Alkaline digestion behavior and alumina extraction from sodium aluminosilicate generated in pyrometallurgical process
来源期刊：International Journal of Minerals Metallurgy and Materials2018年第12期
论文作者：Bo-na Deng Guang-hui Li Jun Luo Jing-hua Zeng Ming-jun Rao Zhi-wei Peng Tao Jiang
文章页码：1380 - 1388
摘 要：In pyrometallurgical process, Al-and Si-bearing minerals in iron and aluminum ores are easily transformed into sodium aluminosilicates in the presence of Na2O constituents, which alters the leaching behaviors of Al2O3 and SiO2. It was confirmed that sodium aluminosilicates with different phase compositions synthesized at various roasting conditions were effectively digested in the alkaline digestion process. Under the optimum conditions at temperature of 100–120°C, liquid-to-solid ratio（L/S） of 10:2 mL/g, caustic ratio of 4, and Na2O concentration of 240 g/L, the actual and relative digestion ratio of Al2O3 from the synthesized sodium aluminosilicates reached maximums of about 65% and 95%, respectively, while SiO2 was barely leached out. To validate the superior digestion property of sodium aluminosilicate generated via an actual process, the Bayer digestion of an Al2O3-rich material derived from reductive roasting of bauxite and comprising Na1.75 Al1.75 Si0.25O4 was conducted; the relative digestion ratio of Al2O3 attained 90% at 200°C.
Bo-na Deng，Guang-hui Li，Jun Luo，Jing-hua Zeng，Ming-jun Rao，Zhi-wei Peng，Tao Jiang
School of Minerals Processing & Bioengineering, Central South University
摘 要：In pyrometallurgical process, Al-and Si-bearing minerals in iron and aluminum ores are easily transformed into sodium aluminosilicates in the presence of Na2O constituents, which alters the leaching behaviors of Al2O3 and SiO2. It was confirmed that sodium aluminosilicates with different phase compositions synthesized at various roasting conditions were effectively digested in the alkaline digestion process. Under the optimum conditions at temperature of 100–120°C, liquid-to-solid ratio（L/S） of 10:2 mL/g, caustic ratio of 4, and Na2O concentration of 240 g/L, the actual and relative digestion ratio of Al2O3 from the synthesized sodium aluminosilicates reached maximums of about 65% and 95%, respectively, while SiO2 was barely leached out. To validate the superior digestion property of sodium aluminosilicate generated via an actual process, the Bayer digestion of an Al2O3-rich material derived from reductive roasting of bauxite and comprising Na1.75 Al1.75 Si0.25O4 was conducted; the relative digestion ratio of Al2O3 attained 90% at 200°C.
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