminous,
3.1 Thistestmethoddevelopsameasurementofgrindingor
subbituminous, and lignite coals, can undergo physical change
asthenaturalorseammoistureisreleasedduringhandlingand pulverizing characteristics that can be used to evaluate the
yield, or energy input, or both, required in a grinding or
preparation. This change is often sufficient to alter the grind-
ability characteristics that will be reported when tested in the pulverizing process.
laboratory and could produce different indices dependent on
4. Apparatus
theconditionsofdryingandthemoisturelevelofthe1.18-mm
4.1 Air-Drying Oven—A device for passing slightly heated
by 600-µm (No. 16 3No. 30) (see Test Method D4749)
air over the sample. The oven shall be capable of maintaining
materials used for the test. Therefore, the repeatability and
a temperature of 10 to 15°C (18 to 27°F) above room
reproducibilitycitedinthistestmethodmaynotapplyforthese
temperature with a maximum oven temperature of 40°C
high-volatile bituminous, subbituminous, and lignite coals.
(104°F) unless ambient temperature is above 40°C, in which
1.2 The values stated in SI units are to be regarded as the
case ambient temperature shall be used. In the case of easily
standard.Thevaluesgiveninparenthesesmaybeapproximate.
oxidized coals, the temperature shall not be over 10°C (18°F)
1.3 It is recognized that the term weight is considered
above room temperature unless ambient temperature is above
equivalent to mass as used in this test method.
37°C(100°F)inwhichcaseambienttemperatureshallbeused.
1.4 This standard does not purport to address all of the
Air changes shall be at the rate of 1 to 4 air volumes of oven
safety concerns, if any, associated with its use. It is the
capacity per minute.
responsibility of the user of this standard to establish appro-
4.2 Drying Pans—Drying pans of sufficient size so that the
priate safety and health practices and determine the applica-
sample may be spread to a depth of not more than 25 mm (1.0
bility of regulatory limitations prior to use.
in.) with sides not more than 38 mm (1.5 in.) high. The pans
shall be nonreactive with coal and unaffected by the method of
air drying selected.
1
This test method is under the jurisdiction of ASTM Committee D05 on Coal
4.3 Balances—Two balances may be required: one with a
and Coke and is the direct responsibility of D05.07 on Physical Characteristics of
sensitivity of 10 mg and a minimum capacity of 800 g and one
Coal.
Current edition approved April 10, 2002. Published July 2002. Originally with a sensitivity of 0.5 g in 1000 g and sufficient capacity to
e2
published as D409–51. Last previous edition D409–97 .
weigh a$1000-g sample along with the drying pan. A single
2
Forinformationconcerningtheexperimentalworkonwhichthistestmethodis
balance meeting these specifications is permitted.
based, see paper by Hardgrove, R. M., “Grindability of Coal,” Transactions,
American Society of Mechanical Engineers, Vol 54, F.S.P., p. 37, 1932.
D05.07.02 on Grindability is conducting ongoing investigations in regard to
3
quality control during preparation, distribution, and use of standard reference Annual Book of ASTM Standards, Vol 05.06.
4
materials and during preparation and testing of actual samples. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 -------------------
...