Mechano-Chemical Processing of Diaspore Sample for Extraction and Synthesis of Gamma-Alumina and Potash Values

Abstract

In this study, a diaspore sample is evaluated as a dual source of alumina and potash. The thermal treatment of diaspore with sodium hydroxide yielded alumina and potash values. Microwave heating resulted in enhanced diffusion with improved precipitate purity and recovery with a significant reduction in reaction time. The thermal treatment precipitate comprises alumina purity of 48% with a recovery of 49%. The mechanical milling route yields optimal conditions of 8 h milling followed by acid leaching in 2 M HCl at 50°C for 1 h with ~ 70% and 45% potash and alumina extraction, respectively. The dissociation of the muscovite structure is crucial for high extraction values, and milling time was found to be the significant factor. The milling route at optimal conditions yielded an alumina precipitate with ~ 89% purity with a surface area of 104.6 m2/g and a sylvinite-rich solution, which can be used in fertilizer application.