Enrichment possibilities of Adana region bauxite ore and investigation of production of alumina

Bauxite ore is commonly used as a source of raw material in the production of alumina and aluminum. Currently, aluminum production is carried out using the Bayer process from bauxite ore. The impurities in the ore can lead to technical and economic losses in the Bayer process. Therefore, the modulus ratio of the ore plays a significant role in the efficiency and cost-effectiveness of the Bayer process. In this study, enrichment of bauxite ore with a low modulus content supplied from the Adana-Tufanbeyli-Gümelektepe region and the leaching in sulfuric acid solutions were examined. To enrichment the ore, size separation, magnetic separation and flotation methods were performed. It was observed that a benefication in the ore was not occured in terms of the modulus ratio by these enrichment methods. In the leaching tests, run-of-mine and calcined ore samples were leached in sulfuric acid solutions. The experimental findings were evaluated by response surface methodology, and the optimal leaching conditions were determined. In the leaching of run-of-mine, the optimal values for acid concentration, reaction temperature, solid to liquid ratio, and reaction time were found to be 1 M, 40 °C, 42,29 g/mL, and 30 min, respectively. Under these conditions, it was detected that 8.37% of aluminum in the ore was leached. In the experiments performed by using the calcined samples, the optimal values for acid concentration, reaction temperature, and reaction time were determined to be 2,7 M, 60,90 °C ve 70,14 min, respectively. Under these conditions, it was calculated that 22% of aluminum in the calcined ore was dissolved. Aluminum ions in the solution was recovered in the form of aluminum hydroxide by precipitation method, and alumina was produced by calcination at 1050 °C.