大洋多金属结核碱浸脱硅及浸出动力学

Desiliconization and Leaching Kinetics of Ocean Polymetallic Nodules Using Alkali

研究了在高温高压条件下用高浓度NaOH溶液从大洋多金属结核中浸出硅,考察了反应温度、浸出时间、NaOH初始质量浓度、液固体积质量比对SiO2浸出率的影响,探究了碱浸脱硅动力学。试验结果表明:大洋多金属结核碱浸脱硅反应的表观活化能为44.31kJ/mol,浸出反应遵循化学反应控制的粒径缩小收缩核模型;在170℃、NaOH初始质量浓度480g/L、液固体积质量比4∶1条件下反应180min,SiO2浸出率达81.5%。该方法可避免物理选矿环节且无废渣产生,为大洋多金属结核清洁生产提供了一条可供选择的新途径。

Pre-desiliconization of ocean polymetallic nodules by NaOH solution under and temperature high pressure was investigated. The effects of initial NaOH concentration, leaching temperature, mass ratio of liquid-to-solid, leaching time on leaching of silicon and the leaching kinetic were examined. The results show that under the conditions of reaction temperature of 170 ℃, the NaOH mass concentration of 480 g/L,the ratio of liquid-to-solid of 4 ： 1 and reaction time of 180 min,the leaching of Si（）2 can up to 81.5%. The reaction apparent activation energy is 44.31 kJ/mol. By the process,the majority of SiO2 can be removed from the ocean polymetallic nodules, no physical processing and no tailings. The process accords with cleaning production request,and may provide a new alternative way for ocean polymetallic nodules.