This paper aims to study monoisomeric 4-phenyl dodecyl benzene, a synthetic anionic surfactant as a collector in the flotation of an Egyptian petroleum coke to minimize its ash content as well as its heavy metals to be suitable for manufacture of electrodes. The structure of the surfactant was identified by IR, NMR and mass spectra. The surface properties and the thermodynamic characters of this surfactant were also studied. With raising the temperature from 25 to 55^oC the value of critical micelle concentration (cmc) increases slightly while the surface excess concentration at the surface saturation (Γ_max) shows a small reduction. This is accompanied by an increase in area occupied per molecule at the interface at surface saturation (A_max). The results reveal also that the values of the free energy change upon adsorption (∆G_ads) are all negative at different temperatures. This indicates that the adsorption of this collector at the aqueous solution/air and the aqueous solution/solid interface is spontaneous. The flotation tests were carried out using a laboratory “Denver” flotation cell at 10 wt.% solids using sodium silicate as a depressant. Different parameters affecting flotation of coke such as the dosage of the surfactant, its mode of addition, dosage of depressant and pH, were studied. The results showed that at the optimum conditions for flotation a coke concentrate assaying only 0.19% ash in comparison with 1.38% in the feed samples is obtained. At the same time, the tail fractions had high ash contents (12.5%) and it was very contaminated with heavy metals. The flotation results are in good agreement with that of the surface properties and the thermodynamic characters of the surfactant.