电解锰渣碱浸提硅工艺及动力学研究

研究了电解锰渣碱浸提硅过程中, 浸出时间、浸出温度、氢氧化钠初始浓度、液固比(溶液体积与电解锰渣质量比)和搅拌速率对二氧化硅浸出率的影响, 探讨了电解锰渣中二氧化硅的浸出动力学。结果表明, 当浸出温度130 ℃、浸出时间5 h、氢氧化钠初始浓度12.5 mol/L、液固比5 mL/g、搅拌速率300 r/min时, 二氧化硅浸出率达到82.04%; 90~130 ℃时, 浸出过程遵循受界面化学反应控制的收缩未反应核模型, 化学反应活化能为72.0 kJ/mol, 表观反应级数为1.12。

Leaching Process of Electrolytic Manganese Slag by Alkali Solution and Its Kinetics

Effects of leaching time, leaching temperature, an initial concentration of sodium hydroxide, liquid-solid ratio (the ratio of solution volume to electrolytic manganese slag mass), and stirring speed on the leaching of SiO₂ in the process of leaching electrolytic manganese slag by alkali solution for silicon extraction were investigated, as well as the leaching kinetics of SiO₂ in electrolytic manganese slag was discussed. It is shown that leaching process at a temperature of 130 ℃ for 5 h, with an initial concentration of sodium hydroxide solution at 12.5 mol/L, liquid-solid ratio of 5 mL/g, stirring rate of 300 r/min, resulted in the leaching rate of SiO2 up to 82.04%. At the temperature of 90~130 ℃, the leaching process can be expressed as the shrinking unreacted-core model controlled by surface chemical reaction, which has an activation energy of 72.0 kJ/mol and the apparent reaction order of 1.12.