Sintering of kaolinite in the presence of certain carbonate mineralizers, viz., CaCO 3 , Na 2 CO 3 , and K 2 CO 3 , has been conducted at 950°-1350°C. The influence of these mineralizers at the above temperatures is evaluated using XRD and SEM techniques. A comparative study of phase formation of the above compositions shows that the sodium-and calcium-fluxed samples give rise to multiphase systems, while K 2 CO 3incorporated samples give phase-pure mullite. The observation that kaolinite in the presence of K 2 CO 3 can act as a precursor material for phase-pure mullite is of great industrial significance.