Direct alkaline leaching of mechanically activated diasporic bauxite

Minerals & Metallurgical Processing , 2009, Vol. 26, No. 4, pp. 222-225

Taskin, E.; Yildiz, K.; Alp, A.

ABSTRACT:

Diasporic bauxite from the Mugla-Milas region was mechanically activated in a planetary mill for different activation times and the structural changes were examined by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and specific surface area analysis (BET – Burnauer, Emmett and Teller). Nonactivated and activated bauxite samples were leached directly in alkaline (Na₂O) solution at atmospheric conditions and the activation procedure led to the amorphization and structural disordering of the diasporic bauxite structure, which increased the dissolution efficiency. Effects of milling speed, liquid/bauxite ratio and leaching time on alumina extraction in direct alkaline leaching of diasporic bauxite were also studied. The alumina extraction was ~7% for non-activated bauxite and ~70% for activated (75 minute) bauxite.