Abstract:

Constant current spouted bed particle electro-deposition method had been studied with simulated wastewater containing copper and nickel as the research object under different experimental conditions such as pH, current, temperature with N₂. experimental results showed that under the experiment conditions of pH 3 (first 210 min) and 4.5 (next 270 min), electrolyte concentration 1 g·L^-1, constant current 15 A, cathode particle size 1.8 mm, electrolyte temperature 25℃ with blowing N₂, the largest removal rate of Cu²⁺ was 99.88% and Ni²⁺ was 85.21% after 480 min. During the experiments, DO first rapid increased to the maximum, and then came down slowly. Blowing N₂ into electrolyte could significantly reduce the dissolved oxygen concentration, which could effectively inhibit deposited Cu and Ni once again return to dissolve and improve the removal rate of deposited metals. The replacement reaction between Ni and Cu²⁺ weakened, the corrosion rate of deposited copper while it was intensified for nickel. Thus, the electro-deposition of mixed copper and nickel showed a certain order, which suggested that the separate recycling of metals in wastewater was feasible with the spouted bed particle electro-deposition method under certain conditions.

Key words: electrochemistry, spouted bed, fluidization, current efficiency, mass transfer

摘要：

以实验室模拟酸性铜镍废水为研究对象,采用自制喷射床电沉积实验装置在恒电流条件下对铜镍混合酸性废水进行了沉积实验,研究了pH、电流值、温度和鼓入氮气对沉积效果和电解液DO的影响规律。实验结果表明,在前210 min控制pH为3,后270 min为4.5,电流值15 A,温度25℃,鼓入氮气的条件下,沉积480 min,铜镍离子沉积率可以分别达到99.88%和85.21%;实验过程中DO先迅速增大至最大值,之后缓慢降低;鼓入氮气可以有效降低溶液中溶解氧,提高金属的沉积率;由于Ni和Cu²⁺之间置换反应的存在,削弱了沉积铜的腐蚀但加剧了镍的腐蚀,使得铜镍混合电沉积在宏观上表现出一定的顺序性,这说明在特定条件下采用喷射床电沉积法分类回收废水中的混合金属是可行的。

关键词: 电化学, 喷射床, 流态化, 电流效率, 传质