Combustion characteristic of TDS, coal and their blend were compared. Combustion under CO2/O2 conditions resulted in a negative effect. Combustion characteristic of the blend in N2/O2 and CO2/O2 could be comparable at v% (O2) = 60%. The difference of Ea in N2/O2 and CO2/O2 decreased with the increase of oxygen concentration. Combustion kinetics models were established with a high coincidence.