In this study, it was discovered that a mixture of dodecylamine (DDA)-kerosene demonstrated a stronger collecting ability for pure quartz and higher selectivity for magnetite ore. The relationship between the DDA-kerosene composition and mineral flotation performance on reverse flotation of magnetite ore was investigated. The results showed that floatability of the floating material increased when the DDA consumption increased. Specifically, during flotation, the fine particles (-0.074 mm fraction) selectively floated with DDA-kerosene. The difficult to float coarser particles (+0.074 mm fraction) with high content of quartz, required higher DDA dosage. However, higher DDA input during the flotation process did not necessarily yield better outcomes. The best results were obtained for 40/60 amine-to-oil ratio, as the quartz floated markedly with smaller magnetite loss and the flotation behavior was superior to pure DDA. Magnetite concentrates with 1.83% SiO2 and 71.04% Fe were produced using 120 g/Mg of DDA-kerosene (WDDA=40%).