Experimental Research On Low-temperature Oxidation Of Coal

The coal spontaneous combustion has been the major factor threatening the mine safety. production. Since the work of coal fire prevention is more effective based on the principle of coal oxidation, research on the principle of coal oxidation under moderate temperature becomes more significant.Study on characteristics of coal spontaneous combustion mainly focused on two aspects, one is coal spontaneous combustion stage, which is a time dimension reflecting coal spontaneous combustion dangerousness; the other is tendency of spontaneous combustion, which reflecting the ease of coal spontaneous combustion.(1) Based on the theoretical study about coal spontaneous combustion, Adiabatic Oxidation is designed,which is made up of four parts:the reaction equipment,the temperature measurement and control system,the oxygen supplying system and the gas products analyzing system.(2) Huangling coal sample 2# is tested by kilogram-level coal spontaneous combustion equipment. Relation between gas and temperature change in process is raised. After analyzing the gas concentration and the temperature,some featured parameters could be determined such as heat release intensity,oxygen consumption rate,index gas concentration and changing rate, characteristic temperature value,limit parameters of coal spontaneous combustion. Because this experiment simulate situation of coal mine spontaneous combustion more realistically, it has more important implications for determining coal spontaneous combustion dangerousness.(3) To study the tendency of spontaneous combustion reflecting the ease of coal spontaneous combustion, Adiabatic Oxidation experiment is done. In experiment the coal sample is dried firstly,at the same time,high purity oxygen gas passes through the coal sample. Those related parameters changing rate of all three samples including heating rate,index gas concentration is falling with the increase of coalification. The results shows that Adiabatic Oxidation experiment duration decreased a lot when the air is replaced by pure oxygen.