熔盐净化-电解法制备高纯铟

Preparation of high-purity indium by molten-purification and electrolysis process

为研究成熟、可靠的5N高纯铟生产技术,以4N精铟为原料,采用熔盐净化-电解法制备出5N高纯铟.熔盐净化的反应温度为200～220℃,反应时间约2h,实验中I2和KI用量为理论用量的5～10倍, 电解工艺要点为： 以除镉后的4N金属铟熔铸成阳极,以纯钛板为阴极,电解液采用硫酸铟体系,其中In^2＋浓度为60～80g/L、NaCl 60～80g/L、明胶1g/L、pH值为2.0～2.8,电解过程中控制槽电压为0.2V左右、温度20～30℃、电流密度40～70mA/cm2,同时采取措施防止其它杂质离子的污染,即可制备出5N高纯铟产品,而且工艺流程简单、条件容易控制.

In order to find out a mature and reliable production technology of 5N high-purity indium metal,the 5N high-purity indium was prepared by using molten-purification and electrolysis process with 4N indium metal as raw material.The 5N high-purity indium can be prepared if the preferred conditions in the process of molten-purification are： 200-220 ℃ of temperature,2 h of reacting time,the dosage of I2 and KI being 5-10 times of the theoretical dosage.The condition of the electrolysis process is as follows：4N indium metal being melted and cast as anode after removing cadmium, titanium board as cathode, In2（SO4）3 solution system as electrolyte whose concentration of In^2＋ is 60 - 80 g/L, concentration of NaCl is 60 - 80 g/L, concentration of glutin is 1 g/L, pH Value 2.0 - 2.8, bath voltage about 0.2 V, temperature 20 - 30 ℃, current density 40 - 70 mA/cm^2. And it is proved that the quality of the 5N indium prepared is high, the technology used is simple and the condition iseasy to control.