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Sealed Flask Test for Evaluating the Self-heating Tendencies of Coals.

Miron Y; Smith AC; Lazzara CP
MISSING :18 pages
This report describes laboratory studies by the U.S. Bureau of Mines to determine the suitability of a static oxygen (o2) adsorption test for evaluating the self-heating tendencies of coals. Reliable minimum self-heating temperature (sht) values from adiabatic oven tests were used as standards for comparison and evaluation. A suite of six coals was tested in the adiabatic oven and in sealed flasks. In the latter tests, both undried and dried samples, in a range of four particle sizes, were examined. Miniature pressure transducers monitored pressures in the flasks, and gas samples taken at the end of the tests quantified all the gases present. An excellent correlation was found between the minimum sht's and amounts of o2 adsorbed over a 7-day period of dried coals, independent of particle size. In addition, a good correlation was obtained between the minimum sht's and pressure changes in the flasks at the end of the test for the same coals, also independent of particle size. Based on these results, the sealed flask test can be reliably used to determine the self-heating tendency of a bituminous coal sample.
Publication Date
Document Type
IH; Report of Investigations;
Fiscal Year
Identifying No.
RI 9330
NIOSH Division
Source Name
Page last reviewed: December 3, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division