Directly application of waste cooking oil on the flotation of coal gasification fine slag

Waste cooking oil (WCO) and coal gasification fine slag (CGFS) are both wastes and harmful to human health and environment without proper disposal. In this work, co-dispose of the two wastes was investigated, i.e. the WCO was directly used as a flotation collector for carbon ash separation of the CGFS. The WCO contains numbers of long-chain fatty acids and esters, thereby is a potential flotation collector for carbon ash separation of the CGFS. As a result, the recovery of unburned carbon increased with the WCO dosage increased, but the loss-on ignition (LOI) of tailings gradually decreased. The optimum flotation condition is 6 ∼ 7 kg/t of WCO with 3 kg/t of frother. In this condition, the recovery of unburned carbon increases to 89.59 ∼ 90.34 wt%, while the LOI of tailings decreases to 4.48 ∼ 4.15 wt%. Therefore, the WCO is a feasible and efficient flotation collector for carbon ash separation of the CGFS. It also has potential industrial application, because this approach is also economical and eco-friendly for co-dispose of the two wastes.