Straight synthesis of α and γ alumina from kaolin by HCl acid leaching

This paper investigates the production of alumina from kaolinite by leaching method using hydrochloric acid. Raw kaolin was calcined at 850?C then leached with 6 M acid 90?C, followed addition HCl solution to leachate aluminum hydroxide precipitated. Finally, precipitated heated 1100?C and turned into oxide. Materials were identified XRF, XRD SEM-EDX techniques. Alumina recovery percentage determined different particle sizes (-200 -400 standard Tyler screen mesh), times (1, 2, 3 4 h), temperatures (80, 90, 100 104?C) concentrations (20, 25, 30 37%). phase changes also investigated two calcination (1100 1200?C). The purity oxide obtained this process is about 97% its 98%. It observed that granulation dimensions less than 75 ?m had no significant effect on percentage. found that, increased increasing temperature.