【摘要】 以铁尾矿为原料,研究了矿中SiO2的NaOH浸出过程,确定了铁尾矿用碱(NaOH)浸出过程中,影响SiO2浸出率的主要因素为:铁尾矿和NaOH与水的固液比,浸出反应温度,浸出反应时间.以此为条件,研究了铁尾矿在碱溶液中浸取SiO2反应的动力学行为.结果表明:铁尾矿中SiO2浸出的最佳因素为,固液比1?2,反应温度110℃,反应时间6 h.SiO2的浸出动力学过程可用界面反应模型来描述,其浸出反应动力学方程为1-(3-X)2/3+2(1-X)=k″2t,表观活化能约为14.2 kJ/mol,属于固体内扩散控制.更多还原

【Abstract】 Using iron ore tailings as raw materials,the process of leaching SiO2 was investigated.The main factors i.e.ratios between solid and liquid,reaction time,reaction temperatures,that affect the leaching rate of iron ore tailings in sodium hydroxide were determined,and the digestion kinetics of iron ore tailings in sodium hydroxide was investigated correspondingly.The results showed that the optimum leaching ratios is obtained when the ratios between solid and liquid is 1∶2 under 110 ℃ for 6 h.The leaching kinetics of SiO2 can be represented by the interface reaction model,which is written as the following equation: 1-(3-X)2/3+2(1-X)=k″2t.The apparent activation energy calculated for SiO2 leaching is about 14.2 kJ/mol,and the overall leaching rate appears to be controlled by the diffusion in solid.更多还原