Research Article
Characterization and Optimization of Calcination Process Parameters for Extraction of Aluminum from Ethiopian Kaolinite
Table 5
ANOVA for surface quadratic model (response: degree of conversion of kaolinite dehydroxylation reaction).
| | Source | Sum of squares | Df | Mean square | F value | P value | |
| | Model | 3.384 × 10−3 | 9 | 3.760 × 10−3 | 212.40 | <0.0001 | Significant | | X1, temperature | 1.024 × 10−3 | 1 | 1.024 × 10−3 | 578.72 | <0.0001 | Significant | | X2, time | 7.560 × 10−5 | 1 | 7.560 × 10−5 | 42.71 | <0.0001 | Significant | | X3, particles size | 4.950 × 10−4 | 1 | 4.950 × 10−4 | 279.61 | <0.0001 | Significant | | X1X2 | 1.125 × 10−6 | 1 | 1.125 × 10−6 | 0.64 | 0.4439 | Not significant | | X1X3 | 1.343 × 10−5 | 1 | 1.343 × 10−5 | 7.59 | 0.0203 | Significant | | X2X3 | 1.365 × 10−6 | 1 | 1.365 × 10−6 | 0.77 | 0.4005 | Not significant | | 3.346 × 10−4 | 1 | 3.346 × 10−4 | 189.00 | <0.0001 | Significant | | 1.094 × 10−6 | 1 | 1.094 × 10−6 | 0.62 | 0.4500 | Not significant | | 1.183 × 10−4 | 1 | 1.183.110−4 | 66.83 | <0.0001 | Significant | | Residual | 1.770 × 10−5 | 10 | 1.770 × 10−6 | | | | | Lack of fit | 1.220 × 10−5 | 5 | 2.441 × 10−6 | 2.22 | 0.2011 | Not significant | | Pure error | 5.500 × 10−6 | 5 | 1.100 × 10−6 | | | | | Cor total SS | 3.402 × 10−3 | 19 | | | | |
|
|
