The effect of various reaction parameters on carbothermal reduction of kaolinite

Preliminary studies on the carbothermal reduction of kaolinite (Al2O3.2SiO( 2).2H(2)O) in argon atmosphere are reported. The effect of various reaction parameters e.g. temperature (1550-1700 degrees C) and time (1-3 h) of the reaction, nature and source of carbon, e.g. activated charcoal (sp. surface area, 1000 m(2)/gm) and carbon black (sp. surface area, 300 m(2)/gm), addi tion of reaction catalysts (FeCl3, CoCl2) and variation of mole ratios of c arbon to silica (4.5-9) and state of mixing of carbon and kaolinite, etc., on carbothermal reduction have been investigated. It is observed that the r eaction is completed at 1700 degrees C in 1 h or at 1650 degrees C in 3 h. Higher mole ratios of carbon, addition of catalysts, pelletisation of the r eactants and longer reaction times accelerate the reaction rate at a given temperature. (C) 1999 Elsevier Science Limited and Techna S.r.l. All rights reserved.