Oxidation studies on coking coal related to weathering. 4. Oxygen linkages influencing the dilatometric properties and the effect of cleavage of ether linkages

摘要: Abstract Samples of a vitrinite concentrate Balmer 10, medium-volatile bituminous coal (433) and high-volatile Moss 3 (535) were oxidized in air at 85°C for four days to partially destroy the swelling characteristics as measured by Ruhr dilatometer. Similar samples 100°C three completely properties. These artificially weathered coals then treated with reagents remove peroxides, keto aldehyde groups. The hydroxyl groups also blocked prevent condensation reactions. result removal these functional blocking had little influence restoring This suggested that properties largely destroyed ether-type cross-links which form low temperature. cleavage ether linkages using potassium tetrahydrofuran resulted lowering melting point large increase dilatation. values after essentially same fresh indicating no significant amount polymerization through carbon-carbon bond formation occurred during low-temperatureoxidation step. Indications obtained dilatation was due steam resulting from reactions occurring temperature measurements. After linkages, could be reduced or removing water heat treatment under vacuum.