Abstract:Aluminum-iron minerals in high-iron bauxite were separated by high-pressure hydrothermal reduction applying degradation products of starch in alkalinity system as reductant. The results show that aluminum dissolution rate and iron reduction rate is as high as 88.2% and 92.3% respectively under the conditions of temperature of 280 ℃ and NaOH concentration of 180 g/L. Average particle size of product is about 2.6 μm. Under the condition of ensuring complete dissolution of aluminum, temperature is the main factor to control reduction of iron oxide, while NaOH concentration has little effect.