Hello. Sign In
Standards Store


2008 Edition, May 15, 2008

Complete Document

Standard Test Method for Grindability of Coal by the Hardgrove-Machine Method

View Abstract
Product Details
Document History

Detail Summary

Superseded By: ASTM D409/D409M

Additional Comments:
W/D S/S BY ASTM D409/D409M
Price (USD)
Single User
In Stock
PDF + Print
In Stock
$127.50 You save 15%
Add to Cart

Product Details:

  • Revision: 2008 Edition, May 15, 2008
  • Published Date: May 15, 2008
  • Status: Superseded By:
  • Superseded By: ASTM D409/D409M
  • Document Language: English
  • Published By: ASTM International (ASTM)
  • Page Count: 16
  • ANSI Approved: No
  • DoD Adopted: No

Description / Abstract:

This test method2 covers the determination of the relative grindability or ease of pulverization of coals in comparison with coals chosen as standards. A prepared and sized sample receives a definite amount of grinding energy in a miniature pulverizer, and the size consist of the pulverized product is determined by sieving. The resultant size consist is used to produce an index relative to the ease of grinding (Hardgrove Grindability Index (HGI)).

Some coals, such as some high-volatile bituminous, subbituminous, and lignite coals, can undergo physical change as the natural or seam moisture is released during handling and preparation. This change is often sufficient to alter the grindability characteristics that will be reported when tested in the laboratory and could produce different indices dependent on the conditions of drying and the moisture level of the 1.18-mm by 600-µm (No. 16 x No. 30) (see Test Method D 4749) materials used for the test. Therefore, the repeatability and reproducibility cited in this test method may not apply for these high-volatile bituminous, subbituminous, and lignite coals.

The values stated in SI units are to be regarded as the standard. The values given in parentheses may be approximate. 

It is recognized that the term weight is considered equivalent to mass as used in this test method. 

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2 For information concerning the experimental work on which this test method is 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 quality control during preparation, distribution, and use of standard reference materials and during preparation and testing of actual samples.