The oil sands industry is continuously looking for demulsifiers that effectively dehydrate and demineralize diluted bitumen, minimize rag layer formation by controlling oil/water interface, and reduce naphtha and bitumen losses to tailings. In this paper, the performance of two newly developed demulsifiers, "X" and "Y", were evaluated on the basis of diluted bitumen (dilbit) dehydration, demineralization, and naphtha and bitumen losses to tailings. The results demonstrate that the water removal efficiency of demulsifier Y is 14.15% higher than that of demulsifier X at 50 ppm dosage after 15 min of settling time. The solids removal efficiencies of demulsifiers X and Y at 50 ppm dosage after 15 min settling time, for the top dilbit fraction, were 13.9 and 21.5%, respectively. Demulsifier Y reduced the diluent and bitumen losses to the underflow by 16.7 and 13.8%, respectively, at 50 ppm dosage after 15 min of residence time as compared to demulsifier X. Therefore, demulsifier Y performed superior on all the key performance indicators (KPIs) studied as compared to demulsifier X. To determine the reason why the performance of demulsifier Y is superior to that of demulsifier X on all the KPIs, solids were collected from the original froth and the top, interface, and bottom fractions of the diluted froth after demulsification tests and characterized by X-ray diffraction analysis (XRD), X-ray energy dispersive spectrometry, scanning electron microscopy, particle size distribution (PSD), and wettability studies. XRD data shows that demulsifier Y reduced the clays, iron, and zirconium oxide minerals from the top and interface dilbit fractions when compared to the control sample. PSD data shows that demulsifier Y reduced most of the particles of size less than 0.50 mu m from the interface. Therefore, demulsifier Y helps to resolve the interfacial material by removing the minerals that tend to form a rag layer, especially siderite, pyrite, magnetite, rutile, and anatase, from the oil/water interface to the underflow.