Influence of inorganic salt on the characteristics of oxidation, ignition and combustion of bituminous coal

Abstract

Abstract The processes of oxidation, ignition and combustion of bituminous coal containing 5 wt.% of activating agent (Cu(NO3)2) was studied. The experiment was performed using high-speed video recording of the combustion process of the researched coals in combustion chamber at a temperature of 700°C in the air at atmospheric pressure. Analytical assessment of the characteristics of ignition and combustion processes of the researched coals was carried out based on the obtained results. It was established that addition of Cu(NO3)2 promoter leads to a significant decrease of the time characterizing the delay in the beginning of coal ignition (in 2 times). Effect of the activating additive was also expressed in formation of flame during coal combustion at the stage of volatile substances separation with periodic formation of characteristic flashes formed as a result of decomposition of copper nitrate in the pores of the carbon matrix. This contributed to intensification of the release process of relatively large volume of combustible gases. The obtained results were compared with previously obtained data of the oxidation process of these coals with activating additives of copper salts by thermogravimetric analysis.