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Evaluation of Additivies to Inhibit the Spontaneous Combustion of Coal.

Smith AC; Miron Y
Paper in Chemical & Physical Processes in Combustion Combustion Inst 1988 :40-1to40-4
The effectiveness of several additives to inhibit the self-heating of coal was evaluated in the Bureau of Mines adiabatic heating oven. Aqueous solutions were applied to a bituminous coal with a high spontaneous combustion potential, and the minimum self-heating temperatures (sht's) of the dried coal-additive mixtures were determined. The relative effectiveness of the additives was determined by the observed changes in the minimum sht's of the mixtures compared to the untreated coal and a coal-water blank. The relative effectiveness of the additives within a group of coal- additive mixtures with the same minimum sht was determined by the time required for the sample temperature to reach 150 deg c. Sodium nitrate, sodium chloride, and calcium carbonate were found to be the most effective inhibitors, followed by ammonium dihydrogen phosphate, calcium chloride, ammonium chloride, sodium acetate, and potassium chloride. Two additives, sodium formate and sodium phosphate, promoted the self-heating process. Differential scanning calorimetry experiments on the coal-additive mixtures showed that reactions occurred between the coal and some of the additives, but these reactions did not influence the self-heating process.
Publication Date
Document Type
Fiscal Year
Identifying No.
OP 165-88
NIOSH Division
Source Name
Paper in Chemical & Physical Processes in Combustion. Combustion Inst., 1988, PP. 40-1 to 40-4
Page last reviewed: November 19, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division