Characterization and Optimization of Calcination Process Parameters for Extraction of Aluminum from Ethiopian Kaolinite

Table 4

Summary of lack of fit and statistical analysis in model selection for degree of conversion of kaolinite dehydroxylation reaction.

Source	Sequential value	Lack of fit value	Adj. R^2	Pred. R^2
Linear	<0.0001	0.0003	0.8135	0.7101
2 FI	0.9396	0.0002	0.7773	0.6871
Quadratic	<0.0001	0.2011	0.9901	0.9685
Cubic (cubic model was aliased for dehydroxylation reaction of kaolinite samples degree of conversion)	0.2011		0.9939