Optimization of preparation for α-alumina by calcination from alumninum hydroxide ustng response surface methodology

Abstract

The conditions of technique to prepare a-alumina by calcination rrom aluminum hydroxide were optimized using a central composite design (CCD) of response surface methodology (RSM). A quadratic equation model for field was built and effects of main tactors and their corresponding relationships were obtained. The statistical analysis of the results showed that in the range studied the field of a-alumina was significantly affected by the calcination temperature and calcination time. According to results from analysis of variance (AN OVA), the value of the determination coefficient (R2=0.9890) indicates that the model was a good tit that 98.90% of the variation could be explained weil by the model. The value of the adjusted determination coefficient (adj.R2=0.98 I I) was also very high to advocate tor a high signiticance of the model. The optimized calcination conditions were as folIows: the calcination temperature 1206.81 ‘C and the calcination time 2.06 h respectively. Under these conditions the field of a-alumina was 95.93%. Tn addition, the sampie was characterized by X-ray Diffraction (XRD).