Application of statistical analysis for optimizing of column flotation with pine oil for oil shale cleaning

Oil shale must have a large quantity of kerogen to be of economic benefit, but oil shale with about 30% kerogen is a low-quality ore. Thus, the column flotation technique has been utilized to increase its quality, and the results were analyzed by a reduced two-level factorial design to optimize the interaction effects of seven parameters by response surface modeling. The perturbation plots were used to identify the optimum conditions leading to a predicted maximum kerogen concentration of 53.2% and kerogen recovery of about 81% at estimated optimum conditions of 15% solid concentration, 0.36 cm/s superficial wash water flow rate, 0.28 cm/s superficial feed flow rate, 10 ppm frother concentration, 10 cm froth depth, 1.5 cm/s superficial air flow rate, and 1.5 kg/t pine oil collector dosage. Whereas, the validation experiments under these optimum values gave similar kerogen concentration and recovery of about 52.9-53.6% and 80-82%, respectively.