Abstract

Mohamed Ahmed Tantawy^1,2 and Abdulaziz Ali Alomari²

DOI : http://dx.doi.org/10.13005/ojc/350313

This paper investigated the production of alumina from Nawan kaolin by acid leaching with sulfuric and hydrochloric acids. Kaolin was calcined at 850°C and was leached with 6 M acid at 90°C, 5M NaOH followed by HCl solutions were added to the leaching liquor, and the precipitated aluminum hydroxide was converted to alumina by calcination at 900°C. Materials were characterized by FTIR, XRD, and SEM techniques. The alumina extraction percent was determined at different leaching times (30-180 min) and solid/liquid ratios (0.05-0.15 g/ml). The purity of kaolin is about 95%. The percent of extraction of alumina rapidly increases with the solid/liquid ratio up to 0.1 g/ml then decreases thereafter. The percent of extraction of alumina is higher for HCl than H₂SO₄. The size of the chloride and sulfate ions is the key factor that controls the percent of extraction of alumina from calcined kaolin under the studied conditions.

Acid Leaching; Alumina; FTIR; Kaolin; SEM; XRD

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