In this investigation, a comparison was done between the use of dodecane and oxidized diesel oil as collectors to float oxidized coal. FTIR was used to determine the chemical properties of oxidized diesel oil and oxidized coal, which showed that oxidized coal has less hydrophobic functional groups while oxidized diesel oil has high hydrophobic groups that will enhance oxidized coal flotation. Oxidized coal was dry ground for different times, namely, 0 min, 40 min, and 80 min and the flotation results showed that, compared to the dodecane as the collector, the oxidized diesel provides much higher (40% to 70%) combustible recovery. Grinding of coal and the use of oxidized diesel oil improved the flotation of oxidized coal due to the hydrogen bonding with the polar part of oxidized coal surface and oxidized diesel oil.