Abstract
The effects of vibrating grinding and calcination on the structure and reactivity of Kalabsha kaolinite have been studied by means of XRD, IR, DTA and BET surface area. Leaching experiments on ground and calcinated samples were carried out using 20% HC1 for aluminum extraction.
In the earliest stages of grinding the partial destructive of stacking kaolinite layers is occurred. These changes are associated with increase in surface area due to formation of fine grains with great number of boundaries. Further grinding or calcination lead to a deterioration of kaolinite structure. A Signif icant increase of surface area is observed, starting from 18m2/g for original sample to reach maximum value 42m2/g at 120 min. grinding time and 30m2/g at 300°C for calcination.
The extraction of aluminum after 30 min. leaching time is about 97.52% for the ground kaolinite at 240 min. grinding time and about 93.47% for calci nated kaolinite at about 550°C.
