Statistical analysis of Egyptian oil shale column flotation

Evaluation possibility of a low-quality Egyptian oil shale from Wadii El-Nakhil, Red sea region as an alternative clean fuel by advanced flotation technique via column flotation was investigated. XRD analysis showed that the non-clay minerals associated with the oil shale sample include; quartz, siderite, apatite, anhydrite, and calcite. Column flotation experiments were carried out and results were analyzed according to screening designs which are used when numerous parameters would affect a particular process. Reduced three-factor interactions (3 FI) two-level factorial experimental design were employed to evaluate the effects of the seven independent parameters. Besides, the contour plots were used to summarize the optimum reaction factors leading to a predicted maximum kerogen grade of 52.35% and kerogen recovery of 78.41%. The calculated optimum parameters were 15% solid concentration, 0 cm/s superficial wash water velocity, 0.49 cm/s feed superficial velocity, 40 ppm frother concentration, 40 cm froth depth, 0.67 cm/s superficial air velocity and 0.5 kg/ton kerosene collector dosage. The confirmation tests, at optimum conditions as predicted from the contour plots, gave approximately the same grade and recovery of about 54% and 80%, respectively.